AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 836 PM EST SUN JAN 27 2008 .UPDATE...SFC MAP SHOWS HIGH PRESSURE SYSTEM CENTERED OVER THE LOWER MS VALLEY AREA. A NW FLOW ALOFT NOTED THROUGH A DEEP LAYER LAYER BASED ON 00Z SOUNDING AND WATER VAPOR IMAGERY DUE TO A MID-UPPER TROUGH JUST MOVING FURTHER OFFSHORE OF THE U.S. COAST. LITTLE TO NO CIRRUS EXPECTED TONIGHT. COLDER AIRMASS AND DRY CONDS WILL ALLOW FOR COLD TEMPS TONIGHT WITH AROUND 30 INLAND AND UPPER 30S AT THE COAST. AREAS OF FROST EXPECTED DUE TO FAIRLY MOIST GROUNDS AND LIGHT WINDS. IN LOOKING AT RUC...LIGHT BOUNDARY LAYER WINDS FROM THE NW WILL HELP TO NOT ENSURE A PERFECT RADIATIONAL COOLING NIGHT SO HAVE NOT GONE UNDER GUIDANCE. IN ADDITION...RECENT COLD EVENTS INDICATE MODELS HAVE BEEN SLIGHTLY TOO COOL FOR MIN TEMPS ESPECIALLY THE MAV GUIDANCE. STILL APPEARS TO BE SUFFICIENT DURATION OF FREEZING TEMPS OVER INLAND NE FL ZONES TO WARRANT THE FREEZE WARNING. NORMALLY COLDER LOCATIONS MAY DIP INTO THE UPPER 20S. ANY ADJUSTMENTS TO GRIDS AND ZONES WILL BE MINOR. A PLEASANT DAY ON TAP FOR MONDAY WITH HIGHS IN THE LOWER TO MID 60S WITH HIGH PRESSURE RIDGE AT SFC AND ALOFT DOMINATING THE REGION. SOME INCREASE IN HIGH CLOUDS AS MOISTURE SPILLS OVER THE UPPER RIDGE TO OUR W. && .AVIATION...VFR CONDITIONS EXPECTED NEXT 24 HRS WITH HIGH PRESSURE IN CONTROL. && .MARINE...W TO NW FLOW INDICATED IN THE OBS AT THIS TIME DUE TO A WEAK SFC TROUGH FROM JAX NWD INTO THE OFFSHORE GA WATERS. AS THIS WEAKENS NEXT FEW HOURS ANTICIPATE WINDS TO VEER TO NLY TONIGHT AND INCREASE AS DEPICTED IN NAM AND RUC. CURRENT FORECAST WILL BE ADJUSTED FOR TRENDS. IT APPEARS SCA FOR OFFSHORE WATERS LOOKS GOOD TO LET EXPIRE AT 10 PM AND MAY NEED TO REPLACE WITH SCEC HEADLINE. && .JAX WATCHES/WARNINGS/ADVISORIES... FL...RED FLAG WARNING FROM 12 PM TO 5 PM EST MONDAY FOR ALACHUA-BAKER- BRADFORD-COLUMBIA-GILCHRIST-HAMILTON-MARION-SUWANNEE-UNION. FREEZE WARNING FROM 4 AM TO 8 AM EST MONDAY FOR ALACHUA-BAKER- BRADFORD-COLUMBIA-GILCHRIST-HAMILTON-SUWANNEE-UNION. FIRE WEATHER WATCH MONDAY AFTERNOON FOR CLAY-DUVAL-NASSAU-PUTNAM. GA...NONE. AM...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ALTAMAHA SOUND GA TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE- FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE- ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE. && $$ SHASHY/LETRO/KEEGAN fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE INDIANAPOLIS IN 628 PM EST MON JAN 28 2008 .UPDATE... HAVE WENT AHEAD AND ISSUED A WIND ADVISORY FOR TUESDAY NIGHT. 18Z MODEL DATA CONTINUES TO SHOW STRONG WINDS REACHING THE SURFACE AFTER COLD FRONT PASSES. NAM BUFKIT SOUNDINGS SHOW OVER 40KT POSSIBLE TUE EVENING. RUC13 SFC PROGS SHOWING SUSTAINED 35KT...AND 18Z MAV SHOWING SUSTAINED 30KT WINDS. THUS FEEL CONFIDENT ENOUGH TO ISSUE AT THIS TIME. && .AVIATION... DISCUSSION FOR 00Z TAFS. A STRONG LOW PRESSURE SYSTEM WILL DEVELOP ACROSS THE PLAINS TONIGHT. THIS WILL BRING IN MUCH STRONGER WINDS ALOFT...LIKELY TO BE IN EXCESS OF 40 KTS JUST 2KFT ABOVE THE GROUND. WILL CONTINUE THE MENTION OF WIND SHEAR IN THE TAFS THROUGH TONIGHT AS MOST OF THESE STRONGER WINDS WILL REMAIN ABOVE THE SURFACE. SOME LIGHT RAIN SHOWERS ARE EXPECTED TO WORK THEIR WAY IN AFTER MIDNIGHT AND WILL KEEP THINGS IN THE LOW END OF VFR AS THE SHOWERS SHOULD BE SCATTERED. BY 12Z THEY WILL BECOME MORE WIDESPREAD AND SO WILL GO WITH MVFR CONDITIONS AT ALL SITES. ALSO THINK THAT WIND SHEAR WILL END BY AROUND 12Z AS LIGHTER WINDS ALOFT LOOK TO BE PRESENT...AS WELL AS BETTER MIXING TO THE SURFACE CREATING LESS OF A SHEAR. SCATTERED SHOWERS ARE POSSIBLE ALL DAY TUESDAY AND WILL CONTINUE MVFR CATEGORY CIGS ALL DAY. WINDS WILL BEGIN TO INCREASE AT THE SURFACE THROUGHOUT THE DAY...AND AFTER 22Z WILL BECOME SUSTAINED BETWEEN 16-20 KTS WITH GUSTS UP TO 26 KTS AT THIS TIME. ALSO A CHANCE OF THUNDERSTORMS LATE IN THE AFTERNOON...WILL JUST MENTION CB FOR NOW GIVEN UNCERTAINTY AND HOW FAR AWAY IT STILL IS. && .PREV DISCUSSION... /ISSUED 335 PM EST MON JAN 28 2008/ VIS SAT SHOWS OVC SKIES ACRS THE FA. TEMPS WERE IN THE MID 40S WITH DEWPTS IN THE MID 20S AND WINDS OUT OF THE SSW AROUND 15KTS GUSTING TO AROUND 25KTS. RADAR SHOWS SPRINKLES AND VIRGA OVR THE FA AS WELL. FORECAST FOCUS IS ON POPS...WINDS...AND SVR POTENTIAL WITH FRONTAL SYSTEM TUESDAY/TUESDAY NIGHT. MODELS IN GOOD AGREEMENT FOR THE MOST PART IN THE SHORT TERM SO WL USE A BLEND. TONIGHT...WAA AND CLOUD CVR WL KEEP LOWS UP IN THE LOW TO MID 40S RIGHT WITH GUIDANCE. CHCS FOR POPS SHUD INCREASE DURING THE NIGHT AS A S/W MVS THRU AND ISENTROPIC LIFT CONTINUES. DO NOT EXPECT GREAT AMOUNTS BUT ENUF FORCING TO KEEP LIKELY RAIN. WHILE PRES GRADIENT STRENGTHENS ACRS THE AREA DURING THE NIGHT INVERSION IS STRONG ENUF TO KEEP THE STRONG WIND GUSTS FROM REACHING THE SFC. TUESDAY...NAM HAS SLOWED FROPA FROM YESTERDAYS RUN AND NOW IS ABOUT MIDWAY THRU THE FA BY 0Z AND AGREES WELL WITH THE ECMWF AND THE GFS. NOT A LOT OF SFC INSTABILITY AVAILABLE BUT THERE IS WILL BE ELEVATED INSTABILITY TO TAP INTO. WITH 50+KT LLJ MVING ACRS THE AREA AFTER 18Z AND INVERSION ERODING SHUD HAVE POTENTIAL FOR THESE WINDS TO MIX DOWN TO THE SFC WITH ANY THUNDERSTORMS THAT DEVELOP. MOST OF THE FA IS IN A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR LATE TUE AFTERNOON/EVENING AND THESE WIND GUSTS WILL BE THE PRIMARY THREAT. LOOKS LIKE THE BEST POTENTIAL FOR SYNOPTIC SCALE WINDS OF ADVISORY CRITERIA WILL JUST AFTER FROPA...WHICH WOULD PUT THEM STARTING UP ACRS THE FA AFTER 21Z AND PERHAPS NOT UNTIL AFTER 0Z. BUFKIT GUSTS DURING THIS TIME ARE IN THE 40-45KT RANGE. AFTER COLLABORATION WITH OTHER OFFICES AND NOTING THIS WOULD BE IN THE THIRD PERIOD HAVE DECIDED TO HOLD OFF ISSUANCE OF WIND ADVISORY UNTIL NEXT FCST PACKAGE...BUT DEFINITELY THINK ONE WILL BE NECESSARY FOR TUESDAY NIGHT. TUESDAY NIGHT...HAVE ALREADY DISCUSSED STRONG WINDS ABOVE. COLD FNT WILL FINISH MVING ACRS THE AREA SO HAVE INCLUDED THUNDER OVR AT LEAST THE ERN HALF OF THE AREA THRU 3Z. BRING POPS DOWN FROM W TO E IN 3 HR INCREMENTS AND SHUD SEE CHANGE OVR TO SNOW AT MOST LOCATIONS BEFORE WED MORNING BUT THE SNOW SHUD BE SHORT LIVED WITH LITTLE ACCUMULATION AS THE COLD FNT SHUD SCOUR OUT MOST OF THE MOISTURE. BOTH MODELS SHOW COLD AIR PLUNGING DOWN AFTER FROPA BUT NAM SEEMS A LITTLE OVERZEALOUS WITH ITS H8 TEMPS AND MET GUIDANCE LOOKS TOO COOL DROPPING THINGS INTO THE SINGLE DIGITS BASED ON WHAT LOW TEMPS ARE LIKE IN THE NRN PLAINS RIGHT NOW. WED AND WED NT...HIGH PRESSURE BLDS IN AND THINGS ARE DRY. WED WL BE COLD BECAUSE OF THE PREVIOUSLY MENTIONED COLD AIR SPILLING DOWN SO HIGHS WILL ONLY BE IN THE 20S. WED NT WINDS WILL SHIFT BACK AROUND TO THE S BUT WITH NOT MUCH CLOUD CVR EVEN WITH THE WAA WL STILL SEE LOWS IN THE TEENS. EXTENDED...EXTENDED EMPHASIS IS ON THURSDAY NIGHT/FRIDAY SYSTEM. STILL QUITE A BIT OF UNCERTAINTY IN FCST TRACK OF SFC LOW THU NT/FRI. ECMWF MVS THE LOW THRU IL AND KEEPS THE FA IN ALL RAIN WITH THE POSSIBLE EXCEPTION OF THE FAR NW. GFS TRACKS THE LOW ALONG THE OH RVR AND HAS NRN AND CENTRAL FA ALL SNOW WITH SOME POTENTIAL FOR ICE IN THE S. WHILE THE NAM DOES NOT GO OUT QUITE FAR ENUF YET...IT/S SFC LOW HAS BEEN TRENDING FURTHER S. WITH SYSTEMS THUS FAR THIS WINTER THE NAM AND GFS HAVE HAD A BIAS TOWARD THE SE WITH THEIR SFC LOWS AND GIVEN THAT AM MORE INCLINED TO LEAN ON THE WARMER NW SOLN OF THE ECMWF. WITH THE CURRENT DISAGREEMENT THO AM NOT GOING TO PULL THE SNOW...INSTEAD WILL INCLUDE A MIX FOR MOST OF THE STORM AND WL TRY TO NAIL DOWN A LITTLE BETTER AS /HOPEFULLY/ MODELS COME INTO BETTER AGREEMENT. A WEAK FNT WL MV THRU ON SAT NT/SUN BUT ASSOC FORCING STAYS WELL N OF THE AREA SO WL KEEP A DRY FCST. MON A WARM FNT WL APPROACH FROM THE S AND SO HAVE BROUGHT IN CHC POPS. TEMPS ARE BORDERLINE SO WL INCLUDE A RAIN SNOW MIX. && .IND WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY ALL AREAS 7PM TUE TO 7AM WED. && $$ AVIATION...JOHNSON UPDATE...CS PUBLIC...CP in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 842 PM MST MON JAN 28 2008 .UPDATE...00Z H85 ANALYSIS SHOWING A LARGE CHUNK OF ARCTIC AIR PLUNGING SOUTH INTO THE NORTHERN ROCKIES/NORTHERN PLAINS WHILE 02Z SFC ANALYSIS INDICATES THE LEADING EDGE OF THE ARCTIC AIRMASS ALREADY APPROACHING THE I-80 CORRIDOR. GIVEN SUCH COLD TEMPERATURES (-32C AT KGGW AT H85) AND RAPID TEMPERATURE DROPS ACROSS WESTERN AND NORTHERN NEBRASKA THIS EVENING WILL TREND LOWS DOWN TONIGHT. THE COLD AIRMASS APPEARS TO HAVE A FAVORABLE TRAJECTORY INTO THE CENTRAL HIGH PLAINS WITH UNCERTAINTY IN DEGREE OF MODIFICATION ESPECIALLY ACROSS THE WESTERN ZONES WHERE MIXING WILL BE MORE LIKELY. WILL LOWER HIGHS ACROSS THE FAR EASTERN ZONES WHERE REACHING 20 MAY BE A STRUGGLE ON TUESDAY. A SECONDARY CONCERN WILL BE WIND CHILL READINGS LATE TONIGHT AND THROUGH THE DAY ON TUESDAY. LITTLE CHANGES IN POP ORIENTATION EXPECTED WITH SCATTERED SNOW SHOWERS STILL EXPECTED TO DEVELOP LATE TONIGHT WITH VERY LITTLE ACCUMULATION EXPECTED. DID RAISE POPS INTO THE MID RANGE WEIGHTED IN THE NORTHEAST ZONES WHERE BETTER MID LEVEL FRONTOGENESIS IS JUXTAPOSED WITH STRONG LARGE SCALE FORCING FOR ASCENT BETWEEN 09-13Z. WIND ADVISORY HEADLINES ALSO APPEAR ON TRACK WITH NO CHANGE PLANNED. && .PREV DISCUSSION... /ISSUED 451 PM MST MON JAN 28 2008/ .AVIATION...LATEST METARS INDICATE SOUTHWEST WIND DECREASING LATE THIS AFTERNOON WITH VFR CONDITIONS. THIS WILL BE THE LULL BEFORE WIND INCREASES LATER TONIGHT WITH THE COLD FRONT AROUND 08-09Z. NORTHWEST WIND WILL INCREASE TO 30+ KTS AND CONTINUE THROUGH 00Z WED. MID CLOUDS INCREASE BEHIND THE FRONT WITH SOME LOWER CIGS AT KMCK. BUFKIT POINT SOUNDINGS FOR KGLD AND KMCK INDICATE THAT THERE IS A BRIEF WINDOW WHEN SOME LIGHT SNOW AND SLIGHTLY REDUCED VISIBILITIES WILL BE POSSIBLE FROM 09-12Z TUE. SOME MVFR CONDITIONS WILL BE POSSIBLE DURING THIS PERIOD ESPECIALLY AT KMCK. OTHERWISE CLOUDS SCATTER OUT AFTER 15Z TUE WITH VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD. && .PREV DISCUSSION... /ISSUED 211 PM MST MON JAN 28 2008/ .DISCUSSION... 17Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATE TWO SHORT WAVE TROUGHS UPSTREAM OF THE CWA. THE FIRST WAS LOCATED OVER CENTRAL COLORADO AND WAS RESPONSIBLE FOR CLOUD ACROSS NORTHERN HALF OF CWA. ANOTHER...SHORT WAVE TROUGH WAS DIGGING INTO NEVADA AND UTAH AND WILL BE PRIMARY WX MAKER TONIGHT/TOMORROW. TONIGHT-TOMORROW...WINDS SHOULD WEAKEN/DECOUPLE DURING THE EVENING AS DEEP MIXING COMES TO AN END...AND WILL LET CURRENT HIGHLIGHTS CONTINUE. MAIN CONCERNS AFTER THAT WILL BE HOW STRONG WINDS GET BEHIND FRONTAL PASSAGE AND WEATHER OR NOT ANY PRECIP WILL DEVELOP AS WELL. NAM/GFS/GEM ALL SUPPORT PASSAGE OF STRONG COLD FRONT ACROSS THE CWA AFTER 06Z. POINT SOUNDINGS INDICATE WINDS OFF OF THE SURFACE INCREASE TO OVER 40KTS BEHIND THE FRONT...AND SOUNDINGS SUGGEST THAT LITTLE IN THE WAY OF A SURFACE INVERSION WILL BE IN PLACE BEHIND THE FRONT. ALTHOUGH TIME OF NIGHT IS NOT NORMALLY FAVORABLE FOR STRONG WIND...MINIMAL INVERSION COUPLED WITH STRONG PRESSURE RISES AND CAA SHOULD BE ENOUGH TO ALLOW STRONGER WINDS TO REACH THE SURFACE. GFS ACTUALLY COMES CLOSE TO LOW END WARNING CRITERIA...BUT OTHER MODELS ARE SLIGHTLY WEAKER. THINK AN ADVISORY WILL BE THE WAY TO GO TONIGHT...ALTHOUGH STILL A LITTLE UNCERTAIN DUE TO THE TIMING. OTHER CONCERN WILL BE IF ANY PRECIPITATION CAN FALL AS FRONT PASSES...WHICH WILL MAY CAUSE EVEN MORE PROBLEMS WITH THE WIND. GFS...WHICH ALSO HAS SUPPORT FROM ECMWF AND TO SOME EXTENT THE GEM CONTINUE TO SUGGEST THREAT FOR PRECIPITATION BEHIND FRONT DURING THE MORNING HOURS. CROSS SECTIONS THROUGH THE FRONTAL SURFACE SHOWS A POCKET OF POTENTIAL INSTABILITY JUST ABOVE FRONTAL SURFACE...WITH ENVIRONMENT NEARLY SATURATED. FRONTOGENESIS AT H7...H65 ALSO LINE UP WELL WITH H7-H5 AND H5-H3 DIV Q FORCING FOR ASCENT. ONLY CONCERN IS IF SATURATION WILL BE POSSIBLE AS FORCING SHOULD MOVE BY FAIRLY QUICKLY...AND CURRENT WATER VAPOR IMAGERY INDICATES SUBSTANTIAL DRYING ACROSS THE AREA BEHIND THIS MORNINGS SYSTEM. OBSERVED LAPSE RATES...AND OBSERVED NATURE OF THE CLOUDS OVER THE AREA CURRENTLY...SUGGEST STABILITY IS FAIRLY LOW. IF SNOW DOES DEVELOP WITH THE WIND...WILL LIKELY NEED SOME KIND OF SNOW/BLSN HIGHLIGHT...BUT CONFIDENCE IN MEASURABLE SNOWFALL REMAINS BELOW ADVISORY CRITERIA AT THIS POINT. WILL UP POPS OVERNIGHT AND INCLUDE BLSN IN FORECAST BUT FOR NOW WILL LIKELY GO WITH JUST A WIND ADVISORY. TOMORROW NIGHT-WEDNESDAY NIGHT...SHORT WAVE RIDGING WILL BE IN PLACE ACROSS THE AREA DURING THE EARLY PORTIONS OF TUESDAY EVENING LEADING TO WIDESPREAD SUBSIDENCE ACROSS THE AREA. RIDGE BEGINS TO BREAK DOWN FAIRLY QUICKLY HOWEVER AS H7 TROUGH BEGINS TO IMPACT THE AREA AROUND 12Z WED. FAIRLY STRONG WAA INDICATED AT H7 AS WELL. POINT SOUNDINGS INDICATE A VERY THICK...DRY LAYER BELOW THIS REGION AND WITH FAIRLY HIGH STABILITY DO NOT THINK ANY PRECIPITATION WILL MAKE IT TO THE GROUND BY 12Z WED. MORE WIDESPREAD FORCING FOR ASCENT IS INDICATED BY Q VECTOR FIELDS BEGINS TO OVERSPREAD THE AREA THROUGH THE AFTERNOON AND INTO THE EVENING. FORCING DOES NOT REALLY APPEAR THAT FOCUSED...AND GENERAL TREND IN THE MODELS IS DRIER AND FURTHER SOUTH. AM GOING TO TRIM BACK POPS A LITTLE BIT FOR THE TIME PERIOD...ALTHOUGH STILL ENOUGH UNCERTAINTY TO HOLD ON TO SOME LOW CHANCE POPS THROUGH THE EVENING INTO THURSDAY MORNING. THURS-SATURDAY...OPERATIONAL GFS APPEARS TO BE OUTLIER IN BOTH POSITION AND SPEED OF H5 TROUGH...AND WILL LEAN TOWARDS SLOWER MORE SOUTHERLY SOLUTION THROUGH THIS PERIOD. TAKING THE SLOWER/MORE SOUTHERLY SOLUTIONS WOULD SUGGEST SHORT WAVE TROUGH JUST GLANCES THE CWA...WITH MID LEVEL FRONTAL ZONE JUST TO THE SOUTH OF THE AREA. NOT TO EXCITED ABOUT PRECIP POTENTIAL WITH THIS SYSTEM...BUT WILL INCLUDE SOME LOW POPS ACROSS THE SOUTHEAST AS THEY SHOULD BE THE NEAR THE NORTHERN FRINGE OF PRECIPITATION. OTHER CONCERN THROUGH THE PERIOD WILL BE TEMPS...WITH BIGGEST CONCERN BEING HOW MUCH OF A WARM UP WILL OCCUR ON FRIDAY BETWEEN FRONTAL PASSAGES. GFS/ECMWF AND GFS ENS MEAN WOULD SUGGEST FAIRLY WARM TEMPS DEVELOPING...AND THIS SOLUTION LOOKS FAIRLY REASONABLE. A LITTLE CONCERNED ABOUT GOING TOO WARM AS THIS AIRMASS APPEARS TO BE OVER CWA ONLY A BRIEF TIME BEFORE NEXT FRONT COMES THROUGH...AND DIFFERENCES IN TIMING THIS FRONT COULD HAMPER WARM UP. SUNDAY & MONDAY...H5 LOW TRACKS ACROSS THE SOUTHERN HIGH PLAINS REGION DURING THIS PERIOD. A STRONG PRESSURE GRADIENT SETS UP ON MONDAY AS A SURFACE LOW SLIDES ACROSS THE REGION AHEAD OF A COLD FRONT. IF THE FRONT PICKS UP MOMENTUM THAN MONDAYS HIGH TEMPERATURES MY NEED ADJUSTED DOWN...AS A DECENT AMOUNT OF COLD AIR IS ADVECTED INTO THE REGION BEHIND THE FRONT. IF THE FRONT COMES IN AFTER PEAK HEATING HOURS MONDAYS TEMPERATURES WILL REMAIN SEASONABLE-UPPER 30S TO LOWER 40S && .AVIATION...LATEST METARS JUST TO THE SOUTH OF KGLD INDICATE SOUTHWEST WIND AT 30+ KT MIXING DOWN TO THE SURFACE. EXPECT SAME WIND SPEEDS AT KGLD AND KMCK THIS AFTERNOON AHEAD OF THE COLD FRONT TONIGHT. NORTHWEST WIND WILL INCREASE TO 30+ KTS TONIGHT WITH FRONTAL PASSAGE (AROUND 08-09Z) AND CONTINUE THROUGH 18Z TUE. MID CLOUD WILL INCREASE BEHIND THE FRONT WITH SOME SCATTERED LOWER CLOUDS AT KMCK. HOWEVER THE ENTIRE TAF PERIOD SHOULD REMAIN VFR AT BOTH SITES. && && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND ADVISORY UNTIL 11 AM MST /12 PM CST/ TUESDAY FOR KSZ001>004- 013. WIND ADVISORY FROM 2 AM MST /3 AM CST/ TO 11 AM MST /12 PM CST/ TUESDAY FOR KSZ014>016-027>029-041-042. NE...WIND ADVISORY UNTIL 11 AM MST /12 PM CST/ TUESDAY FOR NEZ079>081. CO...WIND ADVISORY UNTIL 11 AM MST TUESDAY FOR COZ090-091. WIND ADVISORY FROM 2 AM TO 11 AM MST TUESDAY FOR COZ092. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 451 PM MST MON JAN 28 2008 .AVIATION...LATEST METARS INDICATE SOUTHWEST WIND DECREASING LATE THIS AFTERNOON WITH VFR CONDITIONS. THIS WILL BE THE LULL BEFORE WIND INCREASES LATER TONIGHT WITH THE COLD FRONT AROUND 08-09Z. NORTHWEST WIND WILL INCREASE TO 30+ KTS AND CONTINUE THROUGH 00Z WED. MID CLOUDS INCREASE BEHIND THE FRONT WITH SOME LOWER CIGS AT KMCK. BUFKIT POINT SOUNDINGS FOR KGLD AND KMCK INDICATE THAT THERE IS A BRIEF WINDOW WHEN SOME LIGHT SNOW AND SLIGHTLY REDUCED VISIBILITIES WILL BE POSSIBLE FROM 09-12Z TUE. SOME MVFR CONDITIONS WILL BE POSSIBLE DURING THIS PERIOD ESPECIALLY AT KMCK. OTHERWISE CLOUDS SCATTER OUT AFTER 15Z TUE WITH VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD. && .PREV DISCUSSION... /ISSUED 211 PM MST MON JAN 28 2008/ .DISCUSSION... 17Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATE TWO SHORT WAVE TROUGHS UPSTREAM OF THE CWA. THE FIRST WAS LOCATED OVER CENTRAL COLORADO AND WAS RESPONSIBLE FOR CLOUD ACROSS NORTHERN HALF OF CWA. ANOTHER...SHORT WAVE TROUGH WAS DIGGING INTO NEVADA AND UTAH AND WILL BE PRIMARY WX MAKER TONIGHT/TOMORROW. TONIGHT-TOMORROW...WINDS SHOULD WEAKEN/DECOUPLE DURING THE EVENING AS DEEP MIXING COMES TO AN END...AND WILL LET CURRENT HIGHLIGHTS CONTINUE. MAIN CONCERNS AFTER THAT WILL BE HOW STRONG WINDS GET BEHIND FRONTAL PASSAGE AND WEATHER OR NOT ANY PRECIP WILL DEVELOP AS WELL. NAM/GFS/GEM ALL SUPPORT PASSAGE OF STRONG COLD FRONT ACROSS THE CWA AFTER 06Z. POINT SOUNDINGS INDICATE WINDS OFF OF THE SURFACE INCREASE TO OVER 40KTS BEHIND THE FRONT...AND SOUNDINGS SUGGEST THAT LITTLE IN THE WAY OF A SURFACE INVERSION WILL BE IN PLACE BEHIND THE FRONT. ALTHOUGH TIME OF NIGHT IS NOT NORMALLY FAVORABLE FOR STRONG WIND...MINIMAL INVERSION COUPLED WITH STRONG PRESSURE RISES AND CAA SHOULD BE ENOUGH TO ALLOW STRONGER WINDS TO REACH THE SURFACE. GFS ACTUALLY COMES CLOSE TO LOW END WARNING CRITERIA...BUT OTHER MODELS ARE SLIGHTLY WEAKER. THINK AN ADVISORY WILL BE THE WAY TO GO TONIGHT...ALTHOUGH STILL A LITTLE UNCERTAIN DUE TO THE TIMING. OTHER CONCERN WILL BE IF ANY PRECIPITATION CAN FALL AS FRONT PASSES...WHICH WILL MAY CAUSE EVEN MORE PROBLEMS WITH THE WIND. GFS...WHICH ALSO HAS SUPPORT FROM ECMWF AND TO SOME EXTENT THE GEM CONTINUE TO SUGGEST THREAT FOR PRECIPITATION BEHIND FRONT DURING THE MORNING HOURS. CROSS SECTIONS THROUGH THE FRONTAL SURFACE SHOWS A POCKET OF POTENTIAL INSTABILITY JUST ABOVE FRONTAL SURFACE...WITH ENVIRONMENT NEARLY SATURATED. FRONTOGENESIS AT H7...H65 ALSO LINE UP WELL WITH H7-H5 AND H5-H3 DIV Q FORCING FOR ASCENT. ONLY CONCERN IS IF SATURATION WILL BE POSSIBLE AS FORCING SHOULD MOVE BY FAIRLY QUICKLY...AND CURRENT WATER VAPOR IMAGERY INDICATES SUBSTANTIAL DRYING ACROSS THE AREA BEHIND THIS MORNINGS SYSTEM. OBSERVED LAPSE RATES...AND OBSERVED NATURE OF THE CLOUDS OVER THE AREA CURRENTLY...SUGGEST STABILITY IS FAIRLY LOW. IF SNOW DOES DEVELOP WITH THE WIND...WILL LIKELY NEED SOME KIND OF SNOW/BLSN HIGHLIGHT...BUT CONFIDENCE IN MEASURABLE SNOWFALL REMAINS BELOW ADVISORY CRITERIA AT THIS POINT. WILL UP POPS OVERNIGHT AND INCLUDE BLSN IN FORECAST BUT FOR NOW WILL LIKELY GO WITH JUST A WIND ADVISORY. TOMORROW NIGHT-WEDNESDAY NIGHT...SHORT WAVE RIDGING WILL BE IN PLACE ACROSS THE AREA DURING THE EARLY PORTIONS OF TUESDAY EVENING LEADING TO WIDESPREAD SUBSIDENCE ACROSS THE AREA. RIDGE BEGINS TO BREAK DOWN FAIRLY QUICKLY HOWEVER AS H7 TROUGH BEGINS TO IMPACT THE AREA AROUND 12Z WED. FAIRLY STRONG WAA INDICATED AT H7 AS WELL. POINT SOUNDINGS INDICATE A VERY THICK...DRY LAYER BELOW THIS REGION AND WITH FAIRLY HIGH STABILITY DO NOT THINK ANY PRECIPITATION WILL MAKE IT TO THE GROUND BY 12Z WED. MORE WIDESPREAD FORCING FOR ASCENT IS INDICATED BY Q VECTOR FIELDS BEGINS TO OVERSPREAD THE AREA THROUGH THE AFTERNOON AND INTO THE EVENING. FORCING DOES NOT REALLY APPEAR THAT FOCUSED...AND GENERAL TREND IN THE MODELS IS DRIER AND FURTHER SOUTH. AM GOING TO TRIM BACK POPS A LITTLE BIT FOR THE TIME PERIOD...ALTHOUGH STILL ENOUGH UNCERTAINTY TO HOLD ON TO SOME LOW CHANCE POPS THROUGH THE EVENING INTO THURSDAY MORNING. THURS-SATURDAY...OPERATIONAL GFS APPEARS TO BE OUTLIER IN BOTH POSITION AND SPEED OF H5 TROUGH...AND WILL LEAN TOWARDS SLOWER MORE SOUTHERLY SOLUTION THROUGH THIS PERIOD. TAKING THE SLOWER/MORE SOUTHERLY SOLUTIONS WOULD SUGGEST SHORT WAVE TROUGH JUST GLANCES THE CWA...WITH MID LEVEL FRONTAL ZONE JUST TO THE SOUTH OF THE AREA. NOT TO EXCITED ABOUT PRECIP POTENTIAL WITH THIS SYSTEM...BUT WILL INCLUDE SOME LOW POPS ACROSS THE SOUTHEAST AS THEY SHOULD BE THE NEAR THE NORTHERN FRINGE OF PRECIPITATION. OTHER CONCERN THROUGH THE PERIOD WILL BE TEMPS...WITH BIGGEST CONCERN BEING HOW MUCH OF A WARM UP WILL OCCUR ON FRIDAY BETWEEN FRONTAL PASSAGES. GFS/ECMWF AND GFS ENS MEAN WOULD SUGGEST FAIRLY WARM TEMPS DEVELOPING...AND THIS SOLUTION LOOKS FAIRLY REASONABLE. A LITTLE CONCERNED ABOUT GOING TOO WARM AS THIS AIRMASS APPEARS TO BE OVER CWA ONLY A BRIEF TIME BEFORE NEXT FRONT COMES THROUGH...AND DIFFERENCES IN TIMING THIS FRONT COULD HAMPER WARM UP. SUNDAY & MONDAY...H5 LOW TRACKS ACROSS THE SOUTHERN HIGH PLAINS REGION DURING THIS PERIOD. A STRONG PRESSURE GRADIENT SETS UP ON MONDAY AS A SURFACE LOW SLIDES ACROSS THE REGION AHEAD OF A COLD FRONT. IF THE FRONT PICKS UP MOMENTUM THAN MONDAYS HIGH TEMPERATURES MY NEED ADJUSTED DOWN...AS A DECENT AMOUNT OF COLD AIR IS ADVECTED INTO THE REGION BEHIND THE FRONT. IF THE FRONT COMES IN AFTER PEAK HEATING HOURS MONDAYS TEMPERATURES WILL REMAIN SEASONABLE-UPPER 30S TO LOWER 40S && .AVIATION...LATEST METARS JUST TO THE SOUTH OF KGLD INDICATE SOUTHWEST WIND AT 30+ KT MIXING DOWN TO THE SURFACE. EXPECT SAME WIND SPEEDS AT KGLD AND KMCK THIS AFTERNOON AHEAD OF THE COLD FRONT TONIGHT. NORTHWEST WIND WILL INCREASE TO 30+ KTS TONIGHT WITH FRONTAL PASSAGE (AROUND 08-09Z) AND CONTINUE THROUGH 18Z TUE. MID CLOUD WILL INCREASE BEHIND THE FRONT WITH SOME SCATTERED LOWER CLOUDS AT KMCK. HOWEVER THE ENTIRE TAF PERIOD SHOULD REMAIN VFR AT BOTH SITES. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND ADVISORY FROM 11 PM MST /MIDNIGHT CST/ THIS EVENING TO 11 AM MST /12 PM CST/ TUESDAY FOR KSZ001>004-013. RED FLAG WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ013>016-027>029-041-042. WIND ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ013>016-027>029-041-042. WIND ADVISORY FROM 2 AM MST /3 AM CST/ TO 11 AM MST /12 PM CST/ TUESDAY FOR KSZ014>016-027>029-041-042. NE...WIND ADVISORY FROM 11 PM MST /MIDNIGHT CST/ THIS EVENING TO 11 AM MST /12 PM CST/ TUESDAY FOR NEZ079>081. CO...WIND ADVISORY FROM 11 PM THIS EVENING TO 11 AM MST TUESDAY FOR COZ090-091. RED FLAG WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ253-254. WIND ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ091-092. WIND ADVISORY FROM 2 AM TO 11 AM MST TUESDAY FOR COZ092. && $$ JRM/KJ/FS ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 211 PM MST MON JAN 28 2008 .DISCUSSION... 17Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATE TWO SHORT WAVE TROUGHS UPSTREAM OF THE CWA. THE FIRST WAS LOCATED OVER CENTRAL COLORADO AND WAS RESPONSIBLE FOR CLOUD ACROSS NORTHERN HALF OF CWA. ANOTHER...SHORT WAVE TROUGH WAS DIGGING INTO NEVADA AND UTAH AND WILL BE PRIMARY WX MAKER TONIGHT/TOMORROW. TONIGHT-TOMORROW...WINDS SHOULD WEAKEN/DECOUPLE DURING THE EVENING AS DEEP MIXING COMES TO AN END...AND WILL LET CURRENT HIGHLIGHTS CONTINUE. MAIN CONCERNS AFTER THAT WILL BE HOW STRONG WINDS GET BEHIND FRONTAL PASSAGE AND WEATHER OR NOT ANY PRECIP WILL DEVELOP AS WELL. NAM/GFS/GEM ALL SUPPORT PASSAGE OF STRONG COLD FRONT ACROSS THE CWA AFTER 06Z. POINT SOUNDINGS INDICATE WINDS OFF OF THE SURFACE INCREASE TO OVER 40KTS BEHIND THE FRONT...AND SOUNDINGS SUGGEST THAT LITTLE IN THE WAY OF A SURFACE INVERSION WILL BE IN PLACE BEHIND THE FRONT. ALTHOUGH TIME OF NIGHT IS NOT NORMALLY FAVORABLE FOR STRONG WIND...MINIMAL INVERSION COUPLED WITH STRONG PRESSURE RISES AND CAA SHOULD BE ENOUGH TO ALLOW STRONGER WINDS TO REACH THE SURFACE. GFS ACTUALLY COMES CLOSE TO LOW END WARNING CRITERIA...BUT OTHER MODELS ARE SLIGHTLY WEAKER. THINK AN ADVISORY WILL BE THE WAY TO GO TONIGHT...ALTHOUGH STILL A LITTLE UNCERTAIN DUE TO THE TIMING. OTHER CONCERN WILL BE IF ANY PRECIPITATION CAN FALL AS FRONT PASSES...WHICH WILL MAY CAUSE EVEN MORE PROBLEMS WITH THE WIND. GFS...WHICH ALSO HAS SUPPORT FROM ECMWF AND TO SOME EXTENT THE GEM CONTINUE TO SUGGEST THREAT FOR PRECIPITATION BEHIND FRONT DURING THE MORNING HOURS. CROSS SECTIONS THROUGH THE FRONTAL SURFACE SHOWS A POCKET OF POTENTIAL INSTABILITY JUST ABOVE FRONTAL SURFACE...WITH ENVIRONMENT NEARLY SATURATED. FRONTOGENESIS AT H7...H65 ALSO LINE UP WELL WITH H7-H5 AND H5-H3 DIV Q FORCING FOR ASCENT. ONLY CONCERN IS IF SATURATION WILL BE POSSIBLE AS FORCING SHOULD MOVE BY FAIRLY QUICKLY...AND CURRENT WATER VAPOR IMAGERY INDICATES SUBSTANTIAL DRYING ACROSS THE AREA BEHIND THIS MORNINGS SYSTEM. OBSERVED LAPSE RATES...AND OBSERVED NATURE OF THE CLOUDS OVER THE AREA CURRENTLY...SUGGEST STABILITY IS FAIRLY LOW. IF SNOW DOES DEVELOP WITH THE WIND...WILL LIKELY NEED SOME KIND OF SNOW/BLSN HIGHLIGHT...BUT CONFIDENCE IN MEASURABLE SNOWFALL REMAINS BELOW ADVISORY CRITERIA AT THIS POINT. WILL UP POPS OVERNIGHT AND INCLUDE BLSN IN FORECAST BUT FOR NOW WILL LIKELY GO WITH JUST A WIND ADVISORY. TOMORROW NIGHT-WEDNESDAY NIGHT...SHORT WAVE RIDGING WILL BE IN PLACE ACROSS THE AREA DURING THE EARLY PORTIONS OF TUESDAY EVENING LEADING TO WIDESPREAD SUBSIDENCE ACROSS THE AREA. RIDGE BEGINS TO BREAK DOWN FAIRLY QUICKLY HOWEVER AS H7 TROUGH BEGINS TO IMPACT THE AREA AROUND 12Z WED. FAIRLY STRONG WAA INDICATED AT H7 AS WELL. POINT SOUNDINGS INDICATE A VERY THICK...DRY LAYER BELOW THIS REGION AND WITH FAIRLY HIGH STABILITY DO NOT THINK ANY PRECIPITATION WILL MAKE IT TO THE GROUND BY 12Z WED. MORE WIDESPREAD FORCING FOR ASCENT IS INDICATED BY Q VECTOR FIELDS BEGINS TO OVERSPREAD THE AREA THROUGH THE AFTERNOON AND INTO THE EVENING. FORCING DOES NOT REALLY APPEAR THAT FOCUSED...AND GENERAL TREND IN THE MODELS IS DRIER AND FURTHER SOUTH. AM GOING TO TRIM BACK POPS A LITTLE BIT FOR THE TIME PERIOD...ALTHOUGH STILL ENOUGH UNCERTAINTY TO HOLD ON TO SOME LOW CHANCE POPS THROUGH THE EVENING INTO THURSDAY MORNING. THURS-SATURDAY...OPERATIONAL GFS APPEARS TO BE OUTLIER IN BOTH POSITION AND SPEED OF H5 TROUGH...AND WILL LEAN TOWARDS SLOWER MORE SOUTHERLY SOLUTION THROUGH THIS PERIOD. TAKING THE SLOWER/MORE SOUTHERLY SOLUTIONS WOULD SUGGEST SHORT WAVE TROUGH JUST GLANCES THE CWA...WITH MID LEVEL FRONTAL ZONE JUST TO THE SOUTH OF THE AREA. NOT TO EXCITED ABOUT PRECIP POTENTIAL WITH THIS SYSTEM...BUT WILL INCLUDE SOME LOW POPS ACROSS THE SOUTHEAST AS THEY SHOULD BE THE NEAR THE NORTHERN FRINGE OF PRECIPITATION. OTHER CONCERN THROUGH THE PERIOD WILL BE TEMPS...WITH BIGGEST CONCERN BEING HOW MUCH OF A WARM UP WILL OCCUR ON FRIDAY BETWEEN FRONTAL PASSAGES. GFS/ECMWF AND GFS ENS MEAN WOULD SUGGEST FAIRLY WARM TEMPS DEVELOPING...AND THIS SOLUTION LOOKS FAIRLY REASONABLE. A LITTLE CONCERNED ABOUT GOING TOO WARM AS THIS AIRMASS APPEARS TO BE OVER CWA ONLY A BRIEF TIME BEFORE NEXT FRONT COMES THROUGH...AND DIFFERENCES IN TIMING THIS FRONT COULD HAMPER WARM UP. SUNDAY & MONDAY...H5 LOW TRACKS ACROSS THE SOUTHERN HIGH PLAINS REGION DURING THIS PERIOD. A STRONG PRESSURE GRADIENT SETS UP ON MONDAY AS A SURFACE LOW SLIDES ACROSS THE REGION AHEAD OF A COLD FRONT. IF THE FRONT PICKS UP MOMENTUM THAN MONDAYS HIGH TEMPERATURES MY NEED ADJUSTED DOWN...AS A DECENT AMOUNT OF COLD AIR IS ADVECTED INTO THE REGION BEHIND THE FRONT. IF THE FRONT COMES IN AFTER PEAK HEATING HOURS MONDAYS TEMPERATURES WILL REMAIN SEASONABLE-UPPER 30S TO LOWER 40S && .AVIATION...LATEST METARS JUST TO THE SOUTH OF KGLD INDICATE SOUTHWEST WIND AT 30+ KT MIXING DOWN TO THE SURFACE. EXPECT SAME WIND SPEEDS AT KGLD AND KMCK THIS AFTERNOON AHEAD OF THE COLD FRONT TONIGHT. NORTHWEST WIND WILL INCREASE TO 30+ KTS TONIGHT WITH FRONTAL PASSAGE (AROUND 08-09Z) AND CONTINUE THROUGH 18Z TUE. MID CLOUD WILL INCREASE BEHIND THE FRONT WITH SOME SCATTERED LOWER CLOUDS AT KMCK. HOWEVER THE ENTIRE TAF PERIOD SHOULD REMAIN VFR AT BOTH SITES. .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND ADVISORY FROM 11 PM MST /MIDNIGHT CST/ THIS EVENING TO 11 AM MST /12 PM CST/ TUESDAY FOR KSZ001>004-013. RED FLAG WARNING UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ013>016-027>029-041-042. WIND ADVISORY UNTIL 5 PM MST /6 PM CST/ THIS AFTERNOON FOR KSZ013>016-027>029-041-042. WIND ADVISORY FROM 2 AM MST /3 AM CST/ TO 11 AM MST /12 PM CST/ TUESDAY FOR KSZ014>016-027>029-041-042. NE...WIND ADVISORY FROM 11 PM MST /MIDNIGHT CST/ THIS EVENING TO 11 AM MST /12 PM CST/ TUESDAY FOR NEZ079>081. CO...WIND ADVISORY FROM 11 PM THIS EVENING TO 11 AM MST TUESDAY FOR COZ090-091. RED FLAG WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ253-254. WIND ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ091-092. WIND ADVISORY FROM 2 AM TO 11 AM MST TUESDAY FOR COZ092. && $$ JRM/FS/KJ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DODGE CITY KS 248 PM CST MON JAN 28 2008 .DISCUSSION... DAYS 1-2... 12Z UPPER AIR ANALYSIS HAD A STRONG TROUGH OVER THE WESTERN CONUS, WITH A 140 KT JET ON THE FRONT SIDE OF IT AND 500MB TEMPS DOWN IN THE -30S C OVER THE PAC NW. 500MB CHART ALSO HAD 140 M HEIGHT FALLS OVER THE ROCKIES, AND WV LOOP SHOWS A WEAK LEAD SHORTWAVE EJECTING OUT TOWARDS THE PLAINS. THIS HAS HELPED PUSH THE SFC TROUGH AXIS/WEAK PACIFIC FRONT OUT INTO THE CWA. THE TRUE COLD AIR IS STILL UP OVER MT, WITH 850MB TEMPS IN THE -20S C. LATEST 19Z SFC OBS HAVE THE FRONT STARTING TO ENTER SD, WITH 54 F REPORTED AT RAP, WHILE READINGS AROUND AROUND 11 F IN THE NORTHWEST PART OF THE STATE AND BELOW ZERO BACK IN MT. THE STRONG WINDS WE HAVE THIS AFTERNOON WILL START TO TAPER OFF FOR A BIT TONIGHT AS THE MAIN SHORTWAVE TROUGH APPROACHES THE PLAINS AND THE SFC TROUGH MOVES EAST OVER KS. THE 12Z GFS AND NAM SEEM TO BE A BIT SLOW ON THE FRONTAL PASSAGE IN COMPARISON TO OBSERVATIONS, WHILE THE ECMWF WAS A BIT FAST. FRONT SHOULD PROBABLY COME BLASTING THROUGH SOMETIME BETWEEN 09 AND 12Z, POSSIBLY A BIT FASTER THAN THE GFS/NAM ARE INDICATING. STRONG PRESSURE GRADIENT WILL BE BEHIND THE FRONT, WITH BOTH THE NAM AND RUC SHOWING AREAS OF 25-30KTS. SREF PROBABILITIES ALSO SHOW OVER 40 PERCENT FOR SFC WINDS GREATER THAN 25 KTS. MAY HAVE TO HOLD OFF ON ISSUANCE UNTIL THIS EVENING FOR VTEC COMPLICATIONS, BUT EXPECT THAT A WIND ADVISORY WILL BE NEEDED FOR TOMORROW MORNING BETWEEN 12 AND 18Z. THE MODELS ALL HAVE GOOD DYNAMIC LIFT AS THE UPPER SYSTEM COMES OUT INTO THE PLAINS, AND THE NAM HAS SOME DECENT 700MB FRONTOGENESIS. MODEL SOUNDINGS SHOW THE LAYER BECOMING MORE SATURATED FOR A BRIEF PERIOD TOMORROW MORNING. HOWEVER, THINK THAT AS FAST AS THE SYSTEM IS MOVING THERE WILL BE A QUICK SHOT AND NOT A LOT OF ACCUMULATION. KEPT THE 20 POPS WE HAD GOING, WITH LESS THAN A HALF AN INCH EXPECTED. THE TROUGH WILL CONTINUE MOVING EASTWARD LATE TUESDAY, WITH FLOW BECOMING MORE ZONAL BETWEEN SYSTEMS TUESDAY NIGHT. THE NEXT TROUGH SHOULD START TO DIG INTO THE WESTERN CONUS ON WEDNESDAY. THE FRONT SHOULD BRING DOWN ARCTIC AIR INTO THE PLAINS, BUT WITH THE PROGRESSIVE NATURE OF THE SYSTEM THAT COLD AIR SHOULD QUICKLY BE SHUNTED EAST. THE SFC HIGH WILL MOVE EAST TUESDAY NIGHT AND LEE TROUGHING WILL RE-DEVELOP OVER THE WESTERN PLAINS, WITH QUIET AND DRY WEATHER EXPECTED. AS FOR TEMPERATURES, LOWS TONIGHT WILL STAY UP FOR A WHILE BUT THEN DROP OFF AS THE FRONT COMES THROUGH. CONTINUED WITH READINGS IN THE 20S. LOWERED HIGHS FOR TUESDAY A BIT, PARTICULARLY IN THE NORTHEAST WHERE 850MB TEMPS WILL GET DOWN WELL BELOW ZERO. BEST ARCTIC AIR WILL BE TO OUR NORTHEAST, BUT THE FRONT SHOULD BE ENOUGH TO DROP HIGHS IN THE 30S. CLEARING SKIES AND FAIRLY LIGHT WINDS WILL BE OVER THE AREA FOR TUESDAY NIGHT, AND LOWS SHOULD HAVE LITTLE TROUBLE DROPPING OFF INTO THE TEENS. HIGHS ON WEDNESDAY SHOULD RETURN TO THE 40S AND EVEN AROUND 50 IN THE SOUTH AS SOUTHERLY WINDS AND SOUTHWESTERLY FLOW ALOFT HELP BRING 850MB TEMPS BACK UP ABOVE ZERO C. DAYS 3-7... A SERIES OF UPPER LEVEL DISTURBANCES WERE LINING UP FROM THE WESTERN CONUS INTO THE NORTHERN PACIFIC EARLIER TODAY. OUR NEXT MORE SIGNIFICANT S/W TROF IS CURRENTLY PROGGED BY ALL THE MODELS TO MOVE ACROSS THE SOUTHWEST CONUS INTO NM...THEN WEST TEXAS AND OKLAHOMA BY EARLY THURSDAY. AS IT MOVES INTO THE SOUTHERN PLAINS A COLD FRONT WILL CROSS WESTERN KS LATE WED. BY WEDNESDAY NIGHT MOISTURE DOES RETURN NORTHWARD ACROSS TX INTO OK BUT IT APPEARS THE AREA WHO WILL HAVE THE BETTER MOISTURE RETURN WILL BE CONFINED TO OUR FAR E/SE. MOISTURE RETURN ALONG WITH 85H-7H FGEN DEVELOPING JUST NORTHWEST OF OUR SFC LOW SUPPORTS AT LEAST KEEPING CHC POPS GOING IN THE EAST. DID HOWEVER RAISE CHC POPS TO LIKELY POPS ACROSS OUR FAR SE CWA LATE WED NIGHT AND EARLY THURSDAY GIVEN THE LIFT PROGGED FROM THE FGEN AND APPROACHING VORT LOBE. LEFT SLT CHC POPS GOING IN THE WEST GIVEN THE MEAN RH AND UPSLOPE FLOW BUT AM NOT TOO OPTIMISTIC WEST OF GCK AT THIS TIME. AFTER THIS SYSTEM EXITS THE AREA TEMPERATURES WILL BEGIN TO REBOUND ONCE AGAIN. TEMPS SHOULD WARM QUICKLY BACK INTO THE 40S WITH SOME 50S POSSIBLE OVER THE WEEKEND BEFORE OUR NEXT SYSTEM APPROACHES FROM THE SOUTHWEST. MODELS THIS TIME ARE STRUGGLING WITH THE TRACK AND TIMING BUT ALL DO SEEM TO HINT AT A DECENT PERIOD OF TIME FOR MOISTURE TO RETURN TO SOUTHWEST KANSAS. AS A RESULT DID BUMP UP TEMPS SUNDAY NIGHT AS 30 TO 40F DEWPTS RETURN TO THE AREA AND WINDS REMAIN UP DURING THE OVERNIGHT HOURS IN RESPONSE TO THE FALLING PRESSURES OVER THE WESTERN HIGH PLAINS. ALSO INSERTED SOME SMALL POPS IN ON MONDAY BUT TIMING REMAINS AN ISSUE FOR PCPN THAT FAR OUT. -BURGERT && .AVIATION... STRONG GUSTY SW WINDS WILL BEGIN TO SUBSIDE TOWARDS SUNSET BUT SHOULD REMAIN IN THE 15 TO 20 MPH RANGE THROUGH THE OVERNIGHT HOURS. MAIN CHALLENGE TOMORROW MORNING WILL BE TIMING OF THE COLD FRONT. MODELS DIFFERING ON TIMING WITH THE GFS SEEMING MORE OF A COMPROMISE BETWEEN THE SLOWER NAM AND FASTER ECMWF. CONFIDENCE NOT HIGH EITHER WAY SO WILL STAY CLOSE TO THE GFS ON TIMING OF FROPA. TIGHT GRADIENT ONCE AGAIN DEVELOPS OVER SW KS AFTER FROPA SO LOOK FOR ANOTHER VERY WINDY DAY AS NW WINDS ONCE AGAIN INCREASE DURING THE LATE MORNING. && .PRELIMINARY POINT TEMPS/POPS... DDC 27 37 17 47 / 0 20 0 0 GCK 24 37 16 46 / 0 20 0 0 EHA 27 42 19 51 / 0 0 0 0 LBL 27 39 19 51 / 0 20 0 0 HYS 24 31 13 42 / 0 20 0 0 P28 33 39 19 49 / 0 20 0 10 && .DDC WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING UNTIL 6 PM CST /5 PM MST/ THIS AFTERNOON FOR KSZ030-043>045-061>064-074>078-084>088. WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS AFTERNOON FOR KSZ043>046-061>066-074>081-084>090. && $$ FN26/18/18 ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 1015 AM CST MON JAN 28 2008 .UPDATE... DENSE MID LEVEL OVERCAST IS HINDERING TEMPERATURE RISES TODAY. UPSTREAM TEMPS WERE STILL IN THE MID TO UPPER 30S AT MID MORNING. THE COMBINATION OF THE CLOUDS AND LACK OF STRONG WARM ADVECTION WILL KEEP TEMPS COOLER. USED 12Z RUC AS PRIMARY GUIDANCE. 09Z SREF 2 METER TEMPS WERE EVEN COOLER. ADDED A CHANCE OF SPRINKLES IN THE NORTH WHERE RADAR SHOWED QUITE A CONCENTRATION OF 20 TO 30 DBZ RETURNS. && .PREVIOUS DISCUSSION /235 AM CST MON JAN 28 2008/... LATEST SFC MAPS INDICATE A HIGH PRESSURE TO OUR SOUTH...WHICH APPEARS TO BE ON THE MOVE EASTWARD AS A STORM SYSTEM DEVELOPS JUST EAST OF THE ROCKIES. PESKY LOW CLOUDS/FOG WILL JUST NOT LEAVE US ALONE. SHORTLY BEFORE 03Z...LOW CLOUDS BEGAN DEVELOPING OVER SOUTHEAST MISSOURI AND SOUTHWEST ILLINOIS. OTHER THAN THAT...JUST SOME HIGH CLOUDS SPILLING INTO THE AREA FROM THE WEST. FOR TODAY...AS HIGH PRESSURE TO OUR SOUTH CONTINUES TO MOVE TOWARD THE EAST COAST...WINDS WILL CONTINUE TO BLOW OUT OF SOUTH BUT INCREASE DRAMATICALLY. SUSTAINED WINDS OF 20 TO 25 MPH WILL BE LIKELY WITH HIGHER GUSTS...ESPECIALLY BY AFTERNOON. AS WE WAIT FOR THE SYSTEM TO OUR WEST TO MOVE OUT INTO THE CENTRAL PLAINS...CLOUDS WILL CONTINUE TO INCREASE AND THICKEN ACROSS THE AREA. NOT SURE HOW MUCH WARMING WE WILL SEE GIVEN ALL THESE CLOUDS. THE GFS IS STILL HINTING AT A VERY SMALL CHANCE OF PRECIPITATION ACROSS OUR WESTERN AND NORTHERN SECTIONS THIS AFTERNOON. THIS LOOKS TO BE DUE TO SOME MINOR SHORTWAVES RIPPLING THROUGH THE SOUTHWESTERLY FLOW ALOFT. THE NAM FAILS TO INDICATE ANY QPF BUT THE ECMWF DOES HINT AT A LITTLE SOMETHING. STILL THINK IT IS TOO SMALL A CHANCE TO MENTION AT THIS POINT. THE ONE THING THAT MAKES ME WARY...IS THE STRONG LLJ THAT DEVELOPS OVER OUR NORTHWESTERN COUNTIES BY LATE IN THE DAY TODAY. THIS COULD AID IN SOME DEVELOPMENT...ESPECIALLY SINCE MODELS DO NOT SEE THE CURRENT LOW LEVEL MOISTURE ALREADY IN PLACE OVER PORTIONS OF THE AREA. ANOTHER CHANCE FOR PRECIPITATION ARRIVES TONIGHT...AS A STRONGER SHORTWAVE APPROACHES THE REGION...AND WE GET INTO THE WARM SECTOR. THE ENERGY SEEMS TO BE CHANNELED WITHIN THE UPPER FLOW AND THE SHORTWAVE DOES WEAKEN AS IT REACHES THE AREA. QPF AMTS VERY LOW...ALTHOUGH LOW LEVEL MOISTURE WILL BE ON THE INCREASE. ACTUALLY...LOOKING AT THE TIME HEIGHTS...IF ANY PRECIPITATION WERE GOING TO DEVELOP...IT WILL PROBABLY HOLD OFF UNTIL AFTER MIDNIGHT. GUIDANCE POPS SEEM HIGH GIVEN QPF VALUES THROUGH 12Z TUESDAY. WILL LIKELY SPLIT TONIGHTS POP/WX GRID SO THAT WE ONLY HAVE A SLIGHT CHANCE THIS EVENING...WITH HIGHER POPS AFTER MIDNIGHT. MAIN UPPER TROUGH AND COLD FRONT BEGINS TO AFFECT THE AREA DURING THE DAY ON TUESDAY. THE NAM AND GFS IN GOOD AGREEMENT THAT THE COLD FRONT SHOULD BE ENTERING OUR WESTERN COUNTIES BY 18Z TUESDAY...AND THEN SWIFTLY BARRELS ON THROUGH...EXITING THE AREA BY 00Z WEDNESDAY. LOOKS LIKE THE BETTER UPPER LEVEL DYNAMICS DO NOT COINCIDE WITH THE FRONT UNTIL TUESDAY AFTERNOON...SO IT WOULD SEEM THAT WEST KENTUCKY AND SOUTHWEST INDIANA WILL HAVE THE BEST CHANCES FOR PRECIP. PARAMETERS STILL LOOK MARGINAL FOR THUNDERSTORMS...SO WILL JUST LEAVE WHAT IS CURRENTLY MENTIONED IN THE FORECAST. WIND FIELDS IMPRESSIVE WITH 50 KTS AT H85...100 KTS AT H50 AND 130-140 KTS AT H30. DEWPOINTS ARE EXPECTED TO RAMP UP STARTING LATER TONIGHT AND INTO TUESDAY...WITH SFC DEWS REACHING NEAR 50 IN SOME PLACES BY TUESDAY AFTERNOON. WITH INSTABILITY STILL LACKING...SEVERE STORMS CONTINUE TO BE UNLIKELY AT THIS TIME. STRONG COLD AIR ADVECTION WILL ENSUE TUESDAY EVENING AS WINDS SHIFT TO THE NORTHWEST AND BECOME VERY STRONG. MOS GUIDANCE AT SEVERAL LOCATIONS IN THE AREA SHOW 25 TO 27 KTS BTWN 00-03Z WED...WHICH IS THE HIGHEST I HAVE SEEN IN A WHILE. WILL BE QUITE A FRONTAL PASSAGE. WILL BE CLOSE TO WIND ADVISORY CRITERIA FOR THOSE FEW HOURS. WILL HIGHLIGHT IN THE HAZARDOUS WEATHER OUTLOOK AND POSSIBLY A SPECIAL WEATHER STATEMENT. STILL UNSURE OF THE CHANGEOVER TO FLURRIES OR FREEZING DRIZZLE TUESDAY EARLY EVENING. LOOKS LIKE THIS FRONT PUSHES THROUGH SO QUICKLY THAT THE PRECIPITATION SHOULD BE ENDING BEFORE THE COLDER AIR REACHES US. ALTHOUGH MODELS DIFFER ON HOW FAST THAT COLD AIR GETS HERE. THE NAM IS QUICKER...AND SOUNDINGS INDICATE THAT THERE COULD BE SOME LIGHT SNOW ACROSS THE EVV TRI STATE REGION AND PENNYRILE REGION OF WEST KENTUCKY BY 00Z WED...WHILE THE GFS IS STILL MUCH WARMER AT THAT TIME. WILL NOT STRAY TOO MUCH FROM GOING WEATHER GRID AT THIS TIME...BUT MAY END PRECIP SOONER WEST OF THE LAKES AND ALSO IN ILLINOIS. AS MENTIONED BEFORE...VERY COLD AIR COMES IN WITH A VENGEANCE TUESDAY EVENING...WITH H85 TEMPS BTWN -8 AND -12 DEG C BY 06Z WED...AFTER THEY WERE BTWN 8 TO 10 DEG ABOVE ZERO TUESDAY AFTERNOON. HOWEVER...CORE OF THE COLDEST AIR DOES NOT STICK AROUND LONG...AND MOVES NORTHEAST OF THE AREA DURING THE DAY ON WEDNESDAY. ACTUALLY...WARM AIR ADVECTION ACTUALLY STARTS UP LATE IN THE DAY AHEAD OF OUR NEXT SYSTEM. 00Z GFS AND ECMWF IN FAIRLY GOOD AGREEMENT THAT THURSDAY IS GOING TO BE WET...THOUGH THE PLACEMENT OF THE SFC LOW DOES DIFFER. STILL LOOKS LIKE SOUTHEAST MISSOURI AND WEST KENTUCKY HAVE THE BEST CHANCES TO SEE PRECIP ON THURSDAY GIVEN BOTH MODEL SOLUTION. FURTHER NORTH AND EAST...IF GETS IFFY DEPENDING ON WHICH MODEL HAS A BETTER HANDLE ON THIS NEXT SYSTEM. WILL NOT GET TOO CRAZY WITH POPS BUT AT LEAST WILL INCREASE THEM IN AREAS WE ARE MORE CONFIDENT. LOOKS LIKE ALL LIQUID ESPECIALLY SOUTH. FURTHER NORTH...IT COULD BE EVEN FREEZING RAIN DEPENDING ON HOW SFC TEMPS WORK OUT. ON THURSDAY NIGHT...THE 00Z GFS INDICATES COLD AIR BEGINNING TO WRAP AROUND THE LOW AS IT SKIRTS NORTHEAST OVER THE AREA. THEREFORE...WE COULD SEE RAIN OR SNOW IN OUR WESTERN COUNTIES...WITH RAIN IN THE EAST. GOING FORECAST APPEARS TO HAVE THIS HANDLED FINE. MADE NO CHANGES BEYOND THURSDAY NIGHT. && .AVIATION... FIRST CONCERN FOR AVIATION IS EVOLUTION OF LIFR CONDITIONS OVER THE WESTERN HALF OF THE AREA EARLY THIS MORNING. THE MODELS ARE OF ABSOLUTELY NO HELP THIS MORNING...BUT GENERALLY FEEL THAT IT WILL GRADUALLY SPREAD NORTH ACROSS SOUTHERN ILLINOIS AND POSSIBLY EAST SOME INTO THE PURCHASE AREA OF WEST KENTUCKY...BUT IT SHOULD NOT REACH KEVV...KOWB OR KHOP. HOWEVER...SOME MVFR FOG WILL BE POSSIBLE IN THOSE AREAS. THE LIFR CLOUDS ARE VERY SHALLOW AND...WITH GOOD MIXING EXPECTED TO DEVELOP AFTER SUNRISE...IT SHOULD DISSIPATE RAPIDLY BY 15-16Z. THIS SHOULD COINCIDE WITH THE ONSET OF STRONG SOUTH WINDS GUSTING 20-30 KTS. THICK MID AND HIGH CLOUDS MAY SQUEEZE OUT A FEW SPRINKLES ACROSS THE AREA THIS AFTERNOON AND EVENING. FINALLY OVERNIGHT...THE GUSTY SOUTH WINDS WILL CONTINUE...AND MVFR CEILINGS WILL OVERSPREAD THE AREA. A PASSING LIGHT SHOWER WILL BE POSSIBLE MAINLY AFTER 06Z TUESDAY. && .PAH WATCHES/WARNINGS/ADVISORIES... KY...NONE. MO...NONE. IL...NONE. IN...NONE. && $$ UPDATE...MY PREVIOUS...CW AVIATION...DRS ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 1209 PM EST SUN JAN 27 2008 .LATE MORNING UPDATE... SKIES HAVE BECOME SUNNY OR MOSTLY SUNNY ACROSS THE AREA EXCEPT IN THE SOUTHEAST...BUT CLOUDS THERE ARE BREAKING UP TOO AND THE BULK OF THE AFTERNOON WILL STILL BE MOSTLY SUNNY THERE AS WELL. A FEW SLIGHT ADJUSTMENTS TO THE GRIDS TO ACCOUNT FOR CURRENT DATA AND TRENDS...OTHERWISE NO HUGE CHANGES TO THE FORECAST. .EARLY MORNING UPDATE... PESKY STRATUS HAS BEEN SWELLING NORTHWARD OVER THE PAST FEW SATELLITE FRAMES INTO MUCH OF CENTRAL KENTUCKY AND SOUTHERN INDIANA. A FEW BREAKS HAVE BEEN FOUND OVER THE BLUE GRASS BUT THEY HAVE GENERALLY BEEN TRANSIENT. WILL INCREASE CLOUD COVER A BIT IN THE GRIDS EARLY THIS MORNING. THE CLOUDS DO LOOK RATHER THIN THOUGH AND THEY ARE STILL EXPECTED TO BURN OFF AS THE SUN GETS TO WORK ON THEM THIS MORNING. .SHORT TERM (TODAY AND TONIGHT)... FORECAST CHALLENGE IN THE SHORT TERM IS CERTAINLY LOW STRATUS(HOW LONG IT WILL LINGER OVER OUR FA THIS MORNING) AND ITS AFFECT ON TEMPS. SATELLITE IMAGERY SHOWS STRATUS WITH A SLOW SEWD DRIFT AS WINDS AT THAT LEVEL BECOME LIGHT NW. A WEAK TROF IS MOVG SEWD OVER SCNTRL INDIANA ATTM AND SHUD BE THROUGH OUR FA BY SUNRISE WITH SOMEWHAT DRIER AIR(LOWER DEWPOINTS) BEHIND IT. HIGH RESOLUTION NAM APPEARS TO HAVE THE BEST HANDLE ON MOVEMENT OF CLOUDS BASED ON ITS FORECAST OF 975 MB RELATIVE HUMIDITY AND WINDS...WHEREAS THE RUC IS SLOWER MOVG CLOUDS OUT AFTER SUNRISE. MOST OF SOUTHERN INDIANA IS CLEAR ATTM WITH SCT TO BKN STRATUS NEAR THE OH RIVER. ANOTHER CONSIDERATION IS FOG/ADDITIONAL STRATUS DEVELOPMENT WHERE IT DOES CLEAR OUT. WILL MAKE A LAST MINUTE DECISION ON CLOUD TERM TODAY BASED ON SATELLITE TRENDS. OF COURSE...CLOUDS WILL AFFECT TEMPS TDA...MOS GUIDANCE IS CLEAR FOR LOUISVILLE AT 12Z WHILE KEEPING CLOUDS AT LEXINGTON INTO LATE MORNING/EARLY AFTERNOON. ONCE STRATUS DEPARTS THIS MORNING...WE SHUD BE CLR OR MOSTLY CLR THE REST OF TDA AND TONIGHT AS PLAINS UPR LEVEL RIDGE REACHES THE OH VLY BY 12Z MON AND SFC HIGH (SRN PLAINS/LWR MS VLY ATTM) EXTENDS NEWD INTO THE TN/LWR OH VLYS TDA AND CONTS SLOWLY EWD TNGT. WITH WLY WINDS AND SUNSHINE...TEMPS SHUD BE ABLE TO CLIMB AT LEAST INTO THE 40S OVER OUR WRN FA AS THEY DID ACRS MO AND SRN IL SAT. .LONG TERM (MONDAY THROUGH SATURDAY)... MONDAY THROUGH WEDNESDAY... WEATHER EXPECTED TO START OFF FAIRLY TRANQUIL AT THE BEGINNING OF THIS FCST PD AS SFC HIGH PRESSURE SLOWLY DRIFTS EASTWARD TOWARD THE ATLANTIC. CREST OF H5 RIDGE IS FCST TO DRIFT OVERHEAD AS SIGNIFICANT HEIGHT FALLS OCCUR ACROSS THE CENTRAL PLAINS. CLOUDS WILL INCREASE THROUGH THE AFTERNOON WITH MOST LOCATIONS BECOMING OVERCAST BY EVENING. DEEP SOUTHWEST FLOW ON THE BACK SIDE OF THE HIGH WILL ALLOW WARMER AIR TO WORK INTO THE REGION WITH HIGHS REACHING THE MID 50S ACROSS THE NORTH AND UPPER 50S ACROSS THE SOUTH. BY MONDAY NIGHT...WEAK MID-LEVEL WAVE IS FCST TO EJECT EAST INTO THE REGION. THIS COMBINED WITH STRONG ISENTROPIC LIFT AND DEEP MOISTURE TRANSPORT BY INCR LOW-LEVEL JET IMPINGING FROM THE SW SHOULD LEAD TO WIDESPREAD SHOWERS ACROSS THE REGION. THUS...AM GOING TO KEEP LIKELY POPS ACROSS THE REGION MONDAY NIGHT. STRONG WIND FIELDS IN THE BOUNDARY LAYER WILL KEEP TEMPS UP IN THE LOW TO MID 40S. BY TUESDAY...DEEPENING AND POTENT H5 WAVE ADVANCES EAST TOWARD THE GREAT LAKES. SFC CYCLONE WILL MOVE FROM THE MIDWEST INTO THE GREAT LAKES WITH A VERY STRONG AND SHARP COLD FRONT HEADING EAST INTO THE AREA BY TUESDAY EVENING. SURGE OF GULF AIR SHOULD WORK ITS WAY INTO THE LOWER OHIO VALLEY TUESDAY AFTERNOON AND CONVECTION IS LIKELY TO START FIRING WELL TO OUR SOUTHWEST BY EARLY AFTERNOON. TIME-HEIGHT CROSS SECTIONS SUGGEST SOME MID LEVEL WARM AIR WILL INITIALLY KEEP INSTABILITY DOWN. HOWEVER...STRONG HEIGHT FALLS...AND FORCED ASCENT ALONG TRAILING COLD FRONT SHOULD ALLOW SEVERAL LINES OF CONVECTION TO DEVELOP ACROSS THE REGION. WHILE BULK SHEAR IS STRONG FOR POSSIBLE SVR CONVECTION...THE MAIN QUESTION STILL REVOLVES AROUND THE FCST INSTABILITY. ANY CONVECTION THAT FORMS WILL HAVE TO BE WATCHED CLOSELY AS H85 WINDS OF 55-60KTS MAY BE ABLE TO WORK DOWN WITHIN THE STORMS AND PRESENT A DAMAGING WIND THREAT. STRONG FRONT LOOKS TO PUSH THROUGH THE REGION BETWEEN 00-06Z WED WITH TEMPERATURES FALLING QUICKLY. AFTERNOON HIGHS TUE WILL LIKELY WARM INTO THE MID AND UPPER 50S WITH TEMPERATURES QUICKLY FALLING AFTER FRONTAL PASSAGE. IN FACT...COLD SURGE MAY BE QUICK ENOUGH TO SEE SOME POST FRONTAL PRECIP CHANGE OVER TO SNOW. OVERALL CONFIDENCE IN THAT IS FAIRLY LOW AT THIS POINT...GIVEN CURRENT FORECAST DATA. THOUGH SOMETHING TO WATCH HOWEVER. QUICK CLEARING TREND LOOKS TO TAKE PLACE EARLY WED WITH SKIES BECOMING MOSTLY CLEAR BY SUNRISE. MORNING LOWS IN THE 20S WILL GIVE WAY TO HIGHS IN THE MID 30S IN THE NORTH FOR WED WITH UPPER 30S AND LOWER 40S ACROSS THE SOUTH. WEDNESDAY NIGHT THROUGH SATURDAY... A BRIEF LULL IN THE ACTIVE WX PATTERN LOOKS IN THE OFFING FOR WED NIGHT AND EARLY THURSDAY AS WE WILL BE BETWEEN WX SYSTEMS. SFC HIGH PRESSURE WILL DRIFT EASTWARD ACROSS THE SE U.S. DURING THE PD RESULTING IN MOSTLY CLEAR SKIES. TEMPERATURES WED NIGHT LOOK TO DROP INTO THE LOW TO MID 20S ACROSS THE REGION. CLOUDS WILL BE ON THE INCREASE DURING THE DAY ON THU AS NEXT WEATHER SYSTEM GATHERS STRENGTH ACROSS THE SOUTHERN PLAINS. A GRADIENT OF TEMPS LOOKS GOOD WITH HIGHS IN THE UPPER 30S TO AROUND 40 IN THE NORTH WITH MID TO UPPER 40S ACROSS THE SOUTH CENTRAL AND FAR SOUTHERN KY. THE LATEST 00Z RUNS OF THE GFS AND EURO CONTINUE TO TREND WARMER WITH THE THU NIGHT AND FRIDAY WEATHER SYSTEM. WHILE EARLIER RUNS OF THESE MODELS HINTED MORE AT A POSSIBLE WINTER STORM TYPE EVENT...THE GENERAL CONSENSUS IS THAT THE STRONG NORTHWARD TRANSPORT OF GULF AIR AND MOISTURE WILL LIKELY RESULT IN A POSSIBLE HEAVY RAIN EVENT FOR THE REGION. BOTH THE GFS AND EURO SOLUTIONS EJECT A DEEP H5 LOW INTO THE MID-MISSISSIPPI VALLEY LATE THU AND EARLY FRIDAY. BOTH MODELS SHOW THE TROF TAKING ON A NEG TILT WHICH RESULTS IN A SLOWER MOVEMENT AND THE ASSOCIATED SFC CYCLONE WOULD LIKELY TRACK FURTHER NORTH AND WEST. IN FACT...BOTH MODELS HAVE THE SFC LOW GOING RIGHT THROUGH THE STATE. GIVEN THE RECENT TRENDS IN THE MODEL DATA...WE HAVE DECIDED TO REMOVE THE R/S MIX AT THIS TIME AND GO WITH SIMPLY PURE RAIN. RAIN COULD BE HEAVY AT TIMES LATE THU NIGHT AND DURING THE DAY ON FRIDAY AS THE SYSTEM MOVES THROUGH. QPF AMOUNTS FROM THE GFS SUGGEST 1 TO 2 INCHES OF RAIN FOR THE AREA...WITH THE EURO SHOWING SIMILAR AMOUNTS. THIS QPF WOULD LIKELY BE EXCESSIVE FOR THE AREA...AND HYDRO ISSUES COULD BE THE END RESULT. SOMETHING TO WATCH IN THE COMING DAYS. LOWS THU MORNING WILL LIKELY BE IN THE MID TO UPPER 30S WITH TEMPERATURES WARMING VERY LITTLE DURING THE DAY ON FRIDAY. GENERALLY TRENDED TEMPS CLOSER TO THE 2M RAW NUMBERS HERE WITH HIGHS IN THE UPPER 30S TO THE LOWER 40S. NO MAJOR CHANGES WERE MADE TO THE FCST FROM FRIDAY NIGHT ONWARD. && .AVIATION (18Z TAFS)... VFR CONDITIONS THROUGH THE PERIOD AS HIGH PRESSURE MOVES ACROSS THE GULF STATES WITH RIDGING REACHING NORTHEAST INTO QUEBEC. WEST WINDS NEAR 10 KNOTS TODAY WILL GO CALM TONIGHT AND THEN COME OUT OF THE SOUTH/SOUTHWEST NEAR 10 KNOTS TOMORROW. && LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ SHORT TERM...13 LONG TERM....MJ AVIATION.....13 ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 741 AM EST SUN JAN 27 2008 .EARLY MORNING UPDATE... PESKY STRATUS HAS BEEN SWELLING NORTHWARD OVER THE PAST FEW SATELLITE FRAMES INTO MUCH OF CENTRAL KENTUCKY AND SOUTHERN INDIANA. A FEW BREAKS HAVE BEEN FOUND OVER THE BLUE GRASS BUT THEY HAVE GENERALLY BEEN TRANSIENT. WILL INCREASE CLOUD COVER A BIT IN THE GRIDS EARLY THIS MORNING. THE CLOUDS DO LOOK RATHER THIN THOUGH AND THEY ARE STILL EXPECTED TO BURN OFF AS THE SUN GETS TO WORK ON THEM THIS MORNING. .SHORT TERM (TODAY AND TONIGHT)... FORECAST CHALLENGE IN THE SHORT TERM IS CERTAINLY LOW STRATUS(HOW LONG IT WILL LINGER OVER OUR FA THIS MORNING) AND ITS AFFECT ON TEMPS. SATELLITE IMAGERY SHOWS STRATUS WITH A SLOW SEWD DRIFT AS WINDS AT THAT LEVEL BECOME LIGHT NW. A WEAK TROF IS MOVG SEWD OVER SCNTRL INDIANA ATTM AND SHUD BE THROUGH OUR FA BY SUNRISE WITH SOMEWHAT DRIER AIR(LOWER DEWPOINTS) BEHIND IT. HIGH RESOLUTION NAM APPEARS TO HAVE THE BEST HANDLE ON MOVEMENT OF CLOUDS BASED ON ITS FORECAST OF 975 MB RELATIVE HUMIDITY AND WINDS...WHEREAS THE RUC IS SLOWER MOVG CLOUDS OUT AFTER SUNRISE. MOST OF SOUTHERN INDIANA IS CLEAR ATTM WITH SCT TO BKN STRATUS NEAR THE OH RIVER. ANOTHER CONSIDERATION IS FOG/ADDITIONAL STRATUS DEVELOPMENT WHERE IT DOES CLEAR OUT. WILL MAKE A LAST MINUTE DECISION ON CLOUD TERM TODAY BASED ON SATELLITE TRENDS. OF COURSE...CLOUDS WILL AFFECT TEMPS TDA...MOS GUIDANCE IS CLEAR FOR LOUISVILLE AT 12Z WHILE KEEPING CLOUDS AT LEXINGTON INTO LATE MORNING/EARLY AFTERNOON. ONCE STRATUS DEPARTS THIS MORNING...WE SHUD BE CLR OR MOSTLY CLR THE REST OF TDA AND TONIGHT AS PLAINS UPR LEVEL RIDGE REACHES THE OH VLY BY 12Z MON AND SFC HIGH (SRN PLAINS/LWR MS VLY ATTM) EXTENDS NEWD INTO THE TN/LWR OH VLYS TDA AND CONTS SLOWLY EWD TNGT. WITH WLY WINDS AND SUNSHINE...TEMPS SHUD BE ABLE TO CLIMB AT LEAST INTO THE 40S OVER OUR WRN FA AS THEY DID ACRS MO AND SRN IL SAT. .LONG TERM (MONDAY THROUGH SATURDAY)... MONDAY THROUGH WEDNESDAY... WEATHER EXPECTED TO START OFF FAIRLY TRANQUIL AT THE BEGINNING OF THIS FCST PD AS SFC HIGH PRESSURE SLOWLY DRIFTS EASTWARD TOWARD THE ATLANTIC. CREST OF H5 RIDGE IS FCST TO DRIFT OVERHEAD AS SIGNIFICANT HEIGHT FALLS OCCUR ACROSS THE CENTRAL PLAINS. CLOUDS WILL INCREASE THROUGH THE AFTERNOON WITH MOST LOCATIONS BECOMING OVERCAST BY EVENING. DEEP SOUTHWEST FLOW ON THE BACK SIDE OF THE HIGH WILL ALLOW WARMER AIR TO WORK INTO THE REGION WITH HIGHS REACHING THE MID 50S ACROSS THE NORTH AND UPPER 50S ACROSS THE SOUTH. BY MONDAY NIGHT...WEAK MID-LEVEL WAVE IS FCST TO EJECT EAST INTO THE REGION. THIS COMBINED WITH STRONG ISENTROPIC LIFT AND DEEP MOISTURE TRANSPORT BY INCR LOW-LEVEL JET IMPINGING FROM THE SW SHOULD LEAD TO WIDESPREAD SHOWERS ACROSS THE REGION. THUS...AM GOING TO KEEP LIKELY POPS ACROSS THE REGION MONDAY NIGHT. STRONG WIND FIELDS IN THE BOUNDARY LAYER WILL KEEP TEMPS UP IN THE LOW TO MID 40S. BY TUESDAY...DEEPENING AND POTENT H5 WAVE ADVANCES EAST TOWARD THE GREAT LAKES. SFC CYCLONE WILL MOVE FROM THE MIDWEST INTO THE GREAT LAKES WITH A VERY STRONG AND SHARP COLD FRONT HEADING EAST INTO THE AREA BY TUESDAY EVENING. SURGE OF GULF AIR SHOULD WORK ITS WAY INTO THE LOWER OHIO VALLEY TUESDAY AFTERNOON AND CONVECTION IS LIKELY TO START FIRING WELL TO OUR SOUTHWEST BY EARLY AFTERNOON. TIME-HEIGHT CROSS SECTIONS SUGGEST SOME MID LEVEL WARM AIR WILL INITIALLY KEEP INSTABILITY DOWN. HOWEVER...STRONG HEIGHT FALLS...AND FORCED ASCENT ALONG TRAILING COLD FRONT SHOULD ALLOW SEVERAL LINES OF CONVECTION TO DEVELOP ACROSS THE REGION. WHILE BULK SHEAR IS STRONG FOR POSSIBLE SVR CONVECTION...THE MAIN QUESTION STILL REVOLVES AROUND THE FCST INSTABILITY. ANY CONVECTION THAT FORMS WILL HAVE TO BE WATCHED CLOSELY AS H85 WINDS OF 55-60KTS MAY BE ABLE TO WORK DOWN WITHIN THE STORMS AND PRESENT A DAMAGING WIND THREAT. STRONG FRONT LOOKS TO PUSH THROUGH THE REGION BETWEEN 00-06Z WED WITH TEMPERATURES FALLING QUICKLY. AFTERNOON HIGHS TUE WILL LIKELY WARM INTO THE MID AND UPPER 50S WITH TEMPERATURES QUICKLY FALLING AFTER FRONTAL PASSAGE. IN FACT...COLD SURGE MAY BE QUICK ENOUGH TO SEE SOME POST FRONTAL PRECIP CHANGE OVER TO SNOW. OVERALL CONFIDENCE IN THAT IS FAIRLY LOW AT THIS POINT...GIVEN CURRENT FORECAST DATA. THOUGH SOMETHING TO WATCH HOWEVER. QUICK CLEARING TREND LOOKS TO TAKE PLACE EARLY WED WITH SKIES BECOMING MOSTLY CLEAR BY SUNRISE. MORNING LOWS IN THE 20S WILL GIVE WAY TO HIGHS IN THE MID 30S IN THE NORTH FOR WED WITH UPPER 30S AND LOWER 40S ACROSS THE SOUTH. WEDNESDAY NIGHT THROUGH SATURDAY... A BRIEF LULL IN THE ACTIVE WX PATTERN LOOKS IN THE OFFING FOR WED NIGHT AND EARLY THURSDAY AS WE WILL BE BETWEEN WX SYSTEMS. SFC HIGH PRESSURE WILL DRIFT EASTWARD ACROSS THE SE U.S. DURING THE PD RESULTING IN MOSTLY CLEAR SKIES. TEMPERATURES WED NIGHT LOOK TO DROP INTO THE LOW TO MID 20S ACROSS THE REGION. CLOUDS WILL BE ON THE INCREASE DURING THE DAY ON THU AS NEXT WEATHER SYSTEM GATHERS STRENGTH ACROSS THE SOUTHERN PLAINS. A GRADIENT OF TEMPS LOOKS GOOD WITH HIGHS IN THE UPPER 30S TO AROUND 40 IN THE NORTH WITH MID TO UPPER 40S ACROSS THE SOUTH CENTRAL AND FAR SOUTHERN KY. THE LATEST 00Z RUNS OF THE GFS AND EURO CONTINUE TO TREND WARMER WITH THE THU NIGHT AND FRIDAY WEATHER SYSTEM. WHILE EARLIER RUNS OF THESE MODELS HINTED MORE AT A POSSIBLE WINTER STORM TYPE EVENT...THE GENERAL CONSENSUS IS THAT THE STRONG NORTHWARD TRANSPORT OF GULF AIR AND MOISTURE WILL LIKELY RESULT IN A POSSIBLE HEAVY RAIN EVENT FOR THE REGION. BOTH THE GFS AND EURO SOLUTIONS EJECT A DEEP H5 LOW INTO THE MID-MISSISSIPPI VALLEY LATE THU AND EARLY FRIDAY. BOTH MODELS SHOW THE TROF TAKING ON A NEG TILT WHICH RESULTS IN A SLOWER MOVEMENT AND THE ASSOCIATED SFC CYCLONE WOULD LIKELY TRACK FURTHER NORTH AND WEST. IN FACT...BOTH MODELS HAVE THE SFC LOW GOING RIGHT THROUGH THE STATE. GIVEN THE RECENT TRENDS IN THE MODEL DATA...WE HAVE DECIDED TO REMOVE THE R/S MIX AT THIS TIME AND GO WITH SIMPLY PURE RAIN. RAIN COULD BE HEAVY AT TIMES LATE THU NIGHT AND DURING THE DAY ON FRIDAY AS THE SYSTEM MOVES THROUGH. QPF AMOUNTS FROM THE GFS SUGGEST 1 TO 2 INCHES OF RAIN FOR THE AREA...WITH THE EURO SHOWING SIMILAR AMOUNTS. THIS QPF WOULD LIKELY BE EXCESSIVE FOR THE AREA...AND HYDRO ISSUES COULD BE THE END RESULT. SOMETHING TO WATCH IN THE COMING DAYS. LOWS THU MORNING WILL LIKELY BE IN THE MID TO UPPER 30S WITH TEMPERATURES WARMING VERY LITTLE DURING THE DAY ON FRIDAY. GENERALLY TRENDED TEMPS CLOSER TO THE 2M RAW NUMBERS HERE WITH HIGHS IN THE UPPER 30S TO THE LOWER 40S. NO MAJOR CHANGES WERE MADE TO THE FCST FROM FRIDAY NIGHT ONWARD. && .AVIATION (12Z TAFS)... IFR TO MVFR CIGS WILL PREVAIL THIS MORNING TIL ABOUT 15Z OR 16Z IN STRATUS AS WELL AS MVFR VSBY IN FOG...PRIMARILY AT KBWG. SKIES SHUD BECOME CLR BY THE AFTN AND CONTINUE SO THROUGH THE PERIOD AS A RIDGE OF HI PRES MOVES NEWD FROM THE LWR MS/TN VLYS. && LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ SHORT TERM...13 LONG TERM....MJ AVIATION.....11 ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 630 AM EST SUN JAN 27 2008 .SHORT TERM (TODAY AND TONIGHT)... FORECAST CHALLENGE IN THE SHORT TERM IS CERTAINLY LOW STRATUS(HOW LONG IT WILL LINGER OVER OUR FA THIS MORNING) AND ITS AFFECT ON TEMPS. SATELLITE IMAGERY SHOWS STRATUS WITH A SLOW SEWD DRIFT AS WINDS AT THAT LEVEL BECOME LIGHT NW. A WEAK TROF IS MOVG SEWD OVER SCNTRL INDIANA ATTM AND SHUD BE THROUGH OUR FA BY SUNRISE WITH SOMEWHAT DRIER AIR(LOWER DEWPOINTS) BEHIND IT. HIGH RESOLUTION NAM APPEARS TO HAVE THE BEST HANDLE ON MOVEMENT OF CLOUDS BASED ON ITS FORECAST OF 975 MB RELATIVE HUMIDITY AND WINDS...WHEREAS THE RUC IS SLOWER MOVG CLOUDS OUT AFTER SUNRISE. MOST OF SOUTHERN INDIANA IS CLEAR ATTM WITH SCT TO BKN STRATUS NEAR THE OH RIVER. ANOTHER CONSIDERATION IS FOG/ADDITIONAL STRATUS DEVELOPMENT WHERE IT DOES CLEAR OUT. WILL MAKE A LAST MINUTE DECISION ON CLOUD TERM TODAY BASED ON SATELLITE TRENDS. OF COURSE...CLOUDS WILL AFFECT TEMPS TDA...MOS GUIDANCE IS CLEAR FOR LOUISVILLE AT 12Z WHILE KEEPING CLOUDS AT LEXINGTON INTO LATE MORNING/EARLY AFTERNOON. ONCE STRATUS DEPARTS THIS MORNING...WE SHUD BE CLR OR MOSTLY CLR THE REST OF TDA AND TONIGHT AS PLAINS UPR LEVEL RIDGE REACHES THE OH VLY BY 12Z MON AND SFC HIGH (SRN PLAINS/LWR MS VLY ATTM) EXTENDS NEWD INTO THE TN/LWR OH VLYS TDA AND CONTS SLOWLY EWD TNGT. WITH WLY WINDS AND SUNSHINE...TEMPS SHUD BE ABLE TO CLIMB AT LEAST INTO THE 40S OVER OUR WRN FA AS THEY DID ACRS MO AND SRN IL SAT. .LONG TERM (MONDAY THROUGH SATURDAY)... MONDAY THROUGH WEDNESDAY... WEATHER EXPECTED TO START OFF FAIRLY TRANQUIL AT THE BEGINNING OF THIS FCST PD AS SFC HIGH PRESSURE SLOWLY DRIFTS EASTWARD TOWARD THE ATLANTIC. CREST OF H5 RIDGE IS FCST TO DRIFT OVER HEAD AS SIGNIFICANT HEIGHT FALLS OCCUR ACROSS THE CENTRAL PLAINS. CLOUDS WILL INCREASE THROUGH THE AFTERNOON WITH MOST LOCATIONS BECOMING OVERCAST BY EVENING. DEEP SOUTHWEST FLOW ON THE BACK SIDE OF THE HIGH WILL ALLOW WARMER AIR TO WORK INTO THE REGION WITH HIGHS REACHING THE MID 50S ACROSS THE NORTH AND UPPER 50S ACROSS THE SOUTH. BY MONDAY NIGHT...WEAK MID-LEVEL WAVE IS FCST TO EJECT EAST INTO THE REGION. THIS COMBINED WITH STRONG ISENTROPIC LIFT AND DEEP MOISTURE TRANSPORT BY INCR LOW-LEVEL JET IMPINGING FROM THE SW SHOULD LEAD TO WIDESPREAD SHOWERS ACROSS THE REGION. THUS...AM GOING TO KEEP LIKELY POPS ACROSS THE REGION MONDAY NIGHT. STRONG WIND FIELDS IN THE BOUNDARY LAYER WILL KEEP TEMPS UP IN THE LOW TO MID 40S. BY TUESDAY...DEEPENING AND POTENT H5 WAVE ADVANCES EAST TOWARD THE GREAT LAKES. SFC CYCLONE WILL MOVE FROM THE MIDWEST INTO THE GREAT LAKES WITH A VERY STRONG AND SHARP COLD FRONT HEADING EAST INTO THE AREA BY TUESDAY EVENING. SURGE OF GULF AIR SHOULD WORK ITS WAY INTO THE LOWER OHIO VALLEY TUESDAY AFTERNOON AND CONVECTION IS LIKELY TO START FIRING WELL TO OUR SOUTHWEST BY EARLY AFTERNOON. TIME-HEIGHT CROSS SECTIONS SUGGEST SOME MID LEVEL WARM AIR WILL INITIALLY KEEP INSTABILITY DOWN. HOWEVER...STRONG HEIGHT FALLS...AND FORCED ASCENT ALONG TRAILING COLD FRONT SHOULD ALLOW SEVERAL LINES OF CONVECTION TO DEVELOP ACROSS THE REGION. WHILE BULK SHEAR IS STRONG FOR POSSIBLE SVR CONVECTION...THE MAIN QUESTION STILL REVOLVES AROUND THE FCST INSTABILITY. ANY CONVECTION THAT FORMS WILL HAVE TO BE WATCHED CLOSELY AS H85 WINDS OF 55-60KTS MAY BE ABLE TO WORK DOWN WITHIN THE STORMS AND PRESENT A DAMAGING WIND THREAT. STRONG FRONT WILL LOOKS TO PUSH THROUGH THE REGION BETWEEN 00-06Z WED WITH TEMPERATURES FALLING QUICKLY. AFTERNOON HIGHS TUE WILL LIKELY WARM INTO THE MID AND UPPER 50S WITH TEMPERATURES QUICKLY FALLING AFTER FRONTAL PASSAGE. IN FACT...COLD SURGE MAY BE QUICK ENOUGH TO SEE SOME POST FRONTAL PRECIP CHANGE OVER TO SNOW. OVERALL CONFIDENCE IN THAT IS FAIRLY LOW AT THIS POINT...GIVEN CURRENT FORECAST DATA. THOUGH SOMETHING TO WATCH HOWEVER. QUICK CLEARING TREND LOOKS TO TAKE PLACE EARLY WED WITH SKIES BECOMING MOSTLY CLEAR BY SUNRISE. MORNING LOWS IN THE 20S WILL GIVE WAY TO HIGHS IN THE MID 30S IN THE NORTH FOR WED WITH UPPER 30S AND LOWER 40S ACROSS THE SOUTH. WEDNESDAY NIGHT THROUGH SATURDAY... A BRIEF LULL IN THE ACTIVE WX PATTERN LOOKS IN THE OFFING FOR WED NIGHT AND EARLY THURSDAY AS WE WILL BE BETWEEN WX SYSTEMS. SFC HIGH PRESSURE WILL DRIFT EASTWARD ACROSS THE SE U.S. DURING THE PD RESULTING IN MOSTLY CLEAR SKIES. TEMPERATURES WED NIGHT LOOK TO DROP INTO THE LOW TO MID 20S ACROSS THE REGION. CLOUDS WILL BE ON THE INCREASE DURING THE DAY ON THU AS NEXT WEATHER SYSTEM GATHERS STRENGTH ACROSS THE SOUTHERN PLAINS. A GRADIENT OF TEMPS LOOKS GOOD WITH HIGHS IN THE UPPER 30S TO AROUND 40 IN THE NORTH WITH MID TO UPPER 40S ACROSS THE SOUTH CENTRAL AND FAR SOUTHERN KY. THE LATEST 00Z RUNS OF THE GFS AND EURO CONTINUE TO TREND WARMER WITH THE THU NIGHT AND FRIDAY WEATHER SYSTEM. WHILE EARLIER RUNS OF THESE MODELS HINTED MORE AT A POSSIBLE WINTER STORM TYPE EVENT...THE GENERAL CONSENSUS IS THAT THE STRONG NORTHWARD TRANSPORT OF GULF AIR AND MOISTURE WILL LIKELY RESULT IN A POSSIBLE HEAVY RAIN EVENT FOR THE REGION. BOTH THE GFS AND EURO SOLUTIONS EJECT A DEEP H5 LOW INTO THE MID-MISSISSIPPI VALLEY LATE THU AND EARLY FRIDAY. BOTH MODELS SHOW THE TROF TAKING ON A NEG TILT WHICH RESULTS IN A SLOWER MOVEMENT AND THE ASSOCIATED SFC CYCLONE WOULD LIKELY TRACK FURTHER NORTH AND WEST. IN FACT...BOTH MODELS HAVE THE SFC LOW GOING RIGHT THROUGH THE STATE. GIVEN THE RECENT TRENDS IN THE MODEL DATA...WE HAVE DECIDED TO REMOVE THE R/S MIX AT THIS TIME AND GO WITH SIMPLY PURE RAIN. RAIN COULD BE HEAVY AT TIMES LATE THU NIGHT AND DURING THE DAY ON FRIDAY AS THE SYSTEM MOVES THROUGH. QPF AMOUNTS FROM THE GFS SUGGEST 1 TO 2 INCHES OF RAIN FOR THE AREA...WITH THE EURO SHOWING SIMILAR AMOUNTS. THIS QPF WOULD LIKELY BE EXCESSIVE FOR THE AREA...AND HYDRO ISSUES COULD BE THE END RESULT. SOMETHING TO WATCH IN THE COMING DAYS. LOWS THU MORNING WILL LIKELY BE IN THE MID TO UPPER 30S WITH TEMPERATURES WARMING VERY LITTLE DURING THE DAY ON FRIDAY. GENERALLY TRENDED TEMPS CLOSER TO THE 2M RAW NUMBERS HERE WITH HIGHS IN THE UPPER 30S TO THE LOWER 40S. NO MAJOR CHANGES WERE MADE TO THE FCST FROM FRIDAY NIGHT ONWARD. && .AVIATION (12Z TAFS)... IFR TO MVFR CIGS WILL PREVAIL THIS MORNING TIL ABOUT 15Z OR 16Z IN STRATUS AS WELL AS MVFR VSBY IN FOG...PRIMARILY AT KBWG. SKIES SHUD BECOME CLR BY THE AFTN AND CONTINUE SO THROUGH THE PERIOD AS A RIDGE OF HI PRES MOVES NEWD FROM THE LWR MS/TN VLYS. && LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ SHORT TERM...DK LONG TERM....MJ AVIATION.....11 ky AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE SHREVEPORT LA 1156 PM CST SUN JAN 27 2008 .DISCUSSION... HAVE UPDATED THE ZONES TO INCLUDE A DENSE FOG ADVISORY FOR ALL OF SW AR/NW/NCNTRL LA UNTIL 16Z MONDAY. SFC OBS/CALL TO LOCAL S/O`S HAVE VERIFIED PEA SOUP FOG GRADUALLY EXPANDING W ACROSS SW AR/NW LA. ALSO INCLUDED MENTION OF PATCHY/AREAS OF FG FOR E TX...AS VERY LOW STRATUS FIELD HAS RECENTLY DEVELOPED IN VC OF CXO/IAH...WITH 2-3SM VISBIES...SURGING N TOWARDS E TX. HOWEVER...15-20 KT BNDRY LYR FLOW...AND PRESENCE OF 40KTS SRLY LLJ ACROSS CNTRL TX TONIGHT SHOULD KEEP THE AIR WELL ENOUGH MIXED SUCH THAT THE FOG SHOULD NOT GET TOO DENSE ACROSS MUCH OF E TX. WILL ALLOW MID SHIFT TO ADJUST/EXPAND CURRENT DENSE FG ADV. AS NEEDED LATER THIS MORNING. ZONE UPDATE/NPW ALREADY OUT. 15 && .PREV DISCUSSION... /ISSUED 944 PM CST SUN JAN 27 2008/ TOUGH ZONE UPDATE THIS EVENING...AS FOR A 3RD STRAIGHT EVENING...WILL HAVE TO CONTEND WITH LOW STRATUS TRAPPED BENEATH STEEP TEMPERATURE INVERSION OVER SCNTRL AR/NE LA. PRIOR TO SUNSET...LOW CLOUDS WERE MIXING WELL ENOUGH E CLOSER TO THE SFC RIDGE CENTER...BUT CLOUDS NOW HAVE ACTUALLY SPILLED BACK WNW IN THE BNDRY LYR FLOW AROUND THE SFC RIDGE...AND SO THE BIGGEST QUESTIONS ARE 1.) HOW FAR W WILL THE STRATUS REACH BEFORE RETURNING MORE NRLY? 2.) WILL THEY REACH SHV/TXK? 3.) SHOULD THEY EXIT MLU AFTER MIDNIGHT...HOW MUCH WILL THE TEMP CRATER...AND HOW EXTENSIVE WILL THE FG BECOME? CIRRUS SHIELD SPILLING OVER UPPER RIDGE HAS THINNED IN RECENT HOURS...ALLOWING TEMPS OVER MUCH OF THE AREA TO FALL NEAR/BELOW FORECAST MIN TEMPS. HAVE LOWERED NUMBERS A BIT AREAWIDE...BUT BELIEVE WRN SECTIONS OF E TX WILL KEEP SOME WIND OVERNIGHT...THUS REDUCING THEIR TEMP. FALL. BELIEVE GREATEST AREAS FOR FG WILL BE CLOSEST TO THE SFC RIDGE CENTER/WEAKER BNDRY LYR FLOW...OVER SW AR/N LA. WILL MENTION AREAS OF DENSE FG MAINLY E OF A MAGNOLIA AR...TO ARCADIA AND MANY LA LINE...AS PATCHY FG HAS ALREADY FORMED ACROSS MANY OF THESE AREAS AWAY FROM THE STRATUS SHIELD. LATEST RUC IS THE ONLY MODEL THAT HAS INITIALIZED WELL ON THE STRATUS DECK OVER OUR REGION...WHICH QUICKLY SHUNTS THE CLOUDS N AFTER MIDNIGHT AS THE BNDRY LYR FLOW VEERS MORE SRLY. THIS SEEMS FEASABLE...AND BELIEVE SOME AREAS OF NCNTRL LA WILL BE ABLE TO CLEAR...THUS ENABLING MORE FG TO QUICKLY DEVELOP. FORECAST MIN TEMPS ARE ANYONE/S GUESS...AM CONCERNED THAT SHOULD CLOUDS CLEAR MLU/ELD...FZFG WILL BE A CONCERN AS TEMPS SHOULD DROP QUICKLY. PATCHY FG WILL BE POSSIBLE FARTHER W ACROSS THE RED RIVER VALLEY OF SE OK/SW AR...AS WELL AS EXTREME ERN TX/NW LA. UPDATED PRELIM NUMBERS ARE LISTED BELOW. ZONE UPDATE WILL BE OUT SHORTLY. 15 && .AVIATION... WELL...WE ONLY THOUGHT WE WERE THROUGH WITH THE LOW CLOUDS AND LOW VISIBILITIES. AFTERNOON SUN DRIED OUT ALL BUT A NARROW CORRIDOR OF IFR CEILINGS ALONG THE MISSISSIPPI RIVER VALLEY AND NOW WITH THE SETTING OF THE SUN...LOW LEVEL EAST AND SOUTHEAST FLOW IS HELPING TO ADVECT THIS MOISTURE BACK AGAIN TOWARDS THE WEST. CEILINGS FALLING RAPIDLY WITH LIFR ALREADY AT ELD TERMINAL AND VISIBILITIES AT ELD AND MLU TERMINALS LIKELY FOLLOWING SUITE. WOULD NOT BE SURPRISED TO SEE THIS MOISTURE MAKE IT BACK INTO TXK AND SHV TERMINAL LATER TONIGHT BUT WILL KEEP THESE AND NE TX TERMINALS VFR UNTIL THEN. SOUTHEAST WINDS COULD ALLOW FOR THE DEVELOPMENT OF SOME PATCHY FOG ACROSS NORTHEAST TEXAS AND NORTHWEST LA TAF SITES BUT DO NOT EXPECT IT TO BECOME DENSE OVERNIGHT WITH THE HIGH AND EVENTUAL MID CLOUD DECK EXPANDING FROM THE WEST. THE BIGGER STORY WILL BE THE WINDS FOR MONDAY AS A VERY TIGHT PRESSURE GRADIENT DEVELOPS TO OUR WEST. WINDS WILL CONTINUE TO VEER AROUND TO THE SOUTH THROUGH THE DAY ON MONDAY AND AS A RESULT...HAVE GONE WITH PREVAILING GUSTS MOST OF THE DAY MONDAY...ESPECIALLY ACROSS NE TX TERMINALS WITH GUSTS AS HIGH AS 30KTS POSSIBLE. /13/ && .PRELIMINARY POINT TEMPS/POPS... SHV 34 66 61 71 / 0 20 40 40 MLU 33 64 58 73 / 0 10 40 60 DEQ 32 63 54 66 / 0 20 40 20 TXK 37 64 61 68 / 0 20 40 40 ELD 33 63 59 69 / 0 10 40 40 TYR 44 67 63 71 / 0 20 40 40 GGG 39 66 60 70 / 0 20 40 40 LFK 38 68 61 71 / 0 20 40 40 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...DENSE FOG ADVISORY UNTIL 10 AM MONDAY FOR THE FOLLOWING ZONES: COLUMBIA...HEMPSTEAD...HOWARD...LAFAYETTE...LITTLE RIVER... MILLER...NEVADA...SEVIER...AND UNION AR. LA...DENSE FOG ADVISORY UNTIL 10 AM MONDAY FOR THE FOLLOWING ZONES: BIENVILLE...BOSSIER...CADDO...CALDWELL...CLAIBORNE... DE SOTO...GRANT...JACKSON...LA SALLE...LINCOLN... NATCHITOCHES...OUACHITA...RED RIVER...SABINE LA...UNION LA... WEBSTER...AND WINN. OK...NONE. TX...NONE. && $$ 15/13 la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAKE CHARLES LA 1012 PM CST SUN JAN 27 2008 .DISCUSSION...THINNING CIRRUS HAS ALLOWED TEMPERATURES TO FALL BELOW FORECAST MINS...SO HAVE LOWERED TEMPERATURES A FEW DEGREES ALL AREAS. HAVE ALSO SEEN VISIBILITIES FALL ACROSS THE AREA...AND LATEST MOS GUIDANCE AND RUC MODEL FORECASTS ARE HITTING FOG PRETTY HARD OVERNIGHT. THINK AN ADVISORY WOULD BE PREMATURE AT THIS POINT WITH READINGS BOUNCING AROUND A BIT...BUT WILL GO AHEAD AN INSERT PATCHY FOG PRIOR TO MIDNIGHT...AREAS THEREAFTER...AND ENHANCE BOTH OF THESE WITH DENSE WORDING I-10 AND SOUTHWARD. WILL CONTINUE TO MONITOR OBS THROUGH THE REST OF THE EVENING. UPDATED PRODUCTS ALREADY SENT. && .PREV DISCUSSION... /ISSUED 343 PM CST SUN JAN 27 2008/ DISCUSSION...SATELLITE IMAGERY AND SFC OBS INDICATE THAT STRATUS CLEARED OUT MAYBE A LITTLE SOONER THAN EXPECTED THIS MORNING...BUT THATS NOT ALL BAD AS AT LEAST MOST OF THE AREA GOT TO FINALLY SEE SOME SUN. LONE HOLDOUTS IN THE CLOUDS APPEAR TO BE A SMALL AREA FROM EUNICE TO CROWLEY TO WRN VERMILION PARISH...BUT SATELLITE TRENDS INDICATE THESE AREAS WILL CLEAR OUT SHORTLY. TEMPS HAVE REBOUNDED NICELY IN THE SUNSHINE AND READINGS SHOULD FINALLY GET UP TO EXPECTED MAXES OVER THE NEXT HOUR OR SO BEFORE SUNDOWN. SHOULD BE A DECENT 24-36 HOURS BEFORE THE NEXT WEATHER MAKER AFFECTS THE AREA. SOME LOW CLOUDS ARE EXPECTED TO REFORM AGAIN TONIGHT ALTHOUGH LIKELY NOT TO TODAYS EXTENT. HIGH PRESSURE WHICH WAS CENTERED OVER NRN LA EARLIER TODAY WILL CONTINUE TO MOVE EAST THROUGH THE EVENING ALLOWING LOW-LVL RETURN FLOW TO SET UP OVER THE WRN PORTIONS OF THE FORECAST AREA LATER THIS EVENING... SPREADING EAST DURING THE OVERNIGHT. MEANWHILE SFC LOW IS PROGGED TO DEEPEN OVER THE PLAINS TOMORROW FURTHER INCREASING SRLY FLOW OVER THE AREA. MODEL SOUNDINGS INDICATE PWAT VALUES RISING TO 1.2 TO 1.3 INCHES BY 00Z TUESDAY. WEAK VORT CROSSING THE LONE STAR STATE COULD PROVIDE ENOUGH LIFT TO SPARK A FEW SHOWERS DURING THE AFTERNOON MONDAY SO INCLUDED A 20 POP FOR THE WRN ZONES TO ACCOUNT. MOISTURE WILL FURTHER INCREASE ON 30-40 KT LOW-LEVEL JET MONDAY NIGHT WHILE COLD FRONT CONTINUES TO APPROACH THE AREA FROM THE W/NW. HAVE CONTINUED CHANCE POPS FOR THE NRN ZONES MONDAY NIGHT WITH SLIGHTLY HIGHER MOISTURE/BETTER PROXIMITY TO UPPER JET DYNAMICS AND FRONTAL LIFT/SFC CONVERGENCE. SCATTERED SHOWERS AND THUNDERSTORM ARE EXPECTED WITH FROPA ON TUESDAY...NRN ZONES MAY SEE BETTER COVERAGE ALTHOUGH FOR NOW KEPT ENTIRE AREA AT 50 PERCENT. COULD BE A FEW SEVERE STORMS AS WELL BUT TOO EARLY TO PIN DOWN LIKELIHOODS ATTM. HELD ONTO SLIGHT CHANCE TO CHANCE POPS FOR THE SERN 1/2 OF THE AREA FOR TUESDAY EVENING AS FRONT DEPARTS THE REGION. WEDNESDAY LOOKS FINE AS HIGH PRESSURE QUICKLY BUILDS BACK OVER THE REGION. HOWEVER SFC RETURN FLOW AND SRLY LOW-LVL JETTING QUICKLY DEVELOP WEDNESDAY NIGHT AHEAD OF NEXT SHORTWAVE CROSSING THE CENTRAL CONUS. EXPECT ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS LATE WEDNESDAY NIGHT THROUGH THURSDAY AS NEXT FRONT CROSSES THE AREA. DRY WEATHER LOOKS ON TAP FOR THE REMAINDER OF THE WORK WEEK AND INTO THE EARLY PART OF NEXT WEEKEND. A FEW SHOWERS ARE LIKELY NEXT SUNDAY AS NEXT SYSTEM WRAPS UP OVER THE PLAINS. AVIATION...RESIDUAL MOISTURE REMAINS. EXPECTING IFR CIGS TO REFORM THIS EVENING. OCCASIONAL IFR VIS IN FOG FOR S CEN LA TERMINALS LFT AND ARA. CIGS SHOULD BURN OFF EARLIER THAN TODAY ON MONDAY AS SOUTHERLY FLOW INCREASES. 11 MARINE...SCA CONDITIONS POSSIBLE BY MONDAY NIGHT AS SRLY WINDS INCREASE OVER THE COASTAL WATERS AHEAD OF APPROACHING STORM SYSTEM. COLD FRONT CROSSES THE COASTAL WATERS TUESDAY EVENING WITH STRONG NRLY FLOW...AND LIKELY AN ADVISORY...LEFT IN ITS WAKE. CONDITIONS IMPROVE SOMEWHAT BY WEDNESDAY BEFORE ONSET OF NEXT ROUND OF STRONG ONSHORE FLOW PRECEDING THURSDAY FRONTAL BOUNDARY. && .PRELIMINARY POINT TEMPS/POPS... KLCH 39 65 60 73 / 10 10 20 50 KBPT 41 67 59 74 / 10 20 20 50 KAEX 38 67 58 72 / 10 10 30 50 KLFT 39 66 57 73 / 10 10 20 50 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ PUBLIC...05 MARINE....05 la AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE SHREVEPORT LA 944 PM CST SUN JAN 27 2008 .DISCUSSION... TOUGH ZONE UPDATE THIS EVENING...AS FOR A 3RD STRAIGHT EVENING...WILL HAVE TO CONTEND WITH LOW STRATUS TRAPPED BENEATH STEEP TEMPERATURE INVERSION OVER SCNTRL AR/NE LA. PRIOR TO SUNSET...LOW CLOUDS WERE MIXING WELL ENOUGH E CLOSER TO THE SFC RIDGE CENTER...BUT CLOUDS NOW HAVE ACTUALLY SPILLED BACK WNW IN THE BNDRY LYR FLOW AROUND THE SFC RIDGE...AND SO THE BIGGEST QUESTIONS ARE 1.) HOW FAR W WILL THE STRATUS REACH BEFORE RETURNING MORE NRLY? 2.) WILL THEY REACH SHV/TXK? 3.) SHOULD THEY EXIT MLU AFTER MIDNIGHT...HOW MUCH WILL THE TEMP CRATER...AND HOW EXTENSIVE WILL THE FG BECOME? CIRRUS SHIELD SPILLING OVER UPPER RIDGE HAS THINNED IN RECENT HOURS...ALLOWING TEMPS OVER MUCH OF THE AREA TO FALL NEAR/BELOW FORECAST MIN TEMPS. HAVE LOWERED NUMBERS A BIT AREAWIDE...BUT BELIEVE WRN SECTIONS OF E TX WILL KEEP SOME WIND OVERNIGHT...THUS REDUCING THEIR TEMP. FALL. BELIEVE GREATEST AREAS FOR FG WILL BE CLOSEST TO THE SFC RIDGE CENTER/WEAKER BNDRY LYR FLOW...OVER SW AR/N LA. WILL MENTION AREAS OF DENSE FG MAINLY E OF A MAGNOLIA AR...TO ARCADIA AND MANY LA LINE...AS PATCHY FG HAS ALREADY FORMED ACROSS MANY OF THESE AREAS AWAY FROM THE STRATUS SHIELD. LATEST RUC IS THE ONLY MODEL THAT HAS INITIALIZED WELL ON THE STRATUS DECK OVER OUR REGION...WHICH QUICKLY SHUNTS THE CLOUDS N AFTER MIDNIGHT AS THE BNDRY LYR FLOW VEERS MORE SRLY. THIS SEEMS FEASABLE...AND BELIEVE SOME AREAS OF NCNTRL LA WILL BE ABLE TO CLEAR...THUS ENABLING MORE FG TO QUICKLY DEVELOP. FORECAST MIN TEMPS ARE ANYONE/S GUESS...AM CONCERNED THAT SHOULD CLOUDS CLEAR MLU/ELD...FZFG WILL BE A CONCERN AS TEMPS SHOULD DROP QUICKLY. PATCHY FG WILL BE POSSIBLE FARTHER W ACROSS THE RED RIVER VALLEY OF SE OK/SW AR...AS WELL AS EXTREME ERN TX/NW LA. UPDATED PRELIM NUMBERS ARE LISTED BELOW. ZONE UPDATE WILL BE OUT SHORTLY. 15 && .AVIATION... WELL...WE ONLY THOUGHT WE WERE THROUGH WITH THE LOW CLOUDS AND LOW VISIBILITIES. AFTERNOON SUN DRIED OUT ALL BUT A NARROW CORRIDOR OF IFR CEILINGS ALONG THE MISSISSIPPI RIVER VALLEY AND NOW WITH THE SETTING OF THE SUN...LOW LEVEL EAST AND SOUTHEAST FLOW IS HELPING TO ADVECT THIS MOISTURE BACK AGAIN TOWARDS THE WEST. CEILINGS FALLING RAPIDLY WITH LIFR ALREADY AT ELD TERMINAL AND VISIBILITIES AT ELD AND MLU TERMINALS LIKELY FOLLOWING SUITE. WOULD NOT BE SURPRISED TO SEE THIS MOISTURE MAKE IT BACK INTO TXK AND SHV TERMINAL LATER TONIGHT BUT WILL KEEP THESE AND NE TX TERMINALS VFR UNTIL THEN. SOUTHEAST WINDS COULD ALLOW FOR THE DEVELOPMENT OF SOME PATCHY FOG ACROSS NORTHEAST TEXAS AND NORTHWEST LA TAF SITES BUT DO NOT EXPECT IT TO BECOME DENSE OVERNIGHT WITH THE HIGH AND EVENTUAL MID CLOUD DECK EXPANDING FROM THE WEST. THE BIGGER STORY WILL BE THE WINDS FOR MONDAY AS A VERY TIGHT PRESSURE GRADIENT DEVELOPS TO OUR WEST. WINDS WILL CONTINUE TO VEER AROUND TO THE SOUTH THROUGH THE DAY ON MONDAY AND AS A RESULT...HAVE GONE WITH PREVAILING GUSTS MOST OF THE DAY MONDAY...ESPECIALLY ACROSS NE TX TERMINALS WITH GUSTS AS HIGH AS 30KTS POSSIBLE. /13/ && .PRELIMINARY POINT TEMPS/POPS... SHV 35 66 61 71 / 0 20 40 40 MLU 34 64 58 73 / 0 10 40 60 DEQ 32 63 54 66 / 0 20 40 20 TXK 37 64 61 68 / 0 20 40 40 ELD 33 63 59 69 / 0 10 40 40 TYR 45 67 63 71 / 0 20 40 40 GGG 39 66 60 70 / 0 20 40 40 LFK 38 68 61 71 / 0 20 40 40 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 15/13 la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1257 AM EST MON JAN 28 2008 .SYNOPSIS... LOW PRESSURE WILL STRENGTHEN WELL OFFSHORE TONIGHT AS IT ACCELERATES NORTHEAST...FARTHER OFF THE MID ATLANTIC COAST. HIGH PRESSURE WILL SLOWLY BUILD IN FROM THE WEST THROUGH MONDAY. THIS FEATURE WILL SLIDE OFFSHORE LATE TOMORROW NIGHT...WITH THE NEXT COLD FRONT CROSSING THE REGION EARLY ON WEDNESDAY. WEAK HIGH PRESSURE BUILDS IN FOR MIDWEEK....WITH THE NEXT STORM SYSTEM EXPECTED TO PUSH INTO THE AREA BY LATER THURSDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AREAS IS SANDWICHED BETWEEN COASTAL LOW AND HIGH PRESSURE TRYING TO BUILD INTO THE REGION. THIS HAS LEAD TO MORE MOISTURE TO BE TRAPPED BETWEEN THESE TWO SYSTEMS AT 6K FT OVER PORTIONS OF THE ERN THIRD OF VA/MD AWAY FROM THE COAST. REG SAT FOG PROD 11U-3.9U PICKING SHOWS AREA OF CLOUD CVR NICELY. LATEST NAM12 DOING A VERY GOOD JOB ON PICKING UP THIS FEATURE AT H92-85 LVLS (RH) AND KEEPS A CHUNK OF THE ERN SECTIONS OF MD/VA RGN IN CLOUDS THROUGH THE OVERNIGHT AND SHOWS CLOUD DECK SPILLING INTO PORTIONS OF THE ERN SHORE TWRDS SUNRISE. RUC13/NAM12 ALSO SHOW DECENT Q-VECTOR CONVERGENCE AT H85 LVLS WHERE CLOUDS HAVE/WILL DVLP. HAVE INCRSD CLD CVR/MIN TEMPS WHERE NEEDED. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/... RELATIVELY BENIGN WX DAY MONDAY...AS HIGH PRESSURE SLIDES OVERHEAD AND STRENGTHENS OVER THE REGION. IN TERMS OF CLDS...GOOD MODEL AGREEMENT ATTM OF LTL IF ANY CLDS THRU TMRW AFTN WITH DRY SW FLOW AND STRONG SUBSIDENCE ALOFT. WENT SLIGHTLY ABOVE MOS GUIDANCE FOR HIGHS TOMORROW. APPEARS THAT NEARLY FULL SUN WL ALLOW MAX T TMRW TO RISE INTO THE LWR 50S ACRS THE PIEDMONT...CENTRAL/SOUTHSIDE VA. SLIGHTLY COOLER READINGS IN THE M/U40S ACRS NORTHERN NECK AND MUCH OF THE EASTERN SHORE. 09Z SREF APPEARS TO BE A NICE COMPROMISE BETWEEN FASTER GFS AND SLOWER NAM...AND SREF GFS BLEND WAS THE BASIS FOR THIS FORECAST PACKAGE. HIGH PRESSURE TRANSITIONS OFFSHORE BY LATE MON NGT/ERY TUESDAY. CLOUDS WL SLOWLY INCREASE...AS MID/HIGH CLDS PUSH INTO THE REGION AHEAD OF FRONTAL PASSAGE. THIS WL ALLOW TEMPERATURES TO REMAIN NRLY STEADY AFTER MIDNIGHT TMRW NGT. STRONG WAA TUESDAY AHEAD OF THE FRONT. DESPITE THE INCREASING CLDS...THE HIGHLY AMPLIFIED UPPER FLOW PATTERN AND (RATHER WEAK OVERRUNNING MOISTURE) WL KEEP US DRY THRU MUCH OF THE DAY TUESDAY. FRNT AND ASSOCIATED MOISTURE WILL BE SLOW TO ADVANCE EWRD TOWARD THE MID ATLC REGION. AGAIN...TUESDAY LOOKS WARM WITH STRONG SW FLOW...ESP ACRS SE VA/NC WHERE MORE SUNSHINE IS EXPECTED. LOW LVL THICKNESSES SHOW HIGHS IN THE UPR 50S/NEAR 60F...WITH 50-55 ERN SHORE AND NW ZONES. IF FRNT IS INDEED A LITTLE SLOWER TO ARRIVE...MAX T VALUES OVER THE WEST MAY HV TO COME UP A DEGREE OR TWO. WL KEEP POPS FOR TUE AFTN...BUT HV PUSHED THEM BACK UNTIL LATE AFTERNOON TUESDAY FOR I-95 W...WITH HIGH CHC POPS FOR (PROBABLY SCT) SHRAS TUESDAY NIGHT ALL ZONES. POPS TAPER TO SLGT CHC OVER EASTERN HALF OF THE REGION ERY WEDNESDAY MORNING. SREF STILL PICKING UP ON QUICK DRYING WED. MODEL SOUNDINGS SHOWING LLVL LOW TURNS WEST (DOWNSLOPE) AFTER 09Z...WITH EXPECTATION THAT POPS SHUTOFF VERY QUICKLY THEREAFTER AREAWIDE. RATHER WARM LOWS TUE NGT/WED MRNG WILL ALLOW TEMPS TO BE SLIGHTLY ABOVE AVG ON WED...AND WENT A CATEGORY OR TWO ABV MOS GUIDANCE AS A RESULT OF THIS. DID NOTICE THAT LATEST ECMWF/UKMET DID SLOW DOWN FROPA WEDNESDAY MORNING. FOR NOW...WL KEEP FRONTAL TIMING AS IS...WITH THE IDEA THAT WE CAN PUSH BACK TIMING LATER IF NECESSARY. EITHER WAY...QPF FOR THIS EVENT LOOKS RATHER MEAGER AT BEST. SREF PLUMES HINTING AT <0.05 IN QPF FOR MOST OF THE CWA...WITH ALL MODELS SHOWING LESS THAN 0.50 OF QPF. MOST MODELS SEEM TO BE CLOSER TO THE LOWER END OF THAT SCALE...AND HV TRENDED QPF FORECAST THAT WAY PENDING CONVINCING EVIDENCE TO THE CONTRARY. WHILE DEGREE OF CLEARING REMAINS TO BE SEEN...SKIES SHOULD CLR OUT WED MORNING. GENLY ACCEPTED A MEX BASED BLEND FOR HIGHS WEDNESDAY. AS HAS OCCURRED WITH NUMEROUS WEAK FROPAS EARLIER THIS SEASON...BLV THAT CLEARING SKIES...GOOD MIXING CONDITIONS AND SLOW TO ARRIVE COOL AIR WL COMBINE FOR ANOTHER WARMER THAN CLIMO AFTN. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... AFT RECENT BOUT OF COLD AIR...TYPICAL OF LA NINAS (ESP MOD/STRNG)...TEMPS FLIPPING BACK TO AVGG ABV NRML DURG THE XTNDD PD. PTRN ALOFT WL BE TROUGH OUT W...FLAT RDG ACRS SE CONUS - RESULTING STM TRACK FM CNTRL/SRN PLNS THROUGH OH VLY/LAKES STATES. SFC HI PRES SLIDES ACRS FA THU...THEN OFFSHR THU NGT. APRS TO BE PTNTL FOR SHORT PD OF LLVL CAD INLAND THU NGT INTO FRI W/ HI PRES EXITING THE CST...AND NEXT STM TRACKING W OF MTNS. SFC WRMFNT TO PUSH NWD ON FRI AS THE LO MVS THROUGH ERN LAKES RGN. TMG OF PCPN ARRIVAL THU NGT...AND XTNT OF PCPN CVRG/QPF ON FRI (WL BULK OF PCPN LIFT N OF FA BY AFTN HRS?) RMN PROBLEMATIC THIS FAR OUT. HV HUNG ONTO LLVL CAD OVR PDMNT THROUGH FRI (KPG TEMPS IN THE 40S WNW OF RIC)...WHL WRM SCTR NUDGES NWD UP THE CSTL PLN AND PSBL INTO THE I95 CORRIDOR. CDFNT PUSHES OFF THE CST FRI EVE...THEN HI PRES RETURNS W/ DRY WX FOR NEXT WKND. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... SC DECK ARND 6K FT CONTS TO WRAPARND CSTL LOW PULLING FRTHR AWAY. XPCT THIS CLD DECK TO SLOWLY BREAK UP AND BECOME SCT BY 12Z. OTW... VFR THRU FCST PRD. CUD SEE A FEW GUSTS TO 20 KT LATER TDY ALONG THE COAST. HIGH PRESSURE HOLDS OVERHEAD THRU TUE WITH VFR CONDS. LOWER CIGS/VSBYS MAY BE SEEN WITH SHRA ACTIVITY WITH COLD FRONTAL PASSAGE WED AM. && .MARINE... N-NW WNDS SLOWLY INCRG INTO SCA RANGE ERLY THIS AM. XPCT THIS CAA TO CONT KPG LO END SCAS ALL AREAS THROUGH MON AFTN/ERY EVE...THEN ON THE NRN WTRS (FOR LINGERING SEAS ARND 5 FT) MON NGT. HI PRES MVS QUIKLY OVR THE WTRS DURG TUE...THEN OFFSHR. NEXT CDFNT PUSHES ACRS THE WTRS TUE NGT. AHD OF THE FNT...PTNTTLY MOD LLVL FLO FM SW DRCTN...WHICH SHIFTS TO WLY ON WED IN WAKE OF FNTL PASSAGE. ANOTHER PD OF ONSHR LLVL FLO (PSBL SCAS) THU INTO ERY FRI AHD OF DVLPG/INTENSIFYING STM HEADING NE FM THE MID MS VLY TO THE ERN LAKES. XPCTG WNDSHIFT TO SSW FRI AFTN...FOLLOWED BY WLY FLO BEHIND THE CDFNTL PASSAGE BY LT FRI NGT/SAT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR ANZ630>633-656-658. SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ650-652-654. && $$ SYNOPSIS...MAM NEAR TERM...CCW SHORT TERM...BKH/MAM LONG TERM...ALB AVIATION...MPR MARINE...ALB/MPR md AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 738 PM EST MON JAN 28 2008 .SYNOPSIS... 20Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED A TROUGH OVER THE GULF OF ALASKA...A TROUGH ACROSS THE INTERMOUNTAIN WEST...AND RIDGING FROM THE SOUTHERN MISSISSIPPI VALLEY INTO THE EASTERN GREAT LAKES. ALSO WITHIN THE WESTERN TROUGH TO NOTE FOR THE SHORT TERM IS A SHRTWV IN NW KANSAS. SW FLOW BETWEEN THE TROUGH AND RIDGE HAS BROUGHT UPPER LEVEL MOISTURE FROM THE EAST PACIFIC INTO THE CWA...NOTED BY EXTENSIVE HIGH CLOUDS. HOWEVER...ENOUGH SUN WAS ABLE TO PENETRATE THROUGH TO COMBINE WITH THE BREEZY SW FLOW AND WARM 850MB TEMPS (6C AT GRB AND 12C AT MPX) TO BRING TEMPS UP CLOSE TO RECORD LEVELS. THE HIGH TEMP REACHED 41F AT THE OFFICE...JUST 2 DEGREES SHY OF THE RECORD. MORE THICKER CLOUDS CAN BE SEEN ON VISIBLE IMAGERY APPROACHING THE CWA FROM TWO DIFFERENT DIRECTIONS... AND THESE WILL COME INTO PLAY FOR THE FORECAST TONIGHT. THE FIRST IS TO THE SOUTH...STRETCHING FROM SOTUEHRN LAKE MICHGIAN DOWN INTO THE OHIO VALLEY. RADAR AND SURFACE OBS INDICATE SOME LIGHT RAIN TOO WITH THESE CLOUDS. THIS AREA IS BEING SUPPORTED BY ISENTROPIC LIFTING THROUGH THE STRONG WARM ADVECTION PATTERN...NOTED BY 850MB WINDS OF 50-70KT FROM CENTRAL OKLAHOMA INTO NORTHERN ILLINOIS FROM LATEST PROFILERS. THE OTHER AREA OF THICK CLOUDS IS OVER THE DAKOTAS INTO MN...DUE TO A COMBINATION OF DPVA AHEAD OF THE NW KANSAS SHRTWV... UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 100-120KT JET OVER EASTERN NORTH DAKOTA AND UPPER DIVERGENCE IN THE LEFT EXIT REGION OF A 100-120 KT JET EXTENDING FORM NEW MEXICO INTO EASTERN NEBRASKA. SOME LIGHT RAIN HAS ALSO BEEN REPORTED OUT OF THESE CLOUDS. AT THE SURFACE...A 982MB LOW IS LOCATED IN NE SOUTH DAKOTA. VERY CHILLY AIR FLOWING IN BEHIND THE LOW...NOTED BY SURFACE TEMPS IN THE TEENS AND 20S BELOW ZERO OVER ALBERTA...SASKATCHEWAN AND EASTERN MONTANA (850MB TEMPS ARE BELOW -30C). LAST ITEM TO NOTE IS THE STRENGTH OF THE SHRTWV AT THE BASE OF THE WESTERN TROUGH IN NEVADA...WHICH IS NOTED BY LIGHTNING STRIKES OVER UTAH. && .SHORT TERM (TONIGHT AND TUE)... UPPER LEVEL FLOW REMAINS FAIRLY PROGRESSIVE THROUGH THIS PERIOD... LIKELY DUE TO THE TROUGH OVER THE GULF OF ALASKA CONTINUING TO MARCH SE TOWARDS THE PACIFIC NW. THIS PROGRESSION COMES INTO PLAY A BIT MORE IN THE LONG TERM PORTION OF THE FORECAST. FOR TONIGHT...FOCUS IS ON THE TWO FEATURES MENTIONED IN THE SYNOPSIS...THE SHRTWV LIFTING NE OUT OF NW KANSAS...AND THE AREA OF ISENTROPIC LIFT COMING UP THROUGH SOUTHERN LAKE MICHIGAN. SHRTWV LIFTING OUT OF NW KANSAS SHOULD MOVE INTO WI BY 06Z...THEN INTO NE ONTARIO BY 12Z. DPVA AHEAD OF THIS SHRTWV...COMBINED WITH SOME JET COUPLING FROM THE TWO JET AREAS ALSO LIFTING NE...SHOULD BRING SOME LIGHT RAIN INTO THE WESTERN CWA THIS EVENING. PCPN MAY CHANGE TO SNOW AFTER MIDNIGHT AS COOLER AIR WORKS IN...THOUGH AFTER 06Z THE DYNAMICAL FORCING BEGINS TO WANE...SO SNOW ACCUMULATION AT THIS POINT LOOKS MINIMAL. OVER THE EASTERN CWA...AREA OF ISENTROPICALLY LIFTED RAIN IS PROGGED TO MOVE IN THIS EVENING...THEN ALSO EXIT AFTER MIDNIGHT. THE CENTRAL U.P. IS IN THE MIDDLE OF THESE TWO FEATURES...AND IT IS ENTIRELY POSSIBLE THAT VERY LITTLE MAY HAPPEN OTHER THAN DRIZZLE ONCE LOWER CLOUDS DEVELOP. THEREFORE...HIGHEST POPS ARE CONCENTRATED FOR THE WESTERN AND FAR EASTERN CWA...AND BEFORE 06Z. BREEZY SOUTH TO SOUTHWEST WINDS WILL DIMINISH SOME THROUGH THE NIGHT AS THE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT APPROACH. HOWEVER...CLOUD COVER AND SOME WIND...COMBINED WITH RELATIVELY HIGH DEWPOINTS SHOULD HELP KEEP READINGS UP UNTIL THE FRONT PASSES THROUGH (FRONT PROGGED TO BE LOCATED IN THE CENTRAL U.P. AT 12Z TUE). ONLY SLIGHT ADJUSTMENTS MADE TO LOWS. FOR TUE...THE MORNING LOOKS FAIRLY QUIET PCPN WISE AS THE AREA IS PUT IN OVERALL Q-VECTOR DIVERGENCE...CAUSED BY SUBSIDENCE ALOFT IN THE WAKE OF TONIGHTS SHRTWV AND COLD ADVECTION OCCURRING AS THE FRONT CONTINUES TO MOVE ACROSS. THE COLD ADVECTION AT THIS POINT DOES NOT LOOK COLD ENOUGH IN THE MORNING TO GENERATE ANY LAKE EFFECT OFF WESTERN LAKE SUPERIOR. FOCUS OF ATTENTION THEN SHIFTS TO THE MAIN UPPER TROUGH MOVING THROUGH THE WESTERN U.S.. DPVA AHEAD OF THE SHRTWV AT THE BASE OF THE TROUGH SHOULD GENERATE A LOW ALONG THE COLD FRONT THAT WAS MOVING THROUGH THE CWA TONIGHT. THIS LOW IS PROGGED TO LIFT WITH THE SHRTWV FROM SE KANSAS AT 12Z UP INTO SW LOWER MI BY 00Z WED. DPVA AHEAD OF THE SHRTWV...IN CONJUNTION WITH DPVA FROM THE NORTHERN PORTION OF THE TROUGH MOVING INTO NORTHERN MN...AND MID-LEVEL FRONTOGENESIS INDICATED TO MOVE IN SHOULD HELP EXPAND SNOW INTO THE CWA IN THE AFTERNOON. THE HIGHEST POPS ARE CONFINED TO THE WESTERN U.P....WHERE THE COLD AIR IS NOW COLD ENOUGH (850MB TEMPS DROP TO -16 TO -21C BY 00Z) TO GENERATE LAKE EFFECT...AND ALONG THE WISCONSIN BORDER WHERE DPVA FORCING IS MAXIMIZED. SNOWFALL AMOUNTS IN THE GENERAL 1 TO 3 INCH RANGE SEEM REASONABLE...GREATEST IN THE FAR WEST WITH LAKE ENHANCMENT AND FAR SOUTH CENTRAL CLOSER TO THE LOW TRACK. NEW 18Z NAM MIGHT SUGGEST MORE FOR THE SOUTH CENTRAL...AND GIVEN THE UPCOMING WINDS AND SNOW FOR TUE NIGHT...A WATCH IS BEING ISSUED FOR MENOMINEE COUNTY TO SRN SCHOOLCRAFT. TEMPS WILL BE ON THE DECLINE THROUGH THE DAY WITH THE PASSAGE OF THE COLD FRONT...WITH READINGS DROPPING INTO THE SINGLE DIGITS NEAR IWD BY SUNSET. .LONG TERM (TUE NIGHT THRU MON)... DANGEROUS WINTER CONDITIONS APPEAR TO BE SHAPING UP FOR PORTIONS OF THE FCST AREA TUE NIGHT INTO WED. FIRST UP...SNOW ASSOCIATED WITH SHORTWAVE/SFC WAVE AND A BAND OF FAIRLY IMPRESSIVE MIDLEVEL FRONTOGENESIS WILL STREAK NNE THRU THE FCST AREA TUE EVENING... ESPECIALLY CNTRL/ERN PORTIONS. WHILE THIS LOOKS LIKE AN ADVY EVENT WITH REGARD TO SNOW AMOUNTS...THERE IS THE POTENTIAL THAT THE STRENGTH OF SYSTEM MAY LEAD TO MORE SNOW THAN CURRENTLY EXPECTED. NAM HAS BEEN TRENDING HEAVIER WITH PCPN AMOUNTS. IN FACT...18Z RUN HAS 0.75 TO 1 INCH OF PCPN OVER THE CNTRL/ERN FCST AREA. WINDS/BLSN WILL ALSO BE A COMPLICATING FACTOR. IN LIGHT OF THE NAM SOLUTIONS... HAVE OPTED TO CARRY A WINTER STORM WATCH FOR MENOMINEE TO SRN SCHOOLCRAFT THRU TUE NIGHT TO HIGHLIGHT THE POTENTIAL FOR MORE SIGNIFICANT SNOW/BLSN. LATER SHIFTS CAN THEN ADJUST TO SNOW/BLSN ADVY OR UPGRADE TO WARNING IF THE NAM IS ACTUALLY ONTO SOMETHING. ATTENTION THEN TURNS TO LAKE EFFECT AND STRONG WINDS ACROSS LAKE SUPERIOR. LES WILL SWING INTO HIGH GEAR AS ARCTIC SURGES OVER THE UPPER GREAT LAKES. HOWEVER...WITH SUCH STRONG/INTENSE CAA (850MB TEMPS PLUMMET TO AROUND -25C...POSSIBLY AS LOW AS -30C BY 12Z WED)...THERE WILL ONLY BE A SHORT WINDOW FOR FAVORABLE DENDRITIC SNOW GROWTH BEFORE THE COLUMN BECOMES TOO COLD FOR DENDRITES. SO... DO NOT EXPECT SNOW ACCUMULATIONS TO GET OUT OF HAND...ESPECIALLY OVER THE W WHERE SHORT FETCH/STRONG WINDS WILL MINIMIZE HEATING OF THE BOUNDARY LAYER FROM THE LAKE WHICH WOULD IMPROVE SNOW GROWTH. SHOULD ONLY SEE ADVY AMOUNTS THERE. LONGER FETCH/WARMING INTO THE NE FCST AREA MAY OFFER BETTER SNOW GROWTH...SO AMOUNTS MIGHT REACH WARNING CRITERIA THERE. THE BIG COMPLICATING FACTOR WILL BE THE STRONG BOUNDARY LAYER WINDS AND VERY UNSTABLE TEMP PROFILE OVER THE LAKE ENSURING EFFICIENT MIXING. WINDS IN THE MIXED LAYER SHOULD REACH 35 TO 50KT (HIGHEST OVER THE E HALF OF LAKE SUPERIOR)... PROVIDING AN INDICATION OF POSSIBLE GUST SPEEDS. WITH SNOWFLAKE SIZE BECOMING VERY SMALL AND MUCH MORE EFFECTIVE AT REDUCING VSBY... STRONG WINDS AND CONSIDERABLE BLSN WILL LIKELY RESULT IN BLIZZARD CONDITIONS AT SOME POINT TUE NIGHT INTO WED MORNING FOR THE KEWEENAW TO ONTONAGON AND MUNISING EWD. HAVE THUS CHANGED WINTER STORM WATCH TO BLIZZARD WATCH TO PROVIDE INCREASED AWARENESS OF THE POTENTIAL FOR LONG DURATION LOW VIS IN SNOW/BLSN. EXPECT ADVY HEADLINES FOR SNOW/BLSN AND/OR WIND CHILLS FOR THE REMAINING COUNTIES NOT UNDER WATCHES. LES WILL CONTINUE WED...BUT WINDS WILL SLOWLY DIMINISH THRU THE DAY. DUE TO VERY COLD/DRY AIRMASS...SNOW ACCUMULATIONS SHOULD ONLY BE IN THE 1-4INCH RANGE IN THE LAKE EFFECT AREAS. AS FOR TEMPS...FAVORED THE LOWER END OF GUIDANCE FOR MIN TEMPS TUE NIGHT AND FOR MAX TEMPS WED GIVEN THE VERY COLD AIR CURRENTLY OBSERVED UPSTREAM WITHIN THE AIRMASS. WITH LATE AFTN SFC TEMPS IN ALBERTA/SRN SASKATCHEWAN AND ERN MT RANGING FROM -10F TO -25F...IT`S QUITE POSSIBLE TEMPS REFLECTED IN THIS FCST ISSUANCE MAY BE TOO HIGH. THU THRU MON...MEDIUM RANGE MODELS ARE STILL ADVERTISING AN ACTIVE STORM TRACK TO CONTINUE ACROSS THE CONUS INTO THE WEEKEND AND BEYOND AS A SERIES OF SHORTWAVES DROP SE THRU THE GULF OF ALASKA INTO THE WRN STATES AND THEN LIFT E OR NE ACROSS THE CNTRL AND ERN CONUS. SYSTEMS WILL BE SIGNIFICANT PCPN PRODUCERS WITH STRONG GULF OF MEXICO MOISTURE CONNECTIONS. AT THE BEGINNING OF THIS FCST PERIOD...ATTENTION WILL BE ON THE POTENT SHORTWAVE OVER THE SRN PLAINS. THERE IS A LITTLE MORE DISAGREEMENT TODAY IN WHAT THE TRACK OF THE SYSTEM WILL BE AS IT HEADS NE. THE GFS/GFS ENSEMBLES AND GLOBAL CANADIAN ARE INDICATING SYSTEM WILL PROBABLY PASS A LITTLE TOO FAR TO THE SE TO HAVE A BIG AFFECT ON THE WEATHER HERE. HOWEVER...THE ECMWF CONTINUED ITS NW TREND (LAST 4 RUNS THRU 00Z RUN...BUT THE 12Z RUN HAS SHIFTED BACK TO THE SE A LITTLE) AND THE UKMET PROVIDES SUPPORT. THESE SOLUTIONS WOULD PROVIDE A POSSIBLE ADVY SNOWFALL OVER THE SE PART OF THE FCST AREA. SO IN THE END... THIS WILL CONTINUE TO BE A SYSTEM TO WATCH...AND BEST COURSE OF ACTION WILL BE TO STAY CLOSE TO PREVIOUS FCST WHICH DID BRING CHC POPS TO MOST OF THE CNTRL/ERN FCST AREA FRI WITH ASSUMPTION THAT THE NW FRINGE OF THE SYSTEM MIGHT REACH THE AREA. THERE IS REASONABLE AGREEMENT THAT A MUCH WEAKER SHORTWAVE TAKING A MORE NRN ROUTE WILL PASS THRU THE UPPER LAKES SAT. CHC POPS ACROSS THE FCST AREA ARE WARRANTED FOR THIS FEATURE. NEXT POTENT SHORTWAVE DROPPING INTO THE WRN CONUS DURING THE WEEKEND WILL BEGIN TO EDGE OUT INTO THE WRN PLAINS MON. RECENT ECMWF/GFS RUNS HAVE HAD A STRONG SIGNAL FOR THIS TO BE A MAJOR STORM SYSTEM AS IT HEADS ACROSS THE PLAINS TOWARD THE GREAT LAKES EARLY NEXT WEEK. LEADING EDGE OF EXPANDING PCPN SHIELD SHOULD BEGIN TO AFFECT THE AREA MON. DEPENDING ON STRENGTH AND TRACK OF SYSTEM...THERE COULD BE MIXED PCPN ISSUES...BUT ONLY SNOW WILL BE MENTIONED FOR NOW. AFTER THU...DAILY TEMPS SHOULD BE A LITTLE ABOVE NORMAL THRU MON (NORMALS ARE ROUGHLY IN THE SINGLE DIGITS ABOVE ZERO FOR MINS AND MD 20S FOR MAXES). && .AVIATION (FOR THE 00Z TAF ISSUANCE)... TIMING ONSET OF LOW CEILINGS TONIGHT WILL BE A CHALLENGE AS IR SATELLITE AND SFC OBS INDICATE LOW CLOUDS JUST STARTING TO FORM UPSTREAM OVER WRN WI. FOR CMX...AS DISTURBANCE OVER THE ERN DAKOTAS LIFTS NE IT SHOULD DRAW MOISTURE UP FROM THE CENTRAL PLAINS AND PRODUCE ENOUGH FORCING TO GENERATE SOME -RA OR -SN BY 03Z. KEPT IDEA OF PREV FCST WITH PREVAILING MVFR CONDITIONS BY 03Z AND TEMPO GROUPS FOR SOME LOWER VSBYS AND CEILINGS THROUGH MUCH OF THE REST OF NIGHT. A COLD FRONT MOVING IN LATE TONIGHT EARLY TUE WILL RAPIDLY INCREASE THE WINDS WITH GUSTS TO 30 KT...BUT AIR COLD ENOUGH TO PRODUCE LAKE EFFECT SNOW WILL NOT ARRIVE UNTIL AFT 18Z. BY 19Z...CONBINATION OF LES AND SHOULD LOWER PREVAILING VBSY DOWN TO 1/2SM. INCLUDED A TEMPO GROUP 20-24Z FOR 1/4SM IN SNOW/BLOWING SNOW WITH IFR CIGS. AT SAW...INCREASING MOISTURE IN A WARM SRLY FLOW OVER THE COLDER AIRMASS AND SNOWPACK OVER UPPER MICHIGAN SHOULD ALLOW FOR A LOWER IFR DECK TO FORM BY 03Z. LOOK FOR MIST/DRIZZLE CONDITIONS TO BRING VSBYS DOWN INTO THE IFR RANGE AS WELL. THE COLD FRONT MOVING IN TUE MORNING SHOULD RAISE CEILINGS BACK INTO THE MVFR RANGE. ARRIVAL OF ARCTIC AIR AND WAVE MOVING UP BACKSIDE OF COLD FRONT SHOULD RESULT IN PREVAILING MVFR SNOW BY 21Z WITH A TEMPO GROUP 21-24Z FOR IFR CONDITIONS IN SNOW. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... SOUTHERLY GALES OVER EASTERN LAKE SUPERIOR WILL DIMINISH BELOW GALES JUST AFTER MIDNIGHT AS LOW PRESSURE OVER NE SOUTH DAKOTA LIFTS INTO NORTHERN ONTARIO. EXPECT WINDS TO SWITCH TO THE WEST LATE TONIGHT IN THE WAKE OF THE LOWS COLD FRONT...WITH 30 KT SPEEDS LIKELY ON TUE AS ARCTIC AIR FLOWS IN. LOW PRESSURE IS PROGGED TO DEVELOP ALONG THE COLD FRONT AND LIFT TOWARDS FAR EASTERN UPPER MI TUE NIGHT. DEPENDING ON THE TRACK...THERE IS A POSSIBILITY FOR NORTHWEST STORM FORCE WINDS TUE NIGHT...ESPECIALLY ON EASTERN LAKE SUPERIOR. IN ANY EVENT...GALES LOOK LIKE TUE NIGHT ACROSS THE ENTIRE LAKE. WINDS WILL DIMINISH SLOWLY ON WED AND THEN MORE SO WED NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS INTO LAKE SUPERIOR. BEYOND WED NIGHT...THE ONLY SYSTEM OF INTEREST TO BRING POTENTIALLY HIGHER WINDS IS ON FRIDAY WHEN A LOW LIFTS UP FROM THE LOWER MISSISSIPPI VALLEY INTO THE EASTERN GREAT LAKES. RIGHT NOW...WINDS LOOK TO REMAIN BELOW 30 KT AS THE SYSTEM STAYS FAR ENOUGH SOUTH OF LAKE SUPERIOR. WITH THE ARCTIC AIR FLOWING IN ON TUESDAY...HEAVY FREEZING SPRAY WILL BECOME AN ISSUE...BEGINNING IN THE AFTERNOON IN THE FAR WEST...THEN SPREADING EAST TUE NIGHT. HEAVY FREEZING SPRAY WILL DIMINISH WEDNESDAY NIGHT AS WINDS RELAX WITH THE INCOMING HIGH PRESSURE RIDGE. && .MQT WATCHES/WARNINGS/ADVISORIES... MICHIGAN... BLIZZARD WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR MIZ001>003. BLIZZARD WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING FOR MIZ006-007-085. WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING FOR MIZ012>014. LAKE SUPERIOR... GALE WARNING UNTIL 1 AM EST TUESDAY FOR LSZ266-267. HEAVY FREEZING SPRAY WARNING FROM 7 PM TUESDAY TO 7 AM EST THURSDAY FOR LSZ263-264. LAKE MICHIGAN... GALE WARNING UNTIL 1 AM EST TUESDAY FOR LMZ248-250. && $$ SHORT TERM...AJ LONG TERM...ROLFSON AVIATION...VOSS MARINE...AJ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1248 PM EST MON JAN 28 2008 UPDATED AVIATION SECTION FOR 18Z TAF ISSUANCE .UPDATE... FORECAST IS RATHER TRICKY FOR THIS AFTERNOON...PARTICULARLY WITH REGARDS TO PCPN POTENTIAL. 15Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED GENERAL UPPER LEVEL SW FLOW...BETWEEN A TROUGH OVER THE WESTERN U.S. AND A RIDGE FROM THE SOUTHERN PLAINS INTO THE EASTERN GREAT LAKES. PLENTY OF UPPER LEVEL MOISTURE STREAMING UP FROM THE EAST PACIFIC INTO THE GREAT LAKES REGION AS SEEN ON WATER VAPOR...WHICH VISIBLE SATELLITE IMAGERY AND SURFACE OBS INDICATES IS MOSTLY IN THE FORM OF HIGH CLOUDS. BELOW THESE HIGH CLOUDS...12Z RAOB AND TAMDAR SOUNDINGS ARE QUITE DRY...WITH 10-20C DEWPOINT DEPRESSIONS ACROSS THE REGION BETWEEN 900-500MB. THE SOUNDINGS DEPICT A STRONG INVERSION BETWEEN 900-850MB THANKS TO 850MB TEMPS OF 3C AT APX...7C AT GRB AND 12C AT MPX. NORMALLY THIS INVERSION WOULD MEAN TRAPPED LOW CLOUDS OVER THE AREA. HOWEVER...VISIBLE IMAGERY AND MOST SURFACE OBS (EXCLUDING SAW) SHOW VERY FEW IF ANY LOW CLOUDS ACROSS THE MIDWEST OR GREAT LAKES. THIS APPEARS MOSTLY DUE TO THE LACK OF LOW LEVEL MOISTURE...THOUGH DEWPOINTS ARE GENERALLY ON THE WAY UP NOW WITH MOST READINGS IN THE 25 TO 30 F RANGE. HIGHER DEWPOINTS...NEAR 40...ARE MOVING NORTHEAST THROUGH KS INTO SW IA ON A STRONG LOW LEVEL JET. 850MB WINDS ARE SW AT 60-65 KT AT PROFILERS ACROSS KS INTO NORTHERN MO. AT THE SURFACE...A 987MB LOW IS SITUATED NEAR BISMARCK...WITH ALL OF THE UPPER MISSISSIPPI VALLEY INTO THE GREAT LAKES IN THE WARM SECTOR. GIVEN THE PRESENCE OF SO MUCH DRY AIR IN THE LOW AND MID LEVELS...AM HIGHLY UNCERTAIN ON ANY PCPN OCCURRING TODAY. FOLLOWED THE DRIER NAM/RUC SCENARIO OVER THE GFS AS THEY SEEM TO BE DOING BETTER WITH RESPECT TO MOISTURE IN CURRENT TAMDAR SOUNDINGS. PLUS... CLIMATOLOGICALLY SPEAKING THE WARM SECTOR OF A SYSTEM IN WINTER IS NOT VERY FAVORABLE FOR PCPN BECAUSE MOISTURE IS HARDER TO COME BY. THEREFORE MADE A SOMEWHAT DRASTIC CHANGE AND WENT COMPLETELY DRY FOR TODAY. RAISED TEMPS SLIGHTLY GIVEN CURRENT READINGS ARE NEAR PREVIOUS FORECAST HIGHS...BUT HIGH CLOUDS WHICH SHOULD INCREASE THROUGH THE AFTERNOON WILL TEMPER READINGS FROM CLIMBING TOO HIGH. AS FAR AS TONIGHT GOES...WANTED TO LOWER POPS ACROSS THE BOARD...BUT THERE IS A BIT MORE DYNAMICAL FORCING TAKING PLACE. OVER THE WESTERN U.P....MODELS INDICATE SOME MID-LEVEL FRONTOGENESIS AND POSSIBLE JET COUPLING TAKING PLACE...WHICH COULD FORCE SATURATION AND PCPN. IN THE FAR EASTERN U.P....ISENTROPIC LIFT MOVING UP THROUGH MISSOURI INTO ILLINOIS (NOTED BY THICK MID-CLOUDS THERE) HEADS NORTHEAST AND COULD PRODUCE SOME LIGHT PCPN. THE CENTRAL U.P. GETS STUCK IN-BETWEEN PERHAPS INTO A DRIZZLE/FREEZING DRIZZLE. WILL SOMEWHAT HEDGE THE GOING FORECAST TOWARDS THIS SCENARIO...WITH MORE CHANGES FORTHCOMING ONCE THE 12Z GFS COMES IN TO SEE IF IT HANDLES THE MOISTURE BETTER. && .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE STORM POTENTIAL FOR TUESDAY THROUGH WEDNESDAY. WATER VAPOR IMAGERY AND RUC SHOWING A LONGWAVE TROUGH OVER THE PACIFIC NORTHWEST AND A FLATTEN RIDGE OVER GREAT LAKES REGION. A CLOSED LOW IS JUST OFF THE COAST OF THE MID ATLANTIC STATES. WEAK SHORTWAVES ARE OVER WESTERN ONTARIO...NORTH DAKOTA...AND WYOMING. SURFACE ANALYSIS DEPICTS A LOW OVER NORTH DAKOTA WITH A WARM FRONT LEADING IT STRETCHING INTO ILLINOIS. ANOTHER FRONTAL SYSTEM EXTENDS FROM WINNIPEG EAST TO JAMES BAY. AN ELONGATED RIDGE STRETCHES FROM GEORGIA NORTHEAST INTO SOUTHERN QUEBEC. THERE IS SOME FOG OVER THE EASTERN OHIO RIVER VALLEY AND THE LOWER GREAT LAKES. THE PACIFIC NORTHWEST LONGWAVE WILL SHIFT INTO THE NORTHERN HIGH PLAINS TODAY. THE RIDGE OVER THE GREAT LAKES WILL SHIFT INTO THE LOWER GREAT LAKES REGION AS THE LOW OFF THE ATLANTIC COAST WORKS NORTHEAST. THE SHORTWAVE CLIMBING THE RIDGE WILL GENERALLY STAY NORTH OF THE AREA TODAY...EXCEPT FOR THE SHORTWAVE OVER WYOMING WHICH WILL RACE UP THE RIDGE INTO THE FORECAST AREA THIS AFTERNOON. THE NOSE OF A 100+ KNOT UPPER LEVEL JET WILL SHIFT INTO WESTERN U.P. BY LATE AFTERNOON. THE SURFACE LOW OVER MONTANA WILL CATCH UP WITH THE LOW OVER NORTH DAKOTA AND MERGE AS THEY MOVE INTO WESTERN MINNESOTA. THE ACCOMPANYING WARM FRONT WILL SHIFT INTO WISCONSIN. THE LARGE RIDGE OVER THE EAST COAST APPEARS TO BE STEERING EVERYTHING NORTHEAST. THE RIDGE KEEPS A SOUTHERLY FLOW THROUGHOUT THE EASTERN CONUS DRAWING WARM AIR INTO THE GREAT LAKES REGION. THIS SHOULD PUSH TEMPERATURES INTO THE MID AND UPPER 30S OVER THE U.P. TODAY. THE INSTABILITY WITH THE SHORTWAVE...ISENTROPIC ASCENT AHEAD OF THE FRONTAL SYSTEM...AND LOW LEVEL MOISTURE WILL GENERATE PRECIPITATION. AN 850MB THERMAL TROUGH WILL SHIFT INTO THE AREA BY LATE AFTERNOON ALONG WITH CLOUD COVER. THE FORECAST SOUNDING PROFILE AND WARMER SURFACE TEMPERATURES SUGGEST THAT THERE WILL BE A MIX OF RAIN AND SNOW. A 50KNOT LOW LEVEL JET WILL SWEEP ACROSS THE FORECAST AREA TODAY. THE WARM SURFACE TEMPERATURES WILL HELP TO MIX SOME OF THESE WINDS TO THE SURFACE. MODELS IN PRETTY GOOD AGREEMENT WITH THE SYSTEM MOVING INTO THE GREAT LAKES WITH THE NAM ONLY A LITTLE FARTHER NORTH THAN THE CONSENSUS AND THE UKMET SLIGHTLY SLOWER. AS SUGGESTED BY HPC WILL GO WITH THE GFS/ECMWF BLEND. THE LONGWAVE TROUGH WILL MOVE INTO THE DAKOTA AND CENTRAL CANADA TONIGHT. SHORTWAVES EJECTED OUT AHEAD OF THE TROUGH WILL SWEEP THROUGH THE AREA TONIGHT. THE SURFACE LOW WILL MOVE OUT OF MINNESOTA AND INTO CENTRAL ONTARIO BY MIDNIGHT DRAGGING THE COLD FRONT INTO THE WESTERN U.P. AND LAKE SUPERIOR. WINDS AT THAT TIME WILL BEGIN TO VEER WEST AND NORTHWEST. ISENTROPIC ASCENT AHEAD OF THE FRONT AND WARM MOISTURE AIR WILL CONTINUE TO FEED RAINS OVER THE AREA. AS THE FRONT MOVES INTO THE AREA LATE TONIGHT...COLD AIR WILL ADVECT IN AND CHANGE THE RAIN TO SNOW OVER THE WESTERN U.P. THE TEMPERATURES WILL DROP RAPIDLY FOLLOWING THE FROPA. A SECONDARY LOW DEVELOPING ALONG THIS FRONT WILL WORK NORTHWARD ALONG THE FRONT AND REACH EASTERN IOWA BY SUNRISE. THE LONGWAVE TROUGH WILL REACH MINNESOTA AND EASTERN MANITOBA BY LATE TUESDAY AFTERNOON. WEAK SHORTWAVES AHEAD OF THE TROUGH WILL SWEEP THROUGH THE FORECAST AREA. THE SURFACE LOW WILL LIFT INTO NORTHEAST ONTARIO DRAGGING THE COLD FRONT INTO THE EASTERN U.P. THE SURFACE LOW MOVING UP THE FRONT AND WILL REACH NORTHERN LOWER MICHIGAN BY LATE TUESDAY. A -32C 850MB THERMAL WILL SHIFT INTO MINNESOTA. LOW LEVEL MOISTURE AND INSTABILITY ALONG WITH THE COLD AIR SPREADING ACROSS THE AREA WILL CHANGE THE PRECIPITATION TO SNOW BY LATE MORNING. THE TIGHT GRADIENTS BEHIND THE FRONT WILL INCREASE THE WINDS OVER THE WEST. THIS WILL PRODUCE SOME BLOWING SNOW BY LATE AFTERNOON. THE LONGWAVE TROUGH WILL MOVE OVER THE FORECAST AREA TUESDAY NIGHT. THE SURFACE LOW WILL TRACK TO EAST CENTRAL ONTARIO DRAGGING THE COLD FRONT THROUGH THE LOWER GREAT LAKES INTO THE MID ATLANTIC STATES. THE CENTRAL PLAINS RIDGE WILL ADVANCE INTO THE MIDDLE MISSISSIPPI RIVER VALLEY. THE 850MB THERMAL TROUGH WILL SHIFT INTO WESTERN LAKE SUPERIOR. WINDS WILL BE MAINLY FROM THE WEST TO NORTHWEST ACROSS LAKE SUPERIOR. A 40KNOT LOW LEVEL JET WILL SETTLE OVER THE FORECAST AREA OVERNIGHT. THE COLD 850MB TEMPERATURES WILL PROMOTE MIXING SOME OF THESE WINDS TO THE SURFACE. THE COLD TEMPERATURES AND WINDS WILL GENERATE LAKE EFFECT SNOWS AND BLOWING SNOW MAINLY OVER THE WEST END. A WINTER STORMS WATCH MAY BE WARRANTED. WIND CHILLS COULD REACH ADVISORY CATEGORY LATE. SINCE IT COULD BE AN ADVISORY WILL HOLD OFF ON ISSUING IT AT THIS TIME. THE LONGWAVE TROUGH WILL SWING INTO NORTHERN ONTARIO AND SOUTHERN QUEBEC ON WEDNESDAY. THE SURFACE LOW WILL LIKEWISE SWING INTO QUEBEC WHILE THE RIDGE PUSHES DEEPER INTO THE UPPER MISSISSIPPI RIVER VALLEY. ANTI-CYCLONIC FLOW WILL DRAW COLDER AIR INTO THE UPPER GREAT LAKES REGION. DRY AIR WILL OVERSPREAD THE REGION AS WELL. THE THERMAL TROUGH WILL SUPPORT LOW LEVEL INSTABILITY AND LAKE EFFECT SNOWS. THE WINDS WILL MIX DOWN OVER LAKE SUPERIOR SO EXPECT TO SEE MORE BLOWING SNOW. WITH THE TEMPERATURES AS COLD AS IT WILL BE...EXPECT TO SEE FINER FLAKES WHICH WITH THE WINDS WILL REDUCE VISIBILITY GREATLY. THE LONGER FETCH ACROSS THE CENTRAL AND EASTERN PART OF LAKE SUPERIOR WILL CONTRIBUTE GREATLY TO SIGNIFICANT LES OVER THE LUCE...ALGER AND EVEN NORTHERN SCHOOLCRAFT COUNTIES. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... TAF FORECAST IS VERY TRICKY...PARTICULARLY WITH REGARDS TO CEILINGS GIVEN THE FACT THAT MUCH OF THE UPPER MISSISSIPPI VALLEY INTO THE GREAT LAKES HAS NO LOW CLOUDS AT ALL AS OF 1730Z. FOR CMX...CLOUD COVER OVER THE DAKOTAS CONTINUES TO BECOME THICKER AHEAD OF AN UPPER LEVEL DISTURBANCE OVER SE COLORADO. AS THIS DISTURBANCE LIFTS NE AND BRINGS MOISTURE UP FROM THE CENTRAL PLAINS...THESE CLOUDS SHOULD LOWER...WITH ENOUGH FORCING TO PRODUCE SOME -RA OR -SN AFTER 02Z. FOR NOW JUST WENT WITH A LOWERING TO MVFR AND PROB30S FOR POSSIBLY SOME LOWER VSBYS AND CEILINGS. A COLD FRONT SLOWLY PASSING TOMORROW MORNING WILL RAPIDLY INCREASE THE WINDS...BUT COLD ENOUGH AIR TO PRODUCE LAKE EFFECT SNOW IS NOT INDICATED UNTIL 17/18Z...AND THUS HAVE LEFT THAT OUT FOR NOW. AT SAW...THE DISTURBANCE MENTIONED AT CMX IS A BIT TOO FAR WEST TO PROVIDE MUCH FORCING FOR PCPN. HOWEVER...THE PERSISTENT BRINGING UP OF MOISTURE FROM KANSAS INTO THE COLDER AIRMASS OVER UPPER MICHIGAN (THANKS ALSO IN PART FROM SNOWPACK MELTING)...WILL LIKELY RESULT IN SOME LOW CLOUD DECK OVER THE AREA. LOOKS LIKE SOMEWHERE AROUND 03Z THIS SHOULD FORM...WITH THE POSSIBILITY OF SOME IFR MIST/DRIZZLE CONDITIONS. THE COLD FRONT MOVING IN TUE MORNING COULD ACTUALLY CLEAR THE SKIES UP SOME...AND AT THE MINIMUM RAISE CEILINGS. HAVE DONE THIS BY SHOWING AN MVFR BKN DECK. HOWEVER...WOULD NOT BE SURPRISED IF SKIES SCATTER OUT...BASED ON WHAT IS HAPPENING NEAR THE COLD FRONT NOW BETWEEN RAPID CITY AND BISMARCK NORTH DAKOTA. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT LO PRES DVLPG IN THE NORTHERN PLAINS THIS MRNG TO MOVE INTO MN THIS EVENING AND THEN ONTARIO ON TUE MRNG WHILE DEEPENING. SLY GALES HAVE DVLPD AS FCST OVER ECNTRL LK SUP...AND THESE WL CONTINUE INTO TNGT BEFORE PRES GRADIENT GRDLY EASES LATE TNGT. A STRONG ARCTIC COLD FRONT WILL CROSS LAKE SUPERIOR ON TUE AS THE LO MOVES TO NEAR JAMES BAY IN THE EVNG. ANOTHER LO PRES SYS WILL DEVELOP ON THE COLD FRONT OVER THE LOWER GREAT LAKES LATE ON TUE AND MOVE INTO SE CAN AND INTENSIFY ON WEDNESDAY. GALE TO STORM FORCE W TO NW WINDS AND HEAVY FRZG SPRAY WL DVLP IN THE WAKE OF THE COLD FNT AND THE DVLPG LO ON THIS BNDRY AS ARCTIC AIR SURGES OVER LK SUP. PLAN ON THE STRONGEST WINDS FM THE KEWEENAW AND ISLE ROYALE TO THE E. AS THE LO CONTINUES NE ON THU...A HI PRES RDG WL BUILD TOWARD THE UPPER GREAT LAKES. ON FRI...A DEVELOPING LO OVER THE TENNESSEE VALLEY IS EXPECTED TO SHIFT NE TO THE EASTERN GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... MICHIGAN... WINTER STORM WATCH FROM 1 PM TUESDAY TO 7 PM WEDNESDAY MIZ001>003. WINTER STORM WATCH FROM 7 PM TUESDAY TO 7 PM WEDNESDAY MIZ006>007-085. LAKE SUPERIOR...GALE WARNING UNTIL 4 AM EST TUESDAY LSZ266-267. LAKE MICHIGAN...GALE WARNING UNTIL 1 AM EST TUESDAY LMZ248-250. && $$ UPDATE...AJ DISCUSSION...DLG AVIATION...AJ MARINE...KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1243 PM EST MON JAN 28 2008 LATEST UPDATE...AVIATION... .SYNOPSIS...(400 AM EST MON JAN 28 2008) IT WILL BECOME WINDY THIS AFTERNOON AND TONIGHT OUT AHEAD OF AN INTENSE LOW PRESSURE SYSTEM WHICH WILL MOVE FROM THE NORTHERN PLAINS STATES TODAY TO THE LAKE SUPERIOR REGION TUESDAY MORNING. THIS SYSTEM WILL BRING RAIN FROM LATE TODAY THROUGH TONIGHT AND TUESDAY. A FEW THUNDERSTORMS ARE POSSIBLE OUT AHEAD OF THE COLD FRONT TUESDAY AFTERNOON AND VERY EARLY EVENING. IT WILL TURN SHARPLY COLDER AND VERY WINDY TUESDAY NIGHT BEHIND THE COLD FRONT. && .SHORT TERM...(1235 PM EST MON JAN 28 2008) (TODAY THROUGH WEDNESDAY AFTERNOON) MADE TWEAKS TO MAX TEMPS AS SOME LOW TO MID 40S OCCURRING ACROSS THE WESTERN CWA AND TEMPS SHOULD REACH 40S MOST PLACES THIS AFTERNOON BEFORE PRECIP ARRIVES. WILL PROBABLY BE HOLDING OFF ON ANY HEADLINES FOR TUESDAY WITH THE LATE AFTERNOON FORECAST ISSUANCE...BUT WINDS AND SNOW TUESDAY EVENING WILL NEED HEADLINES. REST OF PREVIOUS FORECAST DISCUSSION FOLLOWS. WINDY CONDITIONS WILL DEVELOP THIS AFTN AND PARTICULARLY TONIGHT AS A VIGOROUS LOW PRESSURE SYSTEM MOVES TO THE LAKE SUPERIOR REGION BY 12Z TUE. A FEW GUSTS MAY APPROACH WIND ADVISORY CRITERIA TONIGHT NEAR THE LAKE MI SHORELINE. HOWEVER 00Z GUIDANCE CONSENSUS AND 13KM RUC PROGGED SFC WIND GUSTS SUGGEST GUSTS AND CERTAINLY SUSTAINED WIND SPEEDS WILL REMAIN BELOW ADV CRITERIA. GREATEST IMPACTS FROM THIS SYSTEM WILL COME TUE AND TUE NIGHT. WE EXPECT A BAND OF GUSTY SHOWERS AND EMBEDDED CONVECTION TO RACE ACROSS OUR CWFA BETWEEN AROUND 20Z TUE AND 00Z WED. AN NCFR IS CERTAINLY POSSIBLE IN THAT TIME FRAME WITH POTENTIAL TO PRODUCE DAMAGING WIND GUSTS GIVEN KINEMATIC PROFILES AT THAT TIME. VERY WINDY CONDITIONS WILL DEVELOP BEHIND THE COLD FRONT TUE NIGHT. IMPACTS WILL LIKELY INCLUDE SCATTERED POWER OUTAGES. HIGH WIND GUSTS OF AT LEAST 45 TO 55 MPH ARE EXPECTED ACROSS OUR CWFA TUE NIGHT WITH HIGHEST GUSTS POTENTIALLY REACHING 65 MPH ALONG THE LAKE MI SHORELINE. WE ALREADY STRONGLY CONSIDERED A HIGH WIND WATCH FOR OUR CWFA FOR TUE NIGHT (ESPECIALLY FOR OUR LAKESHORE COUNTIES). ULTIMATELY AFTER COORD WITH SURROUNDING OFFICES WE FELT IT WAS A BIT EARLY FOR THIS HEADLINE. FUTURE SHIFTS WILL DEFINITELY NEED TO CONSIDER THIS AND MONITOR FUTURE GUIDANCE TRENDS CLOSELY. VERY STRONG CAA BEHIND THE COLD FRONT WILL RESULT IN A RAPID CHANGEOVER TO SNOW FROM WEST TO EAST TUESDAY EVENING. WE COULD SEE AN INCH OR TWO OF SNOW TUESDAY EVENING ESPECIALLY IF THE SECONDARY LOW PRESSURE WAVE DEVELOPS AS 00Z GFS GUIDANCE SUGGESTS. I BELIEVE THAT THIS SNOW IN CONJUNCTION WITH VERY STRONG WINDS AND PLUMMETING SFC TEMPS WILL LIKELY RESULT IN SLIPPERY TO ICY ROAD CONDITIONS AND VERY HAZARDOUS TRAVEL CONDITIONS TUESDAY NIGHT. WE DO NOT EXPECT MUCH LAKE EFFECT SNOW LATE TUESDAY NIGHT IN SPITE OF THE VERY STRONG CAA AND PLUMMETING 850 MB TEMPS. THE VERY STRONG WINDS WILL REALLY LIMIT AIRMASS RESIDENCE TIME OVER LAKE MI AND INVERSION HEIGHTS WILL CRASH WHICH WILL REALLY INHIBIT LES DEVELOPMENT. MAX TEMPS WED WILL BE ACHIEVED AT 05Z WED. WE WILL INDICATE STEADY TO SLOWLY FALLING TEMPS IN THE NDFD TEMP STRINGS FOR WED WITH APPARENT TEMP VALUES FALLING TO NEAR TO AROUND 10 BELOW ZERO BY WEDNESDAY MORNING. && .LONG TERM...(400 AM EST MON JAN 28 2008) (WEDNESDAY NIGHT THROUGH SUNDAY) THE MAIN CONCERN IN THE LONG TERM DEALS WITH THE STORM FOR THE END OF THE WEEK. RATHER LARGE DISAGREEMENT AMONGST THE MODELS CONCERNING THE TRACK OF THIS STORM. THE LATEST ECMWF HAS THE STORM TRACKING THROUGH SW LOWER MI AND THE TRACK OF THE 850 MB THERMAL RIDGE SUGGEST A MIX POSSIBLE FOR SOUTH CENTRAL LOWER MI. THE GFS TRACKS THE LOW THROUGH OH...WITH A SOLUTION THAT FAVORS SNOW. THE GLOBAL GEM SHOWS A TRACK CLOSER TO TO THE GFS. AT THIS POINT WILL MAINTAIN THE SNOW SCENARIO FOR THIS EVENT. PRECIPITATION IS LIKELY TO OCCUR AND WILL RAISE POPS ON FRI. WILL NEED TO MONITOR THE WED NIGHT FORECAST. THE LATEST NAM SHOWS A WEAK WAVE WITH SOUTHWEST WINDS PASSING THROUGH THE FORECAST AREA. TEMPS ARE COLD ENOUGH FOR LAKE ENHANCEMENT. THE GFS...GLOBAL GEM AND ECMWF DO NOT HAVE THIS...THUS WILL MAINTAIN A DRY FORECAST. && .AVIATION...(1243 PM EST MON JAN 28 2008) MAINLY VFR CONDITIONS WILL PERSIST THROUGH THE AFTERNOON. CLOUDS WILL THEN LOWER AND THICKEN GOING INTO THE EVENING... WITH SOME RAIN ARRIVING BY 21Z. CONDITIONS SHOULD LOWER TO MVFR BETWEEN 00Z AND 03Z. A STRONG LOW LEVEL JET WILL ARRIVE AFTER 00Z. THIS MAY LEAD TO WIND SHEAR CONDITIONS. && .MARINE...(400 AM EST MON JAN 28 2008) GALE WARNING DELAYED (WILL NOT GO INTO EFFECT UNTIL 18Z THIS AFTN RATHER THAN 12Z) AND EXTENDED THROUGH 12Z WED AFTER COORD W/LOT AND IWX. GALE FORCE WINDS WILL DEVELOP THIS AFTN AND OVERNIGHT. WE BELIEVE A LULL IN WIND SPEEDS IS PROBABLE TUE MORNING/AFTN UNTIL FROPA. HOWEVER GALES WILL RETURN IN FORCE BEHIND THE FRONT AND THERE IS POTENTIAL FOR WINDS TO REACH STORM FORCE TUE NIGHT. FUTURE SHIFTS WILL NEED TO MONITOR THIS AND MODEL TRENDS REGARDING WIND SPEEDS/GUSTS CLOSELY. && .HYDROLOGY...(400 AM EST MON JAN 28 2008) SOME ICE JAMMING WILL CONTINUE TO DEVELOP ON VARIOUS RIVERS IN OUR HSA. HIGH STAGES AND/OR SIGNIFICANT FLUCTUATIONS IN RIVER LEVELS ARE POSSIBLE EARLY TO MIDWEEK DUE TO ICE JAM ISSUES. WARM TEMPS AND RAINFALL WILL MELT SOME SNOW COVER AND POTENTIALLY RESULT IN HIGHER RIVER LEVELS MID TO LATE WEEK. HOWEVER THIS SITUATION WILL BE MUCH DIFFERENT THAN WITH THE MUCH MORE SIGNIFICANT WARMUP WE HAD SEVERAL WEEKS AGO. WE DO NOT ANTICIPATE NEARLY AS RAPID A SNOW MELT SINCE THIS TIME TEMPS WILL ONLY REACH THE LOW TO PERHAPS MID 40S... WITH LOWER DEW POINTS TOO. FURTHERMORE BASIN AVG QPF WILL GENERALLY AVG AROUND AN INCH OR LESS FROM THIS AFTERNOON THROUGH TUESDAY NIGHT. WE WILL CONTINUE TO MONITOR ALL THIS VERY CLOSELY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...GALE WARNING ST JOE TO MANISTEE 18Z THIS AFTN TO 12Z WED. && $$ SYNOPSIS: LAURENS SHORT TERM: LAURENS/OSTUNO LONG TERM: MJS AVIATION: IOD MARINE: LAURENS HYDROLOGY: LAURENS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1235 PM EST MON JAN 28 2008 LATEST UPDATE...SHORT TERM... .SYNOPSIS...(400 AM EST MON JAN 28 2008) IT WILL BECOME WINDY THIS AFTERNOON AND TONIGHT OUT AHEAD OF AN INTENSE LOW PRESSURE SYSTEM WHICH WILL MOVE FROM THE NORTHERN PLAINS STATES TODAY TO THE LAKE SUPERIOR REGION TUESDAY MORNING. THIS SYSTEM WILL BRING RAIN FROM LATE TODAY THROUGH TONIGHT AND TUESDAY. A FEW THUNDERSTORMS ARE POSSIBLE OUT AHEAD OF THE COLD FRONT TUESDAY AFTERNOON AND VERY EARLY EVENING. IT WILL TURN SHARPLY COLDER AND VERY WINDY TUESDAY NIGHT BEHIND THE COLD FRONT. && .SHORT TERM...(1235 PM EST MON JAN 28 2008) (TODAY THROUGH WEDNESDAY AFTERNOON) MADE TWEAKS TO MAX TEMPS AS SOME LOW TO MID 40S OCCURRING ACROSS THE WESTERN CWA AND TEMPS SHOULD REACH 40S MOST PLACES THIS AFTERNOON BEFORE PRECIP ARRIVES. WILL PROBABLY BE HOLDING OFF ON ANY HEADLINES FOR TUESDAY WITH THE LATE AFTERNOON FORECAST ISSUANCE...BUT WINDS AND SNOW TUESDAY EVENING WILL NEED HEADLINES. REST OF PREVIOUS FORECAST DISCUSSION FOLLOWS. WINDY CONDITIONS WILL DEVELOP THIS AFTN AND PARTICULARLY TONIGHT AS A VIGOROUS LOW PRESSURE SYSTEM MOVES TO THE LAKE SUPERIOR REGION BY 12Z TUE. A FEW GUSTS MAY APPROACH WIND ADVISORY CRITERIA TONIGHT NEAR THE LAKE MI SHORELINE. HOWEVER 00Z GUIDANCE CONSENSUS AND 13KM RUC PROGGED SFC WIND GUSTS SUGGEST GUSTS AND CERTAINLY SUSTAINED WIND SPEEDS WILL REMAIN BELOW ADV CRITERIA. GREATEST IMPACTS FROM THIS SYSTEM WILL COME TUE AND TUE NIGHT. WE EXPECT A BAND OF GUSTY SHOWERS AND EMBEDDED CONVECTION TO RACE ACROSS OUR CWFA BETWEEN AROUND 20Z TUE AND 00Z WED. AN NCFR IS CERTAINLY POSSIBLE IN THAT TIME FRAME WITH POTENTIAL TO PRODUCE DAMAGING WIND GUSTS GIVEN KINEMATIC PROFILES AT THAT TIME. VERY WINDY CONDITIONS WILL DEVELOP BEHIND THE COLD FRONT TUE NIGHT. IMPACTS WILL LIKELY INCLUDE SCATTERED POWER OUTAGES. HIGH WIND GUSTS OF AT LEAST 45 TO 55 MPH ARE EXPECTED ACROSS OUR CWFA TUE NIGHT WITH HIGHEST GUSTS POTENTIALLY REACHING 65 MPH ALONG THE LAKE MI SHORELINE. WE ALREADY STRONGLY CONSIDERED A HIGH WIND WATCH FOR OUR CWFA FOR TUE NIGHT (ESPECIALLY FOR OUR LAKESHORE COUNTIES). ULTIMATELY AFTER COORD WITH SURROUNDING OFFICES WE FELT IT WAS A BIT EARLY FOR THIS HEADLINE. FUTURE SHIFTS WILL DEFINITELY NEED TO CONSIDER THIS AND MONITOR FUTURE GUIDANCE TRENDS CLOSELY. VERY STRONG CAA BEHIND THE COLD FRONT WILL RESULT IN A RAPID CHANGEOVER TO SNOW FROM WEST TO EAST TUESDAY EVENING. WE COULD SEE AN INCH OR TWO OF SNOW TUESDAY EVENING ESPECIALLY IF THE SECONDARY LOW PRESSURE WAVE DEVELOPS AS 00Z GFS GUIDANCE SUGGESTS. I BELIEVE THAT THIS SNOW IN CONJUNCTION WITH VERY STRONG WINDS AND PLUMMETING SFC TEMPS WILL LIKELY RESULT IN SLIPPERY TO ICY ROAD CONDITIONS AND VERY HAZARDOUS TRAVEL CONDITIONS TUESDAY NIGHT. WE DO NOT EXPECT MUCH LAKE EFFECT SNOW LATE TUESDAY NIGHT IN SPITE OF THE VERY STRONG CAA AND PLUMMETING 850 MB TEMPS. THE VERY STRONG WINDS WILL REALLY LIMIT AIRMASS RESIDENCE TIME OVER LAKE MI AND INVERSION HEIGHTS WILL CRASH WHICH WILL REALLY INHIBIT LES DEVELOPMENT. MAX TEMPS WED WILL BE ACHIEVED AT 05Z WED. WE WILL INDICATE STEADY TO SLOWLY FALLING TEMPS IN THE NDFD TEMP STRINGS FOR WED WITH APPARENT TEMP VALUES FALLING TO NEAR TO AROUND 10 BELOW ZERO BY WEDNESDAY MORNING. && .LONG TERM...(400 AM EST MON JAN 28 2008) (WEDNESDAY NIGHT THROUGH SUNDAY) THE MAIN CONCERN IN THE LONG TERM DEALS WITH THE STORM FOR THE END OF THE WEEK. RATHER LARGE DISAGREEMENT AMONGST THE MODELS CONCERNING THE TRACK OF THIS STORM. THE LATEST ECMWF HAS THE STORM TRACKING THROUGH SW LOWER MI AND THE TRACK OF THE 850 MB THERMAL RIDGE SUGGEST A MIX POSSIBLE FOR SOUTH CENTRAL LOWER MI. THE GFS TRACKS THE LOW THROUGH OH...WITH A SOLUTION THAT FAVORS SNOW. THE GLOBAL GEM SHOWS A TRACK CLOSER TO TO THE GFS. AT THIS POINT WILL MAINTAIN THE SNOW SCENARIO FOR THIS EVENT. PRECIPITATION IS LIKELY TO OCCUR AND WILL RAISE POPS ON FRI. WILL NEED TO MONITOR THE WED NIGHT FORECAST. THE LATEST NAM SHOWS A WEAK WAVE WITH SOUTHWEST WINDS PASSING THROUGH THE FORECAST AREA. TEMPS ARE COLD ENOUGH FOR LAKE ENHANCEMENT. THE GFS...GLOBAL GEM AND ECMWF DO NOT HAVE THIS...THUS WILL MAINTAIN A DRY FORECAST. && .AVIATION...(630 AM EST MON JAN 28 2008) MAINLY MVFR CONDITIONS WILL PERSIST THROUGH THE MORNING...BUT SOME IMPROVEMENT TO VFR SHOULD ARRIVE AROUND NOON. CLOUDS WILL THEN LOWER AND THICKEN GOING INTO THE EVENING...WITH SOME RAIN ARRIVING BY 00Z. CONDITIONS SHOULD LOWER BACK DOWN TO MVFR BETWEEN 00Z AND 06Z. A STRONG LOW LEVEL JET WILL ARRIVE AFT 00Z. THIS MAY LEAD TO SOME WIND SHEAR. && .MARINE...(400 AM EST MON JAN 28 2008) GALE WARNING DELAYED (WILL NOT GO INTO EFFECT UNTIL 18Z THIS AFTN RATHER THAN 12Z) AND EXTENDED THROUGH 12Z WED AFTER COORD W/LOT AND IWX. GALE FORCE WINDS WILL DEVELOP THIS AFTN AND OVERNIGHT. WE BELIEVE A LULL IN WIND SPEEDS IS PROBABLE TUE MORNING/AFTN UNTIL FROPA. HOWEVER GALES WILL RETURN IN FORCE BEHIND THE FRONT AND THERE IS POTENTIAL FOR WINDS TO REACH STORM FORCE TUE NIGHT. FUTURE SHIFTS WILL NEED TO MONITOR THIS AND MODEL TRENDS REGARDING WIND SPEEDS/GUSTS CLOSELY. && .HYDROLOGY...(400 AM EST MON JAN 28 2008) SOME ICE JAMMING WILL CONTINUE TO DEVELOP ON VARIOUS RIVERS IN OUR HSA. HIGH STAGES AND/OR SIGNIFICANT FLUCTUATIONS IN RIVER LEVELS ARE POSSIBLE EARLY TO MIDWEEK DUE TO ICE JAM ISSUES. WARM TEMPS AND RAINFALL WILL MELT SOME SNOW COVER AND POTENTIALLY RESULT IN HIGHER RIVER LEVELS MID TO LATE WEEK. HOWEVER THIS SITUATION WILL BE MUCH DIFFERENT THAN WITH THE MUCH MORE SIGNIFICANT WARMUP WE HAD SEVERAL WEEKS AGO. WE DO NOT ANTICIPATE NEARLY AS RAPID A SNOW MELT SINCE THIS TIME TEMPS WILL ONLY REACH THE LOW TO PERHAPS MID 40S... WITH LOWER DEW POINTS TOO. FURTHERMORE BASIN AVG QPF WILL GENERALLY AVG AROUND AN INCH OR LESS FROM THIS AFTERNOON THROUGH TUESDAY NIGHT. WE WILL CONTINUE TO MONITOR ALL THIS VERY CLOSELY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...GALE WARNING ST JOE TO MANISTEE 18Z THIS AFTN TO 12Z WED. && $$ SYNOPSIS: LAURENS SHORT TERM: LAURENS/OSTUNO LONG TERM: MJS AVIATION: MJS MARINE: LAURENS HYDROLOGY: LAURENS mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1125 AM EST MON JAN 28 2008 .UPDATE... FORECAST IS RATHER TRICKY FOR THIS AFTERNOON...PARTICULARLY WITH REGARDS TO PCPN POTENTIAL. 15Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED GENERAL UPPER LEVEL SW FLOW...BETWEEN A TROUGH OVER THE WESTERN U.S. AND A RIDGE FROM THE SOUTHERN PLAINS INTO THE EASTERN GREAT LAKES. PLENTY OF UPPER LEVEL MOISTURE STREAMING UP FROM THE EAST PACIFIC INTO THE GREAT LAKES REGION AS SEEN ON WATER VAPOR...WHICH VISIBLE SATELLITE IMAGERY AND SURFACE OBS INDICATES IS MOSTLY IN THE FORM OF HIGH CLOUDS. BELOW THESE HIGH CLOUDS...12Z RAOB AND TAMDAR SOUNDINGS ARE QUITE DRY...WITH 10-20C DEWPOINT DEPRESSIONS ACROSS THE REGION BETWEEN 900-500MB. THE SOUNDINGS DEPICT A STRONG INVERSION BETWEEN 900-850MB THANKS TO 850MB TEMPS OF 3C AT APX...7C AT GRB AND 12C AT MPX. NORMALLY THIS INVERSION WOULD MEAN TRAPPED LOW CLOUDS OVER THE AREA. HOWEVER...VISIBLE IMAGERY AND MOST SURFACE OBS (EXCLUDING SAW) SHOW VERY FEW IF ANY LOW CLOUDS ACROSS THE MIDWEST OR GREAT LAKES. THIS APPEARS MOSTLY DUE TO THE LACK OF LOW LEVEL MOISTURE...THOUGH DEWPOINTS ARE GENERALLY ON THE WAY UP NOW WITH MOST READINGS IN THE 25 TO 30 F RANGE. HIGHER DEWPOINTS...NEAR 40...ARE MOVING NORTHEAST THROUGH KS INTO SW IA ON A STRONG LOW LEVEL JET. 850MB WINDS ARE SW AT 60-65 KT AT PROFILERS ACROSS KS INTO NORTHERN MO. AT THE SURFACE...A 987MB LOW IS SITUATED NEAR BISMARCK...WITH ALL OF THE UPPER MISSISSIPPI VALLEY INTO THE GREAT LAKES IN THE WARM SECTOR. GIVEN THE PRESENCE OF SO MUCH DRY AIR IN THE LOW AND MID LEVELS...AM HIGHLY UNCERTAIN ON ANY PCPN OCCURRING TODAY. FOLLOWED THE DRIER NAM/RUC SCENARIO OVER THE GFS AS THEY SEEM TO BE DOING BETTER WITH RESPECT TO MOISTURE IN CURRENT TAMDAR SOUNDINGS. PLUS... CLIMATOLOGICALLY SPEAKING THE WARM SECTOR OF A SYSTEM IN WINTER IS NOT VERY FAVORABLE FOR PCPN BECAUSE MOISTURE IS HARDER TO COME BY. THEREFORE MADE A SOMEWHAT DRASTIC CHANGE AND WENT COMPLETELY DRY FOR TODAY. RAISED TEMPS SLIGHTLY GIVEN CURRENT READINGS ARE NEAR PREVIOUS FORECAST HIGHS...BUT HIGH CLOUDS WHICH SHOULD INCREASE THROUGH THE AFTERNOON WILL TEMPER READINGS FROM CLIMBING TOO HIGH. AS FAR AS TONIGHT GOES...WANTED TO LOWER POPS ACROSS THE BOARD...BUT THERE IS A BIT MORE DYNAMICAL FORCING TAKING PLACE. OVER THE WESTERN U.P....MODELS INDICATE SOME MID-LEVEL FRONTOGENESIS AND POSSIBLE JET COUPLING TAKING PLACE...WHICH COULD FORCE SATURATION AND PCPN. IN THE FAR EASTERN U.P....ISENTROPIC LIFT MOVING UP THROUGH MISSOURI INTO ILLINOIS (NOTED BY THICK MID-CLOUDS THERE) HEADS NORTHEAST AND COULD PRODUCE SOME LIGHT PCPN. THE CENTRAL U.P. GETS STUCK IN-BETWEEN PERHAPS INTO A DRIZZLE/FREEZING DRIZZLE. WILL SOMEWHAT HEDGE THE GOING FORECAST TOWARDS THIS SCENARIO...WITH MORE CHANGES FORTHCOMING ONCE THE 12Z GFS COMES IN TO SEE IF IT HANDLES THE MOISTURE BETTER. && .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE STORM POTENTIAL FOR TUESDAY THROUGH WEDNESDAY. WATER VAPOR IMAGERY AND RUC SHOWING A LONGWAVE TROUGH OVER THE PACIFIC NORTHWEST AND A FLATTEN RIDGE OVER GREAT LAKES REGION. A CLOSED LOW IS JUST OFF THE COAST OF THE MID ATLANTIC STATES. WEAK SHORTWAVES ARE OVER WESTERN ONTARIO...NORTH DAKOTA...AND WYOMING. SURFACE ANALYSIS DEPICTS A LOW OVER NORTH DAKOTA WITH A WARM FRONT LEADING IT STRETCHING INTO ILLINOIS. ANOTHER FRONTAL SYSTEM EXTENDS FROM WINNIPEG EAST TO JAMES BAY. AN ELONGATED RIDGE STRETCHES FROM GEORGIA NORTHEAST INTO SOUTHERN QUEBEC. THERE IS SOME FOG OVER THE EASTERN OHIO RIVER VALLEY AND THE LOWER GREAT LAKES. THE PACIFIC NORTHWEST LONGWAVE WILL SHIFT INTO THE NORTHERN HIGH PLAINS TODAY. THE RIDGE OVER THE GREAT LAKES WILL SHIFT INTO THE LOWER GREAT LAKES REGION AS THE LOW OFF THE ATLANTIC COAST WORKS NORTHEAST. THE SHORTWAVE CLIMBING THE RIDGE WILL GENERALLY STAY NORTH OF THE AREA TODAY...EXCEPT FOR THE SHORTWAVE OVER WYOMING WHICH WILL RACE UP THE RIDGE INTO THE FORECAST AREA THIS AFTERNOON. THE NOSE OF A 100+ KNOT UPPER LEVEL JET WILL SHIFT INTO WESTERN U.P. BY LATE AFTERNOON. THE SURFACE LOW OVER MONTANA WILL CATCH UP WITH THE LOW OVER NORTH DAKOTA AND MERGE AS THEY MOVE INTO WESTERN MINNESOTA. THE ACCOMPANYING WARM FRONT WILL SHIFT INTO WISCONSIN. THE LARGE RIDGE OVER THE EAST COAST APPEARS TO BE STEERING EVERYTHING NORTHEAST. THE RIDGE KEEPS A SOUTHERLY FLOW THROUGHOUT THE EASTERN CONUS DRAWING WARM AIR INTO THE GREAT LAKES REGION. THIS SHOULD PUSH TEMPERATURES INTO THE MID AND UPPER 30S OVER THE U.P. TODAY. THE INSTABILITY WITH THE SHORTWAVE...ISENTROPIC ASCENT AHEAD OF THE FRONTAL SYSTEM...AND LOW LEVEL MOISTURE WILL GENERATE PRECIPITATION. AN 850MB THERMAL TROUGH WILL SHIFT INTO THE AREA BY LATE AFTERNOON ALONG WITH CLOUD COVER. THE FORECAST SOUNDING PROFILE AND WARMER SURFACE TEMPERATURES SUGGEST THAT THERE WILL BE A MIX OF RAIN AND SNOW. A 50KNOT LOW LEVEL JET WILL SWEEP ACROSS THE FORECAST AREA TODAY. THE WARM SURFACE TEMPERATURES WILL HELP TO MIX SOME OF THESE WINDS TO THE SURFACE. MODELS IN PRETTY GOOD AGREEMENT WITH THE SYSTEM MOVING INTO THE GREAT LAKES WITH THE NAM ONLY A LITTLE FARTHER NORTH THAN THE CONSENSUS AND THE UKMET SLIGHTLY SLOWER. AS SUGGESTED BY HPC WILL GO WITH THE GFS/ECMWF BLEND. THE LONGWAVE TROUGH WILL MOVE INTO THE DAKOTA AND CENTRAL CANADA TONIGHT. SHORTWAVES EJECTED OUT AHEAD OF THE TROUGH WILL SWEEP THROUGH THE AREA TONIGHT. THE SURFACE LOW WILL MOVE OUT OF MINNESOTA AND INTO CENTRAL ONTARIO BY MIDNIGHT DRAGGING THE COLD FRONT INTO THE WESTERN U.P. AND LAKE SUPERIOR. WINDS AT THAT TIME WILL BEGIN TO VEER WEST AND NORTHWEST. ISENTROPIC ASCENT AHEAD OF THE FRONT AND WARM MOISTURE AIR WILL CONTINUE TO FEED RAINS OVER THE AREA. AS THE FRONT MOVES INTO THE AREA LATE TONIGHT...COLD AIR WILL ADVECT IN AND CHANGE THE RAIN TO SNOW OVER THE WESTERN U.P. THE TEMPERATURES WILL DROP RAPIDLY FOLLOWING THE FROPA. A SECONDARY LOW DEVELOPING ALONG THIS FRONT WILL WORK NORTHWARD ALONG THE FRONT AND REACH EASTERN IOWA BY SUNRISE. THE LONGWAVE TROUGH WILL REACH MINNESOTA AND EASTERN MANITOBA BY LATE TUESDAY AFTERNOON. WEAK SHORTWAVES AHEAD OF THE TROUGH WILL SWEEP THROUGH THE FORECAST AREA. THE SURFACE LOW WILL LIFT INTO NORTHEAST ONTARIO DRAGGING THE COLD FRONT INTO THE EASTERN U.P. THE SURFACE LOW MOVING UP THE FRONT AND WILL REACH NORTHERN LOWER MICHIGAN BY LATE TUESDAY. A -32C 850MB THERMAL WILL SHIFT INTO MINNESOTA. LOW LEVEL MOISTURE AND INSTABILITY ALONG WITH THE COLD AIR SPREADING ACROSS THE AREA WILL CHANGE THE PRECIPITATION TO SNOW BY LATE MORNING. THE TIGHT GRADIENTS BEHIND THE FRONT WILL INCREASE THE WINDS OVER THE WEST. THIS WILL PRODUCE SOME BLOWING SNOW BY LATE AFTERNOON. THE LONGWAVE TROUGH WILL MOVE OVER THE FORECAST AREA TUESDAY NIGHT. THE SURFACE LOW WILL TRACK TO EAST CENTRAL ONTARIO DRAGGING THE COLD FRONT THROUGH THE LOWER GREAT LAKES INTO THE MID ATLANTIC STATES. THE CENTRAL PLAINS RIDGE WILL ADVANCE INTO THE MIDDLE MISSISSIPPI RIVER VALLEY. THE 850MB THERMAL TROUGH WILL SHIFT INTO WESTERN LAKE SUPERIOR. WINDS WILL BE MAINLY FROM THE WEST TO NORTHWEST ACROSS LAKE SUPERIOR. A 40KNOT LOW LEVEL JET WILL SETTLE OVER THE FORECAST AREA OVERNIGHT. THE COLD 850MB TEMPERATURES WILL PROMOTE MIXING SOME OF THESE WINDS TO THE SURFACE. THE COLD TEMPERATURES AND WINDS WILL GENERATE LAKE EFFECT SNOWS AND BLOWING SNOW MAINLY OVER THE WEST END. A WINTER STORMS WATCH MAY BE WARRANTED. WIND CHILLS COULD REACH ADVISORY CATEGORY LATE. SINCE IT COULD BE AN ADVISORY WILL HOLD OFF ON ISSUING IT AT THIS TIME. THE LONGWAVE TROUGH WILL SWING INTO NORTHERN ONTARIO AND SOUTHERN QUEBEC ON WEDNESDAY. THE SURFACE LOW WILL LIKEWISE SWING INTO QUEBEC WHILE THE RIDGE PUSHES DEEPER INTO THE UPPER MISSISSIPPI RIVER VALLEY. ANTI-CYCLONIC FLOW WILL DRAW COLDER AIR INTO THE UPPER GREAT LAKES REGION. DRY AIR WILL OVERSPREAD THE REGION AS WELL. THE THERMAL TROUGH WILL SUPPORT LOW LEVEL INSTABILITY AND LAKE EFFECT SNOWS. THE WINDS WILL MIX DOWN OVER LAKE SUPERIOR SO EXPECT TO SEE MORE BLOWING SNOW. WITH THE TEMPERATURES AS COLD AS IT WILL BE...EXPECT TO SEE FINER FLAKES WHICH WITH THE WINDS WILL REDUCE VISIBILITY GREATLY. THE LONGER FETCH ACROSS THE CENTRAL AND EASTERN PART OF LAKE SUPERIOR WILL CONTRIBUTE GREATLY TO SIGNIFICANT LES OVER THE LUCE...ALGER AND EVEN NORTHERN SCHOOLCRAFT COUNTIES. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... UPDATE FOR SAW...AMENDED THE TAF AS LOW CLOUDS HAVE COMPLETELY DISSIPATED. 12Z SOUNDINGS AND AREA TAMDARS SHOW PLENTY OF DRY AIR EVEN IN THE LOW LEVELS...WHICH COMBINED WITH THE STRONG SOUTHERLY WIND HAS ALLOWED LOW CLOUDS TO SCATTER OUT. HAVE STILL FOLLOWED THE IDEA OF LOW CLOUDS COMING IN...BUT NOT UNTIL 01Z. EVEN THIS MIGHT BE A LITTLE TOO PESSIMISTIC. MORE DETAILS COMING WITH THE 18Z TAF ISSUANCE. PREVIOUS AVIATION DISCUSSION... TRICKY FCST FOR SAW WITH SHALLOW INVRN AND SOME LO CLD/FOG UPSTREAM TO THE S. TENDED ON THE PESSIMISTIC SIDE WITH LO CLD AS UPSLOPE SLY FLOW THERE WL TEND TO MAINTAIN HI RH IN SHALLOW COLD WEDGE THAT MIGHT HAVE DIFFICULTY MIXING OUT COMPLETELY. A LIGHT WINTRY MIX OF PCPN IS LIKELY LATE TDAY/THIS EVNG AS SOMEWHAT HIER MSTR IS STREAMING NEWD FM THE SRN PLAINS...BUT PCPN SHOULD BE ON THE LGT SIDE WITH PERSISTENT DRY MID LVLS TRYING TO HANG ON. COOLING OF LLVLS TNGT WL MAINTAIN MORE LO CLD/FOG AND PSBLY SOME FZDZ AT SAW. THE FCST FOR CMX IS A BIT MORE STRAIGHT FORWARD AS UPSRTREAM AIRMASS TO THE SSW IS WARMED/DRIED BY DOWNSLOPING OFF THE HIER TERRAIN. SO... EXPECT VFR CONDITIONS TO PREDOMINATE THERE THRU THE DAY. APRCH OF LO PRES TO THE NW OF LK SUP TNGT MAY RESULT IN A PD OF RASN...WITH DETERIORATING CONDITIONS AS LLVLS BEGIN TO MOISTEN. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT LO PRES DVLPG IN THE NORTHERN PLAINS THIS MRNG TO MOVE INTO MN THIS EVENING AND THEN ONTARIO ON TUE MRNG WHILE DEEPENING. SLY GALES HAVE DVLPD AS FCST OVER ECNTRL LK SUP...AND THESE WL CONTINUE INTO TNGT BEFORE PRES GRADIENT GRDLY EASES LATE TNGT. A STRONG ARCTIC COLD FRONT WILL CROSS LAKE SUPERIOR ON TUE AS THE LO MOVES TO NEAR JAMES BAY IN THE EVNG. ANOTHER LO PRES SYS WILL DEVELOP ON THE COLD FRONT OVER THE LOWER GREAT LAKES LATE ON TUE AND MOVE INTO SE CAN AND INTENSIFY ON WEDNESDAY. GALE TO STORM FORCE W TO NW WINDS AND HEAVY FRZG SPRAY WL DVLP IN THE WAKE OF THE COLD FNT AND THE DVLPG LO ON THIS BNDRY AS ARCTIC AIR SURGES OVER LK SUP. PLAN ON THE STRONGEST WINDS FM THE KEWEENAW AND ISLE ROYALE TO THE E. AS THE LO CONTINUES NE ON THU...A HI PRES RDG WL BUILD TOWARD THE UPPER GREAT LAKES. ON FRI...A DEVELOPING LO OVER THE TENNESSEE VALLEY IS EXPECTED TO SHIFT NE TO THE EASTERN GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... MICHIGAN...WINTER STORM WATCH FROM 1 PM TUESDAY TO 7 PM WEDNESDAY FOR MIZ001>003. MICHIGAN...WINTER STORM WATCH FROM 7 PM TUESDAY TO 7 PM WEDNESDAY FOR MIZ006>007-085. LAKE SUPERIOR...GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ266-267. LAKE MICHIGAN...GALE WARNING FROM 11 AM THIS MORNING TO 1 AM EST TUESDAY FOR LMZ248-250. && $$ UPDATE...AJ DISCUSSION...DLG AVIATION...KC/AJ MARINE...KC mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 650 AM EST MON JAN 28 2008 UPDATED FOR AVIATION .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE STORM POTENTIAL FOR TUESDAY THROUGH WEDNESDAY. WATER VAPOR IMAGERY AND RUC SHOWING A LONGWAVE TROUGH OVER THE PACIFIC NORTHWEST AND A FLATTEN RIDGE OVER GREAT LAKES REGION. A CLOSED LOW IS JUST OFF THE COAST OF THE MID ATLANTIC STATES. WEAK SHORTWAVES ARE OVER WESTERN ONTARIO...NORTH DAKOTA...AND WYOMING. SURFACE ANALYSIS DEPICTS A LOW OVER NORTH DAKOTA WITH A WARM FRONT LEADING IT STRETCHING INTO ILLINOIS. ANOTHER FRONTAL SYSTEM EXTENDS FROM WINNIPEG EAST TO JAMES BAY. AN ELONGATED RIDGE STRETCHES FROM GEORGIA NORTHEAST INTO SOUTHERN QUEBEC. THERE IS SOME FOG OVER THE EASTERN OHIO RIVER VALLEY AND THE LOWER GREAT LAKES. THE PACIFIC NORTHWEST LONGWAVE WILL SHIFT INTO THE NORTHERN HIGH PLAINS TODAY. THE RIDGE OVER THE GREAT LAKES WILL SHIFT INTO THE LOWER GREAT LAKES REGION AS THE LOW OFF THE ATLANTIC COAST WORKS NORTHEAST. THE SHORTWAVE CLIMBING THE RIDGE WILL GENERALLY STAY NORTH OF THE AREA TODAY...EXCEPT FOR THE SHORTWAVE OVER WYOMING WHICH WILL RACE UP THE RIDGE INTO THE FORECAST AREA THIS AFTERNOON. THE NOSE OF A 100+ KNOT UPPER LEVEL JET WILL SHIFT INTO WESTERN U.P. BY LATE AFTERNOON. THE SURFACE LOW OVER MONTANA WILL CATCH UP WITH THE LOW OVER NORTH DAKOTA AND MERGE AS THEY MOVE INTO WESTERN MINNESOTA. THE ACCOMPANYING WARM FRONT WILL SHIFT INTO WISCONSIN. THE LARGE RIDGE OVER THE EAST COAST APPEARS TO BE STEERING EVERYTHING NORTHEAST. THE RIDGE KEEPS A SOUTHERLY FLOW THROUGHOUT THE EASTERN CONUS DRAWING WARM AIR INTO THE GREAT LAKES REGION. THIS SHOULD PUSH TEMPERATURES INTO THE MID AND UPPER 30S OVER THE U.P. TODAY. THE INSTABILITY WITH THE SHORTWAVE...ISENTROPIC ASCENT AHEAD OF THE FRONTAL SYSTEM...AND LOW LEVEL MOISTURE WILL GENERATE PRECIPITATION. AN 850MB THERMAL TROUGH WILL SHIFT INTO THE AREA BY LATE AFTERNOON ALONG WITH CLOUD COVER. THE FORECAST SOUNDING PROFILE AND WARMER SURFACE TEMPERATURES SUGGEST THAT THERE WILL BE A MIX OF RAIN AND SNOW. A 50KNOT LOW LEVEL JET WILL SWEEP ACROSS THE FORECAST AREA TODAY. THE WARM SURFACE TEMPERATURES WILL HELP TO MIX SOME OF THESE WINDS TO THE SURFACE. MODELS IN PRETTY GOOD AGREEMENT WITH THE SYSTEM MOVING INTO THE GREAT LAKES WITH THE NAM ONLY A LITTLE FARTHER NORTH THAN THE CONSENSUS AND THE UKMET SLIGHTLY SLOWER. AS SUGGESTED BY HPC WILL GO WITH THE GFS/ECMWF BLEND. THE LONGWAVE TROUGH WILL MOVE INTO THE DAKOTA AND CENTRAL CANADA TONIGHT. SHORTWAVES EJECTED OUT AHEAD OF THE TROUGH WILL SWEEP THROUGH THE AREA TONIGHT. THE SURFACE LOW WILL MOVE OUT OF MINNESOTA AND INTO CENTRAL ONTARIO BY MIDNIGHT DRAGGING THE COLD FRONT INTO THE WESTERN U.P. AND LAKE SUPERIOR. WINDS AT THAT TIME WILL BEGIN TO VEER WEST AND NORTHWEST. ISENTROPIC ASCENT AHEAD OF THE FRONT AND WARM MOISTURE AIR WILL CONTINUE TO FEED RAINS OVER THE AREA. AS THE FRONT MOVES INTO THE AREA LATE TONIGHT...COLD AIR WILL ADVECT IN AND CHANGE THE RAIN TO SNOW OVER THE WESTERN U.P. THE TEMPERATURES WILL DROP RAPIDLY FOLLOWING THE FROPA. A SECONDARY LOW DEVELOPING ALONG THIS FRONT WILL WORK NORTHWARD ALONG THE FRONT AND REACH EASTERN IOWA BY SUNRISE. THE LONGWAVE TROUGH WILL REACH MINNESOTA AND EASTERN MANITOBA BY LATE TUESDAY AFTERNOON. WEAK SHORTWAVES AHEAD OF THE TROUGH WILL SWEEP THROUGH THE FORECAST AREA. THE SURFACE LOW WILL LIFT INTO NORTHEAST ONTARIO DRAGGING THE COLD FRONT INTO THE EASTERN U.P. THE SURFACE LOW MOVING UP THE FRONT AND WILL REACH NORTHERN LOWER MICHIGAN BY LATE TUESDAY. A -32C 850MB THERMAL WILL SHIFT INTO MINNESOTA. LOW LEVEL MOISTURE AND INSTABILITY ALONG WITH THE COLD AIR SPREADING ACROSS THE AREA WILL CHANGE THE PRECIPITATION TO SNOW BY LATE MORNING. THE TIGHT GRADIENTS BEHIND THE FRONT WILL INCREASE THE WINDS OVER THE WEST. THIS WILL PRODUCE SOME BLOWING SNOW BY LATE AFTERNOON. THE LONGWAVE TROUGH WILL MOVE OVER THE FORECAST AREA TUESDAY NIGHT. THE SURFACE LOW WILL TRACK TO EAST CENTRAL ONTARIO DRAGGING THE COLD FRONT THROUGH THE LOWER GREAT LAKES INTO THE MID ATLANTIC STATES. THE CENTRAL PLAINS RIDGE WILL ADVANCE INTO THE MIDDLE MISSISSIPPI RIVER VALLEY. THE 850MB THERMAL TROUGH WILL SHIFT INTO WESTERN LAKE SUPERIOR. WINDS WILL BE MAINLY FROM THE WEST TO NORTHWEST ACROSS LAKE SUPERIOR. A 40KNOT LOW LEVEL JET WILL SETTLE OVER THE FORECAST AREA OVERNIGHT. THE COLD 850MB TEMPERATURES WILL PROMOTE MIXING SOME OF THESE WINDS TO THE SURFACE. THE COLD TEMPERATURES AND WINDS WILL GENERATE LAKE EFFECT SNOWS AND BLOWING SNOW MAINLY OVER THE WEST END. A WINTER STORMS WATCH MAY BE WARRANTED. WIND CHILLS COULD REACH ADVISORY CATEGORY LATE. SINCE IT COULD BE AN ADVISORY WILL HOLD OFF ON ISSUING IT AT THIS TIME. THE LONGWAVE TROUGH WILL SWING INTO NORTHERN ONTARIO AND SOUTHERN QUEBEC ON WEDNESDAY. THE SURFACE LOW WILL LIKEWISE SWING INTO QUEBEC WHILE THE RIDGE PUSHES DEEPER INTO THE UPPER MISSISSIPPI RIVER VALLEY. ANTI-CYCLONIC FLOW WILL DRAW COLDER AIR INTO THE UPPER GREAT LAKES REGION. DRY AIR WILL OVERSPREAD THE REGION AS WELL. THE THERMAL TROUGH WILL SUPPORT LOW LEVEL INSTABILITY AND LAKE EFFECT SNOWS. THE WINDS WILL MIX DOWN OVER LAKE SUPERIOR SO EXPECT TO SEE MORE BLOWING SNOW. WITH THE TEMPERATURES AS COLD AS IT WILL BE...EXPECT TO SEE FINER FLAKES WHICH WITH THE WINDS WILL REDUCE VISIBILITY GREATLY. THE LONGER FETCH ACROSS THE CENTRAL AND EASTERN PART OF LAKE SUPERIOR WILL CONTRIBUTE GREATLY TO SIGNIFICANT LES OVER THE LUCE...ALGER AND EVEN NORTHERN SCHOOLCRAFT COUNTIES. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... TRICKY FCST FOR SAW WITH SHALLOW INVRN AND SOME LO CLD/FOG UPSTREAM TO THE S. TENDED ON THE PESSIMISTIC SIDE WITH LO CLD AS UPSLOPE SLY FLOW THERE WL TEND TO MAINTAIN HI RH IN SHALLOW COLD WEDGE THAT MIGHT HAVE DIFFICULTY MIXING OUT COMPLETELY. A LIGHT WINTRY MIX OF PCPN IS LIKELY LATE TDAY/THIS EVNG AS SOMEWHAT HIER MSTR IS STREAMING NEWD FM THE SRN PLAINS...BUT PCPN SHOULD BE ON THE LGT SIDE WITH PERSISTENT DRY MID LVLS TRYING TO HANG ON. COOLING OF LLVLS TNGT WL MAINTAIN MORE LO CLD/FOG AND PSBLY SOME FZDZ AT SAW. THE FCST FOR CMX IS A BIT MORE STRAIGHT FORWARD AS UPSRTREAM AIRMASS TO THE SSW IS WARMED/DRIED BY DOWNSLOPING OFF THE HIER TERRAIN. SO... EXPECT VFR CONDITIONS TO PREDOMINATE THERE THRU THE DAY. APRCH OF LO PRES TO THE NW OF LK SUP TNGT MAY RESULT IN A PD OF RASN...WITH DETERIORATING CONDITIONS AS LLVLS BEGIN TO MOISTEN. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT LO PRES DVLPG IN THE NORTHERN PLAINS THIS MRNG TO MOVE INTO MN THIS EVENING AND THEN ONTARIO ON TUE MRNG WHILE DEEPENING. SLY GALES HAVE DVLPD AS FCST OVER ECNTRL LK SUP...AND THESE WL CONTINUE INTO TNGT BEFORE PRES GRADIENT GRDLY EASES LATE TNGT. A STRONG ARCTIC COLD FRONT WILL CROSS LAKE SUPERIOR ON TUE AS THE LO MOVES TO NEAR JAMES BAY IN THE EVNG. ANOTHER LO PRES SYS WILL DEVELOP ON THE COLD FRONT OVER THE LOWER GREAT LAKES LATE ON TUE AND MOVE INTO SE CAN AND INTENSIFY ON WEDNESDAY. GALE TO STORM FORCE W TO NW WINDS AND HEAVY FRZG SPRAY WL DVLP IN THE WAKE OF THE COLD FNT AND THE DVLPG LO ON THIS BNDRY AS ARCTIC AIR SURGES OVER LK SUP. PLAN ON THE STRONGEST WINDS FM THE KEWEENAW AND ISLE ROYALE TO THE E. AS THE LO CONTINUES NE ON THU...A HI PRES RDG WL BUILD TOWARD THE UPPER GREAT LAKES. ON FRI...A DEVELOPING LO OVER THE TENNESSEE VALLEY IS EXPECTED TO SHIFT NE TO THE EASTERN GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... MICHIGAN...WINTER STORM WATCH FROM 1 PM TUESDAY TO 7 PM WEDNESDAY FOR MIZ001>003. MICHIGAN...WINTER STORM WATCH FROM 7 PM TUESDAY TO 7 PM WEDNESDAY FOR MIZ006>007-085. LAKE SUPERIOR...GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ266-267. LAKE MICHIGAN...GALE WARNING FROM 11 AM THIS MORNING TO 1 AM EST TUESDAY FOR LMZ248-250. && $$ DISCUSSION...DLG AVIATION...KC MARINE...KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 443 AM EST MON JAN 28 2008 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE STORM POTENTIAL FOR TUESDAY THROUGH WEDNESDAY. WATER VAPOR IMAGERY AND RUC SHOWING A LONGWAVE TROUGH OVER THE PACIFIC NORTHWEST AND A FLATTEN RIDGE OVER GREAT LAKES REGION. A CLOSED LOW IS JUST OFF THE COAST OF THE MID ATLANTIC STATES. WEAK SHORTWAVES ARE OVER WESTERN ONTARIO...NORTH DAKOTA...AND WYOMING. SURFACE ANALYSIS DEPICTS A LOW OVER NORTH DAKOTA WITH A WARM FRONT LEADING IT STRETCHING INTO ILLINOIS. ANOTHER FRONTAL SYSTEM EXTENDS FROM WINNIPEG EAST TO JAMES BAY. AN ELONGATED RIDGE STRETCHES FROM GEORGIA NORTHEAST INTO SOUTHERN QUEBEC. THERE IS SOME FOG OVER THE EASTERN OHIO RIVER VALLEY AND THE LOWER GREAT LAKES. THE PACIFIC NORTHWEST LONGWAVE WILL SHIFT INTO THE NORTHERN HIGH PLAINS TODAY. THE RIDGE OVER THE GREAT LAKES WILL SHIFT INTO THE LOWER GREAT LAKES REGION AS THE LOW OFF THE ATLANTIC COAST WORKS NORTHEAST. THE SHORTWAVE CLIMBING THE RIDGE WILL GENERALLY STAY NORTH OF THE AREA TODAY...EXCEPT FOR THE SHORTWAVE OVER WYOMING WHICH WILL RACE UP THE RIDGE INTO THE FORECAST AREA THIS AFTERNOON. THE NOSE OF A 100+ KNOT UPPER LEVEL JET WILL SHIFT INTO WESTERN U.P. BY LATE AFTERNOON. THE SURFACE LOW OVER MONTANA WILL CATCH UP WITH THE LOW OVER NORTH DAKOTA AND MERGE AS THEY MOVE INTO WESTERN MINNESOTA. THE ACCOMPANYING WARM FRONT WILL SHIFT INTO WISCONSIN. THE LARGE RIDGE OVER THE EAST COAST APPEARS TO BE STEERING EVERYTHING NORTHEAST. THE RIDGE KEEPS A SOUTHERLY FLOW THROUGHOUT THE EASTERN CONUS DRAWING WARM AIR INTO THE GREAT LAKES REGION. THIS SHOULD PUSH TEMPERATURES INTO THE MID AND UPPER 30S OVER THE U.P. TODAY. THE INSTABILITY WITH THE SHORTWAVE...ISENTROPIC ASCENT AHEAD OF THE FRONTAL SYSTEM...AND LOW LEVEL MOISTURE WILL GENERATE PRECIPITATION. AN 850MB THERMAL TROUGH WILL SHIFT INTO THE AREA BY LATE AFTERNOON ALONG WITH CLOUD COVER. THE FORECAST SOUNDING PROFILE AND WARMER SURFACE TEMPERATURES SUGGEST THAT THERE WILL BE A MIX OF RAIN AND SNOW. A 50KNOT LOW LEVEL JET WILL SWEEP ACROSS THE FORECAST AREA TODAY. THE WARM SURFACE TEMPERATURES WILL HELP TO MIX SOME OF THESE WINDS TO THE SURFACE. MODELS IN PRETTY GOOD AGREEMENT WITH THE SYSTEM MOVING INTO THE GREAT LAKES WITH THE NAM ONLY A LITTLE FARTHER NORTH THAN THE CONSENSUS AND THE UKMET SLIGHTLY SLOWER. AS SUGGESTED BY HPC WILL GO WITH THE GFS/ECMWF BLEND. THE LONGWAVE TROUGH WILL MOVE INTO THE DAKOTA AND CENTRAL CANADA TONIGHT. SHORTWAVES EJECTED OUT AHEAD OF THE TROUGH WILL SWEEP THROUGH THE AREA TONIGHT. THE SURFACE LOW WILL MOVE OUT OF MINNESOTA AND INTO CENTRAL ONTARIO BY MIDNIGHT DRAGGING THE COLD FRONT INTO THE WESTERN U.P. AND LAKE SUPERIOR. WINDS AT THAT TIME WILL BEGIN TO VEER WEST AND NORTHWEST. ISENTROPIC ASCENT AHEAD OF THE FRONT AND WARM MOISTURE AIR WILL CONTINUE TO FEED RAINS OVER THE AREA. AS THE FRONT MOVES INTO THE AREA LATE TONIGHT...COLD AIR WILL ADVECT IN AND CHANGE THE RAIN TO SNOW OVER THE WESTERN U.P. THE TEMPERATURES WILL DROP RAPIDLY FOLLOWING THE FROPA. A SECONDARY LOW DEVELOPING ALONG THIS FRONT WILL WORK NORTHWARD ALONG THE FRONT AND REACH EASTERN IOWA BY SUNRISE. THE LONGWAVE TROUGH WILL REACH MINNESOTA AND EASTERN MANITOBA BY LATE TUESDAY AFTERNOON. WEAK SHORTWAVES AHEAD OF THE TROUGH WILL SWEEP THROUGH THE FORECAST AREA. THE SURFACE LOW WILL LIFT INTO NORTHEAST ONTARIO DRAGGING THE COLD FRONT INTO THE EASTERN U.P. THE SURFACE LOW MOVING UP THE FRONT AND WILL REACH NORTHERN LOWER MICHIGAN BY LATE TUESDAY. A -32C 850MB THERMAL WILL SHIFT INTO MINNESOTA. LOW LEVEL MOISTURE AND INSTABILITY ALONG WITH THE COLD AIR SPREADING ACROSS THE AREA WILL CHANGE THE PRECIPITATION TO SNOW BY LATE MORNING. THE TIGHT GRADIENTS BEHIND THE FRONT WILL INCREASE THE WINDS OVER THE WEST. THIS WILL PRODUCE SOME BLOWING SNOW BY LATE AFTERNOON. THE LONGWAVE TROUGH WILL MOVE OVER THE FORECAST AREA TUESDAY NIGHT. THE SURFACE LOW WILL TRACK TO EAST CENTRAL ONTARIO DRAGGING THE COLD FRONT THROUGH THE LOWER GREAT LAKES INTO THE MID ATLANTIC STATES. THE CENTRAL PLAINS RIDGE WILL ADVANCE INTO THE MIDDLE MISSISSIPPI RIVER VALLEY. THE 850MB THERMAL TROUGH WILL SHIFT INTO WESTERN LAKE SUPERIOR. WINDS WILL BE MAINLY FROM THE WEST TO NORTHWEST ACROSS LAKE SUPERIOR. A 40KNOT LOW LEVEL JET WILL SETTLE OVER THE FORECAST AREA OVERNIGHT. THE COLD 850MB TEMPERATURES WILL PROMOTE MIXING SOME OF THESE WINDS TO THE SURFACE. THE COLD TEMPERATURES AND WINDS WILL GENERATE LAKE EFFECT SNOWS AND BLOWING SNOW MAINLY OVER THE WEST END. A WINTER STORMS WATCH MAY BE WARRANTED. WIND CHILLS COULD REACH ADVISORY CATEGORY LATE. SINCE IT COULD BE AN ADVISORY WILL HOLD OFF ON ISSUING IT AT THIS TIME. THE LONGWAVE TROUGH WILL SWING INTO NORTHERN ONTARIO AND SOUTHERN QUEBEC ON WEDNESDAY. THE SURFACE LOW WILL LIKEWISE SWING INTO QUEBEC WHILE THE RIDGE PUSHES DEEPER INTO THE UPPER MISSISSIPPI RIVER VALLEY. ANTI-CYCLONIC FLOW WILL DRAW COLDER AIR INTO THE UPPER GREAT LAKES REGION. DRY AIR WILL OVERSPREAD THE REGION AS WELL. THE THERMAL TROUGH WILL SUPPORT LOW LEVEL INSTABILITY AND LAKE EFFECT SNOWS. THE WINDS WILL MIX DOWN OVER LAKE SUPERIOR SO EXPECT TO SEE MORE BLOWING SNOW. WITH THE TEMPERATURES AS COLD AS IT WILL BE...EXPECT TO SEE FINER FLAKES WHICH WITH THE WINDS WILL REDUCE VISIBILITY GREATLY. THE LONGER FETCH ACROSS THE CENTRAL AND EASTERN PART OF LAKE SUPERIOR WILL CONTRIBUTE GREATLY TO SIGNIFICANT LES OVER THE LUCE...ALGER AND EVEN NORTHERN SCHOOLCRAFT COUNTIES. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... LLJ MOVING OVER THE AREA WILL RESULT IN LLWS AT BOTH TAF SITES THROUGH MID MORNING AT WHICH TIME DIURNAL MIXING SHOULD HELP BRING HIGHER WINDS ALOFT TO THE SFC. EXPECT VFR CONDITIONS TO PERSIST UNTIL MID-LATE MON AFTERNOON AT BOTH TAF SITES. BY 21Z...LOW TO MID LEVELS SLOWLY SATURATE WITH INCREASING WAA AHEAD OF NORTHERN PLAINS SHORTWAVE AND ASSOC LOW PRES SYSTEM...SO EXPECT MVFR CIGS TO DEVELOP AT THIS TIME WITH LIGHT PRECIP BEGINNING. WARMER LOW-LEVELS OF MAJORITY OF MODEL SOUNDINGS WOULD SUGGEST RAIN AS PREDOMINANT PCPN TYPE...ALTHOUGH THERE IS STILL ENOUGH OF A POTENTIAL FOR EVAPORATIVE COOLING TO INCLUDE A TEMPO GROUP FM 21-24Z FOR A MIX OF RAIN/SNOW AND MVFR VSBYS. BY EVENING...CIGS WILL BEGIN TO LOWER INTO THE IFR CATEGORY AS ARRIVAL OF SECONDARY SHORTWAVE AND LOW PRES TROUGH BRING A BETTER CHANCE OF RAIN. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT LO PRES DVLPG IN THE NORTHERN PLAINS THIS MRNG TO MOVE INTO MN THIS EVENING AND THEN ONTARIO ON TUE MRNG WHILE DEEPENING. SLY GALES HAVE DVLPD AS FCST OVER ECNTRL LK SUP...AND THESE WL CONTINUE INTO TNGT BEFORE PRES GRADIENT GRDLY EASES LATE TNGT. A STRONG ARCTIC COLD FRONT WILL CROSS LAKE SUPERIOR ON TUE AS THE LO MOVES TO NEAR JAMES BAY IN THE EVNG. ANOTHER LO PRES SYS WILL DEVELOP ON THE COLD FRONT OVER THE LOWER GREAT LAKES LATE ON TUE AND MOVE INTO SE CAN AND INTENSIFY ON WEDNESDAY. GALE TO STORM FORCE W TO NW WINDS AND HEAVY FRZG SPRAY WL DVLP IN THE WAKE OF THE COLD FNT AND THE DVLPG LO ON THIS BNDRY AS ARCTIC AIR SURGES OVER LK SUP. PLAN ON THE STRONGEST WINDS FM THE KEWEENAW AND ISLE ROYALE TO THE E. AS THE LO CONTINUES NE ON THU...A HI PRES RDG WL BUILD TOWARD THE UPPER GREAT LAKES. ON FRI...A DEVELOPING LO OVER THE TENNESSEE VALLEY IS EXPECTED TO SHIFT NE TO THE EASTERN GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... MICHIGAN...WINTER STORM WATCH FROM 1 PM TUESDAY TO 7 PM WEDNESDAY FOR MIZ001>003. MICHIGAN...WINTER STORM WATCH FROM 7 PM TUESDAY TO 7 PM WEDNESDAY FOR MIZ006>007-085. LAKE SUPERIOR...GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ266-267. LAKE MICHIGAN...GALE WARNING FROM 11 AM THIS MORNING TO 1 AM EST TUESDAY FOR LMZ248-250. && $$ DISCUSSION...DLG AVIATION...VOSS MARINE...KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 400 AM EST MON JAN 28 2008 LATEST UPDATE...ALL EXCEPT AVIATION... .SYNOPSIS...(400 AM EST MON JAN 28 2008) IT WILL BECOME WINDY THIS AFTERNOON AND TONIGHT OUT AHEAD OF AN INTENSE LOW PRESSURE SYSTEM WHICH WILL MOVE FROM THE NORTHERN PLAINS STATES TODAY TO THE LAKE SUPERIOR REGION TUESDAY MORNING. THIS SYSTEM WILL BRING RAIN FROM LATE TODAY THROUGH TONIGHT AND TUESDAY. A FEW THUNDERSTORMS ARE POSSIBLE OUT AHEAD OF THE COLD FRONT TUESDAY AFTERNOON AND VERY EARLY EVENING. IT WILL TURN SHARPLY COLDER AND VERY WINDY TUESDAY NIGHT BEHIND THE COLD FRONT. && .SHORT TERM...(400 AM EST MON JAN 28 2008) (TODAY THROUGH WEDNESDAY AFTERNOON) WINDY CONDITIONS WILL DEVELOP THIS AFTN AND PARTICULARLY TONIGHT AS A VIGOROUS LOW PRESSURE SYSTEM MOVES TO THE LAKE SUPERIOR REGION BY 12Z TUE. A FEW GUSTS MAY APPROACH WIND ADVISORY CRITERIA TONIGHT NEAR THE LAKE MI SHORELINE. HOWEVER 00Z GUIDANCE CONSENSUS AND 13KM RUC PROGGED SFC WIND GUSTS SUGGEST GUSTS AND CERTAINLY SUSTAINED WIND SPEEDS WILL REMAIN BELOW ADV CRITERIA. GREATEST IMPACTS FROM THIS SYSTEM WILL COME TUE AND TUE NIGHT. WE EXPECT A BAND OF GUSTY SHOWERS AND EMBEDDED CONVECTION TO RACE ACROSS OUR CWFA BETWEEN AROUND 20Z TUE AND 00Z WED. AN NCFR IS CERTAINLY POSSIBLE IN THAT TIME FRAME WITH POTENTIAL TO PRODUCE DAMAGING WIND GUSTS GIVEN KINEMATIC PROFILES AT THAT TIME. VERY WINDY CONDITIONS WILL DEVELOP BEHIND THE COLD FRONT TUE NIGHT. IMPACTS WILL LIKELY INCLUDE SCATTERED POWER OUTAGES. HIGH WIND GUSTS OF AT LEAST 45 TO 55 MPH ARE EXPECTED ACROSS OUR CWFA TUE NIGHT WITH HIGHEST GUSTS POTENTIALLY REACHING 65 MPH ALONG THE LAKE MI SHORELINE. WE ALREADY STRONGLY CONSIDERED A HIGH WIND WATCH FOR OUR CWFA FOR TUE NIGHT (ESPECIALLY FOR OUR LAKESHORE COUNTIES). ULTIMATELY AFTER COORD WITH SURROUNDING OFFICES WE FELT IT WAS A BIT EARLY FOR THIS HEADLINE. FUTURE SHIFTS WILL DEFINITELY NEED TO CONSIDER THIS AND MONITOR FUTURE GUIDANCE TRENDS CLOSELY. VERY STRONG CAA BEHIND THE COLD FRONT WILL RESULT IN A RAPID CHANGEOVER TO SNOW FROM WEST TO EAST TUESDAY EVENING. WE COULD SEE AN INCH OR TWO OF SNOW TUESDAY EVENING ESPECIALLY IF THE SECONDARY LOW PRESSURE WAVE DEVELOPS AS 00Z GFS GUIDANCE SUGGESTS. I BELIEVE THAT THIS SNOW IN CONJUNCTION WITH VERY STRONG WINDS AND PLUMMETING SFC TEMPS WILL LIKELY RESULT IN SLIPPERY TO ICY ROAD CONDITIONS AND VERY HAZARDOUS TRAVEL CONDITIONS TUESDAY NIGHT. WE DO NOT EXPECT MUCH LAKE EFFECT SNOW LATE TUESDAY NIGHT IN SPITE OF THE VERY STRONG CAA AND PLUMMETING 850 MB TEMPS. THE VERY STRONG WINDS WILL REALLY LIMIT AIRMASS RESIDENCE TIME OVER LAKE MI AND INVERSION HEIGHTS WILL CRASH WHICH WILL REALLY INHIBIT LES DEVELOPMENT. MAX TEMPS WED WILL BE ACHIEVED AT 05Z WED. WE WILL INDICATE STEADY TO SLOWLY FALLING TEMPS IN THE NDFD TEMP STRINGS FOR WED WITH APPARENT TEMP VALUES FALLING TO NEAR TO AROUND 10 BELOW ZERO BY WEDNESDAY MORNING. && .LONG TERM...(400 AM EST MON JAN 28 2008) (WEDNESDAY NIGHT THROUGH SUNDAY) THE MAIN CONCERN IN THE LONG TERM DEALS WITH THE STORM FOR THE END OF THE WEEK. RATHER LARGE DISAGREEMENT AMONGST THE MODELS CONCERNING THE TRACK OF THIS STORM. THE LATEST ECMWF HAS THE STORM TRACKING THROUGH SW LOWER MI AND THE TRACK OF THE 850 MB THERMAL RIDGE SUGGEST A MIX POSSIBLE FOR SOUTH CENTRAL LOWER MI. THE GFS TRACKS THE LOW THROUGH OH...WITH A SOLUTION THAT FAVORS SNOW. THE GLOBAL GEM SHOWS A TRACK CLOSER TO TO THE GFS. AT THIS POINT WILL MAINTAIN THE SNOW SCENARIO FOR THIS EVENT. PRECIPITATION IS LIKELY TO OCCUR AND WILL RAISE POPS ON FRI. WILL NEED TO MONITOR THE WED NIGHT FORECAST. THE LATEST NAM SHOWS A WEAK WAVE WITH SOUTHWEST WINDS PASSING THROUGH THE FORECAST AREA. TEMPS ARE COLD ENOUGH FOR LAKE ENHANCEMENT. THE GFS...GLOBAL GEM AND ECMWF DO NOT HAVE THIS...THUS WILL MAINTAIN A DRY FORECAST. && .AVIATION...(1134 PM EST SUN JAN 28 2008) THE LOW CLOUDS CONTINUE TO MOVE NORTH NORTHEAST OUT OF THE GRR CWA AS OF 11 PM. SEEMS THE LOW LEVEL "JET" ABOVE THE DISCONNECTED AIR BELOW RADIATION INVERSION HAS INCREASED WINDS NEAR 1500 AGL TO NEAR 20 KNOTS...BASED ON THE LATEST TAMDAR SOUNDINGS FROM THE LOCAL AREA. THAT HAS KEEP DENSE FOG FROM FORMING. DEW POINTS DOWN TO I-80 AT 11 PM WERE STILL IN THE MID TEENS. THAT AIR IS NOT MOIST ENOUGH TO RESULT IN ADVECTION FOG. BOTTOM LINE IS 3 TO 5 MILE VIS INTO MID MORNING WITH JUST CIRRUS CLOUDS OVER THE TAF SITES. THE WARM ADVECTION RAIN EVENT BEGINS MONDAY AFTERNOON AFTER 4 PM. CIGS WILL BECOME MVFR AS RAIN CONTINUES. MONDAY WILL BE WINDY AS THE 925 MB WIND IS 50 KNOTS BY 18Z. THUS THE TAF SITES WILL HAVE SOUTH WINDS AROUND 20 KNOTS WITH GUSTS NEAR 30 KNOTS BY MID DAY MONDAY. && .MARINE...(400 AM EST MON JAN 28 2008) GALE WARNING DELAYED (WILL NOT GO INTO EFFECT UNTIL 18Z THIS AFTN RATHER THAN 12Z) AND EXTENDED THROUGH 12Z WED AFTER COORD W/LOT AND IWX. GALE FORCE WINDS WILL DEVELOP THIS AFTN AND OVERNIGHT. WE BELIEVE A LULL IN WIND SPEEDS IS PROBABLE TUE MORNING/AFTN UNTIL FROPA. HOWEVER GALES WILL RETURN IN FORCE BEHIND THE FRONT AND THERE IS POTENTIAL FOR WINDS TO REACH STORM FORCE TUE NIGHT. FUTURE SHIFTS WILL NEED TO MONITOR THIS AND MODEL TRENDS REGARDING WIND SPEEDS/GUSTS CLOSELY. && .HYDROLOGY...(400 AM EST MON JAN 28 2008) SOME ICE JAMMING WILL CONTINUE TO DEVELOP ON VARIOUS RIVERS IN OUR HSA. HIGH STAGES AND/OR SIGNIFICANT FLUCTUATIONS IN RIVER LEVELS ARE POSSIBLE EARLY TO MIDWEEK DUE TO ICE JAM ISSUES. WARM TEMPS AND RAINFALL WILL MELT SOME SNOW COVER AND POTENTIALLY RESULT IN HIGHER RIVER LEVELS MID TO LATE WEEK. HOWEVER THIS SITUATION WILL BE MUCH DIFFERENT THAN WITH THE MUCH MORE SIGNIFICANT WARMUP WE HAD SEVERAL WEEKS AGO. WE DO NOT ANTICIPATE NEARLY AS RAPID A SNOW MELT SINCE THIS TIME TEMPS WILL ONLY REACH THE LOW TO PERHAPS MID 40S... WITH LOWER DEW POINTS TOO. FURTHERMORE BASIN AVG QPF WILL GENERALLY AVG AROUND AN INCH OR LESS FROM THIS AFTERNOON THROUGH TUESDAY NIGHT. WE WILL CONTINUE TO MONITOR ALL THIS VERY CLOSELY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...GALE WARNING ST JOE TO MANISTEE 18Z THIS AFTN TO 12Z WED. && $$ SYNOPSIS: LAURENS SHORT TERM: LAURENS LONG TERM: MJS AVIATION: WDM MARINE: LAURENS HYDROLOGY: LAURENS mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1237 PM EST SUN JAN 27 2008 UPDATED FOR 18Z TAF DISCUSSION .UPDATE... SIGNIFICANT CHANGES WITH RESPECT TO CLOUD COVER...AS WE WERE WAY TOO HIGH EARLY ON TODAY AND TONIGHT. MADE CLOUD CHANGES THROUGH THURSDAY AFTERNOON...ALTHOUGH THEY ARE MOST SIGNIFICANT FOR THE NEAR TERM. MAY HAVE NOT GONE LOW ENOUGH...BUT TRIED TO ACCOUNT FOR THE SLOWLY ERODING FOG ACROSS THE SOUTH CENTRAL PORTIONS OF THE CWA. OTHERWISE...INCREASED TEMPS SLIGHTLY FAR SOUTH AND SLOWED DOWN THE APPROACH OF PRECIPITATION FOR MONDAY MORNING CENTRAL AND EAST. WILL REVISIT THIS WITH THE FULL AFTERNOON FORECAST PACKAGE. && .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE PRECIPITATION AND WIND POTENTIAL FOR MONDAY AND TUESDAY. WATER VAPOR IMAGERY AND RUC SHOWING A LONGWAVE TROUGH OFF THE WEST COAST...A BROAD RIDGE OVER NORTH CENTRAL CONUS AND ANOTHER TROUGH OVER THE LOWER GREAT LAKES. WEAK SHORTWAVES ARE OVER MINNESOTA AND EAST CENTRAL ONTARIO. SURFACE ANALYSIS DEPICTS A RIDGE OVER UPPER MISSISSIPPI RIVER VALLEY...A LOW TROUGH THROUGH THE EASTERN OHIO RIVER VALLEY AND LOWER MICHIGAN...AND A LOW OVER SOUTHERN ALBERTA WITH A COLD FRONT DRAPED SOUTHWEST THROUGH THE PACIFIC NORTHWEST. A LARGE HIGH IS OVER THE LOWER MISSISSIPPI RIVER VALLEY. FOG AND SNOW IS OVER THE LOWER GREAT LAKES AND EASTERN OHIO RIVER VALLEY IN ASSOCIATION WITH THE MID LEVEL TROUGH. THE SHORTWAVE OVER MINNESOTA WILL SWEEP ACROSS THE FORECAST AREA THIS MORNING AND EARLY AFTERNOON INTO EASTERN ONTARIO. A BROAD RIDGE WILL FOLLOW BY LATE AFTERNOON. THE SURFACE LOW OVER ALBERTA WILL RACE ACROSS SOUTHWEST CANADA REACHING SOUTHEAST SASKATCHEWAN BY LATE AFTERNOON WHILE PUSHING A WARM FRONT AHEAD OF IT INTO WESTERN WISCONSIN. A SOUTHWEST FLOW NORTH OF THE LOWER MISSISSIPPI RIVER VALLEY HIGH WILL HELP BRING THE TEMPERATURES UP TODAY TO AROUND 30. THE WARMEST TEMPERATURES WILL BE OVER THE WESTERN U.P. THE AIR MASS WILL BE FAIRLY DRY ACROSS THE AREA TODAY. THERE IS A POSSIBILITY OF PICKING UP SOME CIRRUS THIS AFTERNOON...AND A SOME LOW CLOUDS. AS HPC SUGGEST THE GEM/ECMWF SOLUTION IS THE PREFERRED SOLUTION FOR THE SYSTEMS MOVING OUT OF THE ROCKIES THROUGH THE NORTHERN PLAINS INTO THE GREAT LAKES. AFTER MONDAY NIGHT...THE GFS LED SOLUTION BECOMES THE PREFERRED. THE MID LEVEL RIDGE WILL SHIFT INTO QUEBEC TONIGHT. A COUPLE OF WEAK SHORTWAVE WILL SHIFT ACROSS THE AREA. THE SURFACE RIDGE WILL WORK EASTWARD TO THE EAST COAST. THE SASKATCHEWAN LOW WILL SETTLE SOUTHWARD INTO MONTANA. SOUTHWEST FLOW WEST OF THE EAST COAST RIDGE WILL CONTINUE TO POUR WARMER AIR INTO THE GREAT LAKES REGION. LOW LEVEL MOISTURE WILL CONTINUE TO BE RATHER SPARSE. FORECAST SOUNDINGS SUGGEST THAT THERE COULD STILL BE SOME LOW CLOUDS AND FOG ESPECIALLY OVER THE WEST...AND MID LEVEL CLOUD AS WELL. SOUNDINGS ALSO SHOWING A STRONG INVERSION AROUND 2K FEET AND VERY DRY FROM THERE TO 500MB. THE MID LEVEL RIDGE WILL PUSH TO THE EAST COAST WHILE A WEST COAST LONGWAVE TROUGH CROSSES THE CANADIAN AND NORTHERN ROCKIES ON MONDAY. THE SURFACE LOW WILL EDGE INTO EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA. THE FORECAST SOUNDINGS SHOWING A STRONG INVERSION AROUND 850MB...AND NEARLY SATURATED BELOW THIS LEVEL AND DRY FROM 850 TO 600MB. TEMPERATURES AROUND 750MB WILL BE 3C TO 7C...WHILE THOSE AT 900MB WILL BE -2C TO -4C. WHILE SURFACE TEMPERATURES SHOULD BE AROUND ZERO. THUS CONDITIONS STILL LOOK FAVORABLE FOR A MIX OF PRECIPITATION WITH SOME FOG. THE LONGWAVE TROUGH WILL MOVE INTO THE NORTHERN PLAINS MONDAY NIGHT PUSHING A SHORTWAVE THROUGH THE FORECAST AREA. THE SURFACE LOW WILL LIFT INTO THE ARROWHEAD OF MINNESOTA THEN INTO CENTRAL LAKE SUPERIOR DRAGGING A COLD FRONT INTO THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN WISCONSIN. WARM AIR CONTINUES TO FLOW INTO THE GREAT LAKES REGION AHEAD OF THE FRONTAL SYSTEM. ISENTROPIC ASCENT AHEAD OF THE FRONTAL SYSTEM AND LOW LEVEL MOISTURE WILL CONTINUE TO POUR INTO THE REGION FEEDING A MIX OF RAIN AND SNOW. AS THE LOW TRACKS NORTHEAST TO JAMES BAY ON TUESDAY...IT WILL DRAG THE COLD FRONT THROUGH THE WEST OF THE FORECAST AREA. VERY COLD AIR BEHIND THE FRONT WILL SPREAD INTO THE AREA ON TUESDAY. AN 850MB THERMAL TROUGH WILL PUSH -26C TEMPERATURES INTO NORTHERN MINNESOTA. CONDITIONS OVER CENTRAL AND EASTERN LAKE SUPERIOR WILL EXPERIENCE SOME ENHANCE LAKE EFFECT SNOW OVER THE NORTHERN U.P. SOME OF THE A LOW LEVEL JET SWEEPING THROUGH THE BASE OF THE LOW WILL MIX TO SURFACE OVER LAKE SUPERIOR PRODUCING SOME GALES OVER THE LAKE AND ALONG THE LAKE SHORE. INLAND CAN STILL EXPERIENCE WINDS AROUND 20 MPH. THE LONGWAVE TROUGH WILL SWEEP THROUGH THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY. THE COLD FRONT WILL TRACK EAST INTO QUEBEC AND A SURFACE RIDGE OVER THE NORTHERN PLAINS WILL MOVE INTO WISCONSIN. DRIER AIR WILL MOVE INTO THE AREA. THE THERMAL TROUGH WILL SHIFT NORTHEAST INTO ONTARIO. HOWEVER...THE DELTA-T`S OVER LAKE SUPERIOR WILL REMAIN AROUND 26C...WHICH WILL CAUSE ENOUGH INSTABILITY AT THE LOW LEVELS TO KEEP LES GOING. THE WINDS WILL BE MAINLY FROM THE WEST CAUSING LES OVER AREAS OF THE KEWEENAW PENINSULA AND THE EASTERN U.P. ALONG THE LAKE SHORE. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... SLOWED DOWN THE APPROACH OF HIGH CLOUDS FOR LATE THIS AFTERNOON. KEPT WITH THE POTENTIAL OF LLWS WITH THE DEVELOPING LLJ TONIGHT INTO MID MORNING BEFORE HIGHER WINDS ABOVE SFC ARE TAPPED. OTHERWISE...PRECIPITATION MAY STILL HOLD OFF TO THE WEST THROUGH THE END OF THIS FORECAST PERIOD. IT WILL BE VERY CLOSE AT CMX...AS LOW TO MID LEVELS SLOWLY SATURATE...SO HAVE ADDED PRECIP FOR 17Z. HAVE ALSO HINTED AT MORNING BR BEFORE STRONGER WINDS TAKE EFFECT. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT A WEAK HI PRES RDG TO DRIFT ACROSS THE UPR GRT LKS TDAY BEFORE MOVING INTO THE MID ATLANTIC STATES BY MON. MEANWHILE...A LO PRES SYS WILL TAKE SHAPE IN THE NRN PLAINS ON MON AND MOVE INTO MN LATE IN THE DAY. THIS LO WL BE DEEP ENUF TO CAUSE S GALES OVER THE E HALF OF LK SUP LATE TNGT THRU MON NGT...SO ISSUED GALE WRNG FOR THOSE AREAS WHERE S GALES ARE ALMOST CERTAIN. LOOK FOR THE LO TO MOVE INTO ONTARIO ON TUE AND DRIVE A SHARP COLD FRONT ACROSS LK SUP...WITH WNW GALES IN ITS WAKE AS H85 THERMAL TROF DRIVES OVHD COINCIDENT WITH SHARP PRES GRADIENT. HEAVY FRZG SPRAY WL RETURN. AS THIS LO SLIDES INTO QUEBEC ON WED AND DEEPENS...A HI PRES RDG WL BLD INTO THE NRN PLAINS THRU THU. && .MQT WATCHES/WARNINGS/ADVISORIES... MICHIGAN...NONE. LAKE SUPERIOR...GALE WARNING FROM 4 AM MONDAY TO 4 AM EST TUESDAY FOR LSZ266-267. LAKE MICHIGAN...NONE. && $$ UPDATE...KF DISCUSSION...DLG AVIATION...KF MARINE...KC mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1048 AM EST SUN JAN 27 2008 .UPDATE... SIGNIFICANT CHANGES WITH RESPECT TO CLOUD COVER...AS WE WERE WAY TOO HIGH EARLY ON TODAY AND TONIGHT. MADE CLOUD CHANGES THROUGH THURSDAY AFTERNOON...ALTHOUGH THEY ARE MOST SIGNIFICANT FOR THE NEAR TERM. MAY HAVE NOT GONE LOW ENOUGH...BUT TRIED TO ACCOUNT FOR THE SLOWLY ERODING FOG ACROSS THE SOUTH CENTRAL PORTIONS OF THE CWA. OTHERWISE...INCREASED TEMPS SLIGHTLY FAR SOUTH AND SLOWED DOWN THE APPROACH OF PRECIPITATION FOR MONDAY MORNING CENTRAL AND EAST. WILL REVISIT THIS WITH THE FULL AFTERNOON FORECAST PACKAGE. && .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE PRECIPITATION AND WIND POTENTIAL FOR MONDAY AND TUESDAY. WATER VAPOR IMAGERY AND RUC SHOWING A LONGWAVE TROUGH OFF THE WEST COAST...A BROAD RIDGE OVER NORTH CENTRAL CONUS AND ANOTHER TROUGH OVER THE LOWER GREAT LAKES. WEAK SHORTWAVES ARE OVER MINNESOTA AND EAST CENTRAL ONTARIO. SURFACE ANALYSIS DEPICTS A RIDGE OVER UPPER MISSISSIPPI RIVER VALLEY...A LOW TROUGH THROUGH THE EASTERN OHIO RIVER VALLEY AND LOWER MICHIGAN...AND A LOW OVER SOUTHERN ALBERTA WITH A COLD FRONT DRAPED SOUTHWEST THROUGH THE PACIFIC NORTHWEST. A LARGE HIGH IS OVER THE LOWER MISSISSIPPI RIVER VALLEY. FOG AND SNOW IS OVER THE LOWER GREAT LAKES AND EASTERN OHIO RIVER VALLEY IN ASSOCIATION WITH THE MID LEVEL TROUGH. THE SHORTWAVE OVER MINNESOTA WILL SWEEP ACROSS THE FORECAST AREA THIS MORNING AND EARLY AFTERNOON INTO EASTERN ONTARIO. A BROAD RIDGE WILL FOLLOW BY LATE AFTERNOON. THE SURFACE LOW OVER ALBERTA WILL RACE ACROSS SOUTHWEST CANADA REACHING SOUTHEAST SASKATCHEWAN BY LATE AFTERNOON WHILE PUSHING A WARM FRONT AHEAD OF IT INTO WESTERN WISCONSIN. A SOUTHWEST FLOW NORTH OF THE LOWER MISSISSIPPI RIVER VALLEY HIGH WILL HELP BRING THE TEMPERATURES UP TODAY TO AROUND 30. THE WARMEST TEMPERATURES WILL BE OVER THE WESTERN U.P. THE AIR MASS WILL BE FAIRLY DRY ACROSS THE AREA TODAY. THERE IS A POSSIBILITY OF PICKING UP SOME CIRRUS THIS AFTERNOON...AND A SOME LOW CLOUDS. AS HPC SUGGEST THE GEM/ECMWF SOLUTION IS THE PREFERRED SOLUTION FOR THE SYSTEMS MOVING OUT OF THE ROCKIES THROUGH THE NORTHERN PLAINS INTO THE GREAT LAKES. AFTER MONDAY NIGHT...THE GFS LED SOLUTION BECOMES THE PREFERRED. THE MID LEVEL RIDGE WILL SHIFT INTO QUEBEC TONIGHT. A COUPLE OF WEAK SHORTWAVE WILL SHIFT ACROSS THE AREA. THE SURFACE RIDGE WILL WORK EASTWARD TO THE EAST COAST. THE SASKATCHEWAN LOW WILL SETTLE SOUTHWARD INTO MONTANA. SOUTHWEST FLOW WEST OF THE EAST COAST RIDGE WILL CONTINUE TO POUR WARMER AIR INTO THE GREAT LAKES REGION. LOW LEVEL MOISTURE WILL CONTINUE TO BE RATHER SPARSE. FORECAST SOUNDINGS SUGGEST THAT THERE COULD STILL BE SOME LOW CLOUDS AND FOG ESPECIALLY OVER THE WEST...AND MID LEVEL CLOUD AS WELL. SOUNDINGS ALSO SHOWING A STRONG INVERSION AROUND 2K FEET AND VERY DRY FROM THERE TO 500MB. THE MID LEVEL RIDGE WILL PUSH TO THE EAST COAST WHILE A WEST COAST LONGWAVE TROUGH CROSSES THE CANADIAN AND NORTHERN ROCKIES ON MONDAY. THE SURFACE LOW WILL EDGE INTO EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA. THE FORECAST SOUNDINGS SHOWING A STRONG INVERSION AROUND 850MB...AND NEARLY SATURATED BELOW THIS LEVEL AND DRY FROM 850 TO 600MB. TEMPERATURES AROUND 750MB WILL BE 3C TO 7C...WHILE THOSE AT 900MB WILL BE -2C TO -4C. WHILE SURFACE TEMPERATURES SHOULD BE AROUND ZERO. THUS CONDITIONS STILL LOOK FAVORABLE FOR A MIX OF PRECIPITATION WITH SOME FOG. THE LONGWAVE TROUGH WILL MOVE INTO THE NORTHERN PLAINS MONDAY NIGHT PUSHING A SHORTWAVE THROUGH THE FORECAST AREA. THE SURFACE LOW WILL LIFT INTO THE ARROWHEAD OF MINNESOTA THEN INTO CENTRAL LAKE SUPERIOR DRAGGING A COLD FRONT INTO THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN WISCONSIN. WARM AIR CONTINUES TO FLOW INTO THE GREAT LAKES REGION AHEAD OF THE FRONTAL SYSTEM. ISENTROPIC ASCENT AHEAD OF THE FRONTAL SYSTEM AND LOW LEVEL MOISTURE WILL CONTINUE TO POUR INTO THE REGION FEEDING A MIX OF RAIN AND SNOW. AS THE LOW TRACKS NORTHEAST TO JAMES BAY ON TUESDAY...IT WILL DRAG THE COLD FRONT THROUGH THE WEST OF THE FORECAST AREA. VERY COLD AIR BEHIND THE FRONT WILL SPREAD INTO THE AREA ON TUESDAY. AN 850MB THERMAL TROUGH WILL PUSH -26C TEMPERATURES INTO NORTHERN MINNESOTA. CONDITIONS OVER CENTRAL AND EASTERN LAKE SUPERIOR WILL EXPERIENCE SOME ENHANCE LAKE EFFECT SNOW OVER THE NORTHERN U.P. SOME OF THE A LOW LEVEL JET SWEEPING THROUGH THE BASE OF THE LOW WILL MIX TO SURFACE OVER LAKE SUPERIOR PRODUCING SOME GALES OVER THE LAKE AND ALONG THE LAKE SHORE. INLAND CAN STILL EXPERIENCE WINDS AROUND 20 MPH. THE LONGWAVE TROUGH WILL SWEEP THROUGH THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY. THE COLD FRONT WILL TRACK EAST INTO QUEBEC AND A SURFACE RIDGE OVER THE NORTHERN PLAINS WILL MOVE INTO WISCONSIN. DRIER AIR WILL MOVE INTO THE AREA. THE THERMAL TROUGH WILL SHIFT NORTHEAST INTO ONTARIO. HOWEVER...THE DELTA-T`S OVER LAKE SUPERIOR WILL REMAIN AROUND 26C...WHICH WILL CAUSE ENOUGH INSTABILITY AT THE LOW LEVELS TO KEEP LES GOING. THE WINDS WILL BE MAINLY FROM THE WEST CAUSING LES OVER AREAS OF THE KEWEENAW PENINSULA AND THE EASTERN U.P. ALONG THE LAKE SHORE. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... EXPECT LO CLDS TO GRDLY DSPT AT CMX/SAW THIS MRNG WITH LOWERING SUBSIDENCE INVRN. THERE WL BE PLENTY OF HI CLD THRU THE AFTN...BUT UPSTREAM AIRMASS IS SUFFICIENTLY DRY IN THE LO LVLS FOR VFR CONDITIONS. DVLPG LLJ TNGT TO THE E OF DVLPG LO PRES IN THE NRN PLAINS WL CAUSE LLWS AT BOTH TAF SITES BY LATE THIS EVNG. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT A WEAK HI PRES RDG TO DRIFT ACROSS THE UPR GRT LKS TDAY BEFORE MOVING INTO THE MID ATLANTIC STATES BY MON. MEANWHILE...A LO PRES SYS WILL TAKE SHAPE IN THE NRN PLAINS ON MON AND MOVE INTO MN LATE IN THE DAY. THIS LO WL BE DEEP ENUF TO CAUSE S GALES OVER THE E HALF OF LK SUP LATE TNGT THRU MON NGT...SO ISSUED GALE WRNG FOR THOSE AREAS WHERE S GALES ARE ALMOST CERTAIN. LOOK FOR THE LO TO MOVE INTO ONTARIO ON TUE AND DRIVE A SHARP COLD FRONT ACROSS LK SUP...WITH WNW GALES IN ITS WAKE AS H85 THERMAL TROF DRIVES OVHD COINCIDENT WITH SHARP PRES GRADIENT. HEAVY FRZG SPRAY WL RETURN. AS THIS LO SLIDES INTO QUEBEC ON WED AND DEEPENS...A HI PRES RDG WL BLD INTO THE NRN PLAINS THRU THU. && .MQT WATCHES/WARNINGS/ADVISORIES... MICHIGAN...NONE. LAKE SUPERIOR...GALE WARNING FROM 4 AM MONDAY TO 4 AM EST TUESDAY FOR LSZ266-267. LAKE MICHIGAN...NONE. && $$ UPDATE...KF DISCUSSION...DLG AVIATION...KC MARINE...KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 337 AM EST SUN JAN 27 2008 .DISCUSSION... THE MAIN CONCERN WITH THIS FORECAST PACKAGE IS THE PRECIPITATION AND WIND POTENTIAL FOR MONDAY AND TUESDAY. WATER VAPOR IMAGERY AND RUC SHOWING A LONGWAVE TROUGH OFF THE WEST COAST...A BROAD RIDGE OVER NORTH CENTRAL CONUS AND ANOTHER TROUGH OVER THE LOWER GREAT LAKES. WEAK SHORTWAVES ARE OVER MINNESOTA AND EAST CENTRAL ONTARIO. SURFACE ANALYSIS DEPICTS A RIDGE OVER UPPER MISSISSIPPI RIVER VALLEY...A LOW TROUGH THROUGH THE EASTERN OHIO RIVER VALLEY AND LOWER MICHIGAN...AND A LOW OVER SOUTHERN ALBERTA WITH A COLD FRONT DRAPED SOUTHWEST THROUGH THE PACIFIC NORTHWEST. A LARGE HIGH IS OVER THE LOWER MISSISSIPPI RIVER VALLEY. FOG AND SNOW IS OVER THE LOWER GREAT LAKES AND EASTERN OHIO RIVER VALLEY IN ASSOCIATION WITH THE MID LEVEL TROUGH. THE SHORTWAVE OVER MINNESOTA WILL SWEEP ACROSS THE FORECAST AREA THIS MORNING AND EARLY AFTERNOON INTO EASTERN ONTARIO. A BROAD RIDGE WILL FOLLOW BY LATE AFTERNOON. THE SURFACE LOW OVER ALBERTA WILL RACE ACROSS SOUTHWEST CANADA REACHING SOUTHEAST SASKATCHEWAN BY LATE AFTERNOON WHILE PUSHING A WARM FRONT AHEAD OF IT INTO WESTERN WISCONSIN. A SOUTHWEST FLOW NORTH OF THE LOWER MISSISSIPPI RIVER VALLEY HIGH WILL HELP BRING THE TEMPERATURES UP TODAY TO AROUND 30. THE WARMEST TEMPERATURES WILL BE OVER THE WESTERN U.P. THE AIR MASS WILL BE FAIRLY DRY ACROSS THE AREA TODAY. THERE IS A POSSIBILITY OF PICKING UP SOME CIRRUS THIS AFTERNOON...AND A SOME LOW CLOUDS. AS HPC SUGGEST THE GEM/ECMWF SOLUTION IS THE PREFERRED SOLUTION FOR THE SYSTEMS MOVING OUT OF THE ROCKIES THROUGH THE NORTHERN PLAINS INTO THE GREAT LAKES. AFTER MONDAY NIGHT...THE GFS LED SOLUTION BECOMES THE PREFERRED. THE MID LEVEL RIDGE WILL SHIFT INTO QUEBEC TONIGHT. A COUPLE OF WEAK SHORTWAVE WILL SHIFT ACROSS THE AREA. THE SURFACE RIDGE WILL WORK EASTWARD TO THE EAST COAST. THE SASKATCHEWAN LOW WILL SETTLE SOUTHWARD INTO MONTANA. SOUTHWEST FLOW WEST OF THE EAST COAST RIDGE WILL CONTINUE TO POUR WARMER AIR INTO THE GREAT LAKES REGION. LOW LEVEL MOISTURE WILL CONTINUE TO BE RATHER SPARSE. FORECAST SOUNDINGS SUGGEST THAT THERE COULD STILL BE SOME LOW CLOUDS AND FOG ESPECIALLY OVER THE WEST...AND MID LEVEL CLOUD AS WELL. SOUNDINGS ALSO SHOWING A STRONG INVERSION AROUND 2K FEET AND VERY DRY FROM THERE TO 500MB. THE MID LEVEL RIDGE WILL PUSH TO THE EAST COAST WHILE A WEST COAST LONGWAVE TROUGH CROSSES THE CANADIAN AND NORTHERN ROCKIES ON MONDAY. THE SURFACE LOW WILL EDGE INTO EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA. THE FORECAST SOUNDINGS SHOWING A STRONG INVERSION AROUND 850MB...AND NEARLY SATURATED BELOW THIS LEVEL AND DRY FROM 850 TO 600MB. TEMPERATURES AROUND 750MB WILL BE 3C TO 7C...WHILE THOSE AT 900MB WILL BE -2C TO -4C. WHILE SURFACE TEMPERATURES SHOULD BE AROUND ZERO. THUS CONDITIONS STILL LOOK FAVORABLE FOR A MIX OF PRECIPITATION WITH SOME FOG. THE LONGWAVE TROUGH WILL MOVE INTO THE NORTHERN PLAINS MONDAY NIGHT PUSHING A SHORTWAVE THROUGH THE FORECAST AREA. THE SURFACE LOW WILL LIFT INTO THE ARROWHEAD OF MINNESOTA THEN INTO CENTRAL LAKE SUPERIOR DRAGGING A COLD FRONT INTO THE UPPER MISSISSIPPI RIVER VALLEY AND WESTERN WISCONSIN. WARM AIR CONTINUES TO FLOW INTO THE GREAT LAKES REGION AHEAD OF THE FRONTAL SYSTEM. ISENTROPIC ASCENT AHEAD OF THE FRONTAL SYSTEM AND LOW LEVEL MOISTURE WILL CONTINUE TO POUR INTO THE REGION FEEDING A MIX OF RAIN AND SNOW. AS THE LOW TRACKS NORTHEAST TO JAMES BAY ON TUESDAY...IT WILL DRAG THE COLD FRONT THROUGH THE WEST OF THE FORECAST AREA. VERY COLD AIR BEHIND THE FRONT WILL SPREAD INTO THE AREA ON TUESDAY. AN 850MB THERMAL TROUGH WILL PUSH -26C TEMPERATURES INTO NORTHERN MINNESOTA. CONDITIONS OVER CENTRAL AND EASTERN LAKE SUPERIOR WILL EXPERIENCE SOME ENHANCE LAKE EFFECT SNOW OVER THE NORTHERN U.P. SOME OF THE A LOW LEVEL JET SWEEPING THROUGH THE BASE OF THE LOW WILL MIX TO SURFACE OVER LAKE SUPERIOR PRODUCING SOME GALES OVER THE LAKE AND ALONG THE LAKE SHORE. INLAND CAN STILL EXPERIENCE WINDS AROUND 20 MPH. THE LONGWAVE TROUGH WILL SWEEP THROUGH THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY. THE COLD FRONT WILL TRACK EAST INTO QUEBEC AND A SURFACE RIDGE OVER THE NORTHERN PLAINS WILL MOVE INTO WISCONSIN. DRIER AIR WILL MOVE INTO THE AREA. THE THERMAL TROUGH WILL SHIFT NORTHEAST INTO ONTARIO. HOWEVER...THE DELTA-T`S OVER LAKE SUPERIOR WILL REMAIN AROUND 26C...WHICH WILL CAUSE ENOUGH INSTABILITY AT THE LOW LEVELS TO KEEP LES GOING. THE WINDS WILL BE MAINLY FROM THE WEST CAUSING LES OVER AREAS OF THE KEWEENAW PENINSULA AND THE EASTERN U.P. ALONG THE LAKE SHORE. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... EXPECT PREVAILING MVFR CIG AT CMX INTO SUN MRNG WITH LOWERING SUBSIDENCE INVRN TRAPPING LO SC DECK. VFR CIG AT SAW AT TAF ISSUANCE WL GRDLY TRANSITION TO AN MVFR CIG EARLY THIS MRNG WITH ARRIVAL OF SUBSIDENCE/LOWER INVRN BASE. OTHERWISE...INCREASING SUBSIDENCE AHEAD OF AN ADVANCING NORTHERN PLAINS RIDGE SHOULD HELP BREAK OUT THE SC ACROSS UPR MI LATER THIS MORNING. LOW-LEVEL JET MAX RIDING UP THE BACKSIDE OF THE RIDGE AXIS COULD BRING SOME LOW-LEVEL WIND SHEAR TO BOTH TAF SITES BY LATE SUN EVENING. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... EXPECT A WEAK HI PRES RDG TO DRIFT ACROSS THE UPR GRT LKS TDAY BEFORE MOVING INTO THE MID ATLANTIC STATES BY MON. MEANWHILE...A LO PRES SYS WILL TAKE SHAPE IN THE NRN PLAINS ON MON AND MOVE INTO MN LATE IN THE DAY. THIS LO WL BE DEEP ENUF TO CAUSE S GALES OVER THE E HALF OF LK SUP LATE TNGT THRU MON NGT...SO ISSUED GALE WRNG FOR THOSE AREAS WHERE S GALES ARE ALMOST CERTAIN. LOOK FOR THE LO TO MOVE INTO ONTARIO ON TUE AND DRIVE A SHARP COLD FRONT ACROSS LK SUP...WITH WNW GALES IN ITS WAKE AS H85 THERMAL TROF DRIVES OVHD COINCIDENT WITH SHARP PRES GRADIENT. HEAVY FRZG SPRAY WL RETURN. AS THIS LO SLIDES INTO QUEBEC ON WED AND DEEPENS...A HI PRES RDG WL BLD INTO THE NRN PLAINS THRU THU. && .MQT WATCHES/WARNINGS/ADVISORIES... MICHIGAN...NONE. LAKE SUPERIOR...GALE WARNING FROM 4 AM MONDAY TO 4 AM EST TUESDAY FOR LSZ266-267. LAKE MICHIGAN...NONE. && $$ DISCUSSION...DLG AVIATION...VOSS MARINE...KC mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1230 AM EST SUN JAN 27 2008 UPDATED FOR AVIATION DISCUSSION .SYNOPSIS... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SPLIT FLOW CONTINUING ACROSS NAMERICA. FLOW IS GENERALLY ZONAL. SO AT LEAST FOR THE SHORT TERM...ARCTIC AIR IS NOW BOTTLED UP ACROSS THE N HALF OF CANADA. A WELL-DEFINED SHORTWAVE WAS TRACKING ESE ACROSS SRN LWR MI. -SN OVER UPPER MI ASSOCIATED WITH THIS FEATURE HAS BEEN GRADUALLY ENDING DURING THE AFTN. HOWEVER...MORE PERSISTENT -SN IS OCCURRING OVER PORTIONS OF THE ERN FCST AREA AS SRLY FLOW ACROSS LAKE MICHIGAN IS PROVIDING SOME LAKE ENHANCEMENT. OBS INDICATE LOW-LEVEL CONVERGENCE IS OCCURRING ALONG THE LONG AXIS OF THE LAKE...AND VIS IMAGERY SUGGESTS A MIDLAKE CONVERGENCE BAND OF SNOW IS PRESENT EXTENDING N INTO SCHOOLCRAFT COUNTY. IN FACT...KGRB RADAR HAS BEEN ABLE TO PICK UP SOME OF THIS BAND. ANOTHER SHORTWAVE WAS OVER NW WI. RADARS/SFC OBS INDICATE FLURRIES ASSOCIATED WITH IT. && .SHORT TERM (TONIGHT AND SUNDAY)... ENDING OF -SN OVER THE E AND CLOUDS/TEMPS TONIGHT ARE THE MAIN FCST CONCERNS IN THE SHORT TERM. LOCALLY RUN HIGH RES WRF-ARW HAS DONE AN EXCELLENT JOB DEPICTING THE MIDLAKE CONVERGENCE BAND OVER LAKE MICHIGAN. WITH WEAKENING CONVERGENCE THRU THE EVENING AND A SLOW EWD MOVEMENT OF THE CONVERGENCE AXIS...NOTHING MORE THAN SCT -SHSN SHOULD BE SUFFICIENT FOR THE EVENING. ANY ADDITIONAL ACCUMULATIONS WILL BE UNDER 1 INCH. SINCE FLURRIES ASSOCIATED WITH SHORTWAVE MOVING ACROSS NW WI HAVE BEEN GRADUALLY DISSIPATING...WILL NOT INCLUDE MENTION AFTER 00Z. OTHERWISE...EXTENSIVE CLOUD COVER THAT WAS OVER MUCH OF ERN MN/WI/UPPER MI THIS MORNING HAS BEEN SLOWLY BREAKING UP. VIS SATELLITE IMAGERY INDICATED MUCH OF THE CLOUD COVER WAS QUITE THIN WITH TERRAIN FEATURES AND LAKES FAINTLY VISIBLE THRU THE CLOUDS. WITH THIS IN MIND...WILL CONTINUE TO INDICATE A STEADY DECREASE IN CLOUDS DURING THE NIGHT. THERE IS A RISK THAT LOWERING SUBSIDENCE INVERSION COULD TRAP A LOW STRATUS DECK...BUT AFTN SATELLITE TRENDS SUGGEST LEANING TOWARD AN OPTIMISTIC OUTLOOK. WITH EXPECTATION OF SOME CLEARING...WILL GO BLO MOS GUIDANCE FOR MINS TONIGHT...EXCEPT OVER THE E WHERE LOW-LEVEL MOISTENING OFF LAKE MICHIGAN AND SLOWER CLOUD DEPARTURE WILL KEEP TEMPS UP. QUIET DAY EXPECTED SUN. OTHER THAN SOME MID/HIGH CLOUDS MAINLY LATER IN THE DAY...THERE SHOULD BE A GOOD DISPLAY OF SUNSHINE...PROVIDED A STRATUS DECK DOESN`T GET TRAPPED TONIGHT. GOING FCST HIGHS LOOKED FINE...RISING JUST ABOVE FREEZING OVER THE FAR W AS WAA REGIME STRENGTHENS DURING THE DAY (850MB TEMPS REACH 2C OVER THE W BY EVENING). COOLEST TEMPS (MID 20S) SHOULD BE IN DELTA COUNTY... DOWNWIND OF THE SOLIDLY ICE COVERED BAY OF GREEN BAY. ELSEWHERE... TEMPS SHOULD RISE TO AROUND 30F. && .LONG TERM (SUNDAY NIGHT THROUGH SATURDAY)... SHORTWAVE CURRENTLY OVER LAKE HURON WILL CONTINUE TO SHIFT SOUTHEASTWARD...AND END UP OFF THE MARYLAND COAST AT THE START OF THIS PERIOD. THIS WILL ALLOW FOR SIGNIFICANT RIDGING TO TAKE PLACE OVER THE CENTRAL UNITED STATES...AND A DRY SUNDAY NIGHT. TEMPERATURES SUNDAY NIGHT WILL BE A LITTLE TRICKY...ESPECIALLY FOR OUR EASTERN MOST COUNTIES...AS THEY COULD PLUMMET INTO THE UPPER TEENS DEPENDING ON CLOUD COVER AND HOW QUICKLY THE STRONGER SOUTHWESTERLY WINDS COME INTO PLAY. WILL GO MIDDLE OF THE ROAD FOR NOW AND KEEP AN EYE ON THE INVADING MOISTURE. THE 500MB RIDGE WILL BECOME PINCHED TO OUR EAST ON MONDAY...AS A MORE SIGNIFICANT TROUGH MOVES FROM THE PACIFIC NORTHWEST TO MONTANA AND THE DAKOTAS. AT THIS POINT...MODELS BECOME A LITTLE MORE VARIED IN THE PROGRESSION OF THIS LONGWAVE TROUGH. AT THE SURFACE...STRENGTHENING SOUTHWESTERLY FLOW OUT AHEAD OF THE LOW IN EASTERN MONTANA AND THE DAKOTAS WILL ALLOW FOR MOIST WARM AIR TO SURGE IN. THIS SYSTEM WILL BRING ABOUT BREEZY CONDITIONS BOTH BEFORE AND AFTER ITS PASSAGE...FOR THE FIRST HALF OF THE WORK WEEK FOR MOST. AS FOR SPECIFICS...WITH TEMPERATURES CONTINUING TO HOVER AROUND THE FREEZING MARK ON MONDAY...WILL HAVE A DIFFICULT TIME PINPOINTING ONE PRECIPITATION TYPE AS A MIXED BAG OF WINTER TYPE WEATHER CAN BE ANTICIPATED DEPENDING ON THE LOCATION ACROSS THE U.P. SECONDARY WAVE SLIDING ACROSS 00Z WED CONTINUES TO WREAK HAVOC ON THE FORECAST. IT SHOWED UP AGAIN ON THE 00Z RUN OF THE ECMWF...AND WAS NOT AS EVIDENT ON THE 12Z GFS. WHAT THIS DOES...IS SLOWS DOWN ANY COLD AIR FROM SLIDING IN. THE GFS WOULD HAVE MAX TEMPS ACROSS THE ENTIRE CWA AT OR PRIOR TO 12Z TUESDAY. ACCOUNTING FOR THIS ADDITIONAL WAVE AND ATTEMPTING TO PRODUCE LESS FLIP FLOPPING...AND REMAINED CLOSER TO ECMWF THINKING WITH COLD AIR SLIDING IN TUESDAY...USED THE SERP TOOL TO BRING WARMEST AIR W AT 12Z...CENTRAL AT AROUND 15Z...AND EAST AT 18Z. UTILIZED HPC GUIDANCE GRIDS FOR MUCH OF THE FAR EXTENDED...DAYS 4/WEDNESDAY THROUGH 7/SATURDAY. THIS WAS A GENERAL BLEND OF THE GFS AND ECMWF...WITH A LITTLE VARIATION. THIS MEANT A CHANGE TO AFTERNOON HIGH TEMPERATURES ON WEDNESDAY OF ABOUT 5 DEGREES...AND THURSDAY OF ABOUT 10 DEGREES...COLDER. OTHER SIGNIFICANT CHANGES WERE TO KEEP STRONGER WINDS IN THE FORECAST THROUGH WEDNESDAY NIGHT...INSTEAD OF JUST THE DAYTIME HOURS WEDNESDAY. ALSO KEPT NW WINDS LONGER...BY ABOUT 18 HOURS OR NOW THROUGH THURSDAY AFTERNOON. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... EXPECT PREVAILING MVFR CIG AT CMX INTO SUN MRNG WITH LOWERING SUBSIDENCE INVRN TRAPPING LO SC DECK. VFR CIG AT SAW AT TAF ISSUANCE WL GRDLY TRANSITION TO AN MVFR CIG EARLY THIS MRNG WITH ARRIVAL OF SUBSIDENCE/LOWER INVRN BASE. OTHERWISE...INCREASING SUBSIDENCE AHEAD OF AN ADVANCING NORTHERN PLAINS RIDGE SHOULD HELP BREAK OUT THE SC ACROSS UPR MI LATER THIS MORNING. LOW-LEVEL JET MAX RIDING UP THE BACKSIDE OF THE RIDGE AXIS COULD BRING SOME LOW-LEVEL WIND SHEAR TO BOTH TAF SITES BY LATE SUN EVENING. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... MAIN FEATURE OF INTEREST IS A VERY STRONG LOW PRES SYSTEM MOVING FROM THE NRN PLAINS MON MORNING TO ONTARIO BY TUE MORNING. SYSTEM WILL EASILY BE STRONG ENOUGH TO PRODUCE SRLY GALES OVER THE E HALF OF LAKE SUPERIOR MON. THERE WILL BE A SWITCH TO W TO NW GALES TUE AFTN INTO WED OVER MUCH OF LAKE SUPERIOR AS A BLAST OF ARCTIC AIR SURGES INTO THE REGION BEHIND THE DEEP LOW. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SYNOPSIS/SHORT TERM...ROLFSON LONG TERM...KF AVIATION...VOSS MARINE...ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 345 AM CST SUN JAN 27 2008 .SHORT TERM...TODAY THROUGH MONDAY...WARMER AND DRIER IN THE SHORT TERM. HIGH PRESSURE SURFACE AND ALOFT WILL MOVE OVER OUR CWA TODAY AND SHIFT EAST OF OUR CWA MONDAY. LATEST SURFACE ANALYSIS HAS THE HIGH CENTERED OVER THE ARKLATEX. SATELLITE IMAGERY/RUC ANALYSIS SUGGESTS THE UPPER RIDGE AXIS IS OVER THE CENTRAL CONUS. AS THE RIDGES MOVE OVER OUR REGION TODAY THE PERSISTENT STRATUS THAT HAS BEEN OVER OUR CWFA SINCE FRIDAY WILL FINALLY DISSIPATE AND ALLOW FOR SOME SUNSHINE. THE GFS IS LIKELY STILL A LITTLE TOO FAST IN BREAKING OUT SUNSHINE OVER OUR AREA. WL KEEP AT LEAST MOSTLY CLOUDY SKIES IN UNTIL AROUND NOON TODAY. THE EXPECTED SUNSHINE THIS AFTERNOON SHOULD HELP US REACH HIGHS IN THE UPPER 50S AND MAV GUIDANCE WAS GENERALLY ACCEPTED. MOSTLY CLEAR SKIES AND LIGHT WINDS THIS EVENING WILL ALLOW TEMPERATURES TO DROP OFF RAPIDLY. AS BOTH RIDGES SHIFT EAST TONIGHT AND MONDAY RETURN FLOW WILL INCREASE FROM THE WEST. THIS WILL RESULT IN COLDEST TEMPERATURES OVER THE EAST MONDAY MORNING...DOWN NEAR FREEZING. MOISTURE WILL INCREASE MONDAY RESULTING IN INCREASING MID AND UPPER LEVEL CLOUDS BY AFTERNOON. STRENGTHENING SOUTHERLY WINDS WILL HELP MAKE FOR AN EVEN WARMER DAY. MOST SITES WILL TOP OUT IN THE MIDDLE 60S. /22/ .LONG TERM...TUESDAY THROUGH SUNDAY...THE MODELS (GFS/EURO/CAN) ARE ALL PRETTY CONSISTENT WITH THE TWO SYSTEM ROLLING THROUGH THE ARKLAMISS THIS WEEK. LITTLE HAS CHANGED IN THE MODELS EXCEPT THE TUESDAY SYSTEM IS A LITTLE SLOWER THAN PREVIOUS RUNS. THE TUESDAY SYSTEM CONTINUES LOOKS LIKE IT WILL HAVE STRONG WIND FIELDS...BUT AGAIN THE INSTABILITY LOOKS A BIT ON THE LOW SIDE WITH 200-400 J/KG OF ML CAPE. LIKE MENTIONED IN THE PREVIOUS AFD THE SLOWER SOLUTION SHOULD ALLOW FOR MORE INSTABILITY BUT IT WILL STILL BE MARGINAL. LOOKING AT THE LATEST GFS BUFR SOUNDINGS IT LOOKS LIKE THERE WONT BE MUCH OF A CAP...SO A FEW DISCRETE CELLS LOOK POSSIBLE OUT AHEAD OF THE LINE DURING THE AFTERNOON. WILL CONTINUE TO MENTION STRONG TO SEVERE IN THE HWO WITH THIS SYSTEM. SURFACE HIGH MOVES IN BEHIND THE FRONT ON WEDNESDAY...BUT THIS WILL BE SHORT LIVED AS THE HIGH SHIFTS TO THE EAST AND ONCE AGAIN WE RETURN TO SOUTHEASTERLY MOIST FLOW BY WEDNESDAY NIGHT. THE MODELS ALSO CONTINUE TO BE PERSISTENT WITH THE THURSDAY SYSTEM AND THIS CONTINUES TO LOOK LIKE A SIGNIFICANT SYSTEM FOR THE AREA THURSDAY NIGHT INTO FRIDAY. THE MODELS HAVE CONTINUED TO TREND A LITTLE SLOWER WITH THIS SYSTEM AND THE EURO ACTUALLY DEVELOPS THE SURFACE LOW ACROSS THE SOUTHERN PORTIONS OF MISSISSIPPI AND THIS WOULD KEEP MOST OF THE SEVERE TO THE SOUTH AND EAST OF THE AREA. THE LAST COUPLE OF RUNS HAVE INDICATED THIS...BUT THE GFS/CAN CONTINUES TO KEEP THE SURFACE LOW TRACKING TO OUR NORTHWEST. THINK THE EURO COULD HAVE SOME CONVECTIVE FEEDBACK ISSUES...SO WILL CONTINUE TO LEAN TOWARDS THE GFS/CAN. COOL HIGH PRESSURE BUILDS IN BEHIND THE SYSTEM ON FRIDAY INTO SATURDAY AND THE REMAINDER OF THE PERIOD LOOKS DRY...ALTHOUGH THERE COULD BE SOME WARM ADVECTION SHOWERS DEVELOPING BY SUNDAY OUT AHEAD OF THE NEXT SYSTEM. MADE A FEW CHANGES TO GUIDANCE POPS AND TEMPS THIS MORNING MOSTLY ON TUESDAY. HAVE CONTINUE TO BUMP POPS ABOVE GUIDANCE AS ALL OF THE MODELS ARE IN GOOD AGREEMENT WITH THE TIMING OF THE PRECIP ACROSS THEA AREA. H925/H850 TEMPS CLIMATOLOGICALLY WOULD SUPPORT TEMPS SLIGHTLY ABOVE GUIDANCE SO HAVE RAISED HIGHS A BIT. STUCK CLOSE TO GUIDANCE FOR THE REMAINDER OF THE PERIOD WITH ONE EXCEPTION. EVEN WITH THE DIFFERENCES IN THE MODELS AS FAR AS THE TRACK OF THE SURFACE LOW THURSDAY EVENING THE TIMING OF THE PRECIP IS SIMILAR...SO WILL RAISE POPS A LITTLE ABOVE GUIDANCE THURSDAY NIGHT./15/ && .AVIATION...PERSISTENT STRATUS LAYER RANGING FROM 200FT IN THE DELTA TO NEAR 1000FT OVER SOUTHEAST MISSISSIPPI WILL LAST THROUGH MUCH OF THE MORNING. INSULATION/MIXING WILL FINALLY START TO WORK ON THE STRATUS AND RESULT IN EROSION AND SCATTERING OUT BY THIS AFTERNOON. VFR CONDITIONS ARE EXPECTED TO PREVAIL AREAWIDE BY 21Z AND LAST THROUGH 12Z MONDAY. /22/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 59 33 67 55 / 0 0 0 13 MERIDIAN 59 28 64 49 / 0 0 0 10 VICKSBURG 58 38 69 56 / 0 0 0 17 HATTIESBURG 61 30 68 50 / 0 0 0 9 NATCHEZ 60 38 67 58 / 0 0 0 12 GREENVILLE 57 38 64 56 / 0 0 4 33 GREENWOOD 58 35 63 55 / 0 0 3 31 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 22/15 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 1022 PM CST MON JAN 28 2008 .UPDATE... UPDATED TO BRING AN EARLIER START TO WIND ADVISORY IN NORTHEAST NEBRASKA WITH COLD FRONT MOVING THROUGH SOONER THAN PREVIOUSLY THOUGHT. ADJUSTED TEMPERATURE AND WIND GRIDS ACCORDINGLY. && .DISCUSSION... COLD FRONT WAS SLAMMING NORTHEAST NEBRASKA LATE THIS EVENING WITH WIND GUSTS TO 50 MPH AS PER A COOP OBSERVER NORTH OF NORFOLK. WINDS SHIFTED TO THE NORTHWEST AT NORFOLK JUST AFTER 9 PM AND WAS GUSTING OVER 40 MPH ON THE 10 PM OBSERVATION. THIS IS A BIT QUICKER THAN EARLIER GRIDS SHOWED...SO THEY WERE UPDATED TO REFLECT THIS. EVENING UPPER AIR ANALYSIS SHOWED A VERY POWERFUL STORM SYSTEM ENTERING THE REGION. 190M 500MB HEIGHT FALLS WERE NOTED AT OMAHA WITH AN EXTREMELY TIGHT BAROCLINIC ZONE AT 850MB FROM NORTH CENTRAL NEBRASKA INTO EASTERN MONTANA. 850 TEMPS RANGED FROM 10C AT NORTH PLATTE TO 32 BELOW AT GLASGOW. WE HAVE BEEN WATCHING THIS SUB 30C BELOW AIR OOZING SOUTHEAST FROM THE CANADIAN HIGH PLAINS FOR THE LAST FEW DAYS...AND IT IS NOW SPILLING INTO THE NORTHERN PLAINS. AND COLD AIR ALWAYS SEEMS TO HAVE A MIND OF ITS OWN...SO INITIAL FEELING IS THAT COLDER NAM MODEL AND ETA MOS IS PROBABLY WORTH CONSIDERING. PRECIPITATION WITH THE COLD FRONT IS MINIMAL RIGHT NOW...BUT EXPECT LIGHT SNOW TO DEVELOP THROUGH THE NIGHT AS MID LEVEL VORT MAX AND ASSOCIATED COUPLED JET MOVE INTO NEBRASKA AND SOUTH DAKOTA. LATEST NAM FORECAST BEARS THIS OUT...AS DOES 00Z RUC. SO FOR THE MOST PART GOING GRIDDED AND ZONE FORECAST LOOKS GOOD. HIGH QPF IS STILL PAINTED OVER NORTHEAST NEBRASKA WHERE AN INCH OR TWO OF SNOW IS POSSIBLE. AND ALONG WITH THE STRONG WINDS...EXPECTED SIGNIFICANT BLOWING SNOW THERE. WILL LIKELY SEE PERIODS OF REDUCED VISIBILITIES OVER THE REST OF THE CWA...BUT ONLY FOR SHORT PERIODS. MIDNIGHT CREW WILL BE SURE TO EVALUATE THE SNOW SITUATION AS THE NIGHT PROGRESSES. DERGAN && .PREV DISCUSSION... /ISSUED 313 PM CST MON JAN 28 2008/ SHORT TERM...TONIGHT THROUGH THURSDAY. SEVERAL ITEMS OF CONCERN FOR THIS PERIOD INCLUDING SHARP ARCTIC FRONT WITH FALLING TEMPERATURES AND SNOW SHOWERS LATER TONIGHT INTO MIDDAY TUESDAY... AND THEN HOW FAR NORTH PCPN SHIELD WILL SPREAD AS AN UPPER TROUGH/LOW SWINGS EWD ACROSS THE SRN PLAINS. STLT IMAGERY AND UA ANLYS SHOWED SEVERAL WEAK EMBEDDED TROUGHS LIFTING NEWD AHEAD OF LARGE SCALE WRN U.S. TROUGH. ONE WAVE WAS LIFTING INTO WRN KS AS OF 19Z WITH AN INCREASE IN MID CLOUDS AND SOME RADAR RETURNS SPREADING INTO NERN NEBR. WL INCLUDE SCT RW-/RW-- THIS EVENING BASED ON TRENDS BEFORE PRODUCT ISSUANCE. ANOTHER PIECE OF ENERGY WAS LIFTING TWD NCNTRL SD...WITH THE ARCTIC CDFNT SURGING SEWD BEHIND IT. AT 19Z CDFNT HAD PUSHED INTO NWRN SD AND WAS APPROACHING GILLETTE IN NERN WY. ALTHOUGH THE 12Z GFS DIDN/T LOOK TOO BAD FOR FRONTAL TIMING...BRINGING FRONT NEAR A LCG-OLU LINE BY 06Z AND THEN THROUGH THE CWA AROUND 12Z...LOOKING AT CURRENT TEMPERATURES BEHIND FRONT...LEANED MORE TOWARD ETA MOS FOR ACTUAL 12/13Z TEMPS. WL THEN ADJUST HOURLIES TO REFLECT FALLING TEMPERATURES MUCH OF THE CWA INTO MIDDAY TUE BEFORE THEY LEVEL OFF OR PERHAPS GO UP A BIT. LOOKS LIKE A 3-6 HOUR PD OF LIFT...PARTIALLY FRONTOGENETIC...POST FRONTAL WITH LIGHT SNOW ACCUMULATIONS. INCREASED AREAL COVERAGE OF LIKELY POPS FAR NE LATE TNGT THEN ROUGHLY NE OF LCG-OMA-ICL LINE IN 12Z-18Z PD TUE. ALTHOUGH NEW SNOW AMOUNTS SHOULD BE MOSTLY UNDER 1 INCH...TROUBLE IS THAT ANY SNOW WILL BE ACCOMPANIED BY ADVISORY CRITERIA WINDS AND COLD TEMPERATURES. OPTED FOR A WIND ADVSRY FOR THE TIME BEING MOST OF THE CWA AS RECENT MILD SPELL HAS MELTED OR CRUSTED CURRENT SNOW PACK AND NEW SNOW AMOUNTS PROBABLY WON/T BE ENOUGH TO LOWER VSBYS TO 1/4 MILE FOR ANY LENGTH OF TIME. HOWEVER...DID ISSUE A WINTER WEATHER ADVSRY FAR NRN ZONES WHERE WIND CHILLS MAY DROP TO 20 BELOW OR COLDER BEFORE SUNRISE ALONG WITH THE FALLING SNOW. WINTER WX ADVSRY MAY NEED EXPANDING LATER IF ACCUMULATING SNOW APPEARS IT WILL LAST MORE THAN SVRL HOURS FARTHER SE. BASED TUE NGT/WED FORECAST MORE IN LINE WITH ETA MOS AND NAM WIND FIELDS...WITH SFC RIDGE AXIS EXTDG SWD NEAR MO RVR BY 12Z WED. THINK GFS MAY BE A BIT TOO QUICK IN SHIFTING RIDGE E. THUS LOWERED TEMPERATURES TUE NGT...BUT IF CLOUDS INCREASE AHEAD OF SCHEDULE THEY MAY BE TOO COOL. ALSO TRIMMED TEMPS BACK A BIT CNTRL/N ON WED DUE TO COLDER START AND THE FACT THAT CLOUDS SHOULD BE INCREASING BY THEN AS ISENTROPIC LIFT BEGINS. ALSO INCLUDED SLGT CHC OF SNOW NERN ZONES AFT MID AFTN AS H7 TROUGH/LOW DVLPS CNTRL NEBR. GFS REMAINED PERSISTENT IN DVLPG QPF BY 00Z THU AND EVEN 12Z ECMWF AND 00Z GFS ENSEMBLE MEAN SUPPORTS IT NOW. SIGNIFICANT UNCERTAINTY STILL EXISTS FOR SNOW CHANCES THURSDAY WITH OPERATIONAL GFS CONTINUING TO BE THE MOST BULLISH FOR SERN NEBRASKA...WITH 00Z ENSEMBLE MEAN SHOWING SUPPORT WHILE NAM/SREF SHOWED LTL/MUCH LESS. EVEN 12Z GEM AND ECMWF QPF FIELDS HAVE SHIFTED MOSTLY/ALL SE OF THE CWA. OPTED TO LEAVE POPS FAIRLY CLOSE TO PREV FORECAST DUE TO UNCERTAINTIES...WHICH WILL INCLUDE LIKELY POPS FAR SE. MADE A FEW MINOR DOWNWARD TEMPERATURE ADJUSTMENTS SINCE CORE OF COLD AIRMASS CURRENTLY PLUNGING SEWD ACROSS NRN PLAINS WON/T BE DISPLACED TOO FAR OR MODERATED GREATLY BEFORE THEN.TONIGHT THROUGH THURSDAY. SEVERAL ITEMS OF CONCERN FOR THIS PERIOD INCLUDING SHARP ARCTIC FRONT WITH FALLING TEMPERATURES AND SNOW SHOWERS LATER TONIGHT INTO MIDDAY TUESDAY... AND THEN HOW FAR NORTH PCPN SHIELD WILL SPREAD AS AN UPPER TROUGH/LOW SWINGS EWD ACROSS THE SRN PLAINS. LONG TERM...THURSDAY NIGHT THROUGH MONDAY. TAIL END OF SOUTHERN PLAINS SYSTEM WILL STILL BE AFFECTING THE SOUTHEAST THE FIRST PART OF THU NIGHT. WENT FOR CONTINUITY FROM THE SHORT TERM WITH LINGERING CHC OF LIGHT SNOW IN THE SOUTHEAST. EXPECT A LOT OF CLEARING BY FRI MORNING...AND THERE WILL BE DECENT RADIATION DURING PART OF THE NIGHT. NW COUNTIES SHOULD NOT RECEIVE ADDITIONAL SNOW AND WOULD NOT RADIATE OUT AS WELL AS IN RECENT DAYS. SOUTHEAST MAY WELL HAVE SOME SNOW COVER...BUT WILL PROBABLY NOT SEE MUCH CLEARING UNTIL LATE. FROM FRIDAY THROUGH SUNDAY TEMPERATURES WILL PROBABLY BE NEAR SEASONAL NORMS. MODELS DEPICT A WEAK TROUGH WITH LIFT PASSING MAINLY NORTH OF THE AREA ON SATURDAY. LEFT THE FORECAST DRY FOR NOW. A STRONGER LONG WAVE TROUGH WILL MOVE FROM THE WEST INTO THE CENTRAL STATES AROUND MONDAY. FOLLOWED HPC TIMING FAIRLY CLOSELY...AND THIS REFLECTS THE 00Z GFS ENSEMBLE MEAN. 12Z GFS IS A LOT FASTER...AND THUS COLDER FOR OUR AREA. 12Z ECMWF IS MUCH WEAKER WITH THE SFC SYSTEM. WARM ADVECTION PCPN COULD BREAK OUT AS EARLY AS SUNDAY NIGHT...BUT THE BEST CHC FOR PRECIP APPEARS TO BE MONDAY. IF WE ARE IN THE WARM SECTOR OF THIS SYSTEM...THERE COULD BE A MIX OF RAIN AND SNOW IN THE NORTH...BUT PRECIP WOULD LIKELY BECOME ALL RAIN ON MONDAY IN THE SOUTH. 12Z GFS SOLUTION SO FAR IS AN OUTLIER IN DEPICTING A MAJOR WINTER STORM...AND WAS NOT FOLLOWED. AVIATION... FOR TAF SITES OMA/LNK/OFK. VALID THRU 18Z 1/30 VFR CONDITIONS EXPECTED UNTIL ARRIVAL OF COLD FRONT...ARND 06Z AT KOFK AND 09Z AT KLNK AND KOMA. MVFR CIGS BEHIND THE FRONT WITH STRONG NW WINDS AND PERIODS OF S-/IP- THRU 18Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY FROM 2 AM TO 3 PM CST TUESDAY FOR NEZ034-044-045- 050>053-065>067-078-088-089. WIND ADVISORY FROM 6 AM TO 3 PM CST TUESDAY FOR NEZ068-090>093. WIND ADVISORY UNTIL 3 PM CST TUESDAY FOR NEZ032-033-042-043. WINTER WEATHER ADVISORY FROM 2 AM TO 1 PM CST TUESDAY FOR NEZ011- 012-015>018-030-031. WIND ADVISORY UNTIL 2 AM CST TUESDAY FOR NEZ011-012-015>018-030- 031. IA...WIND ADVISORY FROM 2 AM TO 3 PM CST TUESDAY FOR IAZ043-055-056- 069. WIND ADVISORY FROM 6 AM TO 3 PM CST TUESDAY FOR IAZ079-080-090- 091. && $$ ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 208 PM EST MON JAN 28 2008 .SYNOPSIS... HIGH PRESSURE WILL BUILD INTO THE AREA TODAY BRINGING DRY CONDITIONS AND MILD AIR. LOW PRESSURE OVER THE MIDWEST WILL PUSH SLOWLY EAST AND PUSH LIGHT PRECIPITATION INTO THE AREA TUESDAY AND EARLY WEDNESDAY. A COLD FRONT ON WEDNESDAY WILL BRING COLDER AIR BACK INTO REGION. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATED AT 950 AM...SFC HI PRES RDG CNTRD OVER WRN NY WITH XTNSV LOW CLD DECK OVER MUCH OF THE BGM CWA. SOME CLEARING ACRS FAR ERN ZONES BUT CLDS HOLDING TUFF ALONG AND W OF I-81. ACARS DATA FROM ASCENDING BGM FLIGHT THIS MRNG SHOWED NEARLY SATURATED CONDITIONS TO JUST BLO 850 MB (SIMILAR TO 12Z BUF SNDG). WITH RDG AXIS OVERHEAD AND LGT WINDS, THINK CLDS WILL HOLD FIRM OVER THE FINGER LAKES AND CNTRL SRN TIER WELL INTO THE AFTN. CLDS MAY EVEN WORK BACK INTO THE WRN MOHAWK VLY AND CATSKILLS THIS AFTN. HOWEVER, THINK OVERALL TREND WIL BE FOR IMPVNG CONDITIONS AND WILL INDICATE PC SKIES BY MID/LATE AFTN MOST AREAS, AS SUGGESTED BY LATEST RUC PROFILES. PREV BLO... LOPRES SPINS OVER THE WRN ATLANTIC WHILE A SHARP RDG BUILDS OVER THE FCST AREA. AS USUAL...LGT NLY FLOW HAS RESULTED IN AN XTNSV SC CVR OVRNGT EVEN WHILE CI DUMPS OVER THE TOP OF THE RDG. BACK EDGE OF THE SC MAKING STEADY PROGRESS OVER WRN PA. LWR DEW PTS IN THE CNTRL AND ERN ZONES MAY HELP ERODE THE CLDS SO WILL SIMPLY FCST PTLY SUNNY SKIES FOR TODAY AS THE BACK EDGE WORKS EAST AND THE ERN CLDS ERODE IN THE DRY AIR. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... LOPRES IS OVER NW MN 00Z TUE AS THE MODELS CONT THEIR TREND OF TRACKING THE SYSTEM FURTHER WEST. UA LOW CLOSES OFF LTR TUE AS THE SYSTEM GOES NEG. REALL NO FRCG MECHANISM FOR PCPN OVER THE FCST AREA UNTIL THE COLD FNT PUSHES THRU 06Z TO 12Z WED. OPERATIONAL GFS HAS BACKED OFF ON THE EARLY QPF AND IS MORE IN LINE WITH THE NAM FOR ANY PREFNTL PCPN. STILL...BOTH THE GFS AND NAM DOP SOME LGT PCPN OVER THE AREA BEGINNING EARLY TUE...AND IF IT FALLS...TEMPS WILL BE COLD ENUF FOR SOME LGT FRZG PCPN. SO WHILE I BELIEVE THE CHANCE IS SMALL...HAVE ELECTED TO KEEP CHANCE POPS IN THE WEST FOR NOW. SOME LGT PCPN IS PSBL DURING TUE DAYLIGHT HRS BUT ONCE AGAIN THERE IS LTL TO FORCE THE PCPN. WILL STICK WITH CONTNUITY AND KEEP THE LGT PCPN DURING TUE. NEG TILT UA TROF ACCOMPANIES THE COLD FNT EARLY WED AND FINALLY SOME LIFT FOR PCPN. DEEPER...FURTHER WEST LOW HAS DELAYED THE PASSAGE OF THE COLD FNT AND ARRIVAL OF THE COLD AIR SO IN TURN HAS DELAYED THE CHG OVER TO SNOW UNTIL LTR. VERY DRY AIR BHD THE FNT WILL LIMT THE LES ACTIVITY BUT IT DOES LOOK AS THOUGH THE FLOW WILL BE FVRBL FOR SOME LES OVER THE NRN ZONES...ESP LTR WED AS THE COLD AIR BECOMES ESTABLISHED. GOOD GRADIENT AND PRESSURE RISES ON WED WILL RESULT IN VERY WINDY CONDS BHD THE FNT. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... MAIN SYSTEM DURING THE EXTENDED PERIOD WILL BE THE LOW PRESSURE SYSTEM FORECAST TO PULL NORTHEAST OUT OF THE OHIO VALLEY ON FRIDAY, TO THE NEW ENGLAND COAST FRIDAY NIGHT. CURRENT INDICATIONS ARE FOR PRECIP TO START AFTER 06Z FRIDAY FROM SOUTHWEST TO NORTHEAST. ATTM, IT LOOKS LIKE IT WILL START AS SNOW, THEN MIX DURING FRIDAY MORNING, WITH A PERIOD OF MAINLY RAIN FOR MUCH OF THE FORECAST AREA DURING THE DAY FRIDAY. MIXED PRECIP MAY WELL HOLD ON FOR MOST OF THE EVENT ACROSS NORTHEAST SECTIONS OF THE AREA, WHERE COLD AIR REMAINS ENTRENCHED. AS THE SYSTEM PULLS EAST LATER IN THE DAY, A CHANGE OVER TO SNOW OR SNOW SHOWERS IS EXPECTED FRIDAY EVENING. SOME LINGERING SHSN ACROSS LAKE EFFECT AREAS OVER THE WEEKEND, BUT OTHERWISE QUIET AS SURFACE HIGH PRESSURE EXTENDS ALONG THE ATLANTIC SEABOARD. && .AVIATION /19Z MONDAY THROUGH SATURDAY/... STRATOCU DECK HAS BEEN SLOW TO ERODE THRU THE MORNING, WITH ONLY KRME MAKING IT OUT OF THE CLDS THUS FAR. THESE MVFR CEILINGS WILL CONTINUE THIS AFTN, WITH NAM 925 MOISTURE SHOWING MOST AREAS LOSING THE CLD COVER BETWEEN 21Z AND 23Z. AFTER THAT...VFR THRU THE NIGHT WITH WINDS BECOMING LGT SE. CLDS WILL LOWER AND THICKEN TUESDAY MRNING WITH THE APPROACH OF A WARM FRONT...TO PERHAPS MVFR WITH CHC FOR SHRA BY ABT 15Z. OUTLOOK...MVFR RESTRICTIONS LIKELY FROM TUES INTO TUES NGT WITH CDFNT. GUSTY WINDS WILL PRECEDE AND FOLLOW THIS FNT. RAPID CLEARING WITH VFR BY WED AFTN...PERSISTING THRU THURSDAY. SRN STREAM SYSTEM APRCHS THU NGT WITH MVFR/IFR CONDITIONS INTO FRIDAY. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DGM NEAR TERM... SHORT TERM...DGM LONG TERM...JML AVIATION...DJP/JML ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BINGHAMTON NY 1002 AM EST SUN JAN 27 2008 .SYNOPSIS... HIGH PRESSURE OVER THE MIDWEST WILL GRADUALLY BUILD INTO THE AREA THIS AFTERNOON, AND CONTROL OUR WEATHER INTO THE FIRST PART OF THE WORK WEEK, BRINGING DRY WEATHER TO THE REGION. && .NEAR TERM /TODAY/... FLURRY/SNOW SHOWER ACTIVITY GRADUALLY DECREASING AS WE START TO LOSE MOISTURE FROM ALOFT AS SUBSIDENCE SURROUNDING LOW PRESSURE DEEPENING OFF THE EAST COAST DEVELOPS OVERHEAD. HAVE SEEN CLOUDS BREAK IN EASTERN ZONES...WITH MORE PERSISTENT CLOUDINESS FURTHER WEST. THIS IS SHOWN PRETTY WELL WITH SHORT TERM RUC GUIDANCE...BOTH THE LLEVEL RH PROGS AS WELL AS LLEVEL ISENTROPIC DESCENT. BELIEVE WE/LL SEE THE MOST SUN THIS AFTERNOON OVER EASTERN ZONES...BUT EVERYWHERE COULD SEE A FEW BREAKS. FLURRIES SHOULD END EARLY THIS AFTERNOON WITH THE LOSS OF UPPER SUPPORT/MOISTURE. TEMPS LOOK ON TRACK. UPDATED ZONES/GRIDS ARE ON THE STREET. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... ENTERING A QUIET WX PD AS HGTS BLD. SHRP RDG DVLPS OVER THE AREA AS THE CSTL LOW DEEPENS EAST OF NJ AND BECOMES SEPARATED FROM THE WLYS. NARROW RDG HOLDS INTO TUE BEFORE HGTS BEGIN TO FALL IN ADVANCE OF THE LRG UA LOW OVER THE MIDWEST. OPERATIONAL NAM/GFS DIFFER WITH THE APRCHG SYSTEM IN THAT THE NAM GENERATES LTL PCPN AHD OF THE COLD FNT. BELIEVE THE DRIER NAM MAKES SENSE GIVEN THE LACK OF ANY REAL UPPER SUPPORT OR LIFT FOR PCPN OUTSIDE OF THE FNTL BNDRY. BEST UPPER DYNAMICS ARE WELL BACK WITH THE CLSD LOW OVER NRN MN. HAVE GONE WITH HIGH CHANCE POPS AND LGT QPF FOR THE SYSTEM. TEMPS WILL RISE ABV NRML WITH THE RDG AND WAA AND ANY PCPN THAT FALLS TUE WILL BE LIQUID. DELAY IN START OF PCPN UNTIL AFTER DAYLIGHT WILL LESSEN THE CHANCE FOR ANY FRZG RAIN. AFTER THE COLD FNT PASSES TUE NGT...SOME LGT SNOW SHWRS PSBL LATE IN THE CAA. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... EXTNDD PORTION OF FCST BEGINS WITH DEPARTING CDFNT WED MRNG. LAKE EFFECT SNOW WILL BE POSSIBLE OVR FAR NRN AREAS ON WED AS H8 TEMPS DROP TO ARND -16C AND WINDS PICK UP OUT OF THE WEST. BRIEF RIDGING WILL BRING AN END TO THE SNOW SHOWERS FOR THURSDAY BEFORE THE NEXT SYSTEM MVS THRU THE PLAINS AND INDUCES A SFC LOW OVR LOWER MS VALLEY ON THUR. THIS LOW FCST TO RIDE NORTHEAST AND SPREAD PCPN ACROSS CWA ON FRIDAY. EXACT PATH OF THIS SYSTEM IS STILL IN QUESTION...ALTHO MODELS CONTINUE TO COME IN WARMER AND FURTHER WEST WITH SOLN. MOST GFS ENSEMBLE MEMBERS BRING LOW TO OUR WEST WITH A FEW TRACKING IT RIGHT OVRHD. 00Z ECMWF IS MUCH STRONGER WITH H5 SYSTEM IN THE PLAINS EJECTING TOWARD THE NE WITH A CLOSED LOW DEVELOPING. THUS IT IS SLOWER AND FURTHER WEST WITH THE SFC LOW AND IS LEADING TO A WRMR SOLN. CONFIDENCE IS NOT HIGH ON THERMAL FIELDS EXPECTED WITH THIS SYSTEM ALTHO SIGNS ARE STARTING TO POINT TO MORE OF A LIQUID PCPN EVENT. GFS BUFKIT PROFILES INDICATE A SNOW/SLEET MIX POSSIBLE EARLY IN THE DAY FRIDAY...THEN MIXING WITH OR CHANGING OVR TO RAIN DRG THE AFTN. POTENT CDFNT IS THEN PROGGED TO MV THRU FRI NIGHT AND SWITCH PCPN BACK OVR TO SNOW. WITH POSSIBLY COLD AIR BEING LOCKED UP ACROSS THE EAST AS HIGH SITS OVR ERN CANADA...MAY SEE SOME FRZG RAIN WITH THIS SYSTEM AS WELL. HAVE OPTED TO LV OUT THIS SCENARIO FOR THE MOMENT AS THREE PTYPES ARE PLENTY THIS FAR IN ADVANCE. DEPARTING SYSTEM RESULTS IN ANOTHER ROUND OF LAKE EFFECT FOR THE WEEKEND ACROSS THE NORTH. TRENDED MOSTLY TOWARD GMOS GUIDANCE FOR THE PD WITH MINOR TWEAKS TO THE POPS FOR TYPICAL LAKE EFFECT ISSUES AND ALSO TO SHOW GRADUAL INCREASE IN POPS FROM SOUTH TO NORTH FOR LATE THUR NIGHT. ONLY OTHER CHG TO PVS FCST WAS TO RAISE TEMPS APPROX 2-4 DEGREES FROM WHAT WAS BEING ADVERTISED. THIS IS A FEW DEGREES BLO WHAT 00Z GMOS NUMBERS SHOW. BASICALLY WENT WITH A BLEND OF PVS FCST TEMPS AND LATEST GMOS GUIDANCE. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... OCNL MVFR CIGS EXPECTED THRU MOST OF THE MRNG HRS WITH CLD BASES ARND 2500FT AT ALL TERMINALS EXCEPT ELM/AVP WHERE CONDS WILL RMN VFR. CUD SEE BRIEF PD OF MVFR VSBYS AT ELM BUT RETURNING CLD CVR WILL ALLOW FOR IMPRVG CONDS BY ARND 13Z. PASSING UPPER LEVEL DISTURBANCE WILL BE RESPONSIBLE FOR LOWER CEILINGS THRU ABOUT 16Z THIS MRNG...BEFORE DRIER AIR LEADS TO BETTER MIXING AND CLDS BCMG MORE SCATTERED THRU THE AFTN. EXPECT VFR FROM ARND 16Z-03Z MONDAY. EAST COAST LOW WILL MOVE EAST AWAY FROM SHORE...BUT NW WINDS BEHIND IT WILL DRAW MOISTURE FROM LK ONTARIO AND LEAD TO BKN CIGS OVRNGT WITH BASES NR 4KFT. SE WINDS FROM 5-10KTS BCM VRB FOR A TIME THIS AFTN BEFORE TURNING TO THE NORTH THIS EVNG. FOR THE SUNDAY NIGHT THROUGH THURSDAY TIMEFRAME...VFR CONDITIONS EXPECTED LATE SUNDAY NIGHT THROUGH MONDAY NIGHT. ON TUESDAY SOME RAIN SHOWERS ARE POSSIBLE...WITH A CHANCE FOR MVFR RESTRICTIONS. BY WEDNESDAY MRNG A POTENT COLD FRONT SWINGS THROUGH WITH MVFR/IFR RESTRICTIONS LIKELY IN RAIN SHOWERS...QUICKLY CHANGING TO SNOW SHOWERS AFTER FRONTAL PASSAGE. BEHIND THIS FRONT...IMPROVEMENT TO VFR LOOKS PROBABLE FOR WEDNESDAY AFTERNOON THROUGH THURSDAY EXCEPT PERHAPS AT KRME WHERE SOME LES IS POSSIBLE WITH MVFR RESTRICTIONS. VFR RETURNS TO ALL TERMINALS BY THURSDAY AFTN. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...NONE. NY...NONE. && $$ SYNOPSIS...DGM NEAR TERM...JMA SHORT TERM...DGM LONG TERM...PVB AVIATION...PVB ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 310 AM EST SUN JAN 27 2008 .SYNOPSIS... LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL MOVE NORTHEAST AWAY FROM THE COAST THROUGH EARLY SUNDAY... WHILE AN UPPER LEVEL DISTURBANCE PASSES QUICKLY OVER THE MIDATLANTIC REGION. HIGH PRESSURE WILL BUILD OVER THE REGION FROM THE SOUTHWEST SUNDAY... AND REMAIN OVER THE AREA INTO TUESDAY. A COLD FRONT IS EXPECTED TO PUSH THROUGH THE AREA TUESDAY NIGHT. && .NEAR TERM /TODAY THROUGH TONIGHT/... AS OF 215 AM SUNDAY... LOOKS LIKE QUIET WEATHER FOR THE NEXT 24 HRS. THE STREAK OF MID CLOUDS ACROSS THE NORTHEAST CWA ASSOCIATED WITH THE SHORTWAVE TROUGH AXIS SWINGING THROUGH WILL BE EXITING THE AREA BY MORNING. CURRENT RUC BOUNDARY LAYER STREAMLINES INDICATE SOME OF THE STRATOCUMULUS OVER N AND CNTRL VA COULD WORK SE INTO THE NORTHEAST CWA THIS MORNING... BUT EVEN SO THESE CLOUDS SHOULD QUICKLY MIX OUT WITH DEEP NW DOWNSLOPE FLOW COMMENCING AS THE SHORTWAVE TROUGH SHIFTS OFFSHORE. THERE MAY BE ENOUGH MOISTURE JUST BENEATH THE SUBSIDENCE INVERSION ALOFT FOR A FEW FLAT CUMULUS THIS AFTERNOON... OTHERWISE PLENTY OF SUNSHINE IS EXPECTED WITH MUCH OF THE CLOUDINESS WITH THE NEXT WEAK VORTICITY MAX NOW OVER THE OH VALLEY HOLDING WEST OF THE MOUNTAINS. OUR LOCAL HIGH TEMP TECHNIQUE USING A NEARLY DRY ADIABATIC LOW LEVEL TEMPERATURE PROFILE GIVES HIGHS OF 48-56... REASONABLE GIVEN THE SLIGHTLY BELOW NORMAL LOW LEVEL THICKNESSES ADJUSTED FOR CONSIDERABLE SUNSHINE. THE SHORTWAVE TROUGH CLOSES OFF JUST EAST OF THE DELMARVA PENINSULA LATE TODAY THROUGH THIS EVENING AS THE SURFACE LOW CONTINUES TO DEEPEN EAST OF NJ. MODEL-DEPICTED NORTHWESTERLY SURFACE WINDS REMAIN GENERALLY BELOW 10 KTS BUT WITH THE LOWER TROPOSPHERIC COLD AIR ADVECTION AUGMENTED BY THE ISALLOBARIC WIND WITH THE DEEPENING LOW... THESE WINDS MAY EXCEED 10 KTS TODAY WITH SPORADIC GUSTS ESPECIALLY IN NORTHEAST NC. THEN TONIGHT... STACKED RIDGING BUILDS INTO NC FROM THE WEST... AND UPSTREAM CONDITIONS ALONG WITH MODEL SOUNDINGS SUGGEST A SUBSIDING COLUMN AND CLEAR SKIES WITH LIGHT TO CALM WINDS. HAVE GONE A BIT BELOW MOS GUIDANCE FOR LOWS... 23-28. -GIH && .SHORT TERM /MONDAY THROUGH WEDNESDAY/... AS OF 230 AM SUNDAY... THE SURFACE RIDGE AXIS SHIFTS OVERHEAD DURING MONDDAY WITH THE RATHER HIGH-AMPLITUDE MID LEVEL RIDGE AXIS LAGGING JUST SLIGHTLY BEHIND. WITH DRY AND SINKING AIR PERSISTING... THERE SHOULD BE FEW IF ANY CLOUDS. THE LOW LEVEL THICKNESS TROUGH DROPS THROUGH NE NC DURING THE DAY BUT THEY BEGIN TO REBOUND QUICKLY FROM THE WEST IN THE AFTERNOON. WILL GO WITH HIGHS MONDAY OF 50 NE TO 57 SW. AS THE MID LEVEL RIDGE AXIS SHIFTS OVERHEAD AND TO OUR EAST MONDAY NIGHT... TRAJECTORIES INDICATE THAT THE HIGH CLOUDS NOW PUSHING INTO THE SOUTHWEST STATES/W TX/NRN MEXICO WILL STREAM INTO THE CAROLINAS. WITH THE FORECAST THERMAL AND WIND PROFILE FAVORABLE FOR OROGRAPHIC ENHANCEMENT OF THIS CLOUDINESS... EXPECT THESE CLOUDS TO THICKEN AND LOWER MONDAY NIGHT INTO TUESDAY MORNING. HAVE RAISED LOWS SLIGHTLY TO 29-34. -GIH TWO EASTPAC VORTICES... ONE NOW NEAR JUNEAU AK AND THE OTHER WEST OF CENTRAL CA... ARE EXPECTED TO PHASE WITH THE RESULTANT LONGWAVE FULL-LATITUDE TROUGH HEADING THROUGH THE ROCKIES INTO THE PLAINS BY TUESDAY. THE ASSOCIATED FAST-MOVING SURFACE FRONT WILL ORGANIZE AND APPROACH WRN NC LATE TUESDAY. THE GFS HAS BEEN TRENDING TOWARD THE ECMWF`S SLOWER SOLUTION WITH THE FRONTAL PRECIP... AND THEY ARE NOW IN GOOD AGREEMENT ON TIMING. VERY LITTLE IF ANY RAIN IS EXPECTED PRIOR TO SUNDOWN TUESDAY... AND WILL STICK WITH ISOLATED POPS LATE TUESDAY AFTERNOON IN THE NW ONLY AS THE 40-50 KT SOUTHWESTERLY LOW LEVEL JET NOSES IN. DESPITE THE MOSTLY BROKEN SKY COVER ESPECIALLY IN THE NORTHWEST THROUGH THE DAY... WITH THE STRONG LOW LEVEL WARM AIR ADVECTION AND 925 MB TEMPS LIKELY TO EXCEED 9-10C... WILL GO WITH HIGHS OF 58 NW TO 65 SE. AS TO BE EXPECTED WITH THIS SORT OF RAPID STEERING FLOW... THE SURFACE FRONT MOVES QUICKLY... REACHING THE COAST BY WEDNESDAY MORNING. WHILE GOOD COVERAGE OF SHOWERS IS EXPECTED TUESDAY NIGHT... AMOUNTS ARE THE BIG QUESTION. MUCH OF THE DYNAMIC FORCING APPEARS LIKELY TO HOLD TO OUR NW AS THE TAIL END OF THE POSITIVELY TILTING MID LEVEL TROUGH AXIS JUST GLANCES NW NC... AND THE INCOMING 130+ KT UPPER JET IS NOT IN A FAVORABLE ORIENTATION TO PROVIDE CONCENTRATED LIFT OVER NC. ISENTROPIC UPGLIDE EXISTS ONLY IN A BRIEF WINDOW... AND MUCH OF THE MARGINAL INSTABILITY WILL BE OVER THE DEEP SOUTH. WILL CARRY 40-50% POPS BUT EXPECT AMOUNTS TO BE LESS THAN TWO TENTHS OF AN INCH IN GENERAL. EXPECT MILD LOWS OF 38-45. DEEP DRY AIR MOVES IN BEHIND THE FRONT WEDNESDAY WITH HIGH PRESSURE BUILDING IN AT THE SURFACE. THICKNESSES DROP BACK TO NEAR NORMAL WEST TO EAST... AND WILL HAVE HIGHS OF 50-58. -GIH && .LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/... AS OF 230 AM SUNDAY... HIGH PRESSURE CONTINUES TO BUILDS IN FROM THE WEST LATE WEDNESDAY INTO EARLY THURSDAY... AND MOSTLY CLEAR SKIES ARE EXPECTED. LOW LEVEL THICKNESSES ARE NEAR TO JUST BELOW NORMAL AND THESE CORRESPOND TO HIGHS OF 46-53... AFTER LOWS OF 27-34. THE NEXT LONGWAVE TROUGH AMPLIFIES OVER THE CENTRAL U.S. THURSDAY. THE SURFACE RIDGE AXIS SHIFTS TO OUR NE THURSDAY AFTERNOON AND THE RESULTING RETURN FLOW AROUND THE SURFACE HIGH WILL PUSH THE FRONT BACK NORTH AS A WARM FRONT. OVERRUNNING 850-700 MB FLOW SHOULD BRING IN A QUICK INCREASE IN CLOUDS THURSDAY AFTERNOON WITH ENOUGH PRECIP COVERAGE FOR MID RANGE CHANCE POPS THURSDAY NIGHT. LAYER THICKNESSES CONTINUE TO SUPPORT AN ALL LIQUID EVENT... DESPITE THE AGREEMENT AMONG THE MODELS ON A LIKELY MILLER TYPE-B CYCLOGENESIS PATTERN DEVELOPING. WE SHOULD SEE A LULL BETWEEN THIS WARM FRONTAL PRECIP AND RAIN WITH THE COLD FRONT LATE FRIDAY THROUGH FRIDAY NIGHT. MODEL DISAGREEMENT CROPS UP WITH THE ECMWF CLOSING OFF A VORTEX OVER THE SOUTHERN PLAINS WHEREAS THE GFS KEEPS IT A PROGRESSIVE OPEN TROUGH... A SOLUTION THE GFS HAS BEEN CONSISTENT WITH. EITHER WAY THE TROUGH AGAIN HITS THE RIDGE OVER THE ATLANTIC AND DAMPENS OUT AS IT TRACKS TO OUR NORTHWEST. THERE SHOULD BE ENOUGH PUSH HOWEVER TO GET THE COLD FRONT THROUGH NC BY SATURDAY MORNING AND WILL DROP POPS OFF THEN. ONLY MINOR ADJUSTMENTS TO CURRENT POPS ARE NEEDED... MAINLY TO SHOW RELATIVE MAXIMA IN PROBABILITY THURSDAY NIGHT AND AGAIN LATE FRIDAY/FRIDAY NIGHT. CURRENT TEMPS THROUGH THE PERIOD LOOK GOOD BUT WILL RAISE HIGHS SLIGHTLY SATURDAY AS THICKNESSES ARE PROJECTED TO REMAIN ABOVE NORMAL. -GIH && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... AS OF 200 AM SUNDAY... VFR CONDITIONS ACROSS CENTRAL NORTH CAROLINA THROUGH MIDNIGHT TUESDAY. AN UPPER LEVEL TROUGH WILL MOVE NORTHEAST OF THE AREA THIS MORNING... RETURNING CLEAR SKIES TO THE AREA. THE TROUGH WILL DEEPEN OFF THE COAST DURING THE DAY... PRODUCING A BRISK NORTHERLY FLOW AT 10 TO 15 KNOTS. WINDS WILL DIMINISH TO 5 TO 10 KNOTS BY THE LATE AFTERNOON. BUFR SOUNDING DATA INDICATES THERE COULD BE A PERIOD OF SCATTERED TO BROKEN CLOUDS AT 3500 TO 5000 FEET FROM 18Z TO 00Z MONDAY. AS A COLD FRONT APPROACHES THE AREA FROM THE WEST TUESDAY NIGHT AND EARLY WEDNESDAY... CONDITIONS COULD LOWER TO MVFR WITH INCREASING MOISTURE DUE TO THE SOUTHERLY FLOW. THERE WILL ALSO BE A CHANCE FOR SCATTERED SHOWERS THROUGH MID DAY WEDNESDAY. WEAK HIGH PRESSURE WILL BUILD OVER THE AREA WEDNESDAY. HIGH PRESSURE MOVING NORTHEAST THURSDAY AND A DEVELOPING SYSTEM OVER THE SOUTH CENTRAL U.S. WILL COME TOGETHER TO GIVE US A CHANCE OF PRECIPITATION LATE IN THE DAY. -RHJ && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...HARTFIELD LONG TERM...HARTFIELD AVIATION...RHJ nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 940 PM CST MON JAN 28 2008 .DISCUSSION... WATER VAPOR LOOP SHOWS UPPER LEVEL TROUGH EXTENDED FROM WESTERN MT TO SOUTHERN NV MOVING EAST ABOUT 25 KNOTS. WATER VAPOR LOOP ALSO INDICATED A SHORT WAVE OVER WESTERN IA MOVING NORTHEAST. RAIN WAS OCCURRING OVER EASTERN MN WITH THIS FEATURE. SURFACE LOW PRESSURE NEAR INL AND IS FORECAST TO MODESTLY DEEPEN AND MOVE NEAR LS BY MORNING. HIGH PRESSURE OVER SOUTHERN BC WILL ALSO INTENSIFY A BIT AND MOVE ALONG THE BC/AB BORDER BY MORNING. GOOD PRESSURE GRADIENT WILL OCCUR ACROSS THE AREA OVERNIGHT. MODEL SOUNDINGS AND AN EAST WEST CROSS SECTION INDICATES A NEARLY ADIABATIC LOW LEVEL LAYER FOR TONIGHT AND SHOULD MAKE FOR GOOD MIXING AND MAINTAINING WINDY CONDITIONS. RADAR INDICATED LIGHT SNOW OVER MUCH OF EASTERN ND MOVING EAST ABOUT 15 KNOTS. SNOW WAS OCCURRING ALONG A COLD FRONT ALOFT. WINDS HAVE INCREASED ACROSS EASTERN ND WITH GUSTS TO 40 KNOTS AT DVL. EXPECT NORTHWEST WINDS TO INCREASE WITH ACROSS THE REST OF THE FORECAST AREA TONIGHT AS PRECIPITATION BAND SWEEPS ACROSS THE AREA. MESOSCALE ANALYSIS SHOWS SURFACE LOWEST MIXING RATIOS WERE MOVING INTO THE WESTERN DAKOTAS. PRESSURE RISE CENTER OVER MT WAS MOVING SOUTHEAST INTO CENTRAL SD. RUC AND NAM HANDLED WITH THE PRESSURE RISES BEST. TAMDAR SOUNDINGS INDICATE NAM WAS A LITTLE COLDER AND WAS BETTER WITH LOW LEVEL TEMP FIELD THAN THE RUC OR THE GFS. WILL USE THE RUC AND NAM FOR TONIGHT. GOING ADVISORIES AND WARNINGS LOOK GOOD. WILL UPDATE ZONES. && .PREVIOUS DISCUSSION.../ISSUED 245 PM CST MON JAN 28 2008/ MAIN FORECAST CHALLENGE IS WHAT TO TRANSITION TO WITH OUR WINTER STORM WATCH HEADLINE. MODELS HAVE BEEN PRETTY CONSISTENT WITH THIS SYSTEM...TRENDING DRIER BUT STILL WITH PLENTY OF COLD/WIND. WILL STICK PRETTY CLOSE TO THE GFS TODAY...ALTHOUGH WILL TREND BACK FROM THE 12Z GFS RUNS HIGHER QPF AMOUNTS. TONIGHT/TUE...SFC LOW AT 20Z IS SOMEWHERE BETWEEN KJMS AND KABR. KFAR/KJMS HAVE SWITCHED FROM SOUTH WINDS TO A NORTHERLY COMPONENT. COLD PUSH AND STRONGER WINDS ARE NOW INTO THE WESTERN HALF OF ND AND WILL PUSH INTO THE FA TONIGHT. BATCH OF MOSTLY MID LEVEL ECHOES ARE NOW MOVING INTO THE SOUTHERN HALF OF MN...AND THERE HAVE BEEN SOME SPRINKLES OR VERY LIGHT RAIN WITH THIS. THIS WILL NOT AFFECT OUR SOUTHEAST FA AT ALL...SO WILL NOT HAVE TO WORRY ABOUT ANY FREEZING OR LIQUID PCPN FOR THIS EVENT. THERE IS ANOTHER BATCH OF ECHOES ON RADAR IN WESTERN ND...AND THIS SHOULD CONTINUE TO PUSH EAST AND GIVE A LITTLE LIGHT SNOW TO OUR FA. AS FAR AS HOW TO TRANSITION FROM OUR CURRENT WINTER STORM WATCH...HAVE ELECTED TO GO WITH A WINTER WEATHER ADVISORY AT FIRST. WILL HAVE THE COMBINATION OF SOME LIGHT SNOW/BLOWING SNOW AND FALLING TEMPS... LEADING TO SOME WIND CHILL ISSUES. ALL THESE PARAMETERS SHOULD STAY IN ADVISORY CRITERIA FOR MOST OF THE NIGHT. THERE COULD BE SOME LOWER VSBYS INITIALLY...BUT AM NOT EXPECTING A DURATION OF VSBYS LESS THAN A QUARTER MILE. AS THE COLDER AIR WORKS INTO THE KDVL REGION TOWARD MORNING...WIND CHILL VALUES START TO GET INTO WIND CHILL WARNING CRITERIA. THEREFORE WILL ISSUE A DOUBLE HEADLINE PRODUCT AND TRANSITION FROM THE WINTER WEATHER ADVISORY TO A WIND CHILL WARNING FOR PORTIONS OF THE FA TOWARD MORNING. WILL KEEP ALL HEADLINES VALID UNTIL 00Z WED. TUE NIGHT...THERE COULD BE A PERIOD OF TIME YET INTO TUE NIGHT WHERE WIND CHILL HEADLINES WILL STILL BE NEEDED. WILL HOLD OFF ON EXTENDING THE PLANNED HEADLINES FOR NOW TO KEEP THINGS FROM GETTING TOO CONFUSING. WILL LEAVE THIS FOR LATER SHIFTS. WED/THU...HIGH PRESSURE WILL AFFECT THE FA FOR A PORTION OF WED... BUT THIS WILL SHIFT OFF TO THE EAST ON THU. FORECAST CHALLENGE WILL TRANSITION TO MAINLY TEMPS...AND THESE GREATLY AFFECTED BY CLOUD TRENDS. .LONG TERM [FRI-MON]... DECENT AGREEMENT AMONG GFS/CANADIAN/ECMWF MODELS WITH POSITION/SPEED OF SFC LOW MOVING ACROSS SRN CANADA LATE THU NIGHT INTO EARLY SAT MORNING. BIGGEST CHALLENGE I SEE AS SYSTEM APPROACHES IS TEMPS THU NIGHT AND FRI. WITH SOUTHERLY FLOW SETTING UP BY 00Z FRIDAY...I INCREASED MIN TEMPS FOR THU NIGHT. MODELS CONSISTENT IN SHOWING A BAND OF CLOUDS ACROSS SRN CANADA AND JUST INTO OUR NORTHERN ZONES. WITH H850 TEMPS PROGGED TO BE AROUND 20 F IN THE NORTHEAST...COUPLED WITH FAIRLY DECENT SOUTHERLY FLOW...SHOULD HAVE ENOUGH MIXING TO KEEP US FROM DROPPING MUCH BELOW NEG 10 F...PROBABLY WARMER. MEX GUIDANCE KEEPS MOST OF FA IN SINGLE DIGITS ABOVE ZERO. THUS STILL WELL BELOW GUIDANCE...BUT ABOUT 5 DEG WARMER THAN PREVIOUS GRIDS SHOWED AND WARMER THAN MOST SURROUNDING OFFICES. INTRODUCED A SLIGHT CHANCE OF LIGHT SNOW BEHIND THE SYSTEM FROM NOON FRIDAY TO MIDNIGHT SATURDAY. && .AVIATION... MOSTLY MVFR CIGS HAVE BEEN ACROSS NORTHEAST ND THIS EVENING. EXPECT CIGS AND VISIBILITIES TO BECOME IFR FOR A COUPLE HOURS AT GFK AND FAR AS WINDS INCREASE AND BAND OF PRECIPITATION MOVES THROUGH THE RED RIVER VALLEY. CIGS MAY RISE TO VFR/MVFR EARLY TUE MORNING THEN FALL BACK INTO MVFR CONDITIONS FOR LATER TONIGHT AND TUE. EXPECT SIMILAR CONDITIONS AT BJI BUT A COUPLE HOURS BEHIND GFK AND FAR. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR NDZ008- 016-027-029-030-039-049-052-053. WIND CHILL WARNING FROM 6 AM TO 6 PM CST TUESDAY FOR NDZ008-016- 027-029-030-039-049-052-053. WINTER WEATHER ADVISORY UNTIL 3 AM CST TUESDAY FOR NDZ006-007- 014-015-024-026-028-038-054. WIND CHILL WARNING FROM 3 AM TO 6 PM CST TUESDAY FOR NDZ006-007- 014-015-024-026-028-038-054. MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST TUESDAY FOR MNZ001>004- 007-029. WIND CHILL WARNING FROM 6 AM TO 6 PM CST TUESDAY FOR MNZ001>004- 007-029. WINTER WEATHER ADVISORY UNTIL 6 PM CST TUESDAY FOR MNZ005-008- 013>015-022-027-030-031-040. WINTER WEATHER ADVISORY FROM 3 AM TO 6 PM CST TUESDAY FOR MNZ006- 009-016-017-023-024-028-032. && $$ HOPPES nd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 723 AM CST MON JAN 28 2008 .UPDATE...BOUNDARY NOW SITTING ACROSS THE NW FA. THIS A BIT FURTHER SOUTH THAN MODELS HAD BEEN SHOWING. 09Z RUC13 KEEPS THIS BOUNDARY STATIONARY THROUGH THE DAY...MAYBE PUSHES IT A BIT FURTHER SOUTH. WILL LOWER TEMPS ACROSS THE LANGDON...CANDO AREA FOR TODAY AS A RESULT. PROBABLY NOT MUCH ADDITIONAL RISE CONSIDERING CURRENT FOG THAT HAS FORMED WITH THIS COOLER AIRMASS. WILL ADD AREAS FOG THROUGH MID-MORNING ACROSS THIS AREA. && .AVIATION...VFR CONDITIONS EXPECTED THROUGH THE DAY. MAIN AVIATION CONCERN WILL BE THE PASSAGE OF A COLD FRONT TONIGHT. STRONG WINDS...REDUCED VSBY...AND LOWER CIGS WILL BECOME LIKELY. && .PREV DISCUSSION... /ISSUED 404 AM CST MON JAN 28 2008/ DISCUSSION...MAIN CHALLENGE WILL CONTINUE TO BE LOW PRESSURE SYSTEM TO IMPACT THE REGION OVER THE NEXT FEW DAYS. 00Z MODELS REMAIN CONSISTENT AND IN GOOD AGREEMENT. WILL FOLLOW GFS FOR DETAILS...ALTHOUGH GFS/NAM/ECMWF VERY CLOSE. TODAY...MAX TEMPS WILL AGAIN BE ABOVE NORMAL WITH WARM AIR MASS AHEAD OF THE SYSTEM. LOW PRESSURE CURRENTLY CENTERED ACROSS W ND/E MONTANA WITH STRONGEST PRESSURE FALLS ACROSS E ND. MODELS SHOW LOW PRESSURE TROUGH ACROSS CENTRAL ND BY 18Z...AND ACROSS THE VALLEY BY 00Z. STILL A SLIGHT CHANCE FOR SOME LIGHT FZRA...BUT CHANCES LOOK LESS AND LESS EACH MODEL RUN. TONIGHT-TUE...MULTIPLE HAZARDS TO CONSIDER AFTER THIS SYSTEM PASSES THROUGH. FIRST...REDUCED VSBY IN FALLING SNOW. COLD FRONTAL PASSAGE WILL BRING VERY STRONG COLD AIR ADVECTION. THINK THERE IS ENOUGH LOW- MID LEVEL FRONTOGENESIS WITH INITIAL COLD SURGE TO PRODUCE A BRIEF PERIOD OF SNOW. THIS FALLING SNOW SHOULD OCCUR IN CONJUNCTION WITH STRONG WINDS. THIS WOULD PRODUCE A BRIEF PERIOD OF GREATLY REDUCED VSBY. SNOWFALL AMTS LOOKS TO BE LESS THAN AN INCH AS MODELS CONTINUE TO SHOW VERY LITTLE QPF. THUS...BLOWING SNOW PROBABLY WILL NOT BE A PROBLEM. SECOND...HOW STRONG WILL WIND SPEEDS BE? STRONG COLD AIR ADVECTION AND 12MB-15MB/6HR PRESSURE RISE WILL OCCUR IN CONJUNCTION. 900MB- 850MB WIND SPEEDS EXPECTED TO BE 38KTS-43KTS. VERY EFFICIENT MIXING SHOULD MEAN WIND SPEEDS 30-40MPH TONIGHT ALONG AND WEST OF THE VALLEY. EAST OF THE VALLEY...IN THE TREES...WIND SIGNALS ARE WEAKER...SO 20-35MPH SPEEDS LIKELY HERE. THERE IS AN OUTSIDE CHANCE FOR WIND GUSTS TO REACH 50KTS ALONG AND WEST OF THE VALLEY WITH INITIAL COLD AIR ADVECTION AS STRONG MOMENTUM TRANSFER COULD INCREASE WIND SPEEDS. ON TUE...WINDY CONDITIONS WILL REMAIN...BUT 850MB WIND SPEEDS LESS. THIRD...WIND CHILL VALUES. VERY COLD AIRMASS WILL BUILD IN BEHIND THIS SYSTEM. THESE TEMPERATURES COMBINED WITH EXPECTED WIND SPEEDS WILL PRODUCE DANGEROUS WIND CHILL VALUES. CURRENT THINKING IS THAT WIND CHILL WARNING CRITERIA (LESS THAN -40F) WILL BE MET ALONG AND WEST OF THE VALLEY DURING THE DAY ON TUESDAY. WIND CHILL ADVISORY CRITERIA (LESS THAN -25F BUT GREATER THAN -40F) WILL BE MET EAST OF THE VALLEY. WILL KEEP CURRENT WINTER STORM WATCH IN EFFECT FOR AREAS ALONG AND WEST OF THE VALLEY. STILL SOME UNCERTAINTY TO HOW MUCH SNOW WILL FALL...AND HOW INTENSE IT WILL BE. THIS IS THE MAIN REASON FOR KEEPING THE WATCH. FIGURE NEXT SHIFT WILL BE ABLE TO GATHER ANOTHER ROUND OF MODEL RUNS...AND WILL ALSO BE ABLE TO SEE THE INTENSITY OF THE SNOW BAND ACROSS W ND AS IT APPROACHES. IF THIS BAND IS INTENSE ENOUGH...COULD BE A BRIEF PERIOD OF NEAR BLIZZARD CONDITIONS. ALSO...EXTENDED THE WINTER STORM WATCH THROUGH THE DAY ON TUESDAY AS WIND CHILL WARNING CRITERIA COULD BE MET...AND IF ENOUGH SNOW FALLS BLOWING SNOW COULD BE A PROBLEM (ALTHOUGH THIS DOES NOT APPEAR TO BE THE CASE AT THIS TIME). ISSUED WINTER WX ADVISORY FOR AREAS EAST OF THE VALLEY. INITIAL SURGE OF COLD AIR AND SNOWFALL WILL CREATE REDUCED VSBY. HOWEVER...WITH LOWER WIND SPEEDS THINK THERE IS NO CHANCE FOR ANY SORT OF WARNING CRITERIA TO BE MET. WIND CHILL ADVISORY CONDITIONS LIKELY DURING THE DAY AND INTO THE EVENING ON TUESDAY AS WELL...THUS MULTIPLE ADVISORY CONDITIONS LEADS TO WINTER WX ADVISORY. SNOWFALL AND REDUCED VSBY MAY LAST INTO TUE AFTERNOON AS WELL ACROSS THIS AREA. WIND SPEEDS SHOULD REDUCE TO BELOW 10 MPH TUESDAY NIGHT...BUT IF THE SFC RIDGE IS A BIT SLOWER TO BUILD INTO THE REGION...WIND CHILL HEADLINES MAY NEED TO BE EXTEND. CONTINUED COLD THROUGH THE REMAINDER OF THE WEEK...BUT MOSTLY DRY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER STORM WATCH FROM THIS EVENING THROUGH TUESDAY AFTERNOON FOR NDZ008-016-027-029-030-039-049-052-053. WINTER STORM WATCH FROM 6 PM CST THIS EVENING THROUGH TUESDAY AFTERNOON FOR NDZ006-007-014-015-024-026-028-038-054. MN...WINTER STORM WATCH FROM THIS EVENING THROUGH TUESDAY AFTERNOON FOR MNZ001>005-007-008-013>015-022-027-029>031-040. WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 9 PM CST TUESDAY FOR MNZ006-009-016-017-023-024-028-032. && $$ TG nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 1231 PM EST SUN JAN 27 2008 .SYNOPSIS... CLOUDS WILL REMAIN TODAY WITH LINGERING LOW LEVEL MOISTURE. HIGH PRESSURE THEN BUILDS IN MONDAY...WITH MODERATING TEMPERATURES. A COLD FRONT WILL MOVE THROUGH ON TUESDAY...WITH ANOTHER SYSTEM TOWARD THE END OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... LATEST RUC13 AND LCL WRF SHOW THE EXITING S/W TAKING A FEW HRS LONGER TO VACATE THAN INITIALLY THOUGHT. IFR -SHSN HAVE BEEN REPORTED THE PAST FEW HRS AT EKN/W22 AND NOW CKB. WITH THAT IN MIND...CARRIED LKLY POPS THROUGH LATE MRNG THEN TAPER OFF TO SW-- THIS AFTN. CONTD FLURRY MENTION ON THROUGH MDNGT IN THE EKN VCNTY AS ANOTHER UPR AIR IMPULSE PASSES. DO NOT NEED TO ADJ TEMPS FOR TDY SINCE NUMBERS ARE ALREADY BELOW GUID. SNOWFALL REPORTS THIS MRNG MATCH WHAT WAS FCST YDY WITH A SKIFF OF SN /< 1.0/ OVER NRN WV WITH 1-2 INCHES ON THE HIGHEST PEAKS. THE 00Z AND 6Z NAM CONTINUE TO SHOW THAT RIGHT AT THE TOP OF THE CLOUD LAYER THAT COLD ADVECTION CONTINUES THROUGH ABOUT 6Z TONIGHT. THIS WILL HELP TO MAINTAIN THAT CLOUD DECK. AFTER 6Z...BEGIN TO SEE SOME WARM ADVECTION AROUND 925 MB WHICH SHOULD INDICATE WHEN THE CLOUDS WILL BEGIN TO BREAK AND THE CLEAR SHOULD FINALLY MOVING ACROSS THE REGION...ALTHOUGH IT MAY NOT REACH THE MOUNTAINS UNTIL MONDAY MORNING. FOR TONIGHT...HAVE GONE ON THE WARM SIDE...ESPECIALLY IN THE MOUNTAINS AND EASTERN HALF OF THE FORECAST. FURTHER WEST...HAVE STAYED CLOSER TO THE NUMBERS AS THE CLEARING SKY AND LIGHT WIND COULD ALLOW THE TEMPERATURES TO DROP MORE. && .SHORT TERM /MONDAY THROUGH TUESDAY/... A HIGH PRESSURE SYSTEM WILL PROVIDE DRY WEATHER AND A SIGNIFICANT MODERATION IN TEMPERATURES FOR MONDAY. GFS IS A BIT FASTER WITH RETURNING MOISTURE ON TUESDAY...AS COMPARED WITH THE NAM. THIS MAY BE VALID HOWEVER...AS OVER RUNNING TENDS TO RUN FASTER THAN THE MODELS NORMALLY SHOW. POPS WILL INCREASE ON TUESDAY WITH A GOOD COLD FRONT COMING THROUGH TUESDAY NIGHT. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... GFS AND ECMWF HAVE CONVERGED DECENTLY THROUGH THE PERIOD. MODELS SHOWING SOME UPSLOPE SNOW SHOWERS ON WEDNESDAY. NEXT SYSTEM THEN ARRIVES THURSDAY NIGHT AND FRIDAY. BIG WARM AIR SURGE SHOULD KEEP ALL PRECIPITATION AS RAIN. BIGGEST DIFFERENCE IN MODELS IS THE AMOUNT OF COLD AIR BEHIND THE SYSTEM ON SATURDAY. DUE TO THE STRENGTH OF THE SYSTEM ON BOTH MODELS...GFS DEPICTION SEEMS MUCH MORE REALISTIC. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... CLOUDS CONT TO RAPIDLY BREAK WITH NO CIGS BEING REPORTED FM RZT TO CRW TO BKW AND POINTS S. CLDS CONT TO LIFT NE AS HIGH PRESS BUILDS IN FM THE W. CLR OUR PKB AND CKB AROUND 0Z...BUT IT WILL TAKE UNTIL MON MRNG BEFORE EKN GOES VFR. ONCE THE STRATUS AT AN AIRPORT DEPARTS CAVU THE BALANCE OF THE PD. AVIATION OUTLOOK /AFTER 18Z MONDAY/...IFR POSSIBLE TUESDAY NIGHT WITH A COLD FRONT...AND IN THE MOUNTAINS IN SNOW SHOWERS ON WEDNESDAY. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SYNOPSIS...ESS/RPY NEAR TERM...29/ESS SHORT TERM...RPY LONG TERM...RPY AVIATION...29 oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 618 AM EST SUN JAN 27 2008 .SYNOPSIS... HIGH PRESSURE WILL BUILD OVER THE REGION FOR THE EARLY PART OF THE WEEK. A COLD FRONT WILL AFFECT THE AREA TUESDAY...WITH HIGH PRESSURE REBUILDING OVER THE REGION WEDNESDAY. ANOTHER FRONT WILL APPROACH THE AREA FROM THE WEST LATE IN THE WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... NAM AND RUC STILL SHOW SHALLOW MOISTURE MOVING UPSLOPE ALONG NC N MTNS AND SAT LOOPS SHOW MOISTURE ENHANCEMENT ALONG NW FACING ESCARPMENT. WITH INCREASING NW WINDS AT 850MB AND THE SHALLOW MOISTURE...KEPT SLIGHT CHANCE POP FOR SNOW SHOWERS OVER NC N MTNS UNTIL 12Z...THEN CLEARING AS HIGH PRESSURE BUILDS IN FROM THE W TODAY. USED MODEL BLEND FOR HIGHS...RANGING FROM UPPER 50S S TO LOW 50S N...MAINLY 40S MTNS WITH A FEW LOW 50S MTN VALLEYS. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... AS OF 245 AM SUNDAY...WARMER WEATHER WILL PERSIST THROUGH THE SHORT TERM...AS SHORT WAVE RIDGING MOVES ACROSS THE EASTERN CONUS. TEMPS SHOULD BE ABOUT 5 DEGREES ABOVE NORMAL THROUGH THE PERIOD. CLOUDS WILL BEGIN TO INCREASE MON NIGHT IN ADVANCE OF A RATHER VIGOROUS TROUGH ACROSS THE PLAINS. ALTHOUGH THERE ARE DIFFERENCES IN THE DETAILS...THE MODELS ARE IN GENERAL AGREEMENT IN BRINGING DEEP LAYER MOISTURE/PRECIP OVER THE AREA ON TUESDAY. CONFIDENCE IN THIS TIMING IS HIGH ENOUGH TO INTRODUCE LIKELY POPS ACROSS THE MTNS. ALTHOUGH THERE WILL LIKELY BE SUB-FREEZING TEMPS IN THE MTN VALLEYS TUE MORNING...IT APPEARS THAT PRECIP MAY BEGIN LATE ENOUGH TO PRECLUDE ANY P-TYPE CONCERNS AT ONSET. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 315 AM SUNDAY...THE MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT REGARDING THE FEATURES OF THE LONG TERM. BEGINNING TUES NIGHT...A COLD FRONT ASSOCIATED WITH LOW PRESSURE OVER THE GREAT LAKES WILL BE CROSSING THE FA. GFS SHOWS BEST DEEP LAYER MOISTURE AND OMEGA MAKING ITS WAY ACROSS THE WESTERN CAROLINAS IN THE 00-06Z TIME FRAME. WILL CARRY LIKELY POPS ACROSS WESTERN HALF OF FA WITH HIGH CHANCE TO THE EAST. COULD MAKE AN ARGUMENT FOR CAT POPS BUT WILL GO WITH LIKELY FOR NOW. THINGS SHOULD DRY OUT PRETTY QUICKLY AS THE FRONT PUSHES EASTWARD ON WED. HIGH PRESSURE BUILDS IN THROUGH WED NIGHT AS THE SOUTHERN END OF THE OLD FRONT BECOMES STATIONARY ALONG THE GULF COAST. ON THURS...HIGH SETTLES IN ACROSS THE MID ATLANTIC AND SETS UP CAD REGIME ACROSS THE CAROLINAS. AN UPPER TROUGH MOVES INTO THE TEXAS PANHANDLE THURS NIGHT AND THE OLD FRONTAL BOUNDARY BEGINS TO LIFT BACK NORTHWARD AS A WARM FRONT. CARRY SOLID CHC POPS THURS NIGHT INTO FRI MORNING AS GOOD MOISTURE TRANSPORT AND UPGLIDE FLOW ARE IN PLACE. FRI IS WHERE GFS AND ECMWF DIFFER...MAINLY WITH THE UPPER LEVEL PATTERN. THE GFS BRINGS A FAIRLY SHARP AND PROGRESSIVE TROUGH TOWARDS THE FA. ON THE OTHER HAND THE ECMWF CREATES A BOWLING BALL UPPER LOW THAT LIFTS NORTHEASTWARD TOWARD THE GREAT LAKES. LIKELY POPS IN PLACE ON FRI AS BOTH MODELS TRACK A SURFACE LOW NORTHEASTWARD OUT OF THE NORTHERN GULF. OBVIOUSLY THE ECMWF IS THE MORE WRAPPED UP SOLUTION BUT AT ANY RATE BOTH MODELS KEEP THINGS WET ACROSS THE WESTERN CAROLINAS THROUGH FRI NIGHT. ALSO OF NOTE IS THAT BOTH MODELS SCOUR OUT THE WEDGE ON FRI WITH A STRONG LOW LEVEL JET. GFS FAILS TO GENERATE MUCH CAPE ACROSS THE FA BUT THIS WILL REQUIRE FURTHER WATCHING AS THE TIME DRAWS CLOSER. COULD BE AN INTERESTING EVENT WITH SOME PTYPE ISSUES DURING THE ONSET OF PRECIP THURS NIGHT...TRANSITIONING TO MORE OF A WARM SECTOR SCENARIO ON FRIDAY. AS USUAL...PLENTY OF UNKNOWN FACTORS AT THIS POINT. HIGH PRESSURE RETURNS TO THE AREA ON SAT AS SURFACE LOW CONTINUES TO PULL AWAY TO THE NORTHEAST. OVERALL...TEMPS RUN A FEW DEGREES ABOVE NORMAL ESPECIALLY INTO THE WEEKEND. && .AVIATION /11Z SUNDAY THROUGH THURSDAY/... OTHER THAN PATCHY MVFR FOG EARLY THIS MORNING...VFR WITH MCLR SKIES UNDER BUILDING HIGH PRESSURE TODAY. LEE SFC TROUGH EXPECTED IN DOWNSLOPE FLOW THIS AFTN...ALLOWING WINDS TO BACK W TO SW ACROSS THE PIEDMONT AROUND 10KTS. N WINDS 12G20KT AT KAVL MOST OF DAY. AVIATION OUTLOOK...HIGH PRESSURE THROUGH MON. GULF MOISTURE WILL REACH CWA WITH A COLD FRONT TUE BRINGING CIG/VIS RESTRICTIONS... PRECIP AND GUSTY WINDS. AREA DRIES OUT EARLY WED WITH HIGH PRESSURE BUILDING IN FROM THE W. GULF MOISTURE SURGES N OVER AREA AS RIDGE OF HIGH PRESSURE MOVES E OF AREA THU...WITH ANOTHER ROUND OF CIG/VIS RESTRICTIONS AND PRECIP FOR LATE WEEK. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ SYNOPSIS...RB NEAR TERM...RB SHORT TERM...JDL LONG TERM...BSH AVIATION...RB sc AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 835 PM MST SUN JAN 27 2008 .DISCUSSION...STRONG SW WINDS CONTINUE ACRS NERN WY INTO THE BLKHLS THIS EVENING. HIGHEST RECORDED SPEED THUS FAR HAS BEEN 101 MPH NEAR CROW PEAK WEST OF SPEARFISH...WITH MANY OTHER LOCATIONS ABOVE 60 MPH FOR PEAK WINDS. SEE NO RELIEF IN SIGHT FROM THE STRONG WINDS OVERNIGHT...AND WITH 00Z NAM/RUC SUGGESTING 50-55KT BL WINDS ACRS THE BLKHLS INTO THE ERN FOOTHILLS...THESE STRONG WINDS WILL LIKELY BE ABLE TO MAKE IT AT LEAST PART WAY DOWN THE ERN FOOTHILLS TOWARDS THE WRN PORTIONS OF RAPID CITY...ALTHOUGH PROBABLY NOT MUCH FURTHER EAST. THUS...WILL KEEP CURRENT HEADLINES IN PLACE. MIDNIGHT SHIFT WILL NEED TO CLOSELY MONITOR TO SEE IF THE HEADLINES WILL NEED TO BE EXTENDED IN TIME...ESPECIALLY NERN WY INTO THE BLKHLS. AS EXPECTED...TEMPS ARE NOT COOLING MUCH...ESPECIALLY FROM THE HILLS WEST. SOMEWHAT LIGHTER WINDS EAST OF THE HILLS ALLOWING TEMPS TO COOL...ALBEIT SLOWLY. HAVE RAISED OVERNIGHT LOWS A FEW DEGREES IN MOST LOCATIONS BASED ON LATEST TRENDS. ALSO...HAVE RAISED HIGHS SEVERAL DEGREES FOR MONDAY ACRS SWRN AND SCNTRL SD. WITH WARMER EXPECTED OVERNIGHT LOWS...SHOULD NOT TAKE LONG FOR TEMPS TO REBOUND MONDAY MRNG AHEAD OF APPROACHING ARCTIC BOUNDARY (CURRENTLY PUSHING THRU NCNTRL MT). && .AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH MONDAY MORNING. VERY STRONG SOUTHWESTERLY WINDS WILL CONTINUE FROM THE BLACK HILLS AREA WESTWARD THROUGH TONIGHT AND INTO MONDAY MORNING. THIS WILL RESULT IN VERY WINDY CONDITIONS AT GCC. LOOKS LIKE COLD FRONT AND ASSOCIATED WIND SHIFT WILL HOLD OFF UNTIL AFTER 18Z MONDAY FOR GCC AND RAP. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...HIGH WIND WARNING UNTIL 8 AM MST MONDAY FOR NORTHERN BLACK HILLS- NORTHERN FOOT HILLS. HIGH WIND WARNING UNTIL 8 AM MST MONDAY FOR CENTRAL BLACK HILLS- HERMOSA FOOT HILLS-RAPID CITY-SOUTHERN BLACK HILLS- STURGIS/PIEDMONT FOOT HILLS. WY...HIGH WIND WARNING UNTIL 8 AM MST MONDAY FOR NORTHERN CAMPBELL- SOUTHERN CAMPBELL-WESTERN CROOK-WESTON-WYOMING BLACK HILLS. && $$ JOHNSON sd AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 223 PM MST SUN JAN 27 2008 .DISCUSSION...CURRENT SURFACE MAP SHOWS LOW ACROSS SOUTHERN SASKATCHEWAN WITH TROF EXTENDING THROUGH EASTERN MONTANA/EASTERN WYOMING. ARCTIC COLD FRONT POISED TO CROSS THE INTO MONTANA NEXT FEW HOURS. FORECAST CONCERN DEALS WITH HIGH WINDS THROUGH TONIGHT...AND TIMING OF ARCTIC FRONT MONDAY. STRONG SOUTHWEST WINDS OCCURRING ACROSS NORTHEAST WYOMING AND NORTHERN BLACK HILLS/FOOTHILLS THIS AFTERNOON. HIGHEST WIND OF 82 MPH HAS BEEN MEASURED NEAR CROW PEAK WEST OF SPEARFISH. 18Z WRF/RUC POINT TO STRONGER WIND POTENTIAL TONIGHT AS SURFACE LOW MOVES EAST ALONG THE INTERNATIONAL BORDER. WITH BEST PRESSURE FALLS MOVING TO THE NORTHEAST OF THE FORECAST AREA TONIGHT ALONG WITH INCREASING 850-700MB FLOW...HAVE EXPANDED THE HIGH WIND WARNING INTO CENTRAL/SOUTHERN BLACK HILLS ALONG WITH STURGIS/RAPID CITY/HERMOSA FOOTHILLS. NEWCASTLE/STURGIS GRADIENT ALONG WITH 50-65 KNOT BOUNDARY LAYER WINDS SUPPORT LOCALIZED HIGH WINDS. BIGGEST UNKNOWN IS WHERE INVERSION HEIGHT WILL SET UP...THUS THE ELEVATION OF THE STRONGER WINDS. STRONGEST WINDS WILL LIKELY OCCUR JUST WEST OF SPEARFISH...WHERE CROW PEAK AREA MAY SEE A FEW GUSTS APPROACH 90 MPH. TEMPERATURES WILL BE VERY MILD OVERNIGHT...WITH SOME LOCATIONS ALONG THE FOOTHILLS STAYING IN THE 40S. 18Z WRF SIMILAR TO 12Z WRF/GFS IN SLOWING ARCTIC FRONT DOWN. WITH SOUTHWEST FLOW ALOFT...THIS SEEMS REASONABLE. THIS WOULD PUT THE ARCTIC FRONT INTO NORTHEAST WYOMING/NORTHWEST SOUTH DAKOTA BY EARLY AFTERNOON...AND INTO SOUTH CENTRAL SOUTH DAKOTA BY EARLY EVENING. TIMING OF ARCTIC FRONT WILL RESULT IN WIDE RANGE OF TEMPERATURES AS THERE WILL BE A SHARP DROP AS THE FRONT MOVES THROUGH. CURRENT TEMPERATURES BEHIND THE FRONT RANGE FROM 5 BELOW TO 20 BELOW ZERO. WITH STRENGTH OF COLD ADVECTION/PRESSURE RISES BEHIND ARCTIC FRONT...WILL LIKELY HAVE SEVERAL HOURS OF ADVISORY CRITERIA WINDS AFTER FROPA. BAND OF 850-700MB FRONTOGENISIS/MOISTURE FOLLOWS SURFACE FRONT...AND WILL SPREAD SOME LIGHT SNOW ACROSS THE AREA. ACCUMULATIONS WILL BE MINIMAL...EXCEPT IN THE NORTHERN BLACK HILLS WHERE A FEW INCHES OF ACCUMULATION IS POSSIBLE. WINDS/ARCTIC AIR WILL RESULT IN WIND CHILL VALUES OF 20 TO 40 BELOW ZERO MONDAY NIGHT AND TUESDAY MORNING...ESPECIALLY NORTH AND EAST OF THE BLACK HILLS. ARCTIC HIGH STRETCHES ACROSS EASTERN MONTANA INTO WESTERN DAKOTAS ON TUESDAY...WITH VERY COLD TEMPERATURES. WRF/GFS TRY TO KEEP THE ARCTIC BOUNDARY ALONG SOUTHWESTERN BORDER OF FORECAST AREA. BASED ON THE DEPTH OF THE COLD AIR ACROSS WESTERN CANADA...WOULD NOT BE SURPRISED TO SEE COLD AIR PUSH FURTHER SOUTH AND WEST. EXTENDED...AT THIS TIME...IT LOOKS LIKE THE ARCTIC BOUNDARY WILL HANG ACROSS THE AREA WEDNESDAY AND INTO THURSDAY BEFORE SHIFTING NORTH AND EAST OF THE CWA. WEAK UPPER LEVEL ENERGY WILL PASS OVER THE BOUNDARY ON WEDNESDAY AND MAY BE ENOUGH TO SQUEEZE OUT A LITTLE LIGHT SNOW OR FLURRIES ACROSS PARTS OF THE AREA. OTHERWISE...AS BOUNDARY MOVES EAST...TEMPERATURES WILL MODERATE FROM SOUTHWEST TO NORTHEAST DURING THE LATTER PART OF THE WEEK. SOME WEAK ENERGY IN NEAR ZONAL FLOW ALOFT WILL BRING SOME CLOUDINESS FROM TIME TO TIME...BUT CHANCES FOR PCPN STILL LOOK PRETTY LOW...SO WILL KEEP REST OF EXTENDED DRY FOR NOW. && .AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH MONDAY MORNING. VERY STRONG SOUTHWESTERLY WINDS WILL CONTINUE FROM THE BLACK HILLS AREA WESTWARD THROUGH TONIGHT AND INTO MONDAY MORNING. THIS WILL RESULT IN VERY WINDY CONDITIONS AT GCC. LOOKS LIKE COLD FRONT AND ASSOCIATED WIND SHIFT WILL HOLD OFF UNTIL AFTER 18Z MONDAY FOR GCC AND RAP. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...HIGH WIND WARNING UNTIL 8 AM MST MONDAY FOR NORTHERN BLACK HILLS- NORTHERN FOOT HILLS. HIGH WIND WARNING UNTIL 8 AM MST MONDAY FOR CENTRAL BLACK HILLS- HERMOSA FOOT HILLS-RAPID CITY-SOUTHERN BLACK HILLS- STURGIS/PIEDMONT FOOT HILLS. WY...HIGH WIND WARNING UNTIL 8 AM MST MONDAY FOR NORTHERN CAMPBELL- SOUTHERN CAMPBELL-WESTERN CROOK-WESTON-WYOMING BLACK HILLS. && $$ KC/ST sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 340 PM CST MON JAN 28 2008 .SHORT TERM... TODAYS STRONG WINDS SHOULD SUBSIDE AROUND SUNSET MOST AREAS AS SHALLOW DECOUPLING OCCURS. THE LATEST RUC RUN SUGGESTS DECOUPLING MAY BE DELAYED SLIGHTLY ACROSS HIGHER WESTERN ZONES WHICH WILL BE MORE UNDER INFLUENCE OF DRYING AND DOWNWARD FORCING...AND THIS MAY REQUIRE A SLIGHT EXTENSION BY AN HOUR OR TWO OF THE WIND ADVISORY. WILL LEAVE THIS FOR THE EVENING SHIFT TO PONDER. OTHERWISE...STRONG MID AND UPPER LEVEL DRYING TREND EXPECTED OVERNIGHT LEADING TO A BREEZY NIGHT TONIGHT AND A CLEAR AND VERY WIND DAY TUESDAY. PACIFIC FRONTAL BOUNDARY ALSO EXPECTED TO PASS LATER TONIGHT AND MAY CAUSE BRIEF HIGHER WINDS AND GUSTS AS IT PASSES ALTHOUGH NOT CONVINCED WINDS WILL REMAIN UP AFTERWORDS DURING THE REMAINING OVERNIGHT HOURS. BUT ALL INDICATIONS POINT TO RAPID MIXING ON TUESDAY LEADING TO ANOTHER VERY WINDY DAY. WE TRENDED SLIGHTLY WARMER THAN GUIDANCE BECAUSE OF THE LOCAL DOWNSLOPE WARMING EFFECTS. ADDED AREAS OF BLOWING DUST TUESDAY MOST AREAS AS WELL. MCQUEEN .LONG TERM... FOR THE LAST SEVERAL DAYS MODELS HAVE BEEN SHOWING EITHER A CLOSED LOW OR SHARP UPPER TROUGH MOVING ACROSS THE SOUTH PLAINS AND SOUTHERN PANHANDLE THURSDAY. TODAYS 12Z AND 18Z RUNS CONTINUE TO SHOW THE SYSTEM AS A CLOSED LOW CENTERED OVER THE LOCAL AREA 12Z THURSDAY. AS SUCH...WE HAVE INCREASED PRECIP CHANCES SLIGHTLY AND FOLLOWING FORECAST SOUNDINGS CHANGED THE TYPE OF PRECIPITATION TO ALL SNOW. SINCE THE ATMOSPHERE AHEAD OF THE SYSTEM WILL BE VERY DRY AND THE SYSTEM WILL BE MOVING VERY QUICKLY...WE HAVE KEPT AMOUNTS ON THE LIGHT SIDE. FOR NOW...WE HAVE KEPT PRECIP CHANCES IN THE 20 TO 30 PERCENT RANGE. BEYOND THURSDAYS SYSTEM WE CAN EXPECT FAIRLY SEASONABLE WEATHER THROUGH NEXT WEEKEND. MODELS SHOW THE NEXT SYSTEM APPROACHING THE AREA NEXT MONDAY. && .FIRE WEATHER... THIS EVENING...WINDS WILL NOT DECOUPLE UNTIL AROUND SUNSET AND MAY BE SLOW TO DO SO IN SOME PLACES. HOWEVER...WITH THE HIGH DEWPOINTS WE ARE SATISFIED RETAINING THE CURRENT RFW UNTIL 1800 ONLY. CASTRO...PARMER...AND BAILEY COUNTIES OFFER BEST CHANCE OF PERHAPS BRIEFLY REACHING HUMIDITY AND WIND CRITERIA EARLY THIS EVENING. TUESDAY...COOLER AIR FOLLOWING PACIFIC FRONT TOMORROW EARLY...BUT DOWNSLOPE COMPONENT WILL BE VERY DRY AND MAYBE NOT QUITE AS COOL AS GUIDANCE TEMPERATURES. EITHER WAY...TOMORROW LOOKS LIKE WINDS SHOULD EASILY REACH 20 MPH OR GREATER AT THE 20 FOOT LEVEL WITH SURFACE RELATIVE HUMIDITIES BELOW 15 PERCENT FOR THE ROLLING PLAINS...AND THE SOUTHERN AND CENTRAL SOUTH PLAINS. MIXING MAY OCCUR EARLY IN THE DAY BUT THE COOLER TEMPERATURES MAY NOT ALLOW HUMIDITIES TO DROP UNTIL LATER IN THE MORNING. ISSUING A FIRE WEATHER WATCH VALID FROM 1100 UNTIL 1700. MCQUEEN && .PRELIMINARY POINT TEMPS/POPS... FRIONA 34 50 21 57 25 / 0 0 0 0 30 TULIA 36 51 22 57 26 / 0 0 0 0 30 PLAINVIEW 37 51 24 57 27 / 0 0 0 0 30 LEVELLAND 39 53 25 60 27 / 0 0 0 0 20 LUBBOCK 39 53 26 59 30 / 0 0 0 0 20 DENVER CITY 39 54 29 60 30 / 0 0 0 0 10 BROWNFIELD 40 53 27 60 29 / 0 0 0 0 20 CHILDRESS 48 57 25 60 30 / 0 0 0 0 30 SPUR 48 56 25 59 31 / 0 0 0 0 20 ASPERMONT 51 59 28 60 37 / 0 0 0 0 10 && .LUB WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON FOR THE FOLLOWING ZONES: TXZ023>026-029>032-034>044. RED FLAG WARNING UNTIL 6 PM CST THIS AFTERNOON FOR THE FOLLOWING ZONES: TXZ021>024-027>029-033-034-039. WIND ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR THE FOLLOWING ZONES: TXZ021>025-027>031-033>036-039>041. && $$ 05/04 tx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tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 1119 AM CST MON JAN 28 2008 .DISCUSSION...UPDATED THE ZFP SINCE THE FOG DISSIPATED. WILL CONTINUE TO MONITOR THE WINDS FOR A POSSIBLE WIND ADVISORY IN THE NEXT HOUR OR TWO...SEE BELOW. && .PREV DISCUSSION...ISSUED 915 AM CST MON JAN 28 2008...ON THE FENCE OF ISSUING A WIND ADVISORY FOR THIS AFTERNOON. NAM AND RUC40 925 TO 1000MB WINDS RANGING FROM 25 TO 35KTS ACROSS THE EASTERN TWO THIRDS OF THE CWA. VAD WINDS FROM KBRO AND 12Z MORNING SOUNDING ALSO INDICATED 25 TO 30KTS AT SAME LEVELS. NAM AND GFS GUIDANCE INDICATES SFC WINDS JUST BELOW LOCAL WIND ADVISORY CRITERIA...GREATER THAN 30KTS SUSTAINED. LOW TO MID LEVEL CU FIELD AND INCREASING HIGH CLOUDS SHOULD LIMIT INSOLATION TODAY THUS MIXING OF THE STRONGEST WINDS TO THE SURFACE IS NOT EXPECTED. WILL MAINTAIN THE WINDY CONDITIONS IN THE ZONES WITH THE STRONGEST PERIOD LIKLEY FROM 1 TO 6 PM. AS FOR THE PATCHY DENSE FOG IN HIDALGO...STARR...ZAPATA AND JIM HOGG COUNTIES...THE FOG SHOULD BEGIN TO LIFT AROUND 11 AM AS THE WINDS BEGIN TO INCREASE. AVIATION...AFTER EARLY MORNING FOG...BREEZY WINDS WITH MOSTLY CLOUDY SKIES WILL PREVAIL OVER THE TRIO OF REGIONAL AIRPORTS LATER THIS MORNING THROUGH EARLY TUESDAY MORNING. MARINE...BUOY 42020 REPORTED SOUTHEAST WINDS AROUND 17 KNOTS GUSTING TO AROUND 19 KNOTS WITH SEAS SLIGHTLY OVER 4 FEET WITH A PERIOD OF 5 SECONDS AT 08 CST/14 UTC. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE LAGUNA MADRE THROUGH THIS AFTERNOON...AS WINDS OF 20 KNOTS OR GREATER ARE EXPECTED TO DEVELOP THERE. THE SMALL CRAFT ADVISORY MAY NEED TO BE EXTENDED TO THE ADJACENT GULF OF MEXICO WATERS TONIGHT THROUGH TUESDAY MORNING DUE TO INCREASING WINDS AND SEAS IN ADVANCE OF A COLD FRONT...WHICH WILL PASS THROUGH THE LOWER TEXAS COAST TUESDAY AFTERNOON. SMALL CRAFT ADVISORY WINDS AND SEAS ARE ANTICIPATED TUESDAY AFTERNOON THROUGH THURSDAY MORNING IN THE WAKE OF THE FRONT...WITH ANOTHER COLD FRONTAL PASSAGE THURSDAY AFTERNOON CONTINUING THE ADVERSE MARINE CONDITIONS THROUGH MOST OF FRIDAY. PREV DISCUSSION...ISSUED 355 CST MON JAN 28 2008...500 MB RIDGING WILL PREVAIL OVER MEXICO AND THE WESTERN GULF COAST IN THE SHORT TERM AS 500 MB TROFFING AFFECTS THE EAST AND WEST COASTS OF THE U.S. THE WEST COAST TROUGH WILL CONTINUE TO DIG EAST TOWARDS THE CENTRAL U.S. EVENTUALLY REACHING THE MID TO UPPER MISS RIVER VALLEY BY LATE TUES. 1000-500 MB THICKNESSES WILL INCREASE AS THE LOW LEVEL WAA AHEAD OF THE WEST COAST TROUGH INCREASES. AS THIS TROUGH AXIS CLEARS THROUGH THE REGION ON TUES...A COLD FRONT WILL MOVE THROUGH THE REGION TUES NIGHT. MOISTURE LEVELS OVER DEEP SOUTH TEXAS REMAIN PRETTY LIMITED AHEAD OF THIS TROUGH AXIS SO WILL NOT INCLUDE ANY SIGNIFICANT POPS FOR TODAY AND TUES. ANOTHER MORE SOUTHWARD POSITIONED 500 MB TROUGH AXIS WILL DIG INTO THE SOUTH CENTRAL PLAINS LATE WED INTO THURS. MOISTURE RETURN AHEAD OF THIS NEXT FEATURE WILL NOT BE MUCH BETTER AND WILL HANDLE THIS WITH ONLY SOME SLGT CHC POPS. FOR SHORT TERM TEMPS AND POPS...THE MAV AND MET NUMBERS ARE IN PRETTY DECENT AGREEMENT WITH THE WARMEST TEMPS FOR THIS WEEK EXPECTED TUES. WILL MENTION THE POTENTIAL FOR SOME NEAR RECORD HIGHS FOR THE THIRD PERIOD AS THE RECORDS OF BRO...HRL AND MFE ARE 86...87 AND 90 RESPECTIVELY. AFTER THIS NEXT 500 MB TROUGH MOVES EAST OF THE REGION LATE THUR INTO FRI...THE FLOW PATTERN WILL GRADUALLY RETURN TO WEAK RIDGING THROUGH THIS COMING WEEKEND WITH PRETTY LOW POPS AND NEAR TO ABOVE NORMAL TEMPS EXPECTED. MODEL TO MODEL CONSISTENCY BETWEEN THE GFS...ECMWF AND THE NAM LOOKS DECENT WHILE THE RUN TO RUN CONSISTENCY OF THE GFS MEX IS PRETTY STABLE. SO WILL STICK PRETTY CLOSE TO THE MEX TEMPS/POPS FOR THE 3 TO 7 DAY RANGE. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 77 67 82 61 / 10 0 0 0 BROWNSVILLE 79 67 84 61 / 10 0 0 0 HARLINGEN 81 66 86 58 / 10 0 0 0 MCALLEN 81 65 88 57 / 0 0 0 0 RIO GRANDE CITY 79 64 85 56 / 10 0 0 0 SOUTH PADRE ISLAND 76 68 79 61 / 10 0 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR GMZ130- 132-135. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WWW.WEATHER.GOV/BROWNSVILLE 59/66 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 1115 AM CST MON JAN 28 2008 .UPDATE... HAVE ISSUED A WIND ADVISORY FOR THE BIG COUNTRY TO REPLACE CURRENT LAKE WIND ADVISORY... ALREADY SURFACE OBS ACROSS THE BIG COUNTRY CLOSE TO WIND ADVISORY CRITERIA. KEPT LAKE WIND ADVISORY FOR THE CONCHO VALLEY AND THE HEARTLAND WHERE WINDS ARE A LITTLE LIGHTER.. WILL HAVE UPDATED GRIDS OUT SHORTLY. && .PREV DISCUSSION... /ISSUED 521 AM CST MON JAN 28 2008/ AVIATION... RAPID GULF MOISTURE RETURN HAS OCCURRED DURING THE OVERNIGHT HOURS ON THE HEELS OF GUSTY SOUTH WINDS. NIGHTTIME FOG/STRATUS SATELLITE IMAGERY SHOWS STRATUS STREAMING NORTH ACROSS WEST CENTRAL TEXAS THIS MORNING. CIGS HAVE BEEN IN THE MVFR RANGE, ALTHOUGH RECENTLY TERMINALS DOWN SOUTH (KSOA, KJCT) HAVE EITHER DROPPED INTO THE IFR CAT OR ARE TRENDING THAT WAY. RUC MODEL SOUNDINGS ALSO SUPPORT THIS NOTION AS WELL. WILL THROW IN TEMPO IFR CIGS FOR ALL TERMINALS EXCEPT KABI WHICH BASED ON RUC SOUNDINGS WILL LIKELY STAY MVFR. THE STRATUS SHOULD BREAK BY AROUND 16 OR 17Z FROM WEST TO EAST. AFTER STRATUS SCATTERS OUT AT THE TERMINALS LATER ON, THE REMAINDER OF THE FORECAST PERIOD SHOULD REMAIN VFR. FOR WINDS, WENT WITH THE STRONGEST WINDS UP NORTH AT KABI FOR TODAY AS THEY WILL APPROACH 20-25KTS BY AFTERNOON. LACY PREV DISCUSSION... /ISSUED 436 AM CST MON JAN 28 2008/ DISCUSSION... WIND WILL BE ONE OF THE MAIN FORECAST ISSUES WITH THIS PACKAGE... AS WELL AS FIRE WEATHER DANGER ON TUESDAY. GUSTY SOUTH WINDS OCCURRING TONIGHT ACROSS THE BIG COUNTRY AND CONCHO VALLEY...IN RESPONSE TO LOW-LEVEL JET. A SURGE IN DEWPOINTS IS ALSO OCCURRING WITH READINGS QUICKLY CLIMBING THROUGH THE 40S. GUSTY SOUTH TO SOUTHWEST WINDS WILL OCCUR THROUGH TODAY WITH THE HIGHEST SPEEDS ACROSS ROUGHLY THE NORTHERN THIRD OF OUR AREA. ON THE FENCE AS TO WHETHER TO ISSUE A WIND ADVISORY FOR THE BIG COUNTRY. WITH THE HIGH CLOUD CANOPY EXPECTED TO THICKEN HOWEVER... THIS SHOULD LIMIT SLIGHTLY THE AMOUNT OF MIXING...SO AT THIS TIME THINK THAT THE SPEEDS WILL STAY JUST BELOW CRITERIA. WILL GO AHEAD AND ISSUE A LAKE WIND ADVISORY TODAY FOR ALL APPLICABLE COUNTIES. THICKENING HIGH CLOUDINESS WILL ALSO HAVE A SLIGHT LIMITATION ON THE AMOUNT OF HEATING...SO GOING WITH HIGHS A FEW DEGREES BELOW GFS MOS GUIDANCE. SURFACE PRESSURE GRADIENT AND MIXING EFFECTS WILL HELP TO KEEP THE WINDS UP TONIGHT ACROSS THE NORTHERN HALF OF WEST-CENTRAL TEXAS. ON TUESDAY...STRONG WINDS AND AN INTRUSION OF VERY DRY AIR WILL RESULT IN A CRITICAL FIRE WEATHER DAY FOR OUR REGION. COLD FRONTAL PASSAGE TO OCCUR TUESDAY MORNING. STRONG GUSTY NORTHWEST WINDS WILL OCCUR FOR SEVERAL HOURS AFTER THE FRONT PASSES. WE HAVE ISSUED A FIRE WEATHER WATCH FOR ALL OF OUR COUNTIES TUESDAY. HAVE UNDERCUT THE MODEL GUIDANCE DEWPOINTS... GIVEN THE STRONG SUBSIDENCE AND INTRUSION OF VERY DRY AIR THAT IS EXPECTED. WILL LIKELY NEED A WIND ADVISORY FOR AT LEAST OUR NORTHERN AND POSSIBLY CENTRAL COUNTIES. DESPITE A GREATER AMOUNT OF SUNSHINE EXPECTED TUESDAY...THE COLD AIR ADVECTION SHOULD LIMIT THE TEMPERATURE CLIMB TO AROUND 7-14 DEGREES ABOVE THE MORNING LOWS. SURFACE HIGH DROPPING SOUTHEAST INTO TEXAS BEHIND THE FRONT WILL BRING A SHORT-LIVED REPRIEVE FROM THE WINDS TUESDAY NIGHT. GUSTY SOUTH WINDS TO REDEVELOP ON WEDNESDAY AS THE NEXT UPPER TROUGH DIGS INTO THE 4-CORNERS REGION AND LEE SIDE SURFACE TROUGH DEVELOPS. THE GFS AND ECMWF CONTINUE TO SHOW DIFFERENCES WITH THIS NEXT UPPER TROUGH AS IT MOVES ACROSS TEXAS. THE ECMWF STILL MAINTAINS CLOSED LOW DEVELOPMENT OVER NEW MEXICO WITH A SUBSEQUENT EASTWARD TRACK ACROS NORTH-CENTRAL TEXAS. THE GFS TRENDS HAVE AN OPEN WAVE TRACKING EAST ACROSS NORTH TX. WITH THE FORECAST SYSTEM TRACK AND LIMITED TIME WINDOW FOR SUFFICIENT MOISTURE RETURN...IT APPEARS THAT THE BETTER RAIN CHANCES WILL BE FOCUSED NORTHEAST AND EAST OF OUR COUNTIES. RATHER GUSTY NORTHWEST WINDS TO FOLLOW PASSAGE OF THE COLD FRONT WITH THIS NEXT SYSTEM. THE EXTENDED FORECAST FRIDAY INTO NEXT WEEKEND LOOKS DRY FOR WEST CENTRAL TEXAS...WITH WEST TO SOUTHWEST FLOW ALOFT. && .PRELIMINARY POINT TEMPS/POPS... ABILENE 74 53 60 35 / 10 10 0 0 SAN ANGELO 74 53 64 32 / 10 10 0 0 JUNCTION 71 54 68 30 / 10 10 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... FIRE WEATHER WATCH TUESDAY AFTERNOON FOR BROWN-CALLAHAN-COKE- COLEMAN-CONCHO-CROCKETT-FISHER-HASKELL-IRION-JONES-KIMBLE-MASON- MCCULLOCH-MENARD-NOLAN-RUNNELS-SAN SABA-SCHLEICHER-SHACKELFORD- STERLING-SUTTON-TAYLOR-THROCKMORTON-TOM GREEN. WIND ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR CALLAHAN-FISHER- HASKELL-JONES-NOLAN-SHACKELFORD-TAYLOR-THROCKMORTON. LAKE WIND ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR BROWN-COKE- COLEMAN-CONCHO-MCCULLOCH-RUNNELS-TOM GREEN. && $$ 99/28 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 915 AM CST MON JAN 28 2008 .DISCUSSION...ON THE FENCE OF ISSUING A WIND ADVISORY FOR THIS AFTERNOON. NAM AND RUC40 925 TO 1000MB WINDS RANGING FROM 25 TO 35KTS ACROSS THE EASTERN TWO THIRDS OF THE CWA. VAD WINDS FROM KBRO AND 12Z MORNING SOUNDING ALSO INDICATED 25 TO 30KTS AT SAME LEVELS. NAM AND GFS GUIDANCE INDICATES SFC WINDS JUST BELOW LOCAL WIND ADVISORY CRITERIA...GREATER THAN 30KTS SUSTAINED. LOW TO MID LEVEL CU FIELD AND INCREASING HIGH CLOUDS SHOULD LIMIT INSOLATION TODAY THUS MIXING OF THE STRONGEST WINDS TO THE SURFACE IS NOT EXPECTED. WILL MAINTAIN THE WINDY CONDITIONS IN THE ZONES WITH THE STRONGEST PERIOD LIKLEY FROM 1 TO 6 PM. AS FOR THE PATCHY DENSE FOG IN HIDALGO...STARR...ZAPATA AND JIM HOGG COUNTIES...THE FOG SHOULD BEGIN TO LIFT AROUND 11 AM AS THE WINDS BEGIN TO INCREASE. && .AVIATION...AFTER EARLY MORNING FOG...BREEZY WINDS WITH MOSTLY CLOUDY SKIES WILL PREVAIL OVER THE TRIO OF REGIONAL AIRPORTS LATER THIS MORNING THROUGH EARLY TUESDAY MORNING. && .MARINE...BUOY 42020 REPORTED SOUTHEAST WINDS AROUND 17 KNOTS GUSTING TO AROUND 19 KNOTS WITH SEAS SLIGHTLY OVER 4 FEET WITH A PERIOD OF 5 SECONDS AT 08 CST/14 UTC. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE LAGUNA MADRE THROUGH THIS AFTERNOON...AS WINDS OF 20 KNOTS OR GREATER ARE EXPECTED TO DEVELOP THERE. THE SMALL CRAFT ADVISORY MAY NEED TO BE EXTENDED TO THE ADJACENT GULF OF MEXICO WATERS TONIGHT THROUGH TUESDAY MORNING DUE TO INCREASING WINDS AND SEAS IN ADVANCE OF A COLD FRONT...WHICH WILL PASS THROUGH THE LOWER TEXAS COAST TUESDAY AFTERNOON. SMALL CRAFT ADVISORY WINDS AND SEAS ARE ANTICIPATED TUESDAY AFTERNOON THROUGH THURSDAY MORNING IN THE WAKE OF THE FRONT...WITH ANOTHER COLD FRONTAL PASSAGE THURSDAY AFTERNOON CONTINUING THE ADVERSE MARINE CONDITIONS THROUGH MOST OF FRIDAY. && .PREV DISCUSSION...ISSUED 355 CST MON JAN 28 2008...500 MB RIDGING WILL PREVAIL OVER MEXICO AND THE WESTERN GULF COAST IN THE SHORT TERM AS 500 MB TROFFING AFFECTS THE EAST AND WEST COASTS OF THE U.S. THE WEST COAST TROUGH WILL CONTINUE TO DIG EAST TOWARDS THE CENTRAL U.S. EVENTUALLY REACHING THE MID TO UPPER MISS RIVER VALLEY BY LATE TUES. 1000-500 MB THICKNESSES WILL INCREASE AS THE LOW LEVEL WAA AHEAD OF THE WEST COAST TROUGH INCREASES. AS THIS TROUGH AXIS CLEARS THROUGH THE REGION ON TUES...A COLD FRONT WILL MOVE THROUGH THE REGION TUES NIGHT. MOISTURE LEVELS OVER DEEP SOUTH TEXAS REMAIN PRETTY LIMITED AHEAD OF THIS TROUGH AXIS SO WILL NOT INCLUDE ANY SIGNIFICANT POPS FOR TODAY AND TUES. ANOTHER MORE SOUTHWARD POSITIONED 500 MB TROUGH AXIS WILL DIG INTO THE SOUTH CENTRAL PLAINS LATE WED INTO THURS. MOISTURE RETURN AHEAD OF THIS NEXT FEATURE WILL NOT BE MUCH BETTER AND WILL HANDLE THIS WITH ONLY SOME SLGT CHC POPS. FOR SHORT TERM TEMPS AND POPS...THE MAV AND MET NUMBERS ARE IN PRETTY DECENT AGREEMENT WITH THE WARMEST TEMPS FOR THIS WEEK EXPECTED TUES. WILL MENTION THE POTENTIAL FOR SOME NEAR RECORD HIGHS FOR THE THIRD PERIOD AS THE RECORDS OF BRO...HRL AND MFE ARE 86...87 AND 90 RESPECTIVELY. AFTER THIS NEXT 500 MB TROUGH MOVES EAST OF THE REGION LATE THUR INTO FRI...THE FLOW PATTERN WILL GRADUALLY RETURN TO WEAK RIDGING THROUGH THIS COMING WEEKEND WITH PRETTY LOW POPS AND NEAR TO ABOVE NORMAL TEMPS EXPECTED. MODEL TO MODEL CONSISTENCY BETWEEN THE GFS...ECMWF AND THE NAM LOOKS DECENT WHILE THE RUN TO RUN CONSISTENCY OF THE GFS MEX IS PRETTY STABLE. SO WILL STICK PRETTY CLOSE TO THE MEX TEMPS/POPS FOR THE 3 TO 7 DAY RANGE. && .PRELIMINARY POINT TEMPS/POPS... BAYVIEW/PORT ISABEL 77 67 82 61 / 10 0 0 0 BROWNSVILLE 79 67 84 61 / 10 0 0 0 HARLINGEN 81 66 86 58 / 10 0 0 0 MCALLEN 81 65 88 57 / 0 0 0 0 RIO GRANDE CITY 79 64 85 56 / 10 0 0 0 SOUTH PADRE ISLAND 76 68 79 61 / 10 0 0 0 && .BRO WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR GMZ130- 132-135. && $$ THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT: HTTP://WWW.WEATHER.GOV/BROWNSVILLE 59/66 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 521 AM CST MON JAN 28 2008 .AVIATION... RAPID GULF MOISTURE RETURN HAS OCCURRED DURING THE OVERNIGHT HOURS ON THE HEELS OF GUSTY SOUTH WINDS. NIGHTTIME FOG/STRATUS SATELLITE IMAGERY SHOWS STRATUS STREAMING NORTH ACROSS WEST CENTRAL TEXAS THIS MORNING. CIGS HAVE BEEN IN THE MVFR RANGE, ALTHOUGH RECENTLY TERMINALS DOWN SOUTH (KSOA, KJCT) HAVE EITHER DROPPED INTO THE IFR CAT OR ARE TRENDING THAT WAY. RUC MODEL SOUNDINGS ALSO SUPPORT THIS NOTION AS WELL. WILL THROW IN TEMPO IFR CIGS FOR ALL TERMINALS EXCEPT KABI WHICH BASED ON RUC SOUNDINGS WILL LIKELY STAY MVFR. THE STRATUS SHOULD BREAK BY AROUND 16 OR 17Z FROM WEST TO EAST. AFTER STRATUS SCATTERS OUT AT THE TERMINALS LATER ON, THE REMAINDER OF THE FORECAST PERIOD SHOULD REMAIN VFR. FOR WINDS, WENT WITH THE STRONGEST WINDS UP NORTH AT KABI FOR TODAY AS THEY WILL APPROACH 20-25KTS BY AFTERNOON. LACY && .PREV DISCUSSION... /ISSUED 436 AM CST MON JAN 28 2008/ DISCUSSION... WIND WILL BE ONE OF THE MAIN FORECAST ISSUES WITH THIS PACKAGE... AS WELL AS FIRE WEATHER DANGER ON TUESDAY. GUSTY SOUTH WINDS OCCURRING TONIGHT ACROSS THE BIG COUNTRY AND CONCHO VALLEY...IN RESPONSE TO LOW-LEVEL JET. A SURGE IN DEWPOINTS IS ALSO OCCURRING WITH READINGS QUICKLY CLIMBING THROUGH THE 40S. GUSTY SOUTH TO SOUTHWEST WINDS WILL OCCUR THROUGH TODAY WITH THE HIGHEST SPEEDS ACROSS ROUGHLY THE NORTHERN THIRD OF OUR AREA. ON THE FENCE AS TO WHETHER TO ISSUE A WIND ADVISORY FOR THE BIG COUNTRY. WITH THE HIGH CLOUD CANOPY EXPECTED TO THICKEN HOWEVER... THIS SHOULD LIMIT SLIGHTLY THE AMOUNT OF MIXING...SO AT THIS TIME THINK THAT THE SPEEDS WILL STAY JUST BELOW CRITERIA. WILL GO AHEAD AND ISSUE A LAKE WIND ADVISORY TODAY FOR ALL APPLICABLE COUNTIES. THICKENING HIGH CLOUDINESS WILL ALSO HAVE A SLIGHT LIMITATION ON THE AMOUNT OF HEATING...SO GOING WITH HIGHS A FEW DEGREES BELOW GFS MOS GUIDANCE. SURFACE PRESSURE GRADIENT AND MIXING EFFECTS WILL HELP TO KEEP THE WINDS UP TONIGHT ACROSS THE NORTHERN HALF OF WEST-CENTRAL TEXAS. ON TUESDAY...STRONG WINDS AND AN INTRUSION OF VERY DRY AIR WILL RESULT IN A CRITICAL FIRE WEATHER DAY FOR OUR REGION. COLD FRONTAL PASSAGE TO OCCUR TUESDAY MORNING. STRONG GUSTY NORTHWEST WINDS WILL OCCUR FOR SEVERAL HOURS AFTER THE FRONT PASSES. WE HAVE ISSUED A FIRE WEATHER WATCH FOR ALL OF OUR COUNTIES TUESDAY. HAVE UNDERCUT THE MODEL GUIDANCE DEWPOINTS... GIVEN THE STRONG SUBSIDENCE AND INTRUSION OF VERY DRY AIR THAT IS EXPECTED. WILL LIKELY NEED A WIND ADVISORY FOR AT LEAST OUR NORTHERN AND POSSIBLY CENTRAL COUNTIES. DESPITE A GREATER AMOUNT OF SUNSHINE EXPECTED TUESDAY...THE COLD AIR ADVECTION SHOULD LIMIT THE TEMPERATURE CLIMB TO AROUND 7-14 DEGREES ABOVE THE MORNING LOWS. SURFACE HIGH DROPPING SOUTHEAST INTO TEXAS BEHIND THE FRONT WILL BRING A SHORT-LIVED REPRIEVE FROM THE WINDS TUESDAY NIGHT. GUSTY SOUTH WINDS TO REDEVELOP ON WEDNESDAY AS THE NEXT UPPER TROUGH DIGS INTO THE 4-CORNERS REGION AND LEE SIDE SURFACE TROUGH DEVELOPS. THE GFS AND ECMWF CONTINUE TO SHOW DIFFERENCES WITH THIS NEXT UPPER TROUGH AS IT MOVES ACROSS TEXAS. THE ECMWF STILL MAINTAINS CLOSED LOW DEVELOPMENT OVER NEW MEXICO WITH A SUBSEQUENT EASTWARD TRACK ACROS NORTH-CENTRAL TEXAS. THE GFS TRENDS HAVE AN OPEN WAVE TRACKING EAST ACROSS NORTH TX. WITH THE FORECAST SYSTEM TRACK AND LIMITED TIME WINDOW FOR SUFFICIENT MOISTURE RETURN...IT APPEARS THAT THE BETTER RAIN CHANCES WILL BE FOCUSED NORTHEAST AND EAST OF OUR COUNTIES. RATHER GUSTY NORTHWEST WINDS TO FOLLOW PASSAGE OF THE COLD FRONT WITH THIS NEXT SYSTEM. THE EXTENDED FORECAST FRIDAY INTO NEXT WEEKEND LOOKS DRY FOR WEST CENTRAL TEXAS...WITH WEST TO SOUTHWEST FLOW ALOFT. && .PRELIMINARY POINT TEMPS/POPS... ABILENE 74 53 60 35 / 10 10 0 0 SAN ANGELO 74 53 64 32 / 10 10 0 0 JUNCTION 71 54 68 30 / 10 10 0 0 && .SJT WATCHES/WARNINGS/ADVISORIES... LAKE WIND ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR BROWN-COKE- COLEMAN-CONCHO-HASKELL-JONES-MCCULLOCH-NOLAN-RUNNELS-TAYLOR-TOM GREEN. FIRE WEATHER WATCH TUESDAY AFTERNOON FOR BROWN-CALLAHAN-COKE- COLEMAN-CONCHO-CROCKETT-FISHER-HASKELL-IRION-JONES-KIMBLE-MASON- MCCULLOCH-MENARD-NOLAN-RUNNELS-SAN SABA-SCHLEICHER-SHACKELFORD- STERLING-SUTTON-TAYLOR-THROCKMORTON-TOM GREEN. && $$ 99/99/30 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WA 836 AM PST SUN JAN 27 2008 .SYNOPSIS... A COLD AND UNSETTLED DEEP WINTER WEATHER PATTERN WILL CONTINUE TODAY AND WELL INTO THE NEW WORK WEEK WITH A NEW STORM SYSTEM PASSING THROUGH THE REGION EVERY 36 TO 48 HOURS THROUGH NEXT SATURDAY. && UPDATED AVIATION DISCUSSION .DISCUSSION... ISSUED 836 AM... THE MID LEVEL BAROCLINIC BAND OVER CENTRAL AND EASTERN WASHINGTON HAS BECOME REFOCUSED ALONG THE I-90 CORRIDOR AGAIN THIS MORNING AFTER DIPPING SOUTH OF THE SPOKANE METRO BRIEFLY PRIOR TO SUNRISE. THE UPPER TROUGH JUST OFF THE COAST OF WASHINGTON CONTINUES TO DIG...WHICH HAS ALLOWED THE FRONT TO BACK UP A BIT THIS MORNING. SURFACE PRESSURE FALLS SHOW THAT THE SURFACE BOUNDARY IS BEGINNING TO DROP SOUTH...WITH THE BEST PRESSURE FALLS OVER THE SOUTHERN PANHANDLE. HOWEVER LOOKING AT THE RADAR AT THE LATEST RUC...AN ADDITIONAL 2 TO 3 INCHES WILL BE POSSIBLE FOR THE I-90 CORRIDOR THROUGH EARLY AFTERNOON. A SNOW ADVISORY WILL BE REISSUED FOR THE SPOKANE AREA...AS WELL AS THE UPPER COLUMBIA BASIN. FOR THE BASIN...THE ADDITIONAL 2-3 INCHES WILL MAINLY BE ALONG AND SOUTH OF I-90. STATEMENTS WILL BE OUT SHORTLY. /GKOCH && .AVIATION... MODERATE TO HEAVY SNOW WILL OCCUR ALONG A MID LEVEL COLD FRONT THAT IS CURRENTLY STALLED OVER EASTERN WASHINGTON. THE HEAVIEST SNOW WILL FALL ALONG A LINE FROM MOSES LAKE TO SPOKANE THROUGH 21Z. BETWEEN 21Z AND 03Z...THE FRONT AND ASSOCIATED SNOW BAND WILL BE FOCUSED INTO THE PULLMAN AND LEWISON ARES. GIVEN THE VERY MOIST ATMOSPHERE...LOW CLOUDS AND FOG WILL BE LIKELY THROUGH 18Z MONDAY FOR MOST AIRPORTS IN CENTRAL AND EASTERN WASHINGTON. /GKOCH && .PRELIMINARY POINT TEMPS/POPS... SPOKANE 33 20 24 18 25 13 / 100 40 60 40 80 30 COEUR D`ALENE 34 22 26 18 25 16 / 100 40 60 40 80 40 PULLMAN 34 24 28 22 28 19 / 100 70 60 50 80 40 LEWISTON 40 29 33 25 36 25 / 90 70 50 40 70 30 COLVILLE 31 18 25 16 25 12 / 40 30 50 40 60 30 SANDPOINT 32 22 26 17 22 12 / 90 50 60 40 70 50 KELLOGG 32 23 27 20 26 15 / 100 90 70 60 80 50 MOSES LAKE 26 17 29 21 29 16 / 40 20 20 30 60 10 WENATCHEE 26 15 28 21 27 16 / 20 20 20 30 60 10 OMAK 25 7 22 10 22 10 / 20 20 20 30 60 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID... SNOW ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR IDAHO PALOUSE... LEWISTON AREA. HEAVY SNOW WARNING UNTIL 10 PM PST THIS EVENING FOR LEWIS AND SOUTHERN NEZ PERCE COUNTIES. HEAVY SNOW WARNING UNTIL 4 PM PST THIS AFTERNOON FOR COEUR D`ALENE AREA. HEAVY SNOW WARNING UNTIL 10 PM PST THIS EVENING FOR CENTRAL PANHANDLE MOUNTAINS...NORTHERN PANHANDLE. WA...SNOW ADVISORY UNTIL 2 PM PST THIS AFTERNOON FOR SPOKANE AREA... UPPER COLUMBIA BASIN. SNOW ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR LOWER GARFIELD AND ASOTIN COUNTIES...WASHINGTON PALOUSE. HEAVY SNOW WARNING UNTIL 4 PM PST THIS AFTERNOON FOR NORTHEAST BLUE MOUNTAINS. && $$ wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE INDIANAPOLIS IN 1206 AM EST TUE JAN 29 2008 .AVIATION...DISCUSSION FOR THE 06Z TAFS. A VERY ACTIVE AND DIFFICULT FORECAST UPCOMING. A STRONG LOW PRESSURE IN THE PLAINS WILL CONTINUE STRONG SOUTHERLY WINDS TONIGHT. MVFR CIGS AND VSBY HEADED THIS WAY AND SHOULD ARRIVE BY 12Z. SCATTERED SHOWERS AND LOW CIGS WILL CONTINUE ALL DAY TOMORROW...REMAINING IN THE MVFR CATEGORY. ADDED CB MENTION AFTER 21Z FOR SCATTERED THUNDERSTORM POSSIBILITY. THE COLD FROPA WILL OCCUR AT HUF AND LAF FIRST AROUND 00-01Z AND THEN OTHER SITES BY 03Z. AFTER FROPA A WIND SHIFT AND DRAMATIC INCREASE IN WIND SPEED. SUSTAINED WINDS WILL BE 25 TO 30 KTS WITH GUSTS APPROACHING 40KTS FROM THE NORTHWEST AFTER 03Z. ANY LINGERING PRECIP WILL CHANGE TO SNOW AND MVFR CONDITIONS WILL CONTINUE. .PREV UPDATE... HAVE WENT AHEAD AND ISSUED A WIND ADVISORY FOR TUESDAY NIGHT. 18Z MODEL DATA CONTINUES TO SHOW STRONG WINDS REACHING THE SURFACE AFTER COLD FRONT PASSES. NAM BUFKIT SOUNDINGS SHOW OVER 40KT POSSIBLE TUE EVENING. RUC13 SFC PROGS SHOWING SUSTAINED 35KT...AND 18Z MAV SHOWING SUSTAINED 30KT WINDS. THUS FEEL CONFIDENT ENOUGH TO ISSUE AT THIS TIME. && .PREV DISCUSSION... /ISSUED 335 PM EST MON JAN 28 2008/ VIS SAT SHOWS OVC SKIES ACRS THE FA. TEMPS WERE IN THE MID 40S WITH DEWPTS IN THE MID 20S AND WINDS OUT OF THE SSW AROUND 15KTS GUSTING TO AROUND 25KTS. RADAR SHOWS SPRINKLES AND VIRGA OVR THE FA AS WELL. FORECAST FOCUS IS ON POPS...WINDS...AND SVR POTENTIAL WITH FRONTAL SYSTEM TUESDAY/TUESDAY NIGHT. MODELS IN GOOD AGREEMENT FOR THE MOST PART IN THE SHORT TERM SO WL USE A BLEND. TONIGHT...WAA AND CLOUD CVR WL KEEP LOWS UP IN THE LOW TO MID 40S RIGHT WITH GUIDANCE. CHCS FOR POPS SHUD INCREASE DURING THE NIGHT AS A S/W MVS THRU AND ISENTROPIC LIFT CONTINUES. DO NOT EXPECT GREAT AMOUNTS BUT ENUF FORCING TO KEEP LIKELY RAIN. WHILE PRES GRADIENT STRENGTHENS ACRS THE AREA DURING THE NIGHT INVERSION IS STRONG ENUF TO KEEP THE STRONG WIND GUSTS FROM REACHING THE SFC. TUESDAY...NAM HAS SLOWED FROPA FROM YESTERDAYS RUN AND NOW IS ABOUT MIDWAY THRU THE FA BY 0Z AND AGREES WELL WITH THE ECMWF AND THE GFS. NOT A LOT OF SFC INSTABILITY AVAILABLE BUT THERE IS WILL BE ELEVATED INSTABILITY TO TAP INTO. WITH 50+KT LLJ MVING ACRS THE AREA AFTER 18Z AND INVERSION ERODING SHUD HAVE POTENTIAL FOR THESE WINDS TO MIX DOWN TO THE SFC WITH ANY THUNDERSTORMS THAT DEVELOP. MOST OF THE FA IS IN A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR LATE TUE AFTERNOON/EVENING AND THESE WIND GUSTS WILL BE THE PRIMARY THREAT. LOOKS LIKE THE BEST POTENTIAL FOR SYNOPTIC SCALE WINDS OF ADVISORY CRITERIA WILL JUST AFTER FROPA...WHICH WOULD PUT THEM STARTING UP ACRS THE FA AFTER 21Z AND PERHAPS NOT UNTIL AFTER 0Z. BUFKIT GUSTS DURING THIS TIME ARE IN THE 40-45KT RANGE. AFTER COLLABORATION WITH OTHER OFFICES AND NOTING THIS WOULD BE IN THE THIRD PERIOD HAVE DECIDED TO HOLD OFF ISSUANCE OF WIND ADVISORY UNTIL NEXT FCST PACKAGE...BUT DEFINITELY THINK ONE WILL BE NECESSARY FOR TUESDAY NIGHT. TUESDAY NIGHT...HAVE ALREADY DISCUSSED STRONG WINDS ABOVE. COLD FNT WILL FINISH MVING ACRS THE AREA SO HAVE INCLUDED THUNDER OVR AT LEAST THE ERN HALF OF THE AREA THRU 3Z. BRING POPS DOWN FROM W TO E IN 3 HR INCREMENTS AND SHUD SEE CHANGE OVR TO SNOW AT MOST LOCATIONS BEFORE WED MORNING BUT THE SNOW SHUD BE SHORT LIVED WITH LITTLE ACCUMULATION AS THE COLD FNT SHUD SCOUR OUT MOST OF THE MOISTURE. BOTH MODELS SHOW COLD AIR PLUNGING DOWN AFTER FROPA BUT NAM SEEMS A LITTLE OVERZEALOUS WITH ITS H8 TEMPS AND MET GUIDANCE LOOKS TOO COOL DROPPING THINGS INTO THE SINGLE DIGITS BASED ON WHAT LOW TEMPS ARE LIKE IN THE NRN PLAINS RIGHT NOW. WED AND WED NT...HIGH PRESSURE BLDS IN AND THINGS ARE DRY. WED WL BE COLD BECAUSE OF THE PREVIOUSLY MENTIONED COLD AIR SPILLING DOWN SO HIGHS WILL ONLY BE IN THE 20S. WED NT WINDS WILL SHIFT BACK AROUND TO THE S BUT WITH NOT MUCH CLOUD CVR EVEN WITH THE WAA WL STILL SEE LOWS IN THE TEENS. EXTENDED...EXTENDED EMPHASIS IS ON THURSDAY NIGHT/FRIDAY SYSTEM. STILL QUITE A BIT OF UNCERTAINTY IN FCST TRACK OF SFC LOW THU NT/FRI. ECMWF MVS THE LOW THRU IL AND KEEPS THE FA IN ALL RAIN WITH THE POSSIBLE EXCEPTION OF THE FAR NW. GFS TRACKS THE LOW ALONG THE OH RVR AND HAS NRN AND CENTRAL FA ALL SNOW WITH SOME POTENTIAL FOR ICE IN THE S. WHILE THE NAM DOES NOT GO OUT QUITE FAR ENUF YET...IT/S SFC LOW HAS BEEN TRENDING FURTHER S. WITH SYSTEMS THUS FAR THIS WINTER THE NAM AND GFS HAVE HAD A BIAS TOWARD THE SE WITH THEIR SFC LOWS AND GIVEN THAT AM MORE INCLINED TO LEAN ON THE WARMER NW SOLN OF THE ECMWF. WITH THE CURRENT DISAGREEMENT THO AM NOT GOING TO PULL THE SNOW...INSTEAD WILL INCLUDE A MIX FOR MOST OF THE STORM AND WL TRY TO NAIL DOWN A LITTLE BETTER AS /HOPEFULLY/ MODELS COME INTO BETTER AGREEMENT. A WEAK FNT WL MV THRU ON SAT NT/SUN BUT ASSOC FORCING STAYS WELL N OF THE AREA SO WL KEEP A DRY FCST. MON A WARM FNT WL APPROACH FROM THE S AND SO HAVE BROUGHT IN CHC POPS. TEMPS ARE BORDERLINE SO WL INCLUDE A RAIN SNOW MIX. && .IND WATCHES/WARNINGS/ADVISORIES...WIND ADVISORY ALL AREAS 7PM TUE TO 7AM WED. && $$ AVIATION...LAJ UPDATE...CS PUBLIC...CP in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1046 PM MST MON JAN 28 2008 .DISCUSSION... && .AVIATION...UPDATE FOR THE 06Z TAFS...COLD FRONT AT THE SURFACE HAS ALREADY REACHED THE NORTHERN EDGE OF OUR CWA. SURFACE OBSERVATIONS SHOWING CEILINGS BETWEEN 1000 AND 2000 WITH AND BEHIND THE FRONT. WITH THE ARRIVAL OF THE ARCTIC COLD FRONT...EXPECT IFR CONDITIONS WITH NORTH WINDS GUSTING TO 40 MPH IN LIGHT BLOWING SNOW...MAINLY BETWEEN 09Z AND 12Z. BY 15Z...EXPECT CONDITIONS TO RETURN TO VFR. && .PREV DISCUSSION... /ISSUED 842 PM MST MON JAN 28 2008/ .UPDATE...00Z H85 ANALYSIS SHOWING A LARGE CHUNK OF ARCTIC AIR PLUNGING SOUTH INTO THE NORTHERN ROCKIES/NORTHERN PLAINS WHILE 02Z SFC ANALYSIS INDICATES THE LEADING EDGE OF THE ARCTIC AIRMASS ALREADY APPROACHING THE I-80 CORRIDOR. GIVEN SUCH COLD TEMPERATURES (-32C AT KGGW AT H85) AND RAPID TEMPERATURE DROPS ACROSS WESTERN AND NORTHERN NEBRASKA THIS EVENING WILL TREND LOWS DOWN TONIGHT. THE COLD AIRMASS APPEARS TO HAVE A FAVORABLE TRAJECTORY INTO THE CENTRAL HIGH PLAINS WITH UNCERTAINTY IN DEGREE OF MODIFICATION ESPECIALLY ACROSS THE WESTERN ZONES WHERE MIXING WILL BE MORE LIKELY. WILL LOWER HIGHS ACROSS THE FAR EASTERN ZONES WHERE REACHING 20 MAY BE A STRUGGLE ON TUESDAY. A SECONDARY CONCERN WILL BE WIND CHILL READINGS LATE TONIGHT AND THROUGH THE DAY ON TUESDAY. LITTLE CHANGES IN POP ORIENTATION EXPECTED WITH SCATTERED SNOW SHOWERS STILL EXPECTED TO DEVELOP LATE TONIGHT WITH VERY LITTLE ACCUMULATION EXPECTED. DID RAISE POPS INTO THE MID RANGE WEIGHTED IN THE NORTHEAST ZONES WHERE BETTER MID LEVEL FRONTOGENESIS IS JUXTAPOSED WITH STRONG LARGE SCALE FORCING FOR ASCENT BETWEEN 09-13Z. WIND ADVISORY HEADLINES ALSO APPEAR ON TRACK WITH NO CHANGE PLANNED. && .PREV DISCUSSION... /ISSUED 451 PM MST MON JAN 28 2008/ .DISCUSSION... 17Z WATER VAPOR IMAGERY AND RUC ANALYSIS INDICATE TWO SHORT WAVE TROUGHS UPSTREAM OF THE CWA. THE FIRST WAS LOCATED OVER CENTRAL COLORADO AND WAS RESPONSIBLE FOR CLOUD ACROSS NORTHERN HALF OF CWA. ANOTHER...SHORT WAVE TROUGH WAS DIGGING INTO NEVADA AND UTAH AND WILL BE PRIMARY WX MAKER TONIGHT/TOMORROW. TONIGHT-TOMORROW...WINDS SHOULD WEAKEN/DECOUPLE DURING THE EVENING AS DEEP MIXING COMES TO AN END...AND WILL LET CURRENT HIGHLIGHTS CONTINUE. MAIN CONCERNS AFTER THAT WILL BE HOW STRONG WINDS GET BEHIND FRONTAL PASSAGE AND WEATHER OR NOT ANY PRECIP WILL DEVELOP AS WELL. NAM/GFS/GEM ALL SUPPORT PASSAGE OF STRONG COLD FRONT ACROSS THE CWA AFTER 06Z. POINT SOUNDINGS INDICATE WINDS OFF OF THE SURFACE INCREASE TO OVER 40KTS BEHIND THE FRONT...AND SOUNDINGS SUGGEST THAT LITTLE IN THE WAY OF A SURFACE INVERSION WILL BE IN PLACE BEHIND THE FRONT. ALTHOUGH TIME OF NIGHT IS NOT NORMALLY FAVORABLE FOR STRONG WIND...MINIMAL INVERSION COUPLED WITH STRONG PRESSURE RISES AND CAA SHOULD BE ENOUGH TO ALLOW STRONGER WINDS TO REACH THE SURFACE. GFS ACTUALLY COMES CLOSE TO LOW END WARNING CRITERIA...BUT OTHER MODELS ARE SLIGHTLY WEAKER. THINK AN ADVISORY WILL BE THE WAY TO GO TONIGHT...ALTHOUGH STILL A LITTLE UNCERTAIN DUE TO THE TIMING. OTHER CONCERN WILL BE IF ANY PRECIPITATION CAN FALL AS FRONT PASSES...WHICH WILL MAY CAUSE EVEN MORE PROBLEMS WITH THE WIND. GFS...WHICH ALSO HAS SUPPORT FROM ECMWF AND TO SOME EXTENT THE GEM CONTINUE TO SUGGEST THREAT FOR PRECIPITATION BEHIND FRONT DURING THE MORNING HOURS. CROSS SECTIONS THROUGH THE FRONTAL SURFACE SHOWS A POCKET OF POTENTIAL INSTABILITY JUST ABOVE FRONTAL SURFACE...WITH ENVIRONMENT NEARLY SATURATED. FRONTOGENESIS AT H7...H65 ALSO LINE UP WELL WITH H7-H5 AND H5-H3 DIV Q FORCING FOR ASCENT. ONLY CONCERN IS IF SATURATION WILL BE POSSIBLE AS FORCING SHOULD MOVE BY FAIRLY QUICKLY...AND CURRENT WATER VAPOR IMAGERY INDICATES SUBSTANTIAL DRYING ACROSS THE AREA BEHIND THIS MORNINGS SYSTEM. OBSERVED LAPSE RATES...AND OBSERVED NATURE OF THE CLOUDS OVER THE AREA CURRENTLY...SUGGEST STABILITY IS FAIRLY LOW. IF SNOW DOES DEVELOP WITH THE WIND...WILL LIKELY NEED SOME KIND OF SNOW/BLSN HIGHLIGHT...BUT CONFIDENCE IN MEASURABLE SNOWFALL REMAINS BELOW ADVISORY CRITERIA AT THIS POINT. WILL UP POPS OVERNIGHT AND INCLUDE BLSN IN FORECAST BUT FOR NOW WILL LIKELY GO WITH JUST A WIND ADVISORY. TOMORROW NIGHT-WEDNESDAY NIGHT...SHORT WAVE RIDGING WILL BE IN PLACE ACROSS THE AREA DURING THE EARLY PORTIONS OF TUESDAY EVENING LEADING TO WIDESPREAD SUBSIDENCE ACROSS THE AREA. RIDGE BEGINS TO BREAK DOWN FAIRLY QUICKLY HOWEVER AS H7 TROUGH BEGINS TO IMPACT THE AREA AROUND 12Z WED. FAIRLY STRONG WAA INDICATED AT H7 AS WELL. POINT SOUNDINGS INDICATE A VERY THICK...DRY LAYER BELOW THIS REGION AND WITH FAIRLY HIGH STABILITY DO NOT THINK ANY PRECIPITATION WILL MAKE IT TO THE GROUND BY 12Z WED. MORE WIDESPREAD FORCING FOR ASCENT IS INDICATED BY Q VECTOR FIELDS BEGINS TO OVERSPREAD THE AREA THROUGH THE AFTERNOON AND INTO THE EVENING. FORCING DOES NOT REALLY APPEAR THAT FOCUSED...AND GENERAL TREND IN THE MODELS IS DRIER AND FURTHER SOUTH. AM GOING TO TRIM BACK POPS A LITTLE BIT FOR THE TIME PERIOD...ALTHOUGH STILL ENOUGH UNCERTAINTY TO HOLD ON TO SOME LOW CHANCE POPS THROUGH THE EVENING INTO THURSDAY MORNING. THURS-SATURDAY...OPERATIONAL GFS APPEARS TO BE OUTLIER IN BOTH POSITION AND SPEED OF H5 TROUGH...AND WILL LEAN TOWARDS SLOWER MORE SOUTHERLY SOLUTION THROUGH THIS PERIOD. TAKING THE SLOWER/MORE SOUTHERLY SOLUTIONS WOULD SUGGEST SHORT WAVE TROUGH JUST GLANCES THE CWA...WITH MID LEVEL FRONTAL ZONE JUST TO THE SOUTH OF THE AREA. NOT TO EXCITED ABOUT PRECIP POTENTIAL WITH THIS SYSTEM...BUT WILL INCLUDE SOME LOW POPS ACROSS THE SOUTHEAST AS THEY SHOULD BE THE NEAR THE NORTHERN FRINGE OF PRECIPITATION. OTHER CONCERN THROUGH THE PERIOD WILL BE TEMPS...WITH BIGGEST CONCERN BEING HOW MUCH OF A WARM UP WILL OCCUR ON FRIDAY BETWEEN FRONTAL PASSAGES. GFS/ECMWF AND GFS ENS MEAN WOULD SUGGEST FAIRLY WARM TEMPS DEVELOPING...AND THIS SOLUTION LOOKS FAIRLY REASONABLE. A LITTLE CONCERNED ABOUT GOING TOO WARM AS THIS AIRMASS APPEARS TO BE OVER CWA ONLY A BRIEF TIME BEFORE NEXT FRONT COMES THROUGH...AND DIFFERENCES IN TIMING THIS FRONT COULD HAMPER WARM UP. SUNDAY & MONDAY...H5 LOW TRACKS ACROSS THE SOUTHERN HIGH PLAINS REGION DURING THIS PERIOD. A STRONG PRESSURE GRADIENT SETS UP ON MONDAY AS A SURFACE LOW SLIDES ACROSS THE REGION AHEAD OF A COLD FRONT. IF THE FRONT PICKS UP MOMENTUM THAN MONDAYS HIGH TEMPERATURES MY NEED ADJUSTED DOWN...AS A DECENT AMOUNT OF COLD AIR IS ADVECTED INTO THE REGION BEHIND THE FRONT. IF THE FRONT COMES IN AFTER PEAK HEATING HOURS MONDAYS TEMPERATURES WILL REMAIN SEASONABLE-UPPER 30S TO LOWER 40S && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND ADVISORY UNTIL 11 AM MST /12 PM CST/ TUESDAY FOR KSZ001>004- 013. WIND ADVISORY FROM 2 AM MST /3 AM CST/ TO 11 AM MST /12 PM CST/ TUESDAY FOR KSZ014>016-027>029-041-042. NE...WIND ADVISORY UNTIL 11 AM MST /12 PM CST/ TUESDAY FOR NEZ079>081. CO...WIND ADVISORY UNTIL 11 AM MST TUESDAY FOR COZ090-091. WIND ADVISORY FROM 2 AM TO 11 AM MST TUESDAY FOR COZ092. && $$ MCGUIRE/JRM/BLM ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 346 AM EST TUE JAN 29 2008 .SYNOPSIS... HIGH PRESSURE CONTINUES TO PUSH FURTHER OFFSHORE TODAY AHEAD OF A COLD FRONT...WHICH WILL CROSS THE REGION EARLY ON WEDNESDAY. WEAK HIGH PRESSURE BUILDING IN FOR MIDWEEK...WITH THE NEXT STORM SYSTEM EXPECTED TO PUSH INTO THE AREA BY FRIDAY. HIGH PRESSURE BUILDS BACK OVER THE REGION BY NEXT WEEKEND. && .NEAR TERM /UNTIL NOON TODAY/... SDGS SHOWED SIGNIFICANT DRY AIR AT H85 TO OVERCOME ON 00Z SNDGS BEFORE ANY PRECIP COULD MITIGATE ITSELF IN THE BL (ESP GSO). BAND OF PRECIP EARLIER MOVD OVER THE ERN PIEDMONT AND ALTHOUGH AT FIRST PRECIP HAD A HARD TIME PUSHING THROUGH...SOME OBS OVER THE PAST FEW HRS HAVE REPORTED VERY -RA/UP BUT NOT MORE THAN A TRACE WAS REPORTED. THIS IS ASSOC WITH A BAND OF WEAK H92 OMEGA SHOWN ON NAM/RUC AND LOCAL WRF. TEMPS HAVE RISEN TO ABV FRG WHERE MID/HIGH LVL RETURNS ON RADAR ARE PRESENT AND THERFORE WILL ADD MENTION OF DZ/SPRINKLES TO MORNING PACKAGE AND TREK IT TO E-NE BEFORE THREAT ENDS BY LATE AM AS FORCING MOVES OFFSHORE. MOST AREAS WILL SEE A TRACE OR LESS...BUT A FEW TENTHS MAY BE POSSIBLE. && .SHORT TERM /NOON TODAY THROUGH WEDNESDAY NIGHT/... LOOK FOR TEMPS TO STILL RECOVER THIS AFTN WITH MAXS IN THE MID 50S N (EVEN WITH AMPLE CLOUD COVER) TO THE LOW 60S S. LOOK FOR BREEZY CONDITIONS TO DEVELOP LATER THIS EVE AND WILL PICK UP AFTER DARK AS DECENT H92 JET AXIS (60-70 KTS) MVNG OVRHD. PRECIP LOOKS TO DVLP LATE EVE/TWRDS MIDNIGHT...AT FIRST WILL BE STRATIFORM (LIGHT). MAIN BATCH OF PRECIP WILL BE DURING THE OVRNT HRS BUT PRECIP LOOKS TO BE LIMITED WITH THIS SYSTEM AS SHRA ACTIVITY WILL BE MOVING AT A QUICK PACE (BUFKIT SUGGESTS 50-60 KTS) AND LACK OF OMEGA/FORCING PRESENT. COULD SEE GUSTS TO 40 MPH FOR A BRIEF TIME WITH ACTUAL COLD FRONTAL PASS (06-12Z). TWRDS 12Z WED MORE LIFT/FORCING IS PRESENT OVER FAR SE CWA (MAINLY NE NC). THIS COULD AID TO MORE WIDESPREAD PRECIP POTENTIAL...BUT STILL FAIRLY LOW (AROUND A QUARTER OF AN INCH POSSIBLE). BULK OF PRECIP LOOKS TO FIRE/DVLP OFFSHORE OF NC (SOUTH AND EAST OF THE CWA). H85 TROF MOVES THROUGH THE REGION 13-17Z (NW/SE) ENDING ANY PRECIP POTENTIAL BEHIND IT. WRLY FLOW WILL AID IN TEMPS RECOVERING LATE AM/EARLY PM BEFORE TEMPS FALL AFTER SUNSET. WINDS DIE OFF WED NIGHT ALLOWING TEMPS TO FALL MAINLY INTO THE 20S (UPPER TEENS SBY AREA). && .LONG TERM /THURSDAY THROUGH MONDAY/... CONDITIONS LOOK MORE FAVORABLE FOR A CAA DAMMING SITUATION TO DVLP THU NIGHT INTO EARLY STAGES OF FRI AHEAD OF NEXT SYSTEM. ALTHOUGH INITIAL START OF PRECIP STILL IN QUESTION FRI AM...BUFKIT SNDGS SUGGEST WET BULB HEIGHTS AT 500-800FT FOR A TIME BEFORE HEIGHTS QUICKLY RISE TO 8-10K FT AS NOSE OF WARM AIR MOVES IN AT H85. HAVE DECIDED TO ADD A SLGHT/LOW CHC OF -RA/FRZ RA TO FAR NW SECTIONS OF THE CWA WITH LOW LVL CAA WEDGE HOLDING TEMPERATURES BLO/AT/NEAR FRZG. IF PRECIP IS DELAYED EVEN FURTHER...THE LIKELIHOOD OF ANY FRZG PRECIP DECREASES. LOOK FOR CHCS OF RAIN TO CONTINUE THROUGH THE DAY FRI AND BREEZY CONDITIONS MAY ONCE AGAIN DVLP (STILL THINK BULK OF PRECIP WILL BE TO THE W/NW OF THE CWA. SYS WILL PUSH NE OF THE FA FRI NIGHT...WITH ONLY A SLGHT CHC OF SHWRS REMAINING OVER THE ERN SHORE AFTER MIDNIGHT. ATTM THE WEEKEND LOOKS GENERALLY QUIET...WITH CLIMO ABV NORMAL HIGH TEMPS IN THE 50S. (LOWS IN THE 30S.) NEXT SYS PROGGED FOR LATE MONDAY/EARLY TUE AS LOW PRES MOVES OVER THE GREAT LAKES LAKES WITH A TRAILING COLD FRONT MOVING ACROSS THE REGION. && .AVIATION /09Z TUESDAY THROUGH SATURDAY/... SOME PTCHY BR DVLPNG ALONG THE COAST DUE TO MAINLY SKC / LGT WNDS. XPCT ANY FOG TO REMAIN ABV 3SM AS SW WNDS PICK UP AS NITE PROGRESSES. OTW...VFR THRU 00Z WITH CLD DECK GRDNLY LWRS FROM 15K FT TO 8K FT. PUSHED BACK ANY SHWRS UNTIL AFTR 00Z FROM RIC-SBY. DON`T SEE MUCH IF ANY PCPN AT SERN TAF SITES DUE TO SE RIDGE HOLDING IN PLACE. SW GRDNT INCRS AFTR 21Z OR SO WITH GUSTS AOA 20 KT XPCTD. LWR CIGS/VSBYS MAY BE SEEN WITH SHRA ACTIVITY WITH COLD FRONTAL PASSAGE WED AM. && .MARINE... SEAS SLOWLY SUBSIDING THIS AM AND JUST WENT BLO SCA AS OF 3 AM. SO WILL LOWER SHORT TERM SCA WITH THIS PACKAGE. XPCT A BRIEF LULL FROM HEADLINES TDY AS SERN RIDGE KEEPS WNDS AOB 15 KT. P-GRDNT INCRS AFTR 21Z AHEAD OF NXT FRNT. WNDS INCRS DRAMATICALLY TONITE WITH IMPRESSIVE 50+ KT H92 JET PROGGED AFTR MIDNITE. FOR NOW...WILL CAP GUSTS AT 30 KT ACROSS WTRS TONITE. THNKG IS THAT ANY 35 KT WNDS WUD BE CONVECTIVELY INDUCED...WHICH WUD BE HANDLED WITH MWS/SMW`S. DESPITE DECENT ADVECTION BEHIND BNDRY WED...H85 TMP DROP NOT THAT IMPRESSIVE. THAT BEING SAID...CAN NOT RULE OUT A FEW GUSTS TO GALE FORCE ACROSS THE CSTL WTRS & MOUTH OF BAY WITH FROPA WED AM...BUT CONFIDENCE NOT HIGH ENUF TO GO WITH A WDSPRD GALE WRNG ATTM. SO WILL CAP WNDS JUST BLO GALES FOR NOW. QUICK MOVG SYSTMS CONT THIS WEEK AS YET ANTHR CHC FOR SCA FLAGS COMES LATE THU NITE AND FRI AS SE WNDS INCRS AHEAD OF LOW PRS PROGGED TO DEEEPEN AS IT LIFTS NE ALONG MTS. TRAILING CDFRNT CROSSES WTRS FRI NITE. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 4 PM EST WEDNESDAY FOR ANZ630>633-650-652-654-656-658. && $$ SYNOPSIS...CCW NEAR TERM...CCW SHORT TERM...CCW LONG TERM...CCW/SMF AVIATION...MPR MARINE...MPR md AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1225 AM EST TUE JAN 29 2008 UPDATED FOR AVIATION .SYNOPSIS... 20Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED A TROUGH OVER THE GULF OF ALASKA...A TROUGH ACROSS THE INTERMOUNTAIN WEST...AND RIDGING FROM THE SOUTHERN MISSISSIPPI VALLEY INTO THE EASTERN GREAT LAKES. ALSO WITHIN THE WESTERN TROUGH TO NOTE FOR THE SHORT TERM IS A SHRTWV IN NW KANSAS. SW FLOW BETWEEN THE TROUGH AND RIDGE HAS BROUGHT UPPER LEVEL MOISTURE FROM THE EAST PACIFIC INTO THE CWA...NOTED BY EXTENSIVE HIGH CLOUDS. HOWEVER...ENOUGH SUN WAS ABLE TO PENETRATE THROUGH TO COMBINE WITH THE BREEZY SW FLOW AND WARM 850MB TEMPS (6C AT GRB AND 12C AT MPX) TO BRING TEMPS UP CLOSE TO RECORD LEVELS. THE HIGH TEMP REACHED 41F AT THE OFFICE...JUST 2 DEGREES SHY OF THE RECORD. MORE THICKER CLOUDS CAN BE SEEN ON VISIBLE IMAGERY APPROACHING THE CWA FROM TWO DIFFERENT DIRECTIONS... AND THESE WILL COME INTO PLAY FOR THE FORECAST TONIGHT. THE FIRST IS TO THE SOUTH...STRETCHING FROM SOTUEHRN LAKE MICHGIAN DOWN INTO THE OHIO VALLEY. RADAR AND SURFACE OBS INDICATE SOME LIGHT RAIN TOO WITH THESE CLOUDS. THIS AREA IS BEING SUPPORTED BY ISENTROPIC LIFTING THROUGH THE STRONG WARM ADVECTION PATTERN...NOTED BY 850MB WINDS OF 50-70KT FROM CENTRAL OKLAHOMA INTO NORTHERN ILLINOIS FROM LATEST PROFILERS. THE OTHER AREA OF THICK CLOUDS IS OVER THE DAKOTAS INTO MN...DUE TO A COMBINATION OF DPVA AHEAD OF THE NW KANSAS SHRTWV... UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A 100-120KT JET OVER EASTERN NORTH DAKOTA AND UPPER DIVERGENCE IN THE LEFT EXIT REGION OF A 100-120 KT JET EXTENDING FORM NEW MEXICO INTO EASTERN NEBRASKA. SOME LIGHT RAIN HAS ALSO BEEN REPORTED OUT OF THESE CLOUDS. AT THE SURFACE...A 982MB LOW IS LOCATED IN NE SOUTH DAKOTA. VERY CHILLY AIR FLOWING IN BEHIND THE LOW...NOTED BY SURFACE TEMPS IN THE TEENS AND 20S BELOW ZERO OVER ALBERTA...SASKATCHEWAN AND EASTERN MONTANA (850MB TEMPS ARE BELOW -30C). LAST ITEM TO NOTE IS THE STRENGTH OF THE SHRTWV AT THE BASE OF THE WESTERN TROUGH IN NEVADA...WHICH IS NOTED BY LIGHTNING STRIKES OVER UTAH. && .SHORT TERM (TONIGHT AND TUE)... UPPER LEVEL FLOW REMAINS FAIRLY PROGRESSIVE THROUGH THIS PERIOD... LIKELY DUE TO THE TROUGH OVER THE GULF OF ALASKA CONTINUING TO MARCH SE TOWARDS THE PACIFIC NW. THIS PROGRESSION COMES INTO PLAY A BIT MORE IN THE LONG TERM PORTION OF THE FORECAST. FOR TONIGHT...FOCUS IS ON THE TWO FEATURES MENTIONED IN THE SYNOPSIS...THE SHRTWV LIFTING NE OUT OF NW KANSAS...AND THE AREA OF ISENTROPIC LIFT COMING UP THROUGH SOUTHERN LAKE MICHIGAN. SHRTWV LIFTING OUT OF NW KANSAS SHOULD MOVE INTO WI BY 06Z...THEN INTO NE ONTARIO BY 12Z. DPVA AHEAD OF THIS SHRTWV...COMBINED WITH SOME JET COUPLING FROM THE TWO JET AREAS ALSO LIFTING NE...SHOULD BRING SOME LIGHT RAIN INTO THE WESTERN CWA THIS EVENING. PCPN MAY CHANGE TO SNOW AFTER MIDNIGHT AS COOLER AIR WORKS IN...THOUGH AFTER 06Z THE DYNAMICAL FORCING BEGINS TO WANE...SO SNOW ACCUMULATION AT THIS POINT LOOKS MINIMAL. OVER THE EASTERN CWA...AREA OF ISENTROPICALLY LIFTED RAIN IS PROGGED TO MOVE IN THIS EVENING...THEN ALSO EXIT AFTER MIDNIGHT. THE CENTRAL U.P. IS IN THE MIDDLE OF THESE TWO FEATURES...AND IT IS ENTIRELY POSSIBLE THAT VERY LITTLE MAY HAPPEN OTHER THAN DRIZZLE ONCE LOWER CLOUDS DEVELOP. THEREFORE...HIGHEST POPS ARE CONCENTRATED FOR THE WESTERN AND FAR EASTERN CWA...AND BEFORE 06Z. BREEZY SOUTH TO SOUTHWEST WINDS WILL DIMINISH SOME THROUGH THE NIGHT AS THE LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT APPROACH. HOWEVER...CLOUD COVER AND SOME WIND...COMBINED WITH RELATIVELY HIGH DEWPOINTS SHOULD HELP KEEP READINGS UP UNTIL THE FRONT PASSES THROUGH (FRONT PROGGED TO BE LOCATED IN THE CENTRAL U.P. AT 12Z TUE). ONLY SLIGHT ADJUSTMENTS MADE TO LOWS. FOR TUE...THE MORNING LOOKS FAIRLY QUIET PCPN WISE AS THE AREA IS PUT IN OVERALL Q-VECTOR DIVERGENCE...CAUSED BY SUBSIDENCE ALOFT IN THE WAKE OF TONIGHTS SHRTWV AND COLD ADVECTION OCCURRING AS THE FRONT CONTINUES TO MOVE ACROSS. THE COLD ADVECTION AT THIS POINT DOES NOT LOOK COLD ENOUGH IN THE MORNING TO GENERATE ANY LAKE EFFECT OFF WESTERN LAKE SUPERIOR. FOCUS OF ATTENTION THEN SHIFTS TO THE MAIN UPPER TROUGH MOVING THROUGH THE WESTERN U.S.. DPVA AHEAD OF THE SHRTWV AT THE BASE OF THE TROUGH SHOULD GENERATE A LOW ALONG THE COLD FRONT THAT WAS MOVING THROUGH THE CWA TONIGHT. THIS LOW IS PROGGED TO LIFT WITH THE SHRTWV FROM SE KANSAS AT 12Z UP INTO SW LOWER MI BY 00Z WED. DPVA AHEAD OF THE SHRTWV...IN CONJUNTION WITH DPVA FROM THE NORTHERN PORTION OF THE TROUGH MOVING INTO NORTHERN MN...AND MID-LEVEL FRONTOGENESIS INDICATED TO MOVE IN SHOULD HELP EXPAND SNOW INTO THE CWA IN THE AFTERNOON. THE HIGHEST POPS ARE CONFINED TO THE WESTERN U.P....WHERE THE COLD AIR IS NOW COLD ENOUGH (850MB TEMPS DROP TO -16 TO -21C BY 00Z) TO GENERATE LAKE EFFECT...AND ALONG THE WISCONSIN BORDER WHERE DPVA FORCING IS MAXIMIZED. SNOWFALL AMOUNTS IN THE GENERAL 1 TO 3 INCH RANGE SEEM REASONABLE...GREATEST IN THE FAR WEST WITH LAKE ENHANCMENT AND FAR SOUTH CENTRAL CLOSER TO THE LOW TRACK. NEW 18Z NAM MIGHT SUGGEST MORE FOR THE SOUTH CENTRAL...AND GIVEN THE UPCOMING WINDS AND SNOW FOR TUE NIGHT...A WATCH IS BEING ISSUED FOR MENOMINEE COUNTY TO SRN SCHOOLCRAFT. TEMPS WILL BE ON THE DECLINE THROUGH THE DAY WITH THE PASSAGE OF THE COLD FRONT...WITH READINGS DROPPING INTO THE SINGLE DIGITS NEAR IWD BY SUNSET. .LONG TERM (TUE NIGHT THRU MON)... DANGEROUS WINTER CONDITIONS APPEAR TO BE SHAPING UP FOR PORTIONS OF THE FCST AREA TUE NIGHT INTO WED. FIRST UP...SNOW ASSOCIATED WITH SHORTWAVE/SFC WAVE AND A BAND OF FAIRLY IMPRESSIVE MIDLEVEL FRONTOGENESIS WILL STREAK NNE THRU THE FCST AREA TUE EVENING... ESPECIALLY CNTRL/ERN PORTIONS. WHILE THIS LOOKS LIKE AN ADVY EVENT WITH REGARD TO SNOW AMOUNTS...THERE IS THE POTENTIAL THAT THE STRENGTH OF SYSTEM MAY LEAD TO MORE SNOW THAN CURRENTLY EXPECTED. NAM HAS BEEN TRENDING HEAVIER WITH PCPN AMOUNTS. IN FACT...18Z RUN HAS 0.75 TO 1 INCH OF PCPN OVER THE CNTRL/ERN FCST AREA. WINDS/BLSN WILL ALSO BE A COMPLICATING FACTOR. IN LIGHT OF THE NAM SOLUTIONS... HAVE OPTED TO CARRY A WINTER STORM WATCH FOR MENOMINEE TO SRN SCHOOLCRAFT THRU TUE NIGHT TO HIGHLIGHT THE POTENTIAL FOR MORE SIGNIFICANT SNOW/BLSN. LATER SHIFTS CAN THEN ADJUST TO SNOW/BLSN ADVY OR UPGRADE TO WARNING IF THE NAM IS ACTUALLY ONTO SOMETHING. ATTENTION THEN TURNS TO LAKE EFFECT AND STRONG WINDS ACROSS LAKE SUPERIOR. LES WILL SWING INTO HIGH GEAR AS ARCTIC SURGES OVER THE UPPER GREAT LAKES. HOWEVER...WITH SUCH STRONG/INTENSE CAA (850MB TEMPS PLUMMET TO AROUND -25C...POSSIBLY AS LOW AS -30C BY 12Z WED)...THERE WILL ONLY BE A SHORT WINDOW FOR FAVORABLE DENDRITIC SNOW GROWTH BEFORE THE COLUMN BECOMES TOO COLD FOR DENDRITES. SO... DO NOT EXPECT SNOW ACCUMULATIONS TO GET OUT OF HAND...ESPECIALLY OVER THE W WHERE SHORT FETCH/STRONG WINDS WILL MINIMIZE HEATING OF THE BOUNDARY LAYER FROM THE LAKE WHICH WOULD IMPROVE SNOW GROWTH. SHOULD ONLY SEE ADVY AMOUNTS THERE. LONGER FETCH/WARMING INTO THE NE FCST AREA MAY OFFER BETTER SNOW GROWTH...SO AMOUNTS MIGHT REACH WARNING CRITERIA THERE. THE BIG COMPLICATING FACTOR WILL BE THE STRONG BOUNDARY LAYER WINDS AND VERY UNSTABLE TEMP PROFILE OVER THE LAKE ENSURING EFFICIENT MIXING. WINDS IN THE MIXED LAYER SHOULD REACH 35 TO 50KT (HIGHEST OVER THE E HALF OF LAKE SUPERIOR)... PROVIDING AN INDICATION OF POSSIBLE GUST SPEEDS. WITH SNOWFLAKE SIZE BECOMING VERY SMALL AND MUCH MORE EFFECTIVE AT REDUCING VSBY... STRONG WINDS AND CONSIDERABLE BLSN WILL LIKELY RESULT IN BLIZZARD CONDITIONS AT SOME POINT TUE NIGHT INTO WED MORNING FOR THE KEWEENAW TO ONTONAGON AND MUNISING EWD. HAVE THUS CHANGED WINTER STORM WATCH TO BLIZZARD WATCH TO PROVIDE INCREASED AWARENESS OF THE POTENTIAL FOR LONG DURATION LOW VIS IN SNOW/BLSN. EXPECT ADVY HEADLINES FOR SNOW/BLSN AND/OR WIND CHILLS FOR THE REMAINING COUNTIES NOT UNDER WATCHES. LES WILL CONTINUE WED...BUT WINDS WILL SLOWLY DIMINISH THRU THE DAY. DUE TO VERY COLD/DRY AIRMASS...SNOW ACCUMULATIONS SHOULD ONLY BE IN THE 1-4INCH RANGE IN THE LAKE EFFECT AREAS. AS FOR TEMPS...FAVORED THE LOWER END OF GUIDANCE FOR MIN TEMPS TUE NIGHT AND FOR MAX TEMPS WED GIVEN THE VERY COLD AIR CURRENTLY OBSERVED UPSTREAM WITHIN THE AIRMASS. WITH LATE AFTN SFC TEMPS IN ALBERTA/SRN SASKATCHEWAN AND ERN MT RANGING FROM -10F TO -25F...IT`S QUITE POSSIBLE TEMPS REFLECTED IN THIS FCST ISSUANCE MAY BE TOO HIGH. THU THRU MON...MEDIUM RANGE MODELS ARE STILL ADVERTISING AN ACTIVE STORM TRACK TO CONTINUE ACROSS THE CONUS INTO THE WEEKEND AND BEYOND AS A SERIES OF SHORTWAVES DROP SE THRU THE GULF OF ALASKA INTO THE WRN STATES AND THEN LIFT E OR NE ACROSS THE CNTRL AND ERN CONUS. SYSTEMS WILL BE SIGNIFICANT PCPN PRODUCERS WITH STRONG GULF OF MEXICO MOISTURE CONNECTIONS. AT THE BEGINNING OF THIS FCST PERIOD...ATTENTION WILL BE ON THE POTENT SHORTWAVE OVER THE SRN PLAINS. THERE IS A LITTLE MORE DISAGREEMENT TODAY IN WHAT THE TRACK OF THE SYSTEM WILL BE AS IT HEADS NE. THE GFS/GFS ENSEMBLES AND GLOBAL CANADIAN ARE INDICATING SYSTEM WILL PROBABLY PASS A LITTLE TOO FAR TO THE SE TO HAVE A BIG AFFECT ON THE WEATHER HERE. HOWEVER...THE ECMWF CONTINUED ITS NW TREND (LAST 4 RUNS THRU 00Z RUN...BUT THE 12Z RUN HAS SHIFTED BACK TO THE SE A LITTLE) AND THE UKMET PROVIDES SUPPORT. THESE SOLUTIONS WOULD PROVIDE A POSSIBLE ADVY SNOWFALL OVER THE SE PART OF THE FCST AREA. SO IN THE END... THIS WILL CONTINUE TO BE A SYSTEM TO WATCH...AND BEST COURSE OF ACTION WILL BE TO STAY CLOSE TO PREVIOUS FCST WHICH DID BRING CHC POPS TO MOST OF THE CNTRL/ERN FCST AREA FRI WITH ASSUMPTION THAT THE NW FRINGE OF THE SYSTEM MIGHT REACH THE AREA. THERE IS REASONABLE AGREEMENT THAT A MUCH WEAKER SHORTWAVE TAKING A MORE NRN ROUTE WILL PASS THRU THE UPPER LAKES SAT. CHC POPS ACROSS THE FCST AREA ARE WARRANTED FOR THIS FEATURE. NEXT POTENT SHORTWAVE DROPPING INTO THE WRN CONUS DURING THE WEEKEND WILL BEGIN TO EDGE OUT INTO THE WRN PLAINS MON. RECENT ECMWF/GFS RUNS HAVE HAD A STRONG SIGNAL FOR THIS TO BE A MAJOR STORM SYSTEM AS IT HEADS ACROSS THE PLAINS TOWARD THE GREAT LAKES EARLY NEXT WEEK. LEADING EDGE OF EXPANDING PCPN SHIELD SHOULD BEGIN TO AFFECT THE AREA MON. DEPENDING ON STRENGTH AND TRACK OF SYSTEM...THERE COULD BE MIXED PCPN ISSUES...BUT ONLY SNOW WILL BE MENTIONED FOR NOW. AFTER THU...DAILY TEMPS SHOULD BE A LITTLE ABOVE NORMAL THRU MON (NORMALS ARE ROUGHLY IN THE SINGLE DIGITS ABOVE ZERO FOR MINS AND MD 20S FOR MAXES). && .AVIATION (FOR THE 06Z TAF ISSUANCE)... LOW CLOUDS TAKING SHAPE AT BOTH TAF SITES AS PCPN MOVES ACROSS THE AREA THIS EVENING. FOR CMX...PREVAILING PCPN TYPE BY 06Z MAY BE MORE SNOW AS COLDER AIR FILTERS IN FROM THE WEST. BEST FORCING AND MOISTURE WILL DEPART NE OF AREA BY LATE TONIGHT SO EXPECT PCPN TO END TOWARD 12Z. UNTIL THEN KEPT IN PREVAILING MVFR CONDITIONS IN LIGHT SNOW WITH A TEMPO GROUP FOR IFR CONDITIONS IN HEAVIER SNOW SHOWERS FM 06-10Z. A COLD FRONT MOVING IN LATE TONIGHT/EARLY TUE WILL RAPIDLY INCREASE THE WRLY WINDS WITH GUSTS TO 30 KT BY SUNRISE...BUT AIR COLD ENOUGH TO PRODUCE LAKE EFFECT SNOW WILL NOT ARRIVE UNTIL AFT 18Z. BY 19Z...CONBINATION OF LES AND SHOULD LOWER PREVAILING VBSY DOWN TO 2SM. INCLUDED A TEMPO GROUP 20-24Z FOR 1/4SM IN SNOW/BLOWING SNOW WITH IFR CIGS. EXPECT LIFR CONDITIONS BY 00Z IN SNOW AND BLOWING SNOW. AT SAW...WARM MOIST FLOW MOVING OVER SNOWPACK SHOULD ALLOW FOR PREVAILING MVFR CONDITIONS WITH CIGS PERHAPS BORDERING ON IFR LATE TONIGHT UNDER DZ SCENARIO. THE COLD FRONT MOVING IN TUE MORNING SHOULD RAISE CEILINGS BACK INTO THE HIGH MVFR RANGE BY LATE MORNING. ARRIVAL OF ARCTIC AIR AND WAVE MOVING UP BACKSIDE OF COLD FRONT SHOULD RESULT IN PREVAILING MVFR VSBYS IN SNOW BY 21Z WITH A TEMPO GROUP 21-24Z FOR IFR CONDITIONS IN SNOW AND BLOWING SNOW. STRONG WEST-NORTHWEST FLOW BY EVENING WILL RESULT IN MVFR CIGS WITH VSBYS AROUND 4SM IN SNOW AND BLOWING SNOW. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... SOUTHERLY GALES OVER EASTERN LAKE SUPERIOR WILL DIMINISH BELOW GALES JUST AFTER MIDNIGHT AS LOW PRESSURE OVER NE SOUTH DAKOTA LIFTS INTO NORTHERN ONTARIO. EXPECT WINDS TO SWITCH TO THE WEST LATE TONIGHT IN THE WAKE OF THE LOWS COLD FRONT...WITH 30 KT SPEEDS LIKELY ON TUE AS ARCTIC AIR FLOWS IN. LOW PRESSURE IS PROGGED TO DEVELOP ALONG THE COLD FRONT AND LIFT TOWARDS FAR EASTERN UPPER MI TUE NIGHT. DEPENDING ON THE TRACK...THERE IS A POSSIBILITY FOR NORTHWEST STORM FORCE WINDS TUE NIGHT...ESPECIALLY ON EASTERN LAKE SUPERIOR. IN ANY EVENT...GALES LOOK LIKE TUE NIGHT ACROSS THE ENTIRE LAKE. WINDS WILL DIMINISH SLOWLY ON WED AND THEN MORE SO WED NIGHT AS A RIDGE OF HIGH PRESSURE BUILDS INTO LAKE SUPERIOR. BEYOND WED NIGHT...THE ONLY SYSTEM OF INTEREST TO BRING POTENTIALLY HIGHER WINDS IS ON FRIDAY WHEN A LOW LIFTS UP FROM THE LOWER MISSISSIPPI VALLEY INTO THE EASTERN GREAT LAKES. RIGHT NOW...WINDS LOOK TO REMAIN BELOW 30 KT AS THE SYSTEM STAYS FAR ENOUGH SOUTH OF LAKE SUPERIOR. WITH THE ARCTIC AIR FLOWING IN ON TUESDAY...HEAVY FREEZING SPRAY WILL BECOME AN ISSUE...BEGINNING IN THE AFTERNOON IN THE FAR WEST...THEN SPREADING EAST TUE NIGHT. HEAVY FREEZING SPRAY WILL DIMINISH WEDNESDAY NIGHT AS WINDS RELAX WITH THE INCOMING HIGH PRESSURE RIDGE. && .MQT WATCHES/WARNINGS/ADVISORIES... MICHIGAN... BLIZZARD WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY AFTERNOON FOR MIZ001>003. BLIZZARD WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING FOR MIZ006-007-085. WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING FOR MIZ012>014. LAKE SUPERIOR... GALE WARNING UNTIL 1 AM EST TUESDAY FOR LSZ266-267. HEAVY FREEZING SPRAY WARNING FROM 7 PM TUESDAY TO 7 AM EST THURSDAY FOR LSZ263-264. LAKE MICHIGAN... GALE WARNING UNTIL 1 AM EST TUESDAY FOR LMZ248-250. && $$ SHORT TERM...AJ LONG TERM...ROLFSON AVIATION...VOSS MARINE...AJ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SEATTLE WA 930 PM PST MON JAN 28 2008 .SYNOPSIS...SNOW OVER PARTS OF THE LOWLANDS WILL CHANGE OVER TO RAIN BY LATE TONIGHT. THE EXCEPTION WILL BE WESTERN WHATCOM COUNTY WHERE SNOW WILL PERSIST INTO EARLY TUESDAY MORNING. HEAVY SNOW WILL FALL IN THE MOUNTAINS TUESDAY AND TUESDAY NIGHT. ANOTHER FRONTAL SYSTEM WILL BRING MORE RAIN AND MOUNTAIN SNOW TO THE AREA ON WEDNESDAY. EXPECT A COOL AND MOIST WEATHER PATTERN TO CONTINUE THROUGH EARLY NEXT WEEK. && .SHORT TERM... MODERATE WAA HAS CHANGED THE SNOW OVER TO A CHILLY RAIN OR A RAIN/ SNOW MIX AT MOST LOCALES. THERE WERE POCKETS OF LIGHT SNOW ACROSS THE N COAST AND STRAIT OF JUAN DE FUCA...WITH MORE WIDESPREAD SNOW OCCURRING OVER WRN WHATCOM COUNTY. THE SNOW OVER THE N COAST AND THE STRAIT WILL CHANGE OVER TO RAIN OR A RAIN/SNOW MIX BY LATE TONIGHT. HOWEVER SNOW WILL PERSIST OVER THE WRN WHATCOM COUNTY WHERE THE DEPTH OF THE COLD AIR WAS DEEPER. THEREFORE WILL CANCEL THE SNOW ADVISORY FOR ALL AREAS EXCEPT WRN WHATCOM COUNTY. ELSEWHERE...WHERE THERE WERE POCKETS OF LIGHT SNOW...AMOUNTS SHOULD BE NEAR AN INCH OR LESS BEFORE THE SNOW ENDS. MEANWHILE...A VIGOROUS CDFNT OFFSHORE WILL MOVE ONTO THE COAST LATE TONIGHT OR EARLY TUE. EXPECT INCREASING SLY WINDS AHEAD OF THIS FRONT. THERE MAY BE SOME LOCALIZED SPOTS IN THE NW INTERIOR WHERE SPEEDS COULD APPROACH WIND ADVISORY CRITERIA. STRONG UPSLOPE FLOW WILL RESULT IN PERIODS OF HEAVY SNOW ACROSS THE OLYMPICS AND CASCADES...ESPECIALLY DURING THE DAY TUE. ANTICIPATE POST-FRONTAL SHOWERY WEATHER TUE NIGHT. A PUGET SOUND CONVERGENCE ZONE WILL LIKELY DEVELOP EARLY TUE NIGHT. THE AIR MASS WILL ONCE AGAIN BECOME CHILLY...SO DO NOT BE SURPRISED TO SEE SOME SNOW OVER SRN SNOHOMISH COUNTY TUE NIGHT WITHIN THE CONVERGENCE ZONE. ANOTHER STRONG SYSTEM WILL AFFECT THE AREA ON WED FOR MORE RAIN AND SIGNIFICANT MOUNTAIN SNOW. .LONG TERM FROM THE PREV DISCUSSION...RATHER LOW AMPLITUDE LONG WAVE RIDGING WILL PERSIST BETWEEN 155W AND 160W THROUGH THE PERIOD...AND SHORT WAVE TROUGHS WILL DROP SE BETWEEN OUR AREA AND CENTRAL OREGON. WEATHER WILL BE COOL AND WET...AND PREFRONTAL PRECIPITATION IN THE FORM OF SNOW AT TIMES IS NOT OUT OF THE QUESTION. THE MOUNTAIN SNOWPACK WILL BUILD NICELY. MODELS ARE CONSISTENT WITH THE PATTERN BUT DIFFER ON TIMING AND EXACT TRACK OF SYSTEMS. FORECASTS WILL GENERALLY BE BROAD BRUSHED. ALBRECHT && .AVIATION....MVFR CEILINGS TO CONTINUE OVERNIGHT WITH LOCALIZED SPOTS OF IFR. EXPECTING TO SCALE BACK ON MENTION OF SNOW IN THE UPCOMING TAF PACKAGE. MOST RECENT RUN OF RUC MODEL PUTS FREEZING LEVEL NEAR 1500 FEET AT 06Z. KSEW PROFILER DATA AT 03Z SUGGESTS FREEZING LEVEL IS ALREADY AT LEAST THAT HIGH. COMBINE THIS WITH DECENT SOUTHERLY WIND AT THE SURFACE AND MANY DEWPOINTS AT OR ABOVE FREEZING...AND SNOW CHANCES DECREASE. WILL MENTION POSSIBLE RAIN AND SNOW MIX EARLY AT MOST INTERIOR TERMINALS...BUT OVERALL TREND WILL BE TOWARD STRAIGHT RAIN BY 09Z OR SO. THE ONLY TERMINAL WHICH WILL BE ALL SNOW WILL BE BELLINGHAM UNTIL 10 OR 12Z...WHEN SOUTHERLIES SCOUR OUT COLD AIR AT THE SURFACE. MESOSCALE MODELS BRING WINDS NEAR 5000 FT UP TO 50 KNOTS OUT OF THE S AND SW NEAR AND JUST AHEAD OF FRONTAL PASSAGE BETWEEN 09Z AND 15Z. WINDS ALOFT BECOMING WESTERLY BEHIND THE FRONT LATER TUESDAY MORNING INTO THE AFTERNOON. THIS MAY FAVOR RAIN SHADOWING AT SOME OF THE PUGET SOUND TERMINALS AND A POSSIBLE IMPROVEMENT IN CEILINGS. FOR KSEA...HAVE DECIDED TO REMOVE MENTION OF PRECIP AS ALL SNOW. A MIX OF RAIN AND SNOW IS POSSIBLE UNTIL ABOUT 09Z...BUT IT SHOULD BE ALL RAIN THEREAFTER. NO SNOW ACCUMULATION IS ANTICIPATED AT THIS TIME. MVFR CEILINGS WILL BE THE RULE OVERNIGHT. AS PREVIOUSLY MENTIONED...SOUTHERLY WINDS AT 5000 FT WILL APPROACH 50 KNOTS BETWEEN 09Z AND 15Z NEAR AND WITH FRONTAL PASSAGE. SURFACE WINDS WILL BECOME GUSTY OUT OF THE SOUTHWEST BEHIND THE FRONT EARLY TUESDAY MORNING...POSSIBLY UP TO 25 KNOTS OR SO AT TIMES. 27 && .MARINE...WILL BE KEEPING EXISTING ADVISORIES AND WARNINGS FOR NOW. POST FRONTAL WINDS OVER INTERIOR WATERS...NAMELY PUGET SOUND...MAY APPROACH GALE EARLY TUESDAY MORNING. WILL TAKE A CLOSER LOOK FOR THE NEXT FORECAST PACKAGE. 27 && .AVALANCHE...AVALANCHE WARNING FOR WASHINGTON CASCADES, OLYMPICS AND MT HOOD AREA FOR EARLY TUESDAY MORNING THROUGH TUESDAY NIGHT. NUMEROUS WEAK LAYERS IN PLACE AS WELL AS FIRM UNDERLYING CRUSTS TO PROVIDE SLIDING SURFACES. INCOMING STRONG WINDS AND HEAVY LOADING WILL TIP THE BALANCE AND MAKE FOR WIDESPREAD AVALANCHES TUESDAY. SEE NWAC.US FOR FORECAST DETAILS. KK && .SEW WATCHES/WARNINGS/ADVISORIES... WA...HEAVY SNOW WARNING UNTIL 4 AM PST WEDNESDAY FOR THE OLYMPICS AND CASCADES. SNOW ADVISORY UNTIL 7 AM PST TUESDAY FOR WESTERN WHATCOM COUNTY. AVALANCHE WARNING IN EFFECT FOR THE OLYMPICS AND CASCADES TUE. PZ...SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR CONDITIONS. GALE WARNING STRAIT OF JUAN DE FUCA-COASTAL WATERS. SMALL CRAFT ADVISORY REMAINING WATERS. $$ WEATHER.GOV wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 309 AM CST TUE JAN 29 2008 .DISCUSSION...FORECAST FOCUS IS ON COLD FRONT AND ASSOCIATED WEATHER. MODELS INDICATE VERY STRONG COLD FRONT WILL SWEEP ACROSS CWA TODAY...BEGINNING IN THE MORNING FAR WEST AND REACHING THE EAST BY MID OR LATE AFTERNOON. 06Z NAM HAS BACKED OFF QPF AMOUNTS TO BE MORE IN LINE WITH HPC..GFS AND ECMWF. TOTAL AMOUNTS NOW EXPECTED TO BE BETWEEN 1 AND 3 INCHES. VERY DRY AIR WILL FOLLOW A FEW HOURS BEHIND THE H850 BAROCLINIC ZONE WHICH WILL SHUT DOWN ACCUMULATING SNOW. MODELS ARE IN LINE WITH BRINGING IN STRONG NORTHWEST WINDS BEHIND THE FRONT. H850 WINDS INCREASE TO AROUND 50KT AROUND 00Z. HOWEVER...BEST 3 HOUR PRESSURE FALLS ARE DIVING TOWARD OKLAHOMA AT THIS TIME ACCORDING TO LATEST RUC WITH AGREES WITH NAM GUIDANCE...AND THE STRONGEST WINDS SHOULD HEAD SOUTH WITH THE PRESSURE FALLS. TEMPERATURES WILL BE FALLING FROM EARLY MORNING HIGHS IN THE WEST...AND LATE MORNING IN THE EAST. THE COMBINATION OF SNOW...BLOWING SNOW...STRONG WINDS...PLUNGING TEMPERATURES...REDUCED VISIBILITIES IN BLOWING SNOW AND DANGEROUS WIND CHILLS HAS PR OPTED THE WINTER STORM WARNING RATHER THAN ANY SINGLE ELEMENT. IN ADDITION...THESE EVENTS WILL LIKELY OCCUR AT A TIME OF HEAVIER TRAFFIC. IT APPEARS THAT THE SNOW WILL SHUT DOWN QUICKLY THIS EVENING. HOWEVER...THE WINDS WILL BE INCREASING AND BLOWING SNOW WILL CONTINUE. WIND CHILLS WILL REACH ADVISORY CRITERIA. WEDNESDAY WILL SEE THE START OF MODERATING TEMPERATURES. A GRADUAL WARMING TREND WILL CONTINUE INTO THE WEEKEND. NO SIGNIFICANT SNOW ACCUMULATIONS ARE EXPECTED WEDNESDAY AND THROUGH THE WEEKEND. HOWEVER...A STORM SYSTEM IS EXPECTED TO PASS WELL SOUTH OF WISCONSIN THURSDAY NIGHT AND FRIDAY. THE GFS IS BASICALLY ALONE IN GENERATING SOME LIGHT ACCUMULATIONS IN THE CWA DURING THIS PERIOD. AMOUNTS IF ANY OCCUR WILL BE LESS THAN 3 INCHES. && .AVIATION...SOUTH WINDS AHEAD OF STRONG LOW PRESSURE NEAR LAKE SUPERIOR WILL BRING MVFR CEILINGS EARLY THIS MORNING. CEILINGS DROP FURTHER TO NEAR 1000 FT TUESDAY MORNING...AND TO NEAR LIFR CONDITIONS BY TUE AFTERNOON IN ADVANCE OF A STRONG COLD FRONT. EXPECT ANY RAIN TO CHANGE TO A SLEET AND FREEZING RAIN MIX BEFORE CHANGING TO ALL SNOW BEHIND THE COLD FRONT. THE PRECIPITATION SHOULD INCREASE AS A SECONDARY LOW MOVES UP THE FRONT LATER THIS AFTERNOON. WINDS WILL SHIFT TO THE NORTHWEST AND INCREASE TO 25 KNOTS WITH GUSTS TO OVER 40 KNOTS. && .MARINE...GUSTY SOUTHERLY WINDS SHOULD SLACKENING THIS MORNING AHEAD OF A STRONG COLD FRONT THAT WILL PUSH ACROSS THE NEARSHORE WATERS THIS AFTERNOON. NORTHWEST GALES TO 40 KNOTS EXPECTED ALTHOUGH SOME ISOLATED GUSTS TO 50 KNOTS ARE POSSIBLE. BITTERLY COLD AIR TO POUR IN BEHIND STRONG COLD FRONT WITH SINGLE DIGITS OR BELOW ZERO TUESDAY NIGHT. WITH THE STRONG WINDS TO CONTINUE...HEAVY FREEZING SPRAY WARNING IS IN EFFECT FOR TONIGHT. && .MKX WATCHES/WARNINGS/ADVISORIES... WI...WINTER STORM WARNING FROM 2 PM THIS AFTERNOON TO MIDNIGHT CST TONIGHT FOR WIZ046-047-051-056>058-062>064-067>069. WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 12 PM CST WEDNESDAY FOR WIZ046-047-051-052-056>060-062>072. WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO MIDNIGHT CST TONIGHT FOR WIZ052-059-060-065-066-070>072. LM...HEAVY FREEZING SPRAY WARNING FROM 6 PM THIS EVENING TO 6 AM CST WEDNESDAY FOR LMZ643>646. GALE WARNING UNTIL 6 AM CST WEDNESDAY FOR LMZ643>646. && $$ SHORT/LONG TERM...35/06 AVIATION/MARINE...06 wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ST LOUIS MO 926 AM CST TUE JAN 29 2008 .UPDATE... FIRST OF I AM SURE MANY UPDATES COMING OUT SHORTLY...WITH NEAR RECORD HIGH TEMPERATURES NOW EXPECTED ALONG THE I-44 CORRIDOR IN MISSOURI AS SKY HAS CLEARED AHEAD OF THE FRONT. RECORD HIGH FOR TODAY AT KSTL IS 67 (1988). THIS WILL ALSO YIELD SURFACE BASED CAPE VALUES BETWEEN 500 AND 700 J/KG EARLY THIS AFTERNOON AHEAD OF THE FRONT...WHICH IS MORE THAN ADEQUATE FOR THUNDERSTORM DEVELOPMENT GIVEN SUCH STRONG FORCING WITH THE COLD FRONT. WITH 0-6KM BULK SHEAR VALUES NEARING 75KTS...SEVERE THUNDERSTORMS ARE VERY POSSIBLE WITH THE MAIN THREAT BEING SEVERE WIND GUSTS. OTHERWISE FRONT ON TRACK TO CLEAR QUINCY AREA WITHIN NEXT HOUR AND COLUMBIA/JEFFERSON CITY BETWEEN 11 AM AND NOON. THE ST. LOUIS METROPOLITAN AREA WILL SEE FROPA BETWEEN 2 AND 3 PM. CVKING && .DISCUSSION... MAIN WX STORY WILL REVOLVE AROUND TWO ITEMS. THE FIRST IS SYSTEM TO AFFECT THE AREA PRIMARILY TODAY...AND WILL LIKELY CARRY A BIT INTO THIS EVENING. A VERY STRONG CDFNT WILL SWEEP THRU THE AREA TODAY...MAINLY BETWEEN 18Z AND 00Z AND RESULT IN AN ENORMOUS TEMP DROP WHEN IT PASSES THRU...OF 30-40F IN MOST LOCATIONS...MOSTLY WITHIN THE SPAN OF ABOUT 4 HOURS. AHEAD OF THE FRONT WILL BE UNSEASONABLY WARM AND MOIST AIR...WITH TEMPS FROM 55 TO 60...AND DEWPOINTS FROM 50 TO 55. ADD IN THE VERY SHARP CDFNT...A STRONG MID LEVEL TROF...A LEFT EXIT REGION OF A 160KT H300 JET BY MIDDAY...AND ONE HAS THE INGREDIENTS FOR EXPLOSIVE PCPN DEVELOPMENT BY LATE MORNING/EARLY AFTERNOON JUST AHEAD OF THE FRONT...WHICH SHOULD BE JUST THRU THE KUIN AND KCOU AREAS BY THAT TIME. P-TYPE WILL BE SHRA/TSRA AHEAD OF THE FRONT...WHERE ENOUGH INSTABILITY WILL EXIST WITH FAVORABLE SHEAR AND DEEP LIFT. HIGH WINDS JUST OFF THE GROUND...WHERE KMDH HAD 47KT GUSTS JUST FROM A LIGHT SHOWER...WILL ENABLE ANY CONVECTION TO NOT HAVE TO WORK TOO HARD TO MIX DOWN SEVERE CRITERIA GUSTS...THUS THE SLIGHT RISK FOR SVR STMS IS JUSTIFIED FOR AREAS AROUND THE STL METRO AREA AND PTS TO THE S AND E. NOT FAR BEHIND THE FRONT...PCPN WILL CHANGE TO SNOW...AND PERHAPS SLEET FOR A BRIEF PERIOD AS SHALLOW ARCTIC AIR UNDERCUTS AIR THAT IS NOT COOLING AS RAPIDLY...CREATING A BRIEF PERIOD WHERE A WARM WEDGE OF AIR ALOFT WILL EXIST. SNOW AMOUNTS WILL BE ON THE LIGHT SIDE...WITH UP TO AN INCH POSSIBLE IN THE NWRN FA...WITH A DUSTING POSSIBLE ELSWHERE. SNOW WILL RAPIDLY COME TO AN END EARLY THIS EVENING. OTHER BIG ITEM TODAY IS WIND. WIND SPEEDS OF 20 TO 30MPH WILL BE COMMON...AND ONCE CDFNT PUSHES THRU...SHEAR STRENGTH OF CAA AND BAROCLINIC ZONE WILL CREATE POTENTIAL FOR WIND GUSTS TO 45MPH. WINDS WILL TAKE ALL NIGHT BEFORE DIMINISHING...BUT NOT BEFORE PUSHING WIND CHILL VALUES TO 10 BELOW IN THE NRN FA LATE TONIGHT. ATTENTION THEN TURNS TO THE SNOW STORM SLATED FOR LATE THIS WEEK. MODELS CONTINUE TO MAKE THEIR MINOR ADJUSTMENTS ON TRACKS...WHILE THE SYSTEM ITSELF IS STILL OVER THE NRN PACIFIC. THEREFORE...ANY ADJUSTMENTS MADE TO THE FORECAST WERE CONSERVATIVE IN NATURE UNTIL THE NOAM UPPER AIR NETWORK CAN GET A BETTER HANDLE ON THIS. THE MODEL TRENDS ARE THUS...THE NAM CONTINUES TO BE THE FURTHEST S ON TRACK...WITH THE GFS CONT TO SLOLY TREND MORE SLY ON ITS TRACK. NAM/GFS REMAIN THE FASTEST ON FORWARD SPEED...BUT THE ECWMF...BY FAR THE MOST CONSISTENT MODEL ON THIS SYSTEM OVER THE PAST SEVERAL DAYS...HAS SPED UP ITS FORWARD SPEED AS WELL TO MORE CLOSELY MATCH THE NAM/GFS. THESE TRENDS ALL SUGGEST THAT MODELS ARE COMING MORE CLOSELY IN LINE WITH THE MORE SLY NAM TRACK. THIS WILL KEEP THE BULK OF THE GOOD SNOW CHANCES TO THE S...AND LIMIT WHAT SNOW CAN LINGER THRU FRIDAY...BUT THE 00Z ECWMF STILL STUBBORNLY SUGGESTS SIGNIFICANT SNOW FOR THE CNTRL/SRN FA DURING THIS TIMEFRAME...AND WILL CONTINUE TO GIVE IT WEIGHT IN THE FORECAST. TES && .AVIATION... FOR THE 12Z TAFS...ST/SC IN WRM SECTOR THAT WAS WDSPRD ERYR IN THE NGT BREAKING UP ATTM. HWVR...THINK THIS WL BE A TEMPORARY CONDITION IN MOST AREAS...AND EXPECTED A SCT-BKN DECK ARND 3KFT TO PREVAIL AHD OF THE FRONT FROM LTR THIS MRNG TIL FROPA. HV TIMED FROPA AT EACH LOCATION WITH A COMBO OF EXTRAPOLATION AND RUC DATA...AND ONCE FROPA OCRS LO MVFR CIGS SHUD QUICKLY MOVE INTO TERMINAL AREA AND NW WNDS WL JUMP RAPIDLY. BLV CNVTN WL FIRE AFT FRONT PASSES BOTH UIN AND COU...SO HV KEPT TS OUT OF THE FCSTS FOR THESE AREAS. FEEL THAT CNVTV THRT ALG FRNT WL BCM MORE ENHANCED JUST ABT THE TIME THE IT ENTERS THE ST LOUIS METRO AREA...AND SINCE CVG OF STORMS SHOULD NOT BE ALL THAT GREAT AT THAT TIME HV USED VC TO HIGHLIGHT TSRA THRT AT BOTH STL AND SUS. IF STORMS DO DVLP SOONER IMPACT...AND INTENSITY...OF THE STORMS WL LIKELY BE MUCH GRTR. THE GOOD NEWS IS THAT THE RPD MVMT OF THE FRONT WL MEAN ONLY A VRY SHORT TIME WINDOW FOR TS TO IMPACT TERMINAL POINTS. TRUETT && .LSX WATCHES/WARNINGS/ADVISORIES... MO...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR AUDRAIN-BOONE- CALLAWAY-COLE-CRAWFORD-FRANKLIN-GASCONADE-IRON-JEFFERSON- KNOX-LEWIS-LINCOLN-MADISON-MARION-MONITEAU-MONROE- MONTGOMERY-OSAGE-PIKE-RALLS-REYNOLDS-SHELBY-ST. CHARLES-ST. FRANCOIS-ST. LOUIS-ST. LOUIS CITY-STE. GENEVIEVE-WARREN- WASHINGTON. IL...WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR ADAMS IL-BOND IL- BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL- PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ST LOUIS MO 649 AM CST TUE JAN 29 2008 .DISCUSSION... MAIN WX STORY WILL REVOLVE AROUND TWO ITEMS. THE FIRST IS SYSTEM TO AFFECT THE AREA PRIMARILY TODAY...AND WILL LIKELY CARRY A BIT INTO THIS EVENING. A VERY STRONG CDFNT WILL SWEEP THRU THE AREA TODAY...MAINLY BETWEEN 18Z AND 00Z AND RESULT IN AN ENORMOUS TEMP DROP WHEN IT PASSES THRU...OF 30-40F IN MOST LOCATIONS...MOSTLY WITHIN THE SPAN OF ABOUT 4 HOURS. AHEAD OF THE FRONT WILL BE UNSEASONABLY WARM AND MOIST AIR...WITH TEMPS FROM 55 TO 60...AND DEWPOINTS FROM 50 TO 55. ADD IN THE VERY SHARP CDFNT...A STRONG MID LEVEL TROF...A LEFT EXIT REGION OF A 160KT H300 JET BY MIDDAY...AND ONE HAS THE INGREDIENTS FOR EXPLOSIVE PCPN DEVELOPMENT BY LATE MORNING/EARLY AFTERNOON JUST AHEAD OF THE FRONT...WHICH SHOULD BE JUST THRU THE KUIN AND KCOU AREAS BY THAT TIME. P-TYPE WILL BE SHRA/TSRA AHEAD OF THE FRONT...WHERE ENOUGH INSTABILITY WILL EXIST WITH FAVORABLE SHEAR AND DEEP LIFT. HIGH WINDS JUST OFF THE GROUND...WHERE KMDH HAD 47KT GUSTS JUST FROM A LIGHT SHOWER...WILL ENABLE ANY CONVECTION TO NOT HAVE TO WORK TOO HARD TO MIX DOWN SEVERE CRITERIA GUSTS...THUS THE SLIGHT RISK FOR SVR STMS IS JUSTIFIED FOR AREAS AROUND THE STL METRO AREA AND PTS TO THE S AND E. NOT FAR BEHIND THE FRONT...PCPN WILL CHANGE TO SNOW...AND PERHAPS SLEET FOR A BRIEF PERIOD AS SHALLOW ARCTIC AIR UNDERCUTS AIR THAT IS NOT COOLING AS RAPIDLY...CREATING A BRIEF PERIOD WHERE A WARM WEDGE OF AIR ALOFT WILL EXIST. SNOW AMOUNTS WILL BE ON THE LIGHT SIDE...WITH UP TO AN INCH POSSIBLE IN THE NWRN FA...WITH A DUSTING POSSIBLE ELSWHERE. SNOW WILL RAPIDLY COME TO AN END EARLY THIS EVENING. OTHER BIG ITEM TODAY IS WIND. WIND SPEEDS OF 20 TO 30MPH WILL BE COMMON...AND ONCE CDFNT PUSHES THRU...SHEAR STRENGTH OF CAA AND BAROCLINIC ZONE WILL CREATE POTENTIAL FOR WIND GUSTS TO 45MPH. WINDS WILL TAKE ALL NIGHT BEFORE DIMINISHING...BUT NOT BEFORE PUSHING WIND CHILL VALUES TO 10 BELOW IN THE NRN FA LATE TONIGHT. ATTENTION THEN TURNS TO THE SNOW STORM SLATED FOR LATE THIS WEEK. MODELS CONTINUE TO MAKE THEIR MINOR ADJUSTMENTS ON TRACKS...WHILE THE SYSTEM ITSELF IS STILL OVER THE NRN PACIFIC. THEREFORE...ANY ADJUSTMENTS MADE TO THE FORECAST WERE CONSERVATIVE IN NATURE UNTIL THE NOAM UPPER AIR NETWORK CAN GET A BETTER HANDLE ON THIS. THE MODEL TRENDS ARE THUS...THE NAM CONTINUES TO BE THE FURTHEST S ON TRACK...WITH THE GFS CONT TO SLOLY TREND MORE SLY ON ITS TRACK. NAM/GFS REMAIN THE FASTEST ON FORWARD SPEED...BUT THE ECWMF...BY FAR THE MOST CONSISTENT MODEL ON THIS SYSTEM OVER THE PAST SEVERAL DAYS...HAS SPED UP ITS FORWARD SPEED AS WELL TO MORE CLOSELY MATCH THE NAM/GFS. THESE TRENDS ALL SUGGEST THAT MODELS ARE COMING MORE CLOSELY IN LINE WITH THE MORE SLY NAM TRACK. THIS WILL KEEP THE BULK OF THE GOOD SNOW CHANCES TO THE S...AND LIMIT WHAT SNOW CAN LINGER THRU FRIDAY...BUT THE 00Z ECWMF STILL STUBBORNLY SUGGESTS SIGNIFICANT SNOW FOR THE CNTRL/SRN FA DURING THIS TIMEFRAME...AND WILL CONTINUE TO GIVE IT WEIGHT IN THE FORECAST. TES && .AVIATION... FOR THE 12Z TAFS...ST/SC IN WRM SECTOR THAT WAS WDSPRD ERYR IN THE NGT BREAKING UP ATTM. HWVR...THINK THIS WL BE A TEMPORARY CONDITION IN MOST AREAS...AND EXPECTED A SCT-BKN DECK ARND 3KFT TO PREVAIL AHD OF THE FRONT FROM LTR THIS MRNG TIL FROPA. HV TIMED FROPA AT EACH LOCATION WITH A COMBO OF EXTRAPOLATION AND RUC DATA...AND ONCE FROPA OCRS LO MVFR CIGS SHUD QUICKLY MOVE INTO TERMINAL AREA AND NW WNDS WL JUMP RAPIDLY. BLV CNVTN WL FIRE AFT FRONT PASSES BOTH UIN AND COU...SO HV KEPT TS OUT OF THE FCSTS FOR THESE AREAS. FEEL THAT CNVTV THRT ALG FRNT WL BCM MORE ENHANCED JUST ABT THE TIME THE IT ENTERS THE ST LOUIS METRO AREA...AND SINCE CVG OF STORMS SHOULD NOT BE ALL THAT GREAT AT THAT TIME HV USED VC TO HIGHLIGHT TSRA THRT AT BOTH STL AND SUS. IF STORMS DO DVLP SOONER IMPACT...AND INTENSITY...OF THE STORMS WL LIKELY BE MUCH GRTR. THE GOOD NEWS IS THAT THE RPD MVMT OF THE FRONT WL MEAN ONLY A VRY SHORT TIME WINDOW FOR TS TO IMPACT TERMINAL POINTS. TRUETT && .LSX WATCHES/WARNINGS/ADVISORIES... MO...WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR AUDRAIN-BOONE-CALLAWAY-COLE-CRAWFORD-FRANKLIN-GASCONADE- IRON-JEFFERSON-KNOX-LEWIS-LINCOLN-MADISON-MARION-MONITEAU- MONROE-MONTGOMERY-OSAGE-PIKE-RALLS-REYNOLDS-SHELBY-ST. CHARLES-ST. FRANCOIS-ST. LOUIS-ST. LOUIS CITY-STE. GENEVIEVE-WARREN-WASHINGTON. IL...WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR ADAMS IL-BOND IL-BROWN IL-CALHOUN IL-CLINTON IL-FAYETTE IL-GREENE IL-JERSEY IL-MACOUPIN IL-MADISON IL-MARION IL-MONROE IL- MONTGOMERY IL-PIKE IL-RANDOLPH IL-ST. CLAIR IL-WASHINGTON IL. && $$ WFO LSX mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 255 PM EST TUE JAN 29 2008 .SHORT TERM (TONIGHT THROUGH WEDNESDAY AFTERNOON)... ...STRONG GUSTY WINDS...THUNDERSTORMS...AND SNOW TONIGHT... STRONG COLD FRONT POISED TO PUSH THROUGH THE REGION THIS EVENING...WITH BIG CHANGES IN-STORE FOR THE AREA. SFC LOW JUST NORTH OF CHICAGO AS OF 2PM EST...WITH THE COLD FRONT EXTENDING ALONG THE AXIS OF LAKE MICHIGAN TO CHICAGO AND ON FURTHER TOWARDS STL INTO THE LITTLE ROCK AREA AND ON INTO EAST TX. DRASTIC TEMPERATURE GRADIENT ACROSS THE FRONT...WITH 20-25 DEGREE FALLS IN TEMPS WITHIN AN HOUR OR SO OF FRONTAL PASSAGE. HAVE USED OB TRENDS BLENDED WITH THE RUC13 RUNS TO CAPTURE SOME DETAIL TO THE FRONTAL POSITION AND RAPID TEMP FALLS...WITH A SLIGHT BLEND OF THE GFS THRU THE END OF THE PERIOD. WAS SUSPECT OF THE NAM12...WHICH USUALLY DOES WELL IN THE VERY NEAR TERM...BUT IT INITIALIZED MORE THAN 7-10 DEGREES TOO COOL AND CONTINUED TO BE AT OR MORE THAN 10 DEGREES TOO COOL THRU THE DAY. BAD THERMAL FIELDS WITH P-TYPE QUESTIONS AT HAND ARE NEVER A GOOD THING SO STAYED AWAY FROM THE MODEL FOR THE MOST PART. AS THE SFC LOW STARTS TO PULL FURTHER NORTH INTO THE GREAT LAKES REGION AND MOVES NORTHWEST OF THE AREA THIS EVENING THE FRONT WILL START TO MAKE ITS WAY RAPIDLY ACROSS THE FORECAST AREA THIS EVENING...COMPLETELY PUSHING ACROSS INDIANA AND SOUTHERN MICHIGAN INTO NORTHCENTRAL OH BY MIDNIGHT. AS THE FRONT PUSHES ACROSS THE REGION IT WILL PROVIDE BETTER FOCUSING OF THE PRECIP...WITH SCTD/NUMEROUS SHOWERS AHEAD OF THE FRONT...AND MOST LIKELY A THIN LINE OF SHOWERS WITH SOME EMBEDDED THUNDERSTORMS ALONG THE FRONT. WITH THE FRONT PUSHING SO QUICK ACROSS THE REGION THE RAINFALL AMOUNTS WILL BE NOT TOO SIGNIFICANT...WITH A LIQUID TOTAL OF AROUND .25 LIKELY ACROSS THE REGION. STRONG WIND FIELDS ALOFT AND PLENTY OF SHEAR IN THE 0-6KM...AND MUCAPES NEAR 200-300 J/KG...STRONG WINDS IN SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TONIGHT UNTIL THE FRONT IS THROUGH...CAN NOT RULE OUT SOME HAIL AS WELL. ANOTHER FACTOR WILL BE AS THE DRY SLOT SEEN ON THE WV IMAGERY STARTS TO DRIFT EAST INTO THE REGION...ALONG WITH A STRONG 160KT JET MAX PUSHING NORTHEAST INTO THE OHIO VALLEY AND SOUTHERN GREAT LAKES WILL ONLY ADD SOME CREDENCE TO THE CHANCES FOR STRONG TO SEVERE THUNDERSTORMS. THEN THE NEXT TWO FEATURES WILL COME TO PLAY ACROSS THE REGION...FIRST THE WINDS BEHIND THE FRONT WILL BE STRONG AND INTENSE PUSHING MUCH COLDER AIR INTO THE REGION...TEMPS WILL DROP BY 20-25 DEGREES BEHIND THE FRONT IN THE FIRST 60-120 MINUTES AFTER FRONTAL PASSAGE. TEMPS WILL PLUMMET INTO THE 20S VERY QUICKLY ALLOWING FOR FAST FREEZING OF THE ROADWAYS AND MAY ALLOW FOR VERY HAZARDOUS TRAVEL CONDITIONS WITH BLACK ICE LIKELY. THE WINDS IN COMBINATION WITH THE MUCH COLDER AIR DRIVEN TEMPS TO OR JUST UNDER 10 BY DAYBREAK WEDNESDAY WITH CREATE APPARENT TEMPS AS LOW AS -15 OR -20 DEGREES. THE SECOND PUNCH WILL BE THE MINOR SNOW ACCUMS FOR MUCH OF THE AREA...THIS FALLING ON TOP OF THE POSSIBLE BLACK ICE WILL ONLY WORSEN ROADWAYS THROUGH THE OVERNIGHT HOURS...BETTER ACCUMS NEARING 2-4 INCHES WILL BE POSSIBLE ACROSS OUR NORTHWESTERN PORTIONS OF THE FORECAST AREA CLOSER TO THE DEFORMATION AREA AND LAKE ENHANCEMENT. THE MAJORITY OF THE REGION WILL FALL UNDER THE DAMPENING POWER OF THE DRY SLOT AND NOT RECEIVE AS MUCH SNOWFALL WITH MOST GETTING AROUND OR LESS THAN AN INCH. BY DAYBREAK WEDNESDAY THE WINDS WILL HAVE LESSENED SLIGHTLY...BUT THE CAA WILL CONTINUE THROUGH MUCH OF THE DAY WITH THE WESTERLY OR NORTHWESTERLY WINDS THROUGH THE DAY. COMBO OF CLOUD COVER MUCH OF THE DAY..AND THE CAA WILL NOT ALLOW THE HIGHS TO CLIMB MUCH MORE THAN INTO THE TEENS FOR MUCH OF THE AREA...WITH THE NORTHERN PORTIONS OF THE AREA STRUGGLING TO REACH 15. AS HIGH PRESSURE SLOWLY PUSHES EAST INTO THE REGION...CLOUDS WILL SLOWLY DISSIPATE THROUGH THE AFTER WITH THE EXCEPTION OF THE AREA JUST EAST OF THE LAKE WHERE SOME LAKE EFFECT CLOUDS MAY LINGER AND PRODUCE SOME LIGHT SNOW IN THE LAKE EFFECT REGION. && .LONG TERM... WEDNESDAY NIGHT THROUGH TUESDAY ...MAJOR WINTER STORM POSSIBLE FRIDAY... SW UPPER MEAN FLOW THROUGH THE PERIOD WILL CONTINUE SUPPORT A VERY ACTIVE PATTERN. NUMEROUS MID LEVEL DISTURBANCES OVER THE EASTERN PACIFIC WILL DIVE SOUTH AROUND MEAN TROUGHING OVER THE WESTERN CONUS...EVENTUALLY EJECTING OUT INTO THE SOUTHERN PLAINS AND INTO THE GREAT LAKES. WITH AMPLE COLD AIR JUST NORTH OF THE REGION THROUGH MUCH OF THE NORTHERN PLAINS AND UPPER MIDWEST...STRONG BAROCLINICITY WILL BE FAVORED. MAIN CONCERN IN THE LONG TERM PERIOD WILL CONTINUE TO BE THE POTENT WINTER STORM STORM SYSTEM TAKING AIM AT THE REGION THURSDAY NIGHT INTO FRIDAY. MODEL GUIDANCE CONSISTENCY IS INCREASING FROM RUN TO RUN...AS A SFC CYCLONE TRACK EAST OF THE REGION THROUGH OH IS FAVORED. GEFS MEAN ENSEMBLE HAS BEEN THE MOST CONSISTENT WITH TRACKING THIS SYSTEM THROUGH WESTERN OH...A SOLUTION THAT IS ALSO FAVORED BY THE LATEST NAM/GFS/UKMET/ECMWF AND GEM. WITH THE OVERALL IMPRESSIVE DYNAMICS IN PLACE...STRONG CYCLONICALLY CURVED UPPER JET/INTENSIFYING SFC CYCLONE/AMPLE GULF MOISTURE/SHALLOW COLD AIR/MAX OMEGA THROUGH THE DENDRITIC GROWTH ZONE...HEAVY ACCUMULATING SNOW WOULD BE FAVORED...ESPECIALLY IN THE DEFORMATION ZONE...WHERE CSI WOULD BE PRESENT UNDER INTENSE FRONTOGENETICAL FORCING. THERE IS LITTLE DOUBT THAT THIS SYSTEM WILL AFFECT THE GREAT LAKES DURING THIS TIME PERIOD. THE ONLY QUESTION STILL REMAINING IS PRECIP TYPE PER SFC LOW TRACK. EARLY RUNS OF THE GFS AND ECMWF HAVE WAVERED ON THE TRACK FROM THE EASTERN SEABOARD TO THE WESTERN GREAT LAKES. EVEN THOUGH A TRACK THROUGH CENTRAL OH LOOKS FAVORED...THERE IS STILL SOME UNCERTAINTY...STEMMING PRIMARILY FROM THE INTENSITY AND LOCATION OF THE UPPER LEVEL VORT MAX. AS FOR NOW...HAVE SHIFTED THE ZR/IP/SN MENTION TO EASTERN PORTIONS OF THE FA WHERE BUFFER SOUNDINGS CONTINUE TO INDICATE A PERIOD OF MIX PRECIP AT LIMA OH. THINGS QUIET DOWN THROUGH THE REST OF THE WEEKEND WHERE HIGH PRESSURE WILL DOMINATE THE WEATHER...SAVE A NORTHERN STREAM WAVE PROGGED SAT/SAT NIGHT WHERE LIGHT SNOW MAY FALL IN MAINLY NORTHERN PORTIONS OF THE FA. ANOTHER POTENT SYSTEM STILL IS IN THE WORKS FOR EARLY NEXT WEEK AS THE THE UPPER TROUGH OVER THE WESTERN CONUS AMPLIFIES. HOWEVER...MUCH UNCERTAINTY IS STILL PRESENT IN THE EVOLUTION/TRACK OF THIS SYSTEM. ONE THING THAT CONTINUES TO BE SUPPORTED BY THE LATEST MODEL RUNS IS THE FA WILL BE IN THE WARM SECTOR WITH THIS STORM. HOWEVER...GIVEN POTENTIAL HEAVY SNOW FRIDAY...WILL HOLD OFF ON ANY SIG WARMUP IN THE EXTENDED. HAVE INTRODUCED RAIN/SNOW WORDING MONDAY INTO TUESDAY WITH THE PROGGED SYSTEM. && .AVIATION (18Z TAFS)... IFR CONDITIONS ARE FOUND NEARLY AREAWIDE...LOWER CIGS THE MAIN REASON..THOUGH SOME SCTD AREAS OF SHOWERS ARE ALSO MOVING ACROSS THE REGION AT THIS TIME...AND WILL CONTINUE THROUGH THE AFTERNOON AND EARLY EVENING...MAYBE EVEN A TSRA. BORDERLINE LLWS ISSUE AT TIME WITH 40KTS AROUND 2.0 K FT...THOUGH WINDS SHOULD START TO INCREASE IN THE NEXT FEW HOURS TO LESSEN THIS ISSUE. CIGS WILL REMAIN IN THE 1 TO 2 K FT RANGE...WITH SCTD SHRA THROUGH THE EVENING WITH THUNDERSTORMS LIKELY ALONG THE COLD FRONT ITSELF. JUST BEHIND THE FRONT THE WINDS WILL VEER TO THE WEST/NORTHWEST AND WILL INCREASE TO 25 TO 30 KTS WITH GUSTS AS HIGHS AS 35-40KTS. RAIN WILL TURN TO /SLEET THEN SNOW ACROSS THE REGION AN HOUR OR SO BEHIND THE FRONT WITH WHATEVER MOISTURE IS LEFT. CIGS MAY LIFT TO 2-2.5 K FT BY LATE MORNING WEDNESDAY WITH THE PRECIP COMING TO AN END ACROSS MUCH/MOST OF THE REGION. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WIND ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST WEDNESDAY FOR INZ007>009-013-015>018-020-022>027-032>034. WINTER WEATHER ADVISORY FROM 7 PM EST /6 PM CST/ THIS EVENING TO 10 AM EST /9 AM CST/ WEDNESDAY FOR INZ003>006-012-014. MI...WIND ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST WEDNESDAY FOR MIZ081. WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST WEDNESDAY FOR MIZ080. WINTER STORM WARNING FROM 7 PM THIS EVENING TO 10 AM EST WEDNESDAY FOR MIZ077>079. OH...WIND ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST WEDNESDAY FOR OHZ001-002-004-005-015-016-024-025. LM...HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 1 PM EST WEDNESDAY FOR LMZ043-046. GALE WARNING UNTIL 1 PM EST WEDNESDAY FOR LMZ043-046. && $$ SHORT TERM...SCHOTT LONG TERM...CHAMBERLAIN AVIATION...SCHOTT in AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1235 PM CST TUE JAN 29 2008 .UPDATE... STRONG UPPER LOW SEEN OVER IA ON LATEST GOES WV LOOP HAS DEVELOPED TIGHT FRONTOGENETIC FORCED BAND ON ITS MOIST UPGLIDE. RUC PARAMETERS ON CROSS SECTIONS THROUGH THE SNOW BAND INDICATE INSTABILITY ALOFT THROUGH MID-AFTERNOON...WHICH THEN RAPIDLY DECREASES AS THE UPPER LEVEL TROUGH SHIFTS EASTWARD THROUGH THE REGION. THIS BAND OF SNOW IS FALLING INTO THE BOUNDARY LAYER ARCTIC AIR MASS AND TOGETHER WITH THE LOW LEVEL NORTHWESTERLY FLOW HAS LED TO WHITEOUT CONDITIONS IN ALBERTA LEA AND NEARBY COMMUNITIES. INTERESTING TO NOTE THAT THERE HAS BEEN DISPLACEMENT OF THE HEAVIEST SNOW SOUTHEAST OF THE GREATEST ECHOS ON RADAR DUE TO THE STRONG LOW LEVEL NORTHWEST WINDS. SO HAVE REALLY CUT BACK POPS NORTH AND WEST OF THE SYSTEM...INCLUDING OVER THE TWIN CITIES THIS AFTN. TEMPS CONTINUE TO FALL AND WIND CHILLS IN THE 25 TO 40 BELOW RANGE CURRENTLY OCCURRING. SOME ISOLATED -40 TO -45 WIND CHILLS ARE POSSIBLE IN SOME OF THE HIGHER GROUNDS NEAR ALEXANDRIA. && .PREV DISCUSSION... /ISSUED 530 AM CST TUE JAN 29 2008/ LONGWAVE TROUGH WILL CONTINUE TO SHARPEN OVER THE EASTERN THIRD OF THE NATION TDA. A FAIRLY PROGRESSIVE WEATHER PATTERN WITH FAST MOVING SHORT WAVE TROUGHS MOVING OVER THE UPPER MIDWEST OVER THE NEXT FEW DAYS. IN THE MEANTIME...TEMPERATURES WILL CONTINUE TO PLUMMET AS ARCTIC AIR SETTLES OVER THE UPPER MIDWEST TODAY AND TONIGHT. STRONG GUSTY NORTHWEST WINDS WILL CONTINUE THROUGHOUT THE DAY. A BAND OF LIGHT SNOW WILL COMMENCES OVER WESTERN HALF OF OUR CWA BEFORE NOON WITH NEW SNOWFALL AMOUNTS AROUND AN INCH OR TWO. BEST FORCING OCCURS OVER SOUTH CENTRAL MN INTO WESTERN WISCONSIN LATE MORNING INTO EARLY EVENING. SNOWFALL AMOUNTS COULD RANGE ANYWHERE FROM ONE TO THREE INCHES. THIS WILL CAUSE SOME CONSIDERABLY BLOWING SNOW...NEAR WHITEOUT CONDITIONS IN OPEN AREAS. WL CONTINUE THE WINTER WEATHER ADVISORY FOR THE ENTIRE AREA TODAY...THEN GO WITH WIND CHILL ADVISORY FOR TONIGHT THROUGH WEDNESDAY MORNING...WHERE WIND CHILL WILL LOWER TO 28-39 BELOW ZERO. BY WEDNESDAY AFTERNOON...THE COLD POOL MOVES OVER THE GREAT LAKES INTO THE OHIO VALLEY. TEMPERATURES BY DAYBREAK WEDNESDAY MORNING WILL DROP TO AROUND 20 BELOW ZERO NEAR MORRIS AND ALEXANDRIA WITH TEMPERATURES LOWERING TO AROUND 10 TO 15 BELOW ZERO IN THE RIVER VALLEYS ALONG THE MISSISSIPPI RIVER. MODELS HAVE BEEN CONSISTENT WITH A WEAK SHORTWAVE TROUGH MOVING OVER THE MIDWEST BY WEDNESDAY NIGHT. 700 MB OMEGA FIELD SHOWED AN INCREASE OVER SOUTH CENTRAL MN...SO HAVE BUMPED UP THE POPS INTO THE LIKELY CATEGORY FOR SNOW. LONGWAVE PATTERN SHIFTS OVER THE UPPER MIDWEST BY THE END OF THE WORK WEEK...AS UPPER AIR FLOW BECOMES MORE ZONAL ACROSS THE NORTHERN TIER OF CONUS. DAYTIME TEMPERATURES SHOULD CONTINUE TO MODERATE INTO THE 20S AS MORE MODIFY PACIFIC AIR FILTER INTO OUR FORECAST AREAS THIS WEEKEND. && .AVIATION.../18Z TAF ISSUANCE/ TIGHT BAND OF SNOW ROTATING NORTH AND EAST ACROSS SOUTHEAST MN AND WEST CTRL WI EARLY THIS AFTN. EAU LOOKS TO FEEL THE BRUNT OF THIS...WITH SOME MODERATE TO BRIEFLY HEAVY SNOW THROUGH MID-AFTERNOON. MVFR CIGS HAVE GENERALLY BEEN CONFINED TO THIS AREA AND HAVE CONTINUED THAT TREND THIS AFTN. MVFR VISBYS HAVE EXISTED OUTSIDE OF THE ACTUAL SNOWFALL WHERE BLOWING SNOW IS OCCURRING. TRENDS HAVE BEEN IMPROVING AND NOT MANY SITES WERE TOO LOW TO BEGIN WITH...LIKELY DUE TO THE SNOW COVER NOT BEING FRESH. GRADIENT MAINTAINS ITSELF THIS AFTERNOON WITH THE MAIN SURFACE PRESSURE RISE AXIS HAVING PASSED...SO WIND SPEEDS AND GUSTS SHOULD BE FAIRLY CONSTANT. THESE SHOULD DECREASE GRADUALLY DURING THE EVENING AND THEN QUICKLY LATE TONIGHT. SKIES SHOULD ALSO SLOWLY WORK THEIR WAY TO SKC TONIGHT AS WELL AS THE DEEP DRY ARCTIC AIR MASS BUILDS IN. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR ANOKA- BENTON-BLUE EARTH-BROWN-CARVER-CHIPPEWA-CHISAGO-DAKOTA- DOUGLAS-FARIBAULT-HENNEPIN-ISANTI-KANABEC-KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN-MCLEOD-MEEKER-MILLE LACS-MORRISON- NICOLLET-POPE-RAMSEY-REDWOOD-RENVILLE-RICE-SCOTT-SHERBURNE- SIBLEY-STEARNS-STEVENS-SWIFT-TODD-WASECA-WASHINGTON- WATONWAN-WRIGHT-YELLOW MEDICINE. WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 12 PM CST WEDNESDAY FOR ANOKA-BENTON-BLUE EARTH-BROWN-CARVER-CHIPPEWA- CHISAGO-DAKOTA-DOUGLAS-FARIBAULT-FREEBORN-GOODHUE-HENNEPIN- ISANTI-KANABEC-KANDIYOHI-LAC QUI PARLE-LE SUEUR-MARTIN- MCLEOD-MEEKER-MILLE LACS-MORRISON-NICOLLET-POPE-RAMSEY- REDWOOD-RENVILLE-RICE-SCOTT-SHERBURNE-SIBLEY-STEARNS-STEELE- STEVENS-SWIFT-TODD-WASECA-WASHINGTON-WATONWAN-WRIGHT-YELLOW MEDICINE. BLIZZARD WARNING UNTIL 6 PM CST THIS AFTERNOON FOR FREEBORN- GOODHUE-STEELE. WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS AFTERNOON FOR BARRON- CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-ST. CROIX. WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 12 PM CST WEDNESDAY FOR BARRON-CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE- POLK-RUSK-ST. CROIX. && $$ mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 222 PM CST TUE JAN 29 2008 .SHORT TERM... FOCUS ON THE IMMEDIATE SHORT TERM WILL BE OVERNIGHT MIN TEMPERATURES...WINDS...AND ASSOCIATED WIND CHILL INDICES. AS OF 19Z...STILL ABOUT A 10 MB PRESSURE GRADIENT ACROSS THE CWA...ALONG WITH STRONG COLD AIR ADVECTION AS AN ARCTIC AIRMASS SINKS IN FROM THE NORTHWEST AND TEMPS STEADILY DECLINE. GENERALLY TRANSITIONED FROM RUC TO NAM GUIDANCE FOR WINDS THROUGH TOMORROW MORNING...AS BOTH MODELS FORECAST WINDS HAVE PERFORMED WELL SO FAR TODAY. IN GENERAL...NAM WINDS REMAIN ABOVE 10 MPH THROUGH 6 AM TOMORROW MORNING. ARCTIC AIRMASS WILL RESULT IN TEMPS DROPPING INTO THE NEG 20S TONIGHT...WITH RESULTING WIND CHILL INDICES REMAINING IN WARNING CRITERIA /LESS THAN NEG 35/ THROUGH 6 AM. WHILE WIND CHILLS WILL REMAIN IN THE NEG 25 TO NEG 35 RANGE THROUGH NOON TOMORROW...WINDS WILL BE TOO LIGHT AFT 6 AM. THEREFORE...LEFT EXPIRATION TIME FOR WARNING AT 6 AM. FOCUS FOR MID PART OF SHORT TERM WILL BE ON TEMPS. BOTH GFS AND NAM HAVE A VORT MAX PUSH INTO THE WEST CENTRAL DAKOTAS WED AFTERNOON. MODELS HAVE A BAND OF MID LEVEL CLOUDS DRIFT IN FROM THE WEST...WITH THE NAM SLOWER AND SLIGHTLY DRIER. I LIKE THE IDEA THAT THE NAM DRIES OUT THE COLUMN AS THE CLOUDS PUSH EAST INTO OUR FA...WHERE THE CENTER OF AN ARCTIC HIGH IS SET UP AROUND 06Z THU. GFS KEEPS RH VALUES HIGHER AND I BELIEVE OVERDOES CLOUD COVERAGE. THUS...COULD SEE SOME CLOUD COVER IN THE FAR WEST...WHICH COULD IMPACT WED NIGHT LOWS. BY FRIDAY...MODELS IN FAIR AGREEMENT WITH A SFC LOW PUSHING ACROSS SRN CANADA. NAM IS MUCH DRIER THAN GFS IN THE QPF FIELD...GENERATING MOST PRECIP NORTH OF THE BORDER. THE GFS SHOWS SOME ISENTROPIC LIFT ACROSS THE CWA...HOWEVER CONDENSATION PRESSURE DEFICITS DONT DROP MUCH BELOW 10...THEREFORE DONT BELIEVE THE COLUMN WILL SATURATE ENOUGH FOR PRECIP. DID KEEP POPS IN IN THE NORTHEAST...WHERE THERE WILL BE MORE TIME FOR SATURATION...BUT NOT A LOT OF CONFIDENCE IN A PRECIP EVENT ASSOCIATED WITH THIS WAVE. .LONG TERM... /SAT TO TUE/ PAST FEW RUNS OF THE GFS HAS BEEN ALL OVER THE PLACE IN REGARDS TO A 500 MB TROUGH EXPECTED TO MOVE THROUGH SUNDAY NIGHT. 00Z AND 06Z RUNS WERE BULLISH WITH A LOW AND LOTS OF PCPN...WHICH SEEMED SUSPECT AS MAIN UPPER JET AT 250 MB WOULD SEND MOST SHORT WAVES TO OUR SOUTH AROUND ERN PACIFIC UPPER RIDGE. 12Z GFS HAS BACKED OFF ON SUNDAY SYTEM AND SHOWS 500 MB TROUGH PASSAGE BUT MAIN VORT WELL TO OUR SOUTH AND A WEAKER SHORT WAVE AND SFC LOW THRU SD INTO MN. AGREE WITH THIS SCENERIO AND IN HAVING LOW 20-30 POPS FOR THIS EVENT SUN AFTN-SUN NIGHT...EXTENDED IT INTO MONDAY PER HPC. NEXT SURGE OF COLD AIR WILL FOLLOW BEHIND SYSTEM FOR MON NIGHT-TUES...BUT DISAGREEMENT EXISTS ON HOW COLD WITH 00Z ECMWF NOT AS COLD AS GFS AND CANADIAN. HPC TEMPS SEEMED TOO WARM MONDAY AND TUESDAY AND LOWERED HIGHS ACCORDINGLY MUCH MORE TOWARD THE 12Z MEX GUIDANCE WHICH FIT THE 00Z ENSEMBLE GFS MOS WELL. && .AVIATION... MAIN CLEARING PROGRESSING EASTWARD...BUT AS IS USUAL WITH VERY COLD ARCTIC AIR OVERHEAD GETTING SOME RESIDUAL THIN BROKEN LAYERS OF STRATOCU AROUND 2000 FT AGL WHICH ARE PICKED UP BY AWOS/ASOS CEILOMETERS. MAY TAKE PAST 00Z FOR RESIDUAL THIN STRATOCU TO GO AWAY. OTHERWISE CLEAR SKY OVERNIGHT INTO WEDNESDAY. WINDS SLOWLY DIMINISHING THRU THE NIGHT WITH GUSTS TAPERING OFF BY 03Z. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WIND CHILL WARNING UNTIL 6 AM CST WEDNESDAY FOR NDZ006>008- 014>016-024-026>030-038-039-049-052>054. MN...WIND CHILL WARNING UNTIL 6 AM CST WEDNESDAY FOR MNZ001>009-013>017- 022>024-027>032-040. && $$ SPEICHER/HOMANN/RIDDLE nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 334 PM CST TUE JAN 29 2008 .SHORT TERM...THIS AFTERNOON THROUGH WEDNESDAY. A LOW PRESSURE SYSTEM WAS IN NORTHEAST ILLINOIS AT 20Z AS IT CONTINUED TO MOVE NORTH ALONG AN ARCTIC FRONT. THE FRONT EXITED THE CWA EARLY THIS AFTERNOON...CAUSING TEMPERATURES TO PLUNGE RAPIDLY. MORNING TEMPERATURES IN THE 30S HAD ALREADY FALLEN INTO THE TEENS IN THE NORTHWEST PART OF THE CWA BY 20Z. FREEZING RAIN AND/OR SLEET CHANGED TO SNOW OVER MOST OF EASTERN WISCONSIN BY 21Z. RADAR MOSAIC SHOWED SNOW BECOMING MORE WIDESPREAD ACROSS THE CWA DURING THE AFTERNOON. SNOW WAS HEAVIER IN THE WESTERN CWA WHERE VISIBILITIES WERE LESS THAN A MILE MUCH OF THE AFTERNOON. THE SNOW STARTED DURING THE LATE MORNING IN CENTRAL WISCONSIN AND WINDS WERE STARTING TO INCREASE IN THAT AREA LATE THIS AFTERNOON. WINDS ARE GOING TO CONTINUE TO INCREASE THIS EVENING AND TONIGHT CAUSING PERIODS OF NEAR-BLIZZARD CONDITIONS. MODELS HAVE NOT DONE WELL WITH THIS SYSTEM BUT AN THE RUC WAS LOOSELY FOLLOWED FOR THE EARLY PART OF THE NIGHT. THEN ATTEMPTED MOSTLY WENT WITH THE COLDEST GUIDANCE NUMBERS AND ATTEMPTED TO MESH WITH ADJACENT FORECASTS. LOOKS LIKE SNOW WILL CONTINUE ACROSS THE AREA THIS EVENING...WITH SOME SNOW STILL POSSIBLE IN DOOR COUNTY UNTIL SHORTLY AFTER MIDNIGHT. KEPT CURRENT WINTER STORM WARNING TO AVOID MAKING THINGS MORE COMPLICATED...BUT IT WILL LIKELY NEED TO BE CANCELED EARLY...ONCE THE SNOW WINDS DOWN...AND REPLACED WITH A WIND CHILL ADVISORY OR WARNING AS COLD TEMPERATURES AND INCREASING WINDS RESULT IN BITTER COLD WIND CHILL READINGS. .LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY. OVERALL LITTLE CHANGES DURING THIS PERIOD. WEAK WAA ALONG THE WEST TO EAST BAROCLINIC ZONE OVER WI MAY GENERATE SOME LIGHT PCPN OVER MAINLY THE SOUTH HALF OF THE FORECAST AREA WED NIGHT INTO THURSDAY. MDM RANGE MODELS CONTINUE TO TRACK THE NEXT SYSTEM SOUTH OF THE STATE TOWARD FRIDAY...PERHAPS JUST BRUSHING THE SOUTH HALF WITH MINOR ACCUM. EAST FETCH AND MARGINAL DELTA T/S CONTINUE TO SUPPORT SOME SNOW SHOWER ACTIVITY ALONG LAKE MICHIGAN SO WILL CONTINUE TO PLACE HIGHER POPS THERE. FOR THE WEEKEND...MDM RANGE MODELS HAVE BEEN CONSISTENT WITH A WEAK SHORT WAVE TO TRACK OVER THE GREAT LAKES REGION. MOISTURE APPEARS MARGINAL SO WILL KEEP LOW END POPS GOING. NEXT WEEK MONDAY INTO TUESDAY SYSTEM NOW TRENDING COLDER...BUT STILL HAS SOME POTENTIAL OF A MIX FOR AT LEAST THE SOUTHEAST HALF OF THE FORECAST AREA. LATEST RUNS INDICATE THE SYSTEM WILL TRACKING TO LOWER MICHIGAN MONDAY INTO MONDAY NIGHT. WILL LINGER SNOW SHOWERS INTO TUESDAY AS THE PROGGED UPPER TROF STILL ROTATING THROUGH. && .AVIATION...MVFR/IFR CIGS EXPECTED ALONG WITH LIFR/VLIFR VSBYS DURING THE LATE AFTERNOON AND EVENING DUE TO SNOW. VSBYS AND CIGS SHOULD IMPROVE AS SNOW ENDS AT MOST LOCATIONS BY MIDNIGHT. && .GRB WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL 8 AM CST WEDNESDAY FOR WIZ005-010>013- 018>022-030-031-035>040-045-048>050-073-074. && $$ MG/TDH wi