AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ALBANY NY 1247 PM EST THU NOV 6 2008 .SYNOPSIS... MILD TEMPERATURES WILL CLOSE OUT THE WORK WEEK...WITH A MORE SEASONABLE AIRMASS ARRIVING OVER THE WEEKEND. AN AREA OF LOW PRESSURE OFF THE MID ATLANTIC COAST WILL WEAKEN AND DRIFT EASTWARD TODAY AND TONIGHT. HIGH PRESSURE WILL BRIEFLY BUILD IN ON FRIDAY. A LOW PRESSURE SYSTEM WILL APPROACH FROM THE WEST FRIDAY NIGHT WITH THE SYSTEM`S COLD FRONT CROSSING THE AREA SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 1040 AM EST...WE HAVE MADE MINOR ADJUSTMENTS TO THE GRIDDED DATABASE...MAINLY TO INCH MAX TEMPS UPWARD ACROSS THE UPPER HUDSON VALLEY...SW VT...AS WELL AS WITHIN THE WESTERN ADIRONDACKS...WHERE THINNER CLOUDS SHOULD ALLOW TEMPS TO REACH THE LOWER/MID 60S BY EARLY AFTERNOON. ELSEWHERE...THICKER CLOUDS AND SOME LIGHT SHOWERS/DRIZZLE SHOULD LIMIT MAX TEMPS FROM RISING MORE THAN 2-4 DEGREES OVER CURRENT TEMPS...MAINLY HOLDING IN THE UPPER 50S ACROSS THE SE CATSKILLS...LITCHFIELD HILLS AND PORTIONS OF THE BERKS...TO THE LOWER 60S ACROSS PORTIONS OF THE MID HUDSON VALLEY...WARMEST CLOSER TO THE CAPITAL REGION. AS FOR RAIN...PATCHY LIGHT RAIN/DRIZZLE IS OCCURRING ACROSS E-FACING SLOPES OF THE CATSKILLS/HELDERBERGS...AND WITHIN PORTIONS OF THE BERKS AND MID HUDSON VALLEY. THE AREAL COVERAGE OF THIS LIGHT RAIN/DRIZZLE SHOULD INCREASE THROUGH EARLY THIS AFTERNOON...WITH SOME SHOWERS/SPRINKLES POSSIBLY REACHING THE CAPITAL REGION AROUND OR AFTER NOONTIME. SHOWERS WILL ALSO INCREASE FURTHER ACROSS PORTIONS OF THE MID HUDSON VALLEY AND NW CT BY MIDDAY...AS CURRENT BAND ACROSS NYC/LI LIFTS NNW. THE RUC13 APPEARS TO BE HANDLING THIS BAND RATHER WELL...DEPICTED WITHIN THE 850-700 MOISTURE FLUX CONVERGENCE. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/... CLOUDS AND NORTH-NORTHEAST FLOW WILL PERSIST ACROSS REGION TONIGHT AS LOW MOVES EASTWARD OUT TO SEA AND WEAKENS. SOME LINGERING PRECIPITATION POSSIBLE. UPPER SYSTEM EXPECTED TO FINALLY OPEN ON FRIDAY. RIDGING BUILDS IN BRIEFLY BETWEEN THE DEPARTING LOW AND AN ADVANCING LOW PRESSURE SYSTEM FRIDAY. WESTERN PORTIONS OF FORECAST AREA MAY GET TO SEE SOME SUN FRIDAY AFTERNOON. MAIN LOW ASSOCIATED WITH NEXT SYSTEM WILL PASS WELL TO OUR NORTH AND WEST SATURDAY. ITS ASSOCIATED COLD FRONT WILL SWING THROUGH ON SATURDAY. HAVE POPS INCREASING FRIDAY NIGHT ESPECIALLY AFTER MIDNIGHT WITH LIKELY FOR SATURDAY AND DECREASING POPS SATURDAY NIGHT. DESPITE THE CLOUD COVER AND RAIN SHOWERS SATURDAY HIGHS ARE EXPECTED TO BE ABOVE NORMAL BUT COOLER THAN PREVIOUS DAYS. THE REINFORCING SHOT OF COLDER AIR NOT EXPECTED UNTIL SUNDAY. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... A DEEP UPPER LOW IS FORECAST TO SLOWLY LIFT OUT OF THE GREAT LAKES REGION SUNDAY AND STALL OVER CENTRAL QUEBEC ON MONDAY. IT WILL BRING UNSETTLED WEATHER TO THE REGION FOR SUNDAY AND MUCH OF THE DAY MONDAY...ESPECIALLY NORTH OF ALBANY...BEFORE A WEAK HIGH OVER THE NORTHERN PLAINS WEDGES IN MONDAY NIGHT FOR A BRIEF BREAK IN THE WEATHER LATE MONDAY NIGHT AND EARLY TUESDAY. COOLER AIR WILL FLOW INTO THE REGION SUNDAY NIGHT WITH 850 HPA TEMPERATURES STEADILY DROPPING SUNDAY NIGHT TO MINUS 3 TO MINUS 7 DEGREES OVER THE REGION...ALONG WITH LOW LEVEL WINDS DOWN THE LENGTH OF LAKE ONTARIO BRINGING ADDED MOISTURE TO THE ADIRONDACKS AND THE MOHAWK VALLEY...AND WITH 850 TEMPS MINUS 5 TO MINUS 7 IN THESE AREAS SUNDAY NIGHT RAIN SHOWERS WILL MIX AND/OR CHANGE TO SNOW SHOWERS...ESPECIALLY OVER THE HIGHER TERRAIN. THE ONLY DECENT DAY IN THE WHOLE EXTENDED PERIOD APPEARS TO BE TUESDAY...AND HIGH CLOUDS ASSOCIATED WITH THE NEXT SYSTEM TO AFFECT THE REGION WILL PROBABLY SPREAD OVER MOST OF THE REGION SHORTLY AFTER DAYBREAK TUESDAY. AT THIS POINT IT LOOKS LIKE THE DAY SHOULD BE CLOUDY...BUT DRY...UNTIL EARLY EVENING WHEN OVERRUNNING PRECIPITATION AHEAD OF THE LOW IN THE OHIO VALLEY SPREADS INTO THE REGION. WE MAY POSSIBLY HAVE SOME P-TYPE ISSUES TO CONTEND WITH EARLY WEDNESDAY...WITH 850 HPA TEMPS RISING TO ABOVE ZERO INTO THE CENTRAL ADIRONDACKS AROUND DAYBREAK WEDNESDAY WITH OVERNIGHT LOWS IN THE LOW 20S. AT THIS STAGE IN THE GAME WILL SLEW THE MIN TEMPS TO EARLIER IN THE NIGHT WHICH MAY WELL END UP BEING THE CASE WITH TEMPS WARMING UP DURING THE NIGHT AND CHANGING SNOW INTO RAIN. IT/S NOT A PLEASANT SCENARIO BY ANY MEANS...WITH HIGHS WEDNESDAY ONLY IN THE LOW 40S...SO IT WILL BE A BITING COLD RAIN...AND SHOULD THE RIGHT CONDITIONS MATERIALIZE TUESDAY NIGHT WE COULD END UP WITH SOME PATCHES OF FREEZING RAIN IN COLDER VALLEYS. FEEL ITS BEST AT THIS POINT TO ADDRESS THE SITUATION OVER THE WEEK END OR EARLY NEXT WEEK AND THINGS WILL LIKELY BE DIFFERENT BY THEN. THE TYPICAL ALBANY WEATHER IN NOVEMBER IS NOT EXACTLY CHAMBER OF COMMERCE QUALITY WITH AN AVERAGE HIGH OF 47...LOW OF 39 AND A MISERLY 37 PERCENT PERCENT OF THE RELATIVELY FEW HOURS OF SUNSHINE THAT ARE EVEN POSSIBLE. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... LOW PRESSURE SYSTEM TO THE SOUTH IS BRINGING IN SOME RAIN SHOWERS TO KPOU AND KALB. THERE/S A CHANCE FOR SOME SHOWERS TO AFFECT KGFL LATER IN THE AFTERNOON. LOW CLOUDS WILL CONTINUE TO MOVE NORTHWARD WITH MVFR CIGS AT ALL TERMINALS AROUND 00Z. OVERNIGHT...WINDS WILL SUBSIDE AT ALL TERMINALS. KPOU WILL CONTINUE TO EXPERIENCE VCSH/-DZ...AS CIGS DECREASE TO IFR AROUND 04Z. KGFL WILL EXPERIENCE IFR VSBYS TOWARDS LATE NIGHT INTO EARLY MORNING. ALL TERMINAL VSBYS WILL REBOUND AROUND 15Z...WHILE CIGS REMAIN MVFR AS A COLD FRONT FROM THE WEST APPROACHES. OUTLOOK... FRI NIGHT...MVFR/IFR...SLGT CHC SHRA. SAT...MVFR/IFR...SHRA. SUN-MON...MVFR/IFR...SLGT CHC/CHC OF SHRA/RASN. TUE AM...VFR...NO SIG WX. && .HYDROLOGY... REFER TO THE LATEST FLOOD ADVISORY...ABOUT A BEAVER DAM IN A CULVERT HAS BACKED UP A SUBSTANTIAL AMOUNT OF WATER BEHIND A RAILROAD TRACK IN NORTH GREENFIELD IN SARATOGA COUNTY WHICH POSES A FLOOD THREAT SHOULD THE TRACKBED SUDDENLY WASH OUT. CREWS HAVE CLEARED SOME OF THE DEBRIS WHICH IS ALLOWING MORE WATER TO FLOW THROUGH AND GRADUALLY LOWER THE IMPOUNDMENT. THE PROCESS IS LIKELY TO TAKE SEVERAL DAYS. OTHERWISE THE PERIOD SHOULD BE RELATIVELY QUIET AS FAR AS THE RIVERS ARE CONCERNED. THE BRUNT OF THE PRECIP FROM THE STORM MOVING UP THE COAST WILL BE WELL SOUTH AND EAST OF THE FORECAST AREA...WITH ONLY LIGHT AMOUNTS OF PRECIP THROUGH FRIDAY. THE PASSING COLD FRONT SATURDAY AND THE UPPER LOW SUNDAY WILL BRING FAIRLY LIGHT AMOUNTS OF PRECIP TO THE REGION...MOST LIKELY AROUND HALF AN INCH. THE STORM MOVING OUT OF THE MISSISSIPPI VALLEY STARTING MIDWEEK HAS A POTENTIAL TO BRING MORE OF A SOAKING RAIN...OVER A PERIOD OF SEVERAL DAYS. THAT SYSTEM IS FIVE TO SIX DAYS OUT...HOWEVER...AND A LOT IS LIKELY TO CHANGE BY THEN. MELTING SNOW IN THE WESTERN ADIRONDACKS HAS INCREASED THE FLOW OF THE MOOSE RIVER FLOWING OUT OF THE FULTON CHAIN AND ALSO THE FLOW OF THE WEST CANADA FLOWING INTO HINCKLEY RESERVOIR. RAIN AND MELTING SNOW IN LATE OCTOBER AND EARLIER THIS MONTH HAS BROUGHT THE LEVEL OF THE SCHOHARIE RESERVOIR UP A LITTLE MORE THAN 25 FEET. THERE WAS ABOUT A FOOT AND A HALF OF WATER FLOWING OVER THE NOTCH. THE WATER LEVEL WILL GRADUALLY DROP OVER THE NEXT FEW DAYS. THE SCHOHARIE CREEK DOWNSTREAM WAS ONLY SLIGHTLY ABOVE NORMAL AND LESS THAN A THIRD BANKFULL. FOR DETAILS ON THE RIVERS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. MA...NONE. VT...NONE. && $$ SYNOPSIS...IAA NEAR TERM...IAA/KL SHORT TERM...IAA LONG TERM...RCK AVIATION...KGS HYDROLOGY...RCK ct AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE UPTON NY 132 PM EST WED NOV 5 2008 .SYNOPSIS... LOW PRES DEEPENING EAST OF CAPE HATTERAS EARLY THIS AFTERNOON WILL MOVE N TO A POSITION E OF THE DELMARVA EARLY THU MORNING BEFORE MOVING E WELL OFFSHORE FRIDAY. A COLD FRONT WILL CROSS THE AREA SATURDAY...FOLLOWED BY UNSETTLED WEATHER SUNDAY AND MONDAY AS A SERIES OF UPPER LEVEL IMPULSES MOVES THROUGH. && .NEAR TERM /THROUGH TONIGHT/... UPR LOW CUTTING OFF NEAR THE NC COAST EARLY THIS AFTERNOON. SFC LOW CONTS TO INTENSIFY E OF HATTERAS AND WILL MOVE SLOWLY N THROUGH TONIGHT. THROUGH EARLY EVENING NAM/GFS ARE FAIRLY CONSISTENT WITH THE TIMING OF PCPN... HOLDING OFF UNTIL LATER THIS AFTERNOON. LINEAR EXTRAPOLATION OF RADAR IMAGERY WOULD PUT LEADING EDGE OF THE RAINFALL REACHING THE SOUTH SHORE OF LI AROUND 20Z. HOWEVER...88D ALSO SHOWING SOME VIRGA OVER THE AREA...WHICH IS CONSISTENT WITH ISENTROPIC ANALYSIS SHOWING COND PRES DEFICITS STAYING PRETTY HIGH THROUGH LATER THIS AFTERNOON BEFORE CRASHING BY EARLY EVENING OBVIOUSLY COINCIDENT WITH THE ONSET OF PCPN. CURIOUSLY...THE RUC SHOWS A SIMILAR ISENTROPIC SETUP YET GENERATES LITTLE OR NO PRECIPITATION THROUGH 00Z. HAVE BACKED OFF A BIT ON EARLY AFTERNOON POPS WITH RAPID INCREASE IN POPS AS THE AFTERNOON GOES ON. NE WINDS WILL CONTINUE TO STRENGTHEN AS SURFACE LOW INTENSIFIES THROUGH THIS EVENING. SCA LOOKS FINE AS IS AND GOOD POTENTIAL FOR GALES TONIGHT. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... MODELS IN GOOD AGREEMENT WITH STACKED LOW PRESSURE SLOWLY FILLING AND DRIFTING EAST FROM THE VIRGINIA CAPES THURS INTO THURS NIGHT. STACKED LOW OPENS UP AND BEGINS LIFTING NE TO NEAR CAPE COD BY FRIDAY EVENING. AS THE STACKED LOW DRIFTS OFF TO THE ENE AND SLOWLY WEAKENS THU/FRI...PLENTY OF CLOUD COVER EXPECTED. LOW LIKELY/HIGH CHANCE FOR LIGHT RAIN/DRIZZLE THROUGH THU...SLIDING EAST THU NIGHT INTO FRI. THIS WILL BE SUPPORTED BY LINGERING LOW LEVEL MOISTURE VIA ONSHORE FLOW AND WEAK LIFT VIA LOW LEVEL CYCLONIC FLOW AND WEAK MID LEVEL SHORTWAVES PIVOTING AROUND THE CLOSED LOW. GUSTY CONDITIONS...10 TO 20 MPH WITH GUSTS UP TO 25 MPH...THURSDAY MORNING...GRADUALLY WEAKENING THURS AFTERNOON INTO THURS NIGHT. SUBTROPICAL AIRMASS AND CLOUD COVER WILL HAVE TEMPS ABOUT 5 DEGREES ABOVE SEASONABLE THURS (LOWER 60S)...AND 8 TO 10 DEGREES ABOVE SEASONABLE THURS NIGHT (50S). SHORTWAVE RIDGING BUILDS IN BY LATE FRIDAY AND COULD EVEN GET A FEW GLIMPSES OF SUN ACROSS WESTERN SECTIONS. HIGHS WELL ABOVE SEASONABLE...LOWER TO MID 60S. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... PRECIP CHANCES DIMINISH FRIDAY NIGHT AS THE COASTAL LOW MOVES TO THE EAST. ON SATURDAY...A CLOSED H5 LOW IS PROGGED TO MOVE INTO THE GREAT LAKES REGION WITH THE ASSOCIATED COLD FRONT SWEEPING THROUGH THE AREA LATE ON SATURDAY. THE UPPER LOW THEN LIFTS NORTHEAST INTO EASTERN CANADA SUNDAY AND MONDAY WITH A SERIES OF SHORTWAVE IMPULSES MOVING THROUGH OR JUST NORTH OF THE REGION. SURFACE HIGH PRESSURE BUILDS IN ON TUESDAY...WITH THE NEXT SURFACE SYSTEM APPROACHING LATE IN THE DAY. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... CONVERSION TO 30 HR TAF FORMAT COMPLETE. PLEASE SEE THE LINK BELOW FOR DETAILS. COASTAL LOW OFF THE MID ATLANTIC COAST WORKS SLOWLY NORTHWARD THE NEXT 12 HOURS BEFORE COMING TO A HALT. MVFR CEILINGS TO DEVELOP LATE THIS AFT/EARLY THIS EVE AS DRY SUB CLOUD LAYER SLOWLY SATURATES. LIGHT RAIN WILL DEVELOP AT ABOUT THE SAME TIME WITH THE HEAVIEST RAIN FALLING BETWEEN 00Z AND 06Z...SPREADING IN OFF THE ATLANTIC FROM SE TO NW. LI AND NYC TERMINALS WILL BE ON THE EARLY END OF THE DETERIORATING CONDITIONS WITH THE INLAND TERMINALS...KHPN AND KSWF LIKELY NOT SUB-VFR UNTIL AFTER 03Z. IN ADDITION...NE WINDS WILL RAMP UP TO 15 TO 20 KT...WITH GUSTS AS HIGH AS 30 KT AFTER 00Z. WITH THE TIGHTEST GRADIENT AND HEAVIEST RAINS BEING ALONG THE COAST...INLAND LOCATIONS WILL BE LOWER BY ABOUT 5 KT. ON THU...DEEP LOW-LEVEL MOISTURE...WEAK LIFT AND A STRENGTHENING LOW-LEVEL INVERSION WILL RESULT IN WIDESPREAD IFR/MVFR CEILINGS AND DRIZZLE. NE WINDS WILL HAVE DIMINISHED TO 10 TO 15 KT...WITH A FEW GUSTS TO 20 KT EARLY IN THE DAY. OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY... SUB-VFR CEILINGS POSSIBLY INTO SAT WITH AN ONSHORE FLOW AND SHALLOW LOW-LEVEL INVERSION IN PLACE. COLD FRONTAL PASSAGE SAT EVE FOLLOWED BY VFR CONDITIONS SUN AND MON. ................................................ TAF CODE CHANGED NOVEMBER 5TH AT 00Z... PLEASE SEE... HTTP:/AVIATIONWEATHER.GOV/NOTICE/TAF30.PHP ................................................... && .MARINE... NE WINDS INCREASE THROUGH THE REMAINDER OF THE DAY WITH APPROACH OF COASTAL LOW. SWELL FROM THE STORM HAS HELPED BUILD WAVES TO SLIGHTLY NEAR 7 FEET AT 44025 ALREADY. HAVE MADE MINOR CHANGES TO WAVE GRIDS THROUGH THIS EVENING TO ACCOUNT FOR INCREASING SWELL. STRONGEST...GUSTIEST WINDS TO ARRIVE LATE AFTERNOON AND THIS EVENING. SCA LOOKS FINE WHERE IT IS CURRENTLY. REMAINDER OF THE MARINE FORECAST UNCHANGED. LOOKS LIKE WE`LL REACH GALE FORCE GUSTS ON THE OCEAN WATERS TONIGHT...BUT DON`T THINK IT WILL ADVANCE FARTHER NORTH. THE HARBOR WILL BE A CLOSE CALL...BUT THINK IT`LL FALL JUST SHY OF 35 KT. SO WILL GO WITH GALE WARNING TONIGHT ON THE OCEAN...AND SCA ELSEWHERE. PRESSURE GRADIENT OVER THE WATERS WEAKENS THROUGH THE DAY ON THURSDAY...BUT WITH RESIDUAL SWELL...OCEAN WATERS WILL EASILY REMAIN SCA. SCA ELSEWHERE MAY HAVE TO BE EXTENDED INTO PART OF THURSDAY MORNING...BUT NOT ENOUGH CONFIDENCE TO DO THAT JUST YET. SWELL FORECAST TO KEEP OCEAN WATERS AT SCA THROUGH AT LEAST FRIDAY NIGHT. APPROACHING COLD FRONT MAY BUMP SEAS OVER 5 FT ONCE AGAIN ON SATURDAY. && .HYDROLOGY... LITTLE IF ANY RAINFALL IS EXPECTED THROUGH MID AFTERNOON. RAIN EXPECTED TO OVERSPREAD REGION LATE THIS AFTERNOON INTO THU MORNING...WITH WITH MESOSCALE BAND OF 3/4 TO 1 INCH POSSIBLE ACROSS LONG ISLAND...SE CONN...AND POSSIBLY AS FAR WEST AS NYC METRO. FURTHER NORTH AND WEST...GENERALLY 1/4 TO 1/2 INCH RAIN. FLOODING IS NOT A LARGE CONCERN...WITH ONLY SOME URBAN AND POOR DRAINAGE PONDING DUE TO FALLEN LEAVES. LESS THAN A TENTH OF AN INCH RAIN EXPECTED REST OF THURS INTO EARLY FRI...HIGHEST AMOUNTS EAST...IN LIGHT RAIN AND DRIZZLE. && .TIDES/COASTAL FLOODING... WITH PERSISTENT NE FLOW THERE IS POTENTIAL FOR COASTAL FLOODING MAINLY WITH TONIGHT`S HIGH TIDE CYCLE. WINDS WON`T BE TOO MUCH OF FACTOR WITH THIS AFTERNOON`S CYCLE...SO NO CONCERNS THERE. THURSDAY AFTERNOON`S HIGH TIDE CYCLE LIKELY WON`T POSE ANY PROBLEMS EITHER AS WINDS ARE FORECAST TO SUBSIDE THROUGH THE DAY...BUT WILL HOWEVER HAVE TO KEEP AN EYE ON TIDAL PILING. FOR TONIGHT AND THURSDAY AFTERNOON...WOULD NEED DEPARTURES OF AROUND 2 1/2 FT FOR MINOR COASTAL FLOODING DURING TIMES OF HIGH TIDE. DEPARTURES OF 3.5-4 FT ARE NEEDED FOR MODERATE. PERHAPS THE BIGGEST THREAT OF ANY FLOODING WILL BE ACROSS THE WESTERN SOUND...WHERE DEPARTURES OF 2 1/2 TO 3 FT WILL BE NEEDED FOR MINOR FLOODING DURING TONIGHT`S AND THURSDAY AFTERNOON`S HIGH TIDE CYCLES. FORECAST GUIDANCE COMES UP SHORT BY ALMOST A FOOT TONIGHT...AND BY EVEN MORE FOR THURSDAY. NO ADVISORIES THEREFORE NEEDED AT THIS TIME. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST THURSDAY FOR ANZ330-335-338-340-345. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR ANZ350- 353-355. GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EST THURSDAY FOR ANZ350-353-355. && $$ AVIATION...DW ct AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE UPTON NY 131 PM EST WED NOV 5 2008 .SYNOPSIS... LOW PRES DEEPENING EAST OF CAPE HATTERAS LATE THIS MORNING WILL MOVE N TO A POSITION E OF THE DELMARVA EARLY THU MORNING BEFORE MOVING E WELL OFFSHORE FRIDAY. A COLD FRONT WILL CROSS THE AREA SATURDAY...FOLLOWED BY UNSETTLED WEATHER SUNDAY AND MONDAY AS A SERIES OF UPPER LEVEL IMPULSES MOVES THROUGH. && .NEAR TERM /THROUGH TONIGHT/... UPR LOW CUTTING OFF NEAR THE NC COAST LATE THIS MORNING. SFC LOW CONTS TO INTENSIFY E OF HATTERAS AND WILL MOVE SLOWLY N THROUGH TONIGHT. THROUGH EARLY EVENING NAM/GFS ARE FAIRLY CONSISTENT WITH THE TIMING OF PCPN... HOLDING OFF UNTIL LATER THIS AFTERNOON. LINEAR EXTRAPOLATION OF RADAR IMAGERY WOULD PUT LEADING EDGE OF THE RAINFALL REACHING THE SOUTH SHORE OF LI AROUND 20Z. HOWEVER...88D ALSO SHOWING SOME VIRGA OVER THE AREA...WHICH IS CONSISTENT WITH ISENTROPIC ANALYSIS SHOWING COND PRES DEFICITS STAYING PRETTY HIGH THROUGH LATER THIS AFTERNOON BEFORE CRASHING BY EARLY EVENING OBVIOUSLY COINCIDENT WITH THE ONSET OF PCPN. CURIOUSLY...THE RUC SHOWS A SIMILAR ISENTROPIC SETUP YET GENERATES LITTLE OR NO PRECIPITATION THROUGH 00Z. HAVE BACKED OFF A BIT ON EARLY AFTERNOON POPS WITH RAPID INCREASE IN POPS AS THE AFTERNOON GOES ON. NE WINDS WILL CONTINUE TO STRENGTHEN AS SURFACE LOW INTENSIFIES THROUGH THIS EVENING. SCA LOOKS FINE AS IS AND GOOD POTENTIAL FOR GALES TONIGHT. && .SHORT TERM /THURSDAY THROUGH FRIDAY/... MODELS IN GOOD AGREEMENT WITH STACKED LOW PRESSURE SLOWLY FILLING AND DRIFTING EAST FROM THE VIRGINIA CAPES THURS INTO THURS NIGHT. STACKED LOW OPENS UP AND BEGINS LIFTING NE TO NEAR CAPE COD BY FRIDAY EVENING. AS THE STACKED LOW DRIFTS OFF TO THE ENE AND SLOWLY WEAKENS THU/FRI...PLENTY OF CLOUD COVER EXPECTED. LOW LIKELY/HIGH CHANCE FOR LIGHT RAIN/DRIZZLE THROUGH THU...SLIDING EAST THU NIGHT INTO FRI. THIS WILL BE SUPPORTED BY LINGERING LOW LEVEL MOISTURE VIA ONSHORE FLOW AND WEAK LIFT VIA LOW LEVEL CYCLONIC FLOW AND WEAK MID LEVEL SHORTWAVES PIVOTING AROUND THE CLOSED LOW. GUSTY CONDITIONS...10 TO 20 MPH WITH GUSTS UP TO 25 MPH...THURSDAY MORNING...GRADUALLY WEAKENING THURS AFTERNOON INTO THURS NIGHT. SUBTROPICAL AIRMASS AND CLOUD COVER WILL HAVE TEMPS ABOUT 5 DEGREES ABOVE SEASONABLE THURS (LOWER 60S)...AND 8 TO 10 DEGREES ABOVE SEASONABLE THURS NIGHT (50S). SHORTWAVE RIDGING BUILDS IN BY LATE FRIDAY AND COULD EVEN GET A FEW GLIMPSES OF SUN ACROSS WESTERN SECTIONS. HIGHS WELL ABOVE SEASONABLE...LOWER TO MID 60S. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... PRECIP CHANCES DIMINISH FRIDAY NIGHT AS THE COASTAL LOW MOVES TO THE EAST. ON SATURDAY...A CLOSED H5 LOW IS PROGGED TO MOVE INTO THE GREAT LAKES REGION WITH THE ASSOCIATED COLD FRONT SWEEPING THROUGH THE AREA LATE ON SATURDAY. THE UPPER LOW THEN LIFTS NORTHEAST INTO EASTERN CANADA SUNDAY AND MONDAY WITH A SERIES OF SHORTWAVE IMPULSES MOVING THROUGH OR JUST NORTH OF THE REGION. SURFACE HIGH PRESSURE BUILDS IN ON TUESDAY...WITH THE NEXT SURFACE SYSTEM APPROACHING LATE IN THE DAY. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... CONVERSION TO 30 HR TAF FORMAT COMPLETE. PLEASE SEE THE LINK BELOW FOR DETAILS. COASTAL LOW OFF THE MID ATLANTIC COAST WORKS SLOWLY NORTHWARD THE NEXT 12 HOURS BEFORE COMING TO A HALT. MVFR CEILINGS TO DEVELOP LATE THIS AFT/EARLY THIS EVE AS DRY SUB CLOUD LAYER SLOWLY SATURATES. LIGHT RAIN WILL DEVELOP AT ABOUT THE SAME TIME WITH THE HEAVIEST RAIN FALLING BETWEEN 00Z AND 06Z...SPREADING IN OFF THE ATLANTIC FROM SE TO NW. LI AND NYC TERMINALS WILL BE ON THE EARLY END OF THE DETERIORATING CONDITIONS WITH THE INLAND TERMINALS...KHPN AND KSWF LIKELY NOT SUB-VFR UNTIL AFTER 03Z. IN ADDITION...NE WINDS WILL RAMP UP TO 15 TO 20 KT...WITH GUSTS AS HIGH AS 30 KT AFTER 00Z. WITH THE TIGHTEST GRADIENT AND HEAVIEST RAINS BEING ALONG THE COAST...INLAND LOCATIONS WILL BE LOWER BY ABOUT 5 KT. ON THU...DEEP LOW-LEVEL MOISTURE...WEAK LIFT AND A STRENGTHENING LOW-LEVEL INVERSION WILL RESULT IN WIDESPREAD IFR/MVFR CEILINGS AND DRIZZLE. NE WINDS WILL HAVE DIMINISHED TO 10 TO 15 KT...WITH A FEW GUSTS TO 20 KT EARLY IN THE DAY. OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY... SUB-VFR CEILINGS POSSIBLY INTO SAT WITH AN ONSHORE FLOW AND SHALLOW LOW-LEVEL INVERSION IN PLACE. COLD FRONTAL PASSAGE SAT EVE FOLLOWED BY VFR CONDITIONS SUN AND MON. ................................................ TAF CODE CHANGED NOVEMBER 5TH AT 00Z... PLEASE SEE... HTTP:/AVIATIONWEATHER.GOV/NOTICE/TAF30.PHP ................................................... && .MARINE... NE WINDS INCREASE THROUGH THE REMAINDER OF THE DAY WITH APPROACH OF COASTAL LOW. SWELL FROM THE STORM HAS HELPED BUILD WAVES TO SLIGHTLY NEAR 7 FEET AT 44025 ALREADY. HAVE MADE MINOR CHANGES TO WAVE GRIDS THROUGH THIS EVENING TO ACCOUNT FOR INCREASING SWELL. STRONGEST...GUSTIEST WINDS TO ARRIVE LATE AFTERNOON AND THIS EVENING. SCA LOOKS FINE WHERE IT IS CURRENTLY. REMAINDER OF THE MARINE FORECAST UNCHANGED. LOOKS LIKE WE`LL REACH GALE FORCE GUSTS ON THE OCEAN WATERS TONIGHT...BUT DON`T THINK IT WILL ADVANCE FARTHER NORTH. THE HARBOR WILL BE A CLOSE CALL...BUT THINK IT`LL FALL JUST SHY OF 35 KT. SO WILL GO WITH GALE WARNING TONIGHT ON THE OCEAN...AND SCA ELSEWHERE. PRESSURE GRADIENT OVER THE WATERS WEAKENS THROUGH THE DAY ON THURSDAY...BUT WITH RESIDUAL SWELL...OCEAN WATERS WILL EASILY REMAIN SCA. SCA ELSEWHERE MAY HAVE TO BE EXTENDED INTO PART OF THURSDAY MORNING...BUT NOT ENOUGH CONFIDENCE TO DO THAT JUST YET. SWELL FORECAST TO KEEP OCEAN WATERS AT SCA THROUGH AT LEAST FRIDAY NIGHT. APPROACHING COLD FRONT MAY BUMP SEAS OVER 5 FT ONCE AGAIN ON SATURDAY. && .HYDROLOGY... LITTLE IF ANY RAINFALL IS EXPECTED THROUGH MID AFTERNOON. RAIN EXPECTED TO OVERSPREAD REGION LATE THIS AFTERNOON INTO THU MORNING...WITH WITH MESOSCALE BAND OF 3/4 TO 1 INCH POSSIBLE ACROSS LONG ISLAND...SE CONN...AND POSSIBLY AS FAR WEST AS NYC METRO. FURTHER NORTH AND WEST...GENERALLY 1/4 TO 1/2 INCH RAIN. FLOODING IS NOT A LARGE CONCERN...WITH ONLY SOME URBAN AND POOR DRAINAGE PONDING DUE TO FALLEN LEAVES. LESS THAN A TENTH OF AN INCH RAIN EXPECTED REST OF THURS INTO EARLY FRI...HIGHEST AMOUNTS EAST...IN LIGHT RAIN AND DRIZZLE. && .TIDES/COASTAL FLOODING... WITH PERSISTENT NE FLOW THERE IS POTENTIAL FOR COASTAL FLOODING MAINLY WITH TONIGHT`S HIGH TIDE CYCLE. WINDS WON`T BE TOO MUCH OF FACTOR WITH THIS AFTERNOON`S CYCLE...SO NO CONCERNS THERE. THURSDAY AFTERNOON`S HIGH TIDE CYCLE LIKELY WON`T POSE ANY PROBLEMS EITHER AS WINDS ARE FORECAST TO SUBSIDE THROUGH THE DAY...BUT WILL HOWEVER HAVE TO KEEP AN EYE ON TIDAL PILING. FOR TONIGHT AND THURSDAY AFTERNOON...WOULD NEED DEPARTURES OF AROUND 2 1/2 FT FOR MINOR COASTAL FLOODING DURING TIMES OF HIGH TIDE. DEPARTURES OF 3.5-4 FT ARE NEEDED FOR MODERATE. PERHAPS THE BIGGEST THREAT OF ANY FLOODING WILL BE ACROSS THE WESTERN SOUND...WHERE DEPARTURES OF 2 1/2 TO 3 FT WILL BE NEEDED FOR MINOR FLOODING DURING TONIGHT`S AND THURSDAY AFTERNOON`S HIGH TIDE CYCLES. FORECAST GUIDANCE COMES UP SHORT BY ALMOST A FOOT TONIGHT...AND BY EVEN MORE FOR THURSDAY. NO ADVISORIES THEREFORE NEEDED AT THIS TIME. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST THURSDAY FOR ANZ330-335-338-340-345. SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS AFTERNOON FOR ANZ350- 353-355. GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EST THURSDAY FOR ANZ350-353-355. && $$ AVIATION...DW ct AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 1028 AM EST THU NOV 6 2008 .UPDATE... QUICK UPDATE TO LOWER TEMPS AND INCREASE CLOUD COVER IN THE WEST PER SATELLITE/METAR TRENDS. TWEAKED POP GRIDS TO INCLUDE JUST A SLIGHT CHC IN THE WEST SLIGHTLY EARLIER PER RADAR TRENDS OF PIVOTING BAND AND REPORT OF -RA AT KPNT. MAIN "SHOW" WILL BE ALONG FRONT LATER TONIGHT...BUT STILL EXPECTING ONLY SHOWERS WITH MAYBE A RUMBLE OF THUNDER AS INSTABILITY AND FORCING WANES AT TIME OF FROPA TONIGHT AS SFC LOW RETROGRADES...FILLS...AND CONTINUES THE OCCLUSION PROCESS. && .PREV DISCUSSION... /ISSUED 650 AM EST THU NOV 6 2008/ AVIATION... LITTLE CHNGS REQRD WITH 12 UTC TAF PACKAGE. EASTERN FRINGE OF LOW LVL JET INVOF KSBN AT 1500FT AGL REMAINS TO CONTINUE UNTIL MID/LATE AM UNTIL SUFFICIENT HEATING WL ALLOW FOR INVERSION TO MIXOUT WITH WIND PROFILE BECMG MORE HOMOGENEOUS. 40KT LLJ PER RUC AT 925MB INTO KSBN WITH 50KT CORE INTO NRN IL...WHILE SIG LESS /AOB 20-25KTS/ INVOF KFWA WHERE WS PRESENCE SHOULD REMAIN LESS PROBLEMATIC...AS JET CORE PUNCHES NWD INTO LAKE MICHIGAN. NEXT FOCUS ON APPROACHING COLD FRONT WITH CONVECTIVE SHRA AHEAD BYD 07/01UTC WHERE LIMITED SFC BASED INSTABILITY CONTS TO PRECLUDE NEED FOR TSRA MENTION ATTM. SHORT TERM... FOCUS PRIMARILY ON CONVECTION THIS EVENING. FAVOR NAM OVERALL WRT DEEP STACKED CYCLONE ACRS ERN SD AS GFS ARND F24-30 BEGINS TO WEAKEN/LIFT NWD TOO FAST GIVEN LACK OF SIG UPSTRM KICKER AS WRN STATES RIDGE QUICKLY REBUILDS AND SYSTEM TO REMAIN LRGLY STEADY STATE S OF SRN CANADIAN COL INTO WEEKEND. AS NAM DEPICTD 24 HRS AGO SPLIT/MLTPL LLJ FEATURE SPRTG CONVCTN EARLIER THIS AM IN MSP/EAU REGIION SUBSQNTLY DRIVEN NWD TO TWRD FAR WRN LK SUP/MN ARWHEAD BECMG MORE HIGHLY ELEVATED. FRTHR S 50-55KT 8H JETLET INTO SERN MO AND IN NERN TX DRIVING MORE SUBSTANTIAL NR SFC-BASED CONV NERN TX NWD INTO ERN IA. NERN JET SEGMENT PROGGED INTO MO BOOTHILL B Y 15 UTC TO CNTL IL BY 18 UTC. BACKED LLVL FLOW IN ADVANCE OF COLD FNT IN STRONG KINEMATIC FIELD PROVIDING STRONG 10-8H DEEP LYR CONVERGENCE AND YEILDING 0-3KM BLS OF 35-45KTS...SHOULD REMAIN SUFFICIENT TO MAINTAIN FINE LINE CONVECTION IMMEDIATELY AHEAD OF FNT WITH SFC DPS POOLED INTO THE MID 50S IN NARROW SWATH. FURTHERMORE CONCERN WITH HIGH AMPLITUDE/LONGITUDINAL ANVIL STEERING FLOW WL SERVE TO MAINTAIN RELATIVELY CLR SKIES/STRONG INSOLATION FOR MUCH OF DAY...ALLOWING FOR GRTR MUCAPE INSTABILITY...POTNLY HIR THAN THE 300-400 J/KG THAN MODEL OUTPUT SUGGESTS ACRS ERN IL BY MIDDAY. SLIGHT BUMP TO MAX TEMPS TODAY WITH LVL THERMAL PLUME IN PLACE. SHRA/TSRA TIMING REMAINS A BIT OF CONCERN WITH NAM SIGNALS INTO FAR WRN CWA AT 00 UTC HAVE CHOPPED AWAY AT ERN TWO-THIRDS POPS/STRENGTHENED POP GRADIENT ACRS FAR WRN CWA IN LATE AFTN. CONVECTIVE SUPRT QUICKLY WANES BY LATE EVENING AS STABILITY INCRSES/JET PUSHES NWD INTO SRN MI. RELEGATED ISOLD TSRA MENTION TO ALL BUT ERN CWA THIS EVENING WITH STRONG DYNAMICS PULLING LIONS SHARE OVER LACK OF THERMODYNAMINCS. NAM SLIGHT SLOWING RUN TO RUN WITH SFC BASED FEATURES ALSO SUPRTS MAJORITY OF POP/WX IN EARLY TONIGHT TIMEFRAME. FURTHERMORE PUSHED TIMING BACK OF WRAPAROUND SHRA IN COLD POOL/INCREASED HGHT FALLS LT FRIDAY AFN INTO FRI NIGHT...IN WAKE OF SCNDRY FNTL PASSAGE. COLUMN COOLING ENOUGH TO SUPORT WET MIX BY MIDNIGHT ALL BUT SRN CWA AND BYND 09 UTC SAT ENTIRE CWA WITH FZLVL LWRG TO 1500 FT. MUCH OF FRI NOW DRY WITH SLOWED TIMING OF SECONDARY SHRTWV/FROPA. LONG TERM... SATURDAY THROUGH WEDNESDAY....THE MAIN CHALLENGE OF THIS PERIOD INCLUDES THE CHANCE AND THE TYPE OF PRECIPITATION SATURDAY THROUGH SUNDAY ASSOCIATED WITH THE UPPER LOW MOVING INTO THE REGION. THE GFS AND NAM/WRF HAVE TRENDED TEMPERATURES COLDER SATURDAY...WITH 850 MB TEMPERATURES BETWEEN -5C AND -7C. SOME CONCERN IF ICE WILL BE INTRODUCED INTO THE CLOUD TOP FOR SNOW...SO HAVE INCLUDED A RAIN SNOW MIX. SLEET IS ALSO POSSIBLE GIVEN THE DEPTH OF THE COLD AIR...BUT FOR NOW WILL LEAVE OUT DUE TO UNCERTAINTY AND EXPECTED LIMITED COVERAGE AND DURATION OF THE SLEET. THE 00Z MEX HAS LOWERED THE HIGH SATURDAY HIGH FROM 49F TO 45F AT SBN IN 24 HRS...BUT STILL APPEARS TO BE TOO HIGH GIVEN CLOUDS...PRECIPITATION AND COLD TEMPERATURES IN THE LOW LEVELS. KEPT THE HIGHEST PRECIPITATION CHANCES OVER FAR LOWER MICHIGAN WHERE MOISTURE SHOULD BE DEEPER AND LIFT BETTER. AN UPPER LEVEL TROF WILL MOVE OVER THE AREA SATURDAY NIGHT...SO HAVE KEPT PRECIPITATION CHANCES INTACT. THERE MAY BE SOME LAKE ENHANCEMENT TO PRECIPITATION OVER FAR SW LOWER MICH...BUT GIVEN 250 TO 280 DEGREE PREVAILING LOW LEVEL WINDS...A PREDOMINANT LAKE EFFECT EVENT IS NOT EXPECTED. OTHERWISE...COLD CONDITIONS WILL PERSIST THROUGH WEDNESDAY. THE 00Z GFS WAS HINTING AT THE POTENTIAL FOR PRECIPITATION WITH ANOTHER UPPER LEVEL SYSTEM EJECTING NORTHEAST INTO THE AREA ABOUT TUESDAY. HOWEVER...FOR THIS PACKAGE...HAVE KEPT MONDAY THROUGH WEDNESDAY DRY DUE TO GFS RUN TO RUN CONSISTENCY ISSUES AND SIGNIFICANT ENSEMBLE SPREADS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR LMZ043-046. && $$ SHORT TERM...MURPHY LONG TERM...SKIPPER AVIATION...MURPHY UPDATE...SIMPSON in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 650 AM EST THU NOV 6 2008 .AVIATION... LITTLE CHNGS REQRD WITH 12 UTC TAF PACKAGE. EASTERN FRINGE OF LOW LVL JET INVOF KSBN AT 1500FT AGL REMAINS TO CONTINUE UNTIL MID/LATE AM UNTIL SUFFICIENT HEATING WL ALLOW FOR INVERSION TO MIXOUT WITH WIND PROFILE BECMG MORE HOMOGENEOUS. 40KT LLJ PER RUC AT 925MB INTO KSBN WITH 50KT CORE INTO NRN IL...WHILE SIG LESS /AOB 20-25KTS/ INVOF KFWA WHERE WS PRESENCE SHOULD REMAIN LESS PROBLEMATIC...AS JET CORE PUNCHES NWD INTO LAKE MICHIGAN. NEXT FOCUS ON APPROACHING COLD FRONT WITH CONVECTIVE SHRA AHEAD BYD 07/01UTC WHERE LIMITED SFC BASED INSTABILITY CONTS TO PRECLUDE NEED FOR TSRA MENTION ATTM. && .SHORT TERM... FOCUS PRIMARILY ON CONVECTION THIS EVENING. FAVOR NAM OVERALL WRT DEEP STACKED CYCLONE ACRS ERN SD AS GFS ARND F24-30 BEGINS TO WEAKEN/LIFT NWD TOO FAST GIVEN LACK OF SIG UPSTRM KICKER AS WRN STATES RIDGE QUICKLY REBUILDS AND SYSTEM TO REMAIN LRGLY STEADY STATE S OF SRN CANADIAN COL INTO WEEKEND. AS NAM DEPICTD 24 HRS AGO SPLIT/MLTPL LLJ FEATURE SPRTG CONVCTN EARLIER THIS AM IN MSP/EAU REGIION SUBSQNTLY DRIVEN NWD TO TWRD FAR WRN LK SUP/MN ARWHEAD BECMG MORE HIGHLY ELEVATED. FRTHR S 50-55KT 8H JETLET INTO SERN MO AND IN NERN TX DRIVING MORE SUBSTANTIAL NR SFC-BASED CONV NERN TX NWD INTO ERN IA. NERN JET SEGMENT PROGGED INTO MO BOOTHILL B Y 15 UTC TO CNTL IL BY 18 UTC. BACKED LLVL FLOW IN ADVANCE OF COLD FNT IN STRONG KINEMATIC FIELD PROVIDING STRONG 10-8H DEEP LYR CONVERGENCE AND YEILDING 0-3KM BLS OF 35-45KTS...SHOULD REMAIN SUFFICIENT TO MAINTAIN FINE LINE CONVECTION IMMEDIATELY AHEAD OF FNT WITH SFC DPS POOLED INTO THE MID 50S IN NARROW SWATH. FURTHERMORE CONCERN WITH HIGH AMPLITUDE/LONGITUDINAL ANVIL STEERING FLOW WL SERVE TO MAINTAIN RELATIVELY CLR SKIES/STRONG INSOLATION FOR MUCH OF DAY...ALLOWING FOR GRTR MUCAPE INSTABILITY...POTNLY HIR THAN THE 300-400 J/KG THAN MODEL OUTPUT SUGGESTS ACRS ERN IL BY MIDDAY. SLIGHT BUMP TO MAX TEMPS TODAY WITH LVL THERMAL PLUME IN PLACE. SHRA/TSRA TIMING REMAINS A BIT OF CONCERN WITH NAM SIGNALS INTO FAR WRN CWA AT 00 UTC HAVE CHOPPED AWAY AT ERN TWO-THIRDS POPS/STRENGTHENED POP GRADIENT ACRS FAR WRN CWA IN LATE AFTN. CONVECTIVE SUPRT QUICKLY WANES BY LATE EVENING AS STABILITY INCRSES/JET PUSHES NWD INTO SRN MI. RELEGATED ISOLD TSRA MENTION TO ALL BUT ERN CWA THIS EVENING WITH STRONG DYNAMICS PULLING LIONS SHARE OVER LACK OF THERMODYNAMINCS. NAM SLIGHT SLOWING RUN TO RUN WITH SFC BASED FEATURES ALSO SUPRTS MAJORITY OF POP/WX IN EARLY TONIGHT TIMEFRAME. FURTHERMORE PUSHED TIMING BACK OF WRAPAROUND SHRA IN COLD POOL/INCREASED HGHT FALLS LT FRIDAY AFN INTO FRI NIGHT...IN WAKE OF SCNDRY FNTL PASSAGE. COLUMN COOLING ENOUGH TO SUPORT WET MIX BY MIDNIGHT ALL BUT SRN CWA AND BYND 09 UTC SAT ENTIRE CWA WITH FZLVL LWRG TO 1500 FT. MUCH OF FRI NOW DRY WITH SLOWED TIMING OF SECONDARY SHRTWV/FROPA. && .LONG TERM... SATURDAY THROUGH WEDNESDAY....THE MAIN CHALLENGE OF THIS PERIOD INCLUDES THE CHANCE AND THE TYPE OF PRECIPITATION SATURDAY THROUGH SUNDAY ASSOCIATED WITH THE UPPER LOW MOVING INTO THE REGION. THE GFS AND NAM/WRF HAVE TRENDED TEMPERATURES COLDER SATURDAY...WITH 850 MB TEMPERATURES BETWEEN -5C AND -7C. SOME CONCERN IF ICE WILL BE INTRODUCED INTO THE CLOUD TOP FOR SNOW...SO HAVE INCLUDED A RAIN SNOW MIX. SLEET IS ALSO POSSIBLE GIVEN THE DEPTH OF THE COLD AIR...BUT FOR NOW WILL LEAVE OUT DUE TO UNCERTAINTY AND EXPECTED LIMITED COVERAGE AND DURATION OF THE SLEET. THE 00Z MEX HAS LOWERED THE HIGH SATURDAY HIGH FROM 49F TO 45F AT SBN IN 24 HRS...BUT STILL APPEARS TO BE TOO HIGH GIVEN CLOUDS...PRECIPITATION AND COLD TEMPERATURES IN THE LOW LEVELS. KEPT THE HIGHEST PRECIPITATION CHANCES OVER FAR LOWER MICHIGAN WHERE MOISTURE SHOULD BE DEEPER AND LIFT BETTER. AN UPPER LEVEL TROF WILL MOVE OVER THE AREA SATURDAY NIGHT...SO HAVE KEPT PRECIPITATION CHANCES INTACT. THERE MAY BE SOME LAKE ENHANCEMENT TO PRECIPITATION OVER FAR SW LOWER MICH...BUT GIVEN 250 TO 280 DEGREE PREVAILING LOW LEVEL WINDS...A PREDOMINANT LAKE EFFECT EVENT IS NOT EXPECTED. OTHERWISE...COLD CONDITIONS WILL PERSIST THROUGH WEDNESDAY. THE 00Z GFS WAS HINTING AT THE POTENTIAL FOR PRECIPITATION WITH ANOTHER UPPER LEVEL SYSTEM EJECTING NORTHEAST INTO THE AREA ABOUT TUESDAY. HOWEVER...FOR THIS PACKAGE...HAVE KEPT MONDAY THROUGH WEDNESDAY DRY DUE TO GFS RUN TO RUN CONSISTENCY ISSUES AND SIGNIFICANT ENSEMBLE SPREADS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR LMZ043-046. && $$ SHORT TERM...MURPHY LONG TERM...SKIPPER AVIATION...MURPHY in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 543 AM EST THU NOV 6 2008 .SHORT TERM... FOCUS PRIMARILY ON CONVECTION THIS EVENING. FAVOR NAM OVERALL WRT DEEP STACKED CYCLONE ACRS ERN SD AS GFS ARND F24-30 BEGINS TO WEAKEN/LIFT NWD TOO FAST GIVEN LACK OF SIG UPSTRM KICKER AS WRN STATES RIDGE QUICKLY REBUILDS AND SYSTEM TO REMAIN LRGLY STEADY STATE S OF SRN CANADIAN COL INTO WEEKEND. AS NAM DEPICTD 24 HRS AGO SPLIT/MLTPL LLJ FEATURE SPRTG CONVCTN EARLIER THIS AM IN MSP/EAU REGIION SUBSQNTLY DRIVEN NWD TO TWRD FAR WRN LK SUP/MN ARWHEAD BECMG MORE HIGHLY ELEVATED. FRTHR S 50-55KT 8H JETLET INTO SERN MO AND IN NERN TX DRIVING MORE SUBSTANTIAL NR SFC-BASED CONV NERN TX NWD INTO ERN IA. NERN JET SEGMENT PROGGED INTO MO BOOTHILL B Y 15 UTC TO CNTL IL BY 18 UTC. BACKED LLVL FLOW IN ADVANCE OF COLD FNT IN STRONG KINEMATIC FIELD PROVIDING STRONG 10-8H DEEP LYR CONVERGENCE AND YEILDING 0-3KM BLS OF 35-45KTS...SHOULD REMAIN SUFFICIENT TO MAINTAIN FINE LINE CONVECTION IMMEDIATELY AHEAD OF FNT WITH SFC DPS POOLED INTO THE MID 50S IN NARROW SWATH. FURTHERMORE CONCERN WITH HIGH AMPLITUDE/LONGITUDINAL ANVIL STEERING FLOW WL SERVE TO MAINTAIN RELATIVELY CLR SKIES/STRONG INSOLATION FOR MUCH OF DAY...ALLOWING FOR GRTR MUCAPE INSTABILITY...POTNLY HIR THAN THE 300-400 J/KG THAN MODEL OUTPUT SUGGESTS ACRS ERN IL BY MIDDAY. SLIGHT BUMP TO MAX TEMPS TODAY WITH LVL THERMAL PLUME IN PLACE. SHRA/TSRA TIMING REMAINS A BIT OF CONCERN WITH NAM SIGNALS INTO FAR WRN CWA AT 00 UTC HAVE CHOPPED AWAY AT ERN TWO-THIRDS POPS/STRENGTHENED POP GRADIENT ACRS FAR WRN CWA IN LATE AFTN. CONVECTIVE SUPRT QUICKLY WANES BY LATE EVENING AS STABILITY INCRSES/JET PUSHES NWD INTO SRN MI. RELEGATED ISOLD TSRA MENTION TO ALL BUT ERN CWA THIS EVENING WITH STRONG DYNAMICS PULLING LIONS SHARE OVER LACK OF THERMODYNAMINCS. NAM SLIGHT SLOWING RUN TO RUN WITH SFC BASED FEATURES ALSO SUPRTS MAJORITY OF POP/WX IN EARLY TONIGHT TIMEFRAME. FURTHERMORE PUSHED TIMING BACK OF WRAPAROUND SHRA IN COLD POOL/INCREASED HGHT FALLS LT FRIDAY AFN INTO FRI NIGHT...IN WAKE OF SCNDRY FNTL PASSAGE. COLUMN COOLING ENOUGH TO SUPORT WET MIX BY MIDNIGHT ALL BUT SRN CWA AND BYND 09 UTC SAT ENTIRE CWA WITH FZLVL LWRG TO 1500 FT. MUCH OF FRI NOW DRY WITH SLOWED TIMING OF SECONDARY SHRTWV/FROPA. && .LONG TERM... SATURDAY THROUGH WEDNESDAY....THE MAIN CHALLENGE OF THIS PERIOD INCLUDES THE CHANCE AND THE TYPE OF PRECIPITATION SATURDAY THROUGH SUNDAY ASSOCIATED WITH THE UPPER LOW MOVING INTO THE REGION. THE GFS AND NAM/WRF HAVE TRENDED TEMPERATURES COLDER SATURDAY...WITH 850 MB TEMPERATURES BETWEEN -5C AND -7C. SOME CONCERN IF ICE WILL BE INTRODUCED INTO THE CLOUD TOP FOR SNOW...SO HAVE INCLUDED A RAIN SNOW MIX. SLEET IS ALSO POSSIBLE GIVEN THE DEPTH OF THE COLD AIR...BUT FOR NOW WILL LEAVE OUT DUE TO UNCERTAINTY AND EXPECTED LIMITED COVERAGE AND DURATION OF THE SLEET. THE 00Z MEX HAS LOWERED THE HIGH SATURDAY HIGH FROM 49F TO 45F AT SBN IN 24 HRS...BUT STILL APPEARS TO BE TOO HIGH GIVEN CLOUDS...PRECIPITATION AND COLD TEMPERATURES IN THE LOW LEVELS. KEPT THE HIGHEST PRECIPITATION CHANCES OVER FAR LOWER MICHIGAN WHERE MOISTURE SHOULD BE DEEPER AND LIFT BETTER. AN UPPER LEVEL TROF WILL MOVE OVER THE AREA SATURDAY NIGHT...SO HAVE KEPT PRECIPITATION CHANCES INTACT. THERE MAY BE SOME LAKE ENHANCEMENT TO PRECIPITATION OVER FAR SW LOWER MICH...BUT GIVEN 250 TO 280 DEGREE PREVAILING LOW LEVEL WINDS...A PREDOMINANT LAKE EFFECT EVENT IS NOT EXPECTED. OTHERWISE...COLD CONDITIONS WILL PERSIST THROUGH WEDNESDAY. THE 00Z GFS WAS HINTING AT THE POTENTIAL FOR PRECIPITATION WITH ANOTHER UPPER LEVEL SYSTEM EJECTING NORTHEAST INTO THE AREA ABOUT TUESDAY. HOWEVER...FOR THIS PACKAGE...HAVE KEPT MONDAY THROUGH WEDNESDAY DRY DUE TO GFS RUN TO RUN CONSISTENCY ISSUES AND SIGNIFICANT ENSEMBLE SPREADS. && .AVIATION... EASTERN FRINGE OF LOW LVL JET INVOF 1500FT AGL TO CONTINUE UNTIL MID/LATE AM UNTIL SUFFICIENT HEATING WL ALLOW FOR INVERSION TO MIXOUT WITH WIND PROFILE BECMG MORE HOMOGENEOUS. 35KT LLJ PER RUC AT 925MB INTO KSBN WHILE SIG LESS/AOB 20-25KTS INVOF KFWA WHERE WS PRESENCE SHOULD REMAIN LESS PROBLEMATIC. NEXT FOCUS ON APPROACHING COLD FRONT WITH CONVECTIVE POTNL BYD 07/00UTC WHERE TIMING AND LIMITED SFC BASED INSTABILITY PRECLUDES NEED FOR TSRA MENTION ATTM. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR LMZ043-046-080. && $$ SHORT TERM...MURPHY LONG TERM...SKIPPER AVIATION...MURPHY in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 100 AM EST THU NOV 6 2008 .AVIATION... EASTERN FRINGE OF LOW LVL JET INVOF 1500FT AGL TO CONTINUE UNTIL MID/LATE AM UNTIL SUFFICIENT HEATING WL ALLOW FOR INVERSION TO MIXOUT WITH WIND PROFILE BECMG MORE HOMOGENEOUS. 35KT LLJ PER RUC AT 925MB INTO KSBN WHILE SIG LESS/AOB 20-25KTS INVOF KFWA WHERE WS PRESENCE SHOULD REMAIN LESS PROBLEMATIC. NEXT FOCUS ON APPROACHING COLD FRONT WITH CONVECTIVE POTNL BYD 07/00UTC WHERE TIMING AND LIMITED SFC BASED INSTABILITY PRECLUDES NEED FOR TSRA MENTION ATTM. && .SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT) WARM TEMPERATURES AGAIN ON THURSDAY CLOSE OUT A WONDERFUL ABOVE NORMAL STRETCH AS TROFING TAKES OVER BEHIND FRONTAL PASSAGE THURSDAY EVENING USHERING IN A RETURN TO REALITY. UPR TROF CLOSING OFF TODAY OVER CENTRAL US MOVES EAST WITH ASSOC SFC LOW AND BECOMES NEARLY VERTICALLY STACKED BY FRI NIGHT. MODELS GENERALLY IN GOOD AGREEMENT THROUGH THE PD AND WITH SFC LOW OCCLUDING AND STACKED SYSTEM SLOWING DOWN...FOLLOWED NAM WHICH IS SLOWEST AMONG MODEL GUIDANCE. INSTABILITY WITH FRONT IS CONFINED TO A NARROW BAND ALONG THE BNDRY WHICH LEAVES THE CWA WARM AND SUNNY YET AGAIN FOR THURSDAY. H85 TEMPS/TRAJECTORIES/FCST SOUNDINGS ALL POINT TO HEAVILY WEIGHTING PERSISTENCE FOR SUNNY HIGH TEMPS IN THE LOW 70S ONCE AGAIN. WITH FRONTAL TIMING SLATED FOR THU EVENING EFFECTS BEGIN TO ARRIVE IN WESTERN CWA NEAR 00Z. INSTABILITY IS LACKING IN GENERAL AND WHAT IS PRESENT IS LOCATED IN A CORRIDOR ALONG THE BNDRY. H85/H92 WINDS AROUND 40KT ACROSS MOST OF CWA IN 12Z NAM...WHILE GFS CONSERVATIVELY BRUSHES ONLY NW PORTIONS AS LL JET TRANSLATES INTO MICHIGAN. COLD AIR ALOFT IS LAGGING AND STRONGER MID LEVEL WINDS ALSO REMAIN POST FRONTAL. NAM BUFR SOUNDINGS PRODUCE ONLY A THIN WINDOW OF INSTABILITY WITH MUCAPES NEAR 300 J/KG ALONG WESTERN CWA DIMINISHING AS BNDRY TRANSLATES EAST IN A 30-40KT 0-3KM BULK SHEAR ENVIRONMENT. SIGNS POINT TO A POSSIBLE LINE OF WEAK/MODERATE CONVECTION APPROACHING FROM THE WEST ALONG OR JUST AHEAD OF BNDRY IN AN AXIS OF STRONGEST LL MOISTURE CONVERGENCE...WEAKENING AS IT MOVES EWARD THROUGH THE CWA. CONCERN IS FOR STRONG WIND GUSTS POSSIBLE WITH 40 KT WINDS ALOFT WHICH COULD MIX DOWN...PARTICULARLY NORTHWEST CWA WHERE THERE IS BETTER CHANCE OF WEAK INSTABILITY BEING REALIZED. MAINTAINED OVERALL THEME OF POP/SKY WITH TWEAKS FOR INITIAL TIMING IN THE WEST AS WELL AS CLEARING BEYOND 06Z AS DRY SLOT MOVES INTO THE AREA BEHIND THE BNDRY. OVERNIGHT TEMPS REMAIN SIMILAR TO PREVIOUS NIGHTS WITH COLDER AIR NOT ARRIVING IMMEDIATELY BEHIND PASSAGE. && .LONG TERM...(FRIDAY THROUGH WEDNESDAY) ...COLD WEEKEND IN STORE FOR THE REGION... NAM/GFS VARY IN TRACK OF THE UPPER LOW AND ASSOCIATED POOL OF COLD AIR. THE TRACK WILL PLAY A KEY ROLE FOR PRECIP CHANCES MAINLY SAT AND SUNDAY. AT THE START OF THE PERIOD MODELS SHOW A LARGE GRADIENT IN 850 TEMPS FROM WEST TO EAST IN THE WAKE OF THE OCCLUDED FRONT WITH VALUES RANGING FROM +1 WEST TO +8 C EAST. UPPER LOW ON THE NAM IS PROGGED TO BE CENTERED OVER SOUTHERN MINNESOTA WITH GFS OVER NW IOWA. MODELS GENERALLY AGREE ON WHAT APPEARS TO BE A NICE DRY SLOT IN BETWEEN THE OCCLUDED FRONT AND THE MAIN TROUGH AND UPPER LOW. 850 MB TEMPS LOWER AS THEY SPREAD ACROSS THE CWA BUT THEN SLOW AS THE UPPER LOW BEGINS TO SLOW ITS EASTWARD PROGRESS SOME. THIS WILL MAKE FOR A PROBLEMATIC TEMP FORECAST ON FRIDAY WITH TEMPS ACTUALLY WARMING BACK INTO THE UPPER 50S TO LOWER 60S INTO EARLY AFTERNOON. AFTER COLLABORATION... HAVE DECIDED TO ADD SOME DETAIL TO FRIDAY AND REMOVE POPS FOR PARTS OF THE DAY WITH LINGERING POPS EAST EARLY THEN A DRY PERIOD FOR ALL FOLLOW BY CHC POPS ARRIVING BACK IN THE NW LATE. BY 12Z SAT...MODELS VARY EVEN GREATER ON LOCATION OF UPPER LOW WITH GFS HAVING THE LOW OVER SW LWR MI WITH 500 MB TEMPS OF -22 TO -26 C AND THE NAM FURTHER WEST AND NORTH OVER SOUTHERN WISCONSIN AND 500 MB TEMPS OF -23 TO -26 C. LATE FRI NGT INTO SATURDAY APPEARS TO BE THE NEXT BEST WINDOW FOR PRECIP WITH S/W ROUNDING THE TROUGH...COLDEST AIR ALOFT OVERHEAD AND FAVORABLE TIME OF DAY. MAY NEED TO INCREASE POPS FURTHER BUT FOR NOW HAVE WENT HIGH CHC NORTH TO LOW CHC SOUTH FOR SATURDAY. THERMAL PROFILES WILL ALSO BE A CHALLENGE WITH SOME HINTS OF MAYBE HAVING TO MIX IN A CHC OF SNOW AS 1000-850 MB THICKNESSES DROP TO AROUND 1290 M. NO CHANGES BEYOND THAT AS NEXT PUSH OF COLD AIR TO ARRIVE ON SUNDAY AND MONDAY. CONCERNED THAT TEMPS MAY NOT BE COLD ENOUGH POSSIBLY INTO MONDAY WITH BUFKIT SOUNDINGS SUGGESTING HIGHS STRUGGLING TO CLIMB OUT OF THE 30S IN SOME AREAS. WILL HOLD POPS THROUGH SUNDAY BUT SOME CHANCE THAT THINGS COULD NEED TO BE EXPANDED IN COLD NW FLOW AND POTENTIAL SETUP FOR LAKE EFFECT AGAIN. HIGH PRESSURE WILL EVENTUALLY BUILD IN COMPLETELY AND BRING AN END TO THE PRECIP CHANCES AND ALSO APPEARS TO KEEP THE NEXT SYSTEM COMPRESSED TO THE SOUTH AT THIS POINT. SO WILL GO DRY INTO THE NEW DAY 7. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && $$ SHORT TERM...LUDINGTON LONG TERM...FISHER AVIATION...MURPHY in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 605 PM MST THU NOV 6 2008 .DISCUSSION... WINDS HAVE FALLEN BELOW ADVISORY AND WARNING CRITERIA WITH THE LOSS OF DAYTIME HEATING. AS A RESULT HAVE CANCELLED ALL HIGHLITES. WILL RE-EVALUATE ALL ELEMENTS FOR FIRST PERIOD ONCE THE 00Z MODELS AND GUIDANCE COME IN. DDT && .PREV DISCUSSION... /ISSUED 305 PM MST THU NOV 6 2008/ .DISCUSSION... 234 PM MST THU NOV 6 2008 17Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATE A DEEP CLOSED H5 LOW ACROSS NORTHEAST NEBRASKA. AT THE SFC...THERE APPEARS TO BE TWO LOW CENTERS...A 997 MB CENTER NEAR KOFK AND A 994 MB LOW NEAR KMSP. IMMEDIATE SHORT TERM CONCERNS WILL CONTINUE TO BE STRONG WINDS ON BACKSIDE OF THE SFC LOW. FOLLOWED BY POTENTIAL WINTER WX SUNDAY AND MONDAY. TONIGHT...DIV Q FIELDS INDICATE FORCING FOR SUBSIDENCE WILL BE IN PLACE INITIALLY ACROSS THE AREA AS H5 LOW SLOWLY MOVES TO THE EAST SOUTHEAST. SURPRISINGLY...DIV Q FIELDS AND OMEGA PROFILES INDICATE ASCENT OVERSPREADING THE AREA DURING THE EVENING. STATIC STABILITY APPEARS TO BE RATHER HIGH...AND DO NOT THINK WEAK FORCING WILL PRODUCE MORE THAN A MIDDLE CLOUD DECK...SO WILL CONTINUE FORECAST OF PRECIP ENDING BY THIS AFTERNOON UNLESS OBSERVATIONAL TRENDS SUGGEST OTHERWISE. BOTH NAM AND GFS SUGGEST WINDS WILL DECOUPLE QUICKLY THIS EVENING AS SFC LOW CONTINUES TO MOVE EAST AND SUBSIDENCE BELOW H7 HELPS STRENGTHEN THE INVERSION AND LIMIT TURBULENT MIXING. BUFR SOUNDINGS SHOW A RESURGENCE IN THE WINDS AROUND 06Z AT MCK...AS WEAK ASCENT OVERSPREADS THE REGION. TIME OF NIGHT WOULD NOT SEEM TO FAVOR AN ATMOSPHERE AS DEEPLY MIXED AS THE SOUNDING SUGGEST AND FOR NOW WILL LET THE WARNING EXPIRE AS IS AND LET OBSERVATIONS DICTATE IF IT NEEDS TO BE EXTENDED. TOMORROW-TOMORROW NIGHT...WINDS WILL LIKELY BE A FACTOR AGAIN ON FRIDAY...ALTHOUGH THEY WILL BE MUCH LIGHTER THAN TODAY. SUSTAINED WINDS AROUND 25KTS LOOK LIKELY ACROSS THE EASTERN CWA THROUGH THE DAY...AND MAY SEE WINDS REACH LOW END ADVISORY AROUND 18Z. WITH WIND HIGHLIGHTS ALREADY ONGOING...AND MARGINAL NATURE OF THE WINDS TOMORROW...WILL NOT ISSUE AN ADDITIONAL HIGHLIGHT AT THIS TIME. SKIES SHOULD BE CLEAR FOR MUCH OF THE MORNING...BUT APPROACHING H3 JET STREAK WILL LIKELY PROVIDE ENOUGH LIFT FOR ANOTHER BATCH OF CLOUDS AS LARGE T-TD SPREADS AND A FAIRLY STABLE AIR MASS WILL LIMIT ANT PRECIPITATION CHANCE WITH THE APPROACHING JET STREAK. VERY DRY AIR TO THE WEST MAY ALSO ADVECT INTO THE AREA TOMORROW AS WIND FIELD WILL HAVE A WESTERLY COMPONENT IN THE MORNING. RH VALUES MAY NEAR CRITICAL FIRE WX VALUES DURING THE AFTERNOON ACROSS THE SOUTHWEST. THIS AREA WILL BE WHERE WINDS ARE THE LIGHTEST...SIMILAR TO TODAY. ALTHOUGH HAVE SOME CONCERNS ABOUT RED FLAG CRITERIA TOMORROW...CONFIDENCE NOT HIGH ENOUGH FOR A WATCH ATTM...AND SATURDAY-SUNDAY...SHORT WAVE RIDGING WILL BUILD OVER THE CWA ON SATURDAY. DESPITE SUBSIDENCE WITH RIDGE...BOTH NAM AND GFS INDICATE PERSISTENT AREA OF SATURATION ALONG H7 THERMAL RIDGE IN AREA OF WAA. STATIC STABILITY ONCE AGAIN APPEARS STRONG SO DO NOT ANTICIPATE MUCH OF A PRECIP THREAT THROUGH THE DAY SATURDAY. NAM...GFS AND SREF ALL AGREE COLD FRONT WILL BACK INTO THE AREA SATURDAY AFTERNOON. MODELS STILL AGREE ON FAIRLY STRONG LOW LEVEL FORCING DEVELOPING OVERNIGHT AS WAA INCREASES ABOVE THE SHALLOW COLD AIRMASS. SOUNDINGS INDICATE ICE WOULD BE HARD TO COME BY AT MOST SITES WITH FORCING PRIMARILY FOCUSED SO LOW TO THE GROUND. ONE EXCEPTION TO THIS WILL BE IN THE NORTHEAST WHERE AFOREMENTIONED AREA OF SATURATION NEAR THE EDGE OF THERMAL RIDGE WHICH MAY BE ABLE TO PROVIDE A FEW ICE CRYSTALS BEFORE IT LIFTS NORTH SUNDAY MORNING. ALTHOUGH MODELS STILL SUPPORT THE POTENTIAL FOR -FZDZ OVERNIGHT SATURDAY INTO SUNDAY MORNING...MODELS STILL SUGGEST THAT BOUNDARY LAYER WILL NOT BE SATURATED WHICH WOULD LEAD ME TO THINK MORE STRATUS THAN ANY KIND OF PCP. MUCH DRIER AIRMASS FORECASTED TO BE IN PLACE BEHIND THE FRONT...AND VERY LIMITED MOISTURE RETURN NORTH OF THE FRONT SUPPORTS THIS LINE OF THINKING AS WELL. AT THIS POINT...THINK A SCHC STILL WARRANTED BUT DO NOT PLAN ON INCREASING CHANCES AT THIS TIME. IN THE EXTENDED(SUNDAY NIGHT-THURSDAY)...MEDIUM RANGE MODELS ALL HAVE THERE SHARE OF DIFFERENCES IN HANDLING OF NEXT SYSTEM ON SUNDAY THROUGH TUESDAY. GFS ENSEMBLES FAVOR THE MORE AMPLIFIED SOLUTION OF THE CANADIAN AND ECMWF AND WILL LEAN IN THIS DIRECTION FOR EXTENDED PERIODS ALTHOUGH CONFIDENCE REMAINS LOW. LOW CONFIDENCE ASIDE...POTENTIAL FOR ANOTHER WET PERIOD ACROSS CWA EXISTS. NUMEROUS DIFFERENCES IN MODEL FORECASTS MAKE DIAGNOSING SPECIFIC FORCING DETAILS AND POTENTIAL PRECIPITATION TYPE DIFFICULT..AND FOR THE TIME BEING WILL TRY TO KEEP WX TYPE SIMPLE FOR MON-TUES. WITH CWA EXPECTED TO BE ON THE NORTH SIDE OF LOW WITH DEEP EASTERLY FLOW AND PRECIP AND CLOUDS HOLDING BACK ANY WARMING DO NOT ANTICIPATE MUCH OF A DIURNAL TREND AND WILL COOL MAX TEMPS SEVERAL DEGREES. WITH A LIMITED DIURNAL RANGE...AND GFS ENS DATA INDICATING >60% CHANCE OF H85 TEMPS BELOW 0C BY MONDAY AFTERNOON...WILL KEEP PRECIP TYPE AS SNOW FOR NOW. ANOTHER TROUGH IS FORECASTED TO IMPACT THE AREA LATTER IN THE PERIOD...BUT WITH ALL THE UNCERTAINTY OF THE FIRST HALF OF THE PERIOD WILL KEEP POPS OUT OF THE FORECAST FOR NOW. JRM && .AVIATION... 304 PM MST THU NOV 6 2008 FOR 00Z TAFS...CLOUDS AND WIND SHOULD SLOWLY DECREASE FOR THIS TAF PERIOD AS THE UPPER LOW MOVES FROM NORTHEAST NEBRASKA TO SOUTH OF THE GREAT LAKES. WIND SPEEDS WILL GRADUALLY DECREASE TO 25KT GUSTING TO 35KT TONIGHT AND FRIDAY. VFR CONDITIONS SHOULD PREVAIL THROUGH THIS TAF PERIOD WITH CLEARING OCCURRING AFTER 12Z FRIDAY. INCREASING MID AND HIGH LEVEL CLOUDS ARE EXPECTED AT BOTH SITES FRIDAY AFTERNOON AS A SHORTWAVE MOVES INTO THE AREA IN NORTHWEST FLOW. FS && && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ WFO GOODLAND ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 305 PM MST THU NOV 6 2008 .DISCUSSION... 234 PM MST THU NOV 6 2008 17Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATE A DEEP CLOSED H5 LOW ACROSS NORTHEAST NEBRASKA. AT THE SFC...THERE APPEARS TO BE TWO LOW CENTERS...A 997 MB CENTER NEAR KOFK AND A 994 MB LOW NEAR KMSP. IMMEDIATE SHORT TERM CONCERNS WILL CONTINUE TO BE STRONG WINDS ON BACKSIDE OF THE SFC LOW. FOLLOWED BY POTENTIAL WINTER WX SUNDAY AND MONDAY. TONIGHT...DIV Q FIELDS INDICATE FORCING FOR SUBSIDENCE WILL BE IN PLACE INITIALLY ACROSS THE AREA AS H5 LOW SLOWLY MOVES TO THE EAST SOUTHEAST. SURPRISINGLY...DIV Q FIELDS AND OMEGA PROFILES INDICATE ASCENT OVERSPREADING THE AREA DURING THE EVENING. STATIC STABILITY APPEARS TO BE RATHER HIGH...AND DO NOT THINK WEAK FORCING WILL PRODUCE MORE THAN A MIDDLE CLOUD DECK...SO WILL CONTINUE FORECAST OF PRECIP ENDING BY THIS AFTERNOON UNLESS OBSERVATIONAL TRENDS SUGGEST OTHERWISE. BOTH NAM AND GFS SUGGEST WINDS WILL DECOUPLE QUICKLY THIS EVENING AS SFC LOW CONTINUES TO MOVE EAST AND SUBSIDENCE BELOW H7 HELPS STRENGTHEN THE INVERSION AND LIMIT TURBULENT MIXING. BUFR SOUNDINGS SHOW A RESURGENCE IN THE WINDS AROUND 06Z AT MCK...AS WEAK ASCENT OVERSPREADS THE REGION. TIME OF NIGHT WOULD NOT SEEM TO FAVOR AN ATMOSPHERE AS DEEPLY MIXED AS THE SOUNDING SUGGEST AND FOR NOW WILL LET THE WARNING EXPIRE AS IS AND LET OBSERVATIONS DICTATE IF IT NEEDS TO BE EXTENDED. TOMORROW-TOMORROW NIGHT...WINDS WILL LIKELY BE A FACTOR AGAIN ON FRIDAY...ALTHOUGH THEY WILL BE MUCH LIGHTER THAN TODAY. SUSTAINED WINDS AROUND 25KTS LOOK LIKELY ACROSS THE EASTERN CWA THROUGH THE DAY...AND MAY SEE WINDS REACH LOW END ADVISORY AROUND 18Z. WITH WIND HIGHLIGHTS ALREADY ONGOING...AND MARGINAL NATURE OF THE WINDS TOMORROW...WILL NOT ISSUE AN ADDITIONAL HIGHLIGHT AT THIS TIME. SKIES SHOULD BE CLEAR FOR MUCH OF THE MORNING...BUT APPROACHING H3 JET STREAK WILL LIKELY PROVIDE ENOUGH LIFT FOR ANOTHER BATCH OF CLOUDS AS LARGE T-TD SPREADS AND A FAIRLY STABLE AIR MASS WILL LIMIT ANT PRECIPITATION CHANCE WITH THE APPROACHING JET STREAK. VERY DRY AIR TO THE WEST MAY ALSO ADVECT INTO THE AREA TOMORROW AS WIND FIELD WILL HAVE A WESTERLY COMPONENT IN THE MORNING. RH VALUES MAY NEAR CRITICAL FIRE WX VALUES DURING THE AFTERNOON ACROSS THE SOUTHWEST. THIS AREA WILL BE WHERE WINDS ARE THE LIGHTEST...SIMILAR TO TODAY. ALTHOUGH HAVE SOME CONCERNS ABOUT RED FLAG CRITERIA TOMORROW...CONFIDENCE NOT HIGH ENOUGH FOR A WATCH ATTM...AND SATURDAY-SUNDAY...SHORT WAVE RIDGING WILL BUILD OVER THE CWA ON SATURDAY. DESPITE SUBSIDENCE WITH RIDGE...BOTH NAM AND GFS INDICATE PERSISTENT AREA OF SATURATION ALONG H7 THERMAL RIDGE IN AREA OF WAA. STATIC STABILITY ONCE AGAIN APPEARS STRONG SO DO NOT ANTICIPATE MUCH OF A PRECIP THREAT THROUGH THE DAY SATURDAY. NAM...GFS AND SREF ALL AGREE COLD FRONT WILL BACK INTO THE AREA SATURDAY AFTERNOON. MODELS STILL AGREE ON FAIRLY STRONG LOW LEVEL FORCING DEVELOPING OVERNIGHT AS WAA INCREASES ABOVE THE SHALLOW COLD AIRMASS. SOUNDINGS INDICATE ICE WOULD BE HARD TO COME BY AT MOST SITES WITH FORCING PRIMARILY FOCUSED SO LOW TO THE GROUND. ONE EXCEPTION TO THIS WILL BE IN THE NORTHEAST WHERE AFOREMENTIONED AREA OF SATURATION NEAR THE EDGE OF THERMAL RIDGE WHICH MAY BE ABLE TO PROVIDE A FEW ICE CRYSTALS BEFORE IT LIFTS NORTH SUNDAY MORNING. ALTHOUGH MODELS STILL SUPPORT THE POTENTIAL FOR -FZDZ OVERNIGHT SATURDAY INTO SUNDAY MORNING...MODELS STILL SUGGEST THAT BOUNDARY LAYER WILL NOT BE SATURATED WHICH WOULD LEAD ME TO THINK MORE STRATUS THAN ANY KIND OF PCP. MUCH DRIER AIRMASS FORECASTED TO BE IN PLACE BEHIND THE FRONT...AND VERY LIMITED MOISTURE RETURN NORTH OF THE FRONT SUPPORTS THIS LINE OF THINKING AS WELL. AT THIS POINT...THINK A SCHC STILL WARRANTED BUT DO NOT PLAN ON INCREASING CHANCES AT THIS TIME. IN THE EXTENDED(SUNDAY NIGHT-THURSDAY)...MEDIUM RANGE MODELS ALL HAVE THERE SHARE OF DIFFERENCES IN HANDLING OF NEXT SYSTEM ON SUNDAY THROUGH TUESDAY. GFS ENSEMBLES FAVOR THE MORE AMPLIFIED SOLUTION OF THE CANADIAN AND ECMWF AND WILL LEAN IN THIS DIRECTION FOR EXTENDED PERIODS ALTHOUGH CONFIDENCE REMAINS LOW. LOW CONFIDENCE ASIDE...POTENTIAL FOR ANOTHER WET PERIOD ACROSS CWA EXISTS. NUMEROUS DIFFERENCES IN MODEL FORECASTS MAKE DIAGNOSING SPECIFIC FORCING DETAILS AND POTENTIAL PRECIPITATION TYPE DIFFICULT..AND FOR THE TIME BEING WILL TRY TO KEEP WX TYPE SIMPLE FOR MON-TUES. WITH CWA EXPECTED TO BE ON THE NORTH SIDE OF LOW WITH DEEP EASTERLY FLOW AND PRECIP AND CLOUDS HOLDING BACK ANY WARMING DO NOT ANTICIPATE MUCH OF A DIURNAL TREND AND WILL COOL MAX TEMPS SEVERAL DEGREES. WITH A LIMITED DIURNAL RANGE...AND GFS ENS DATA INDICATING >60% CHANCE OF H85 TEMPS BELOW 0C BY MONDAY AFTERNOON...WILL KEEP PRECIP TYPE AS SNOW FOR NOW. ANOTHER TROUGH IS FORECASTED TO IMPACT THE AREA LATTER IN THE PERIOD...BUT WITH ALL THE UNCERTAINTY OF THE FIRST HALF OF THE PERIOD WILL KEEP POPS OUT OF THE FORECAST FOR NOW. JRM && .AVIATION... 304 PM MST THU NOV 6 2008 FOR 00Z TAFS...CLOUDS AND WIND SHOULD SLOWLY DECREASE FOR THIS TAF PERIOD AS THE UPPER LOW MOVES FROM NORTHEAST NEBRASKA TO SOUTH OF THE GREAT LAKES. WIND SPEEDS WILL GRADUALLY DECREASE TO 25KT GUSTING TO 35KT TONIGHT AND FRIDAY. VFR CONDITIONS SHOULD PREVAIL THROUGH THIS TAF PERIOD WITH CLEARING OCCURRING AFTER 12Z FRIDAY. INCREASING MID AND HIGH LEVEL CLOUDS ARE EXPECTED AT BOTH SITES FRIDAY AFTERNOON AS A SHORTWAVE MOVES INTO THE AREA IN NORTHWEST FLOW. FS && .GLD WATCHES/WARNINGS/ADVISORIES... KS...HIGH WIND WARNING UNTIL 7 PM MST /8 PM CST/ THIS EVENING FOR KSZ001>004-013>016-028-029. WIND ADVISORY UNTIL 7 PM MST /8 PM CST/ THIS EVENING FOR KSZ027- 041-042. NE...HIGH WIND WARNING UNTIL 7 PM MST /8 PM CST/ THIS EVENING FOR NEZ079>081. CO...HIGH WIND WARNING UNTIL 7 PM MST THIS EVENING FOR COZ090-091. WIND ADVISORY UNTIL 7 PM MST THIS EVENING FOR COZ092. && $$ WFO GOODLAND ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1028 PM MST WED NOV 5 2008 .UPDATE...QUICK UPDATE SENT TO ISSUE THE HIGH WIND WARNING. LATEST MODEL RUNS AND UPSTREAM OBSERVATIONS HAVE PROVIDED ENOUGH CONFIDENCE THAT WARNING CRITERIA WILL BE REACHED BASICALLY NORTH OF INTERSTATE 70 NEAR OR SHORTLY AFTER SUNRISE. STRONG AREA OF SUBSIDENCE ROUNDING THE UPPER LOW COMBINED WITH PRESSURE GRADIENT AT THE SURFACE SHOULD RESULT IN SUSTAINED WINDS NEAR 40 MPH AND GUSTS UP TO 60 MPH. WINDS WILL SUBSIDE AROUND SUNSET ON THURSDAY. && .PREV DISCUSSION... /ISSUED 448 PM MST WED NOV 5 2008/ THE 20Z SURFACE ANALYSIS SHOWS A TROUGH EXTENDING FROM THE TEXAS PANHANDLE TO EASTERN SOUTH DAKOTA. WATER VAPOR IMAGERY SHOWING THE UPPER LOW OVER CENTRAL COLORADO. KGLD RADAR DETECTING SOME LIGHT SHOWERS OR SPRINKLES MAINLY OVER THE NORTHWEST AND FAR SOUTHERN ZONES. THE UPPER LOW IS PROGGED TO MOVE NORTHEAST INTO CENTRAL SOUTH DAKOTA TONIGHT. NORTHWEST FLOW WILL TAKE OVER ON THURSDAY AND CONTINUE THROUGH SATURDAY. SURFACE HIGH PRESSURE WILL BUILD EASTWARD INTO THE CENTRAL PLAINS BEHIND THE EXITING TROUGH. THE MAIN FORECAST ISSUES ARE WIND ON THURSDAY AND WHETHER ANY POPS WILL BE NEEDED FOR TONIGHT/THURSDAY. THE SURFACE PRESSURE GRADIENT TIGHTENS UP THURSDAY BEHIND THE EXITING LOW PRESSURE. LATEST GUIDANCE INDICATES THAT WINDS WILL SATISFY CRITERIA FOR A WIND ADVISORY ON THURSDAY OVER THE CWA. THE NAM AND GFS FORECAST SOUNDINGS INDICATE SUSTAINED WINDS OF 30+ KTS WITH POTENTIAL GUSTS TO 45KTS OVER MOST OF THE FORECAST AREA. THE RUC ALSO SUPPORTS THE WIND ADVISORY WITH SUSTAINED WINDS OF GREATER THAN 30KTS AND GUSTS GREATER THAN 40 KTS. BASED ON THIS HAVE ALREADY ISSUED A WIND ADVISORY FOR THE ENTIRE FORECAST AREA FOR THURSDAY...SEE DETAILS BELOW. FOR POPS...DYNAMICS MOVE TO THE SOUTHEAST AND NORTH THIS EVENING AND THEN TOWARD 12Z THURSDAY WRAPAROUND DYNAMICS START TO AFFECT THE NORTHEAST ZONES. THIS WILL CONTINUE THROUGH ABOUT 18Z THURSDAY. CONSEQUENTLY HAVE RELIED ON SLIGHT CHANCE POPS FOR THESE BASED UPON MARGINAL NATURE OF THIS SYSTEM SO FAR. HOWEVER EXPECT WRAPAROUND TO HAVE BETTER MOISTURE THURSDAY MORNING AND FOR THAT REASON HAVE INCREASE POPS TO CHANCE OVER THE MCK AREA. FORECAST SOUNDINGS INDICATE PRECIPITATION EAST OF COLORADO SHOULD BE LIQUID BUT CANNOT RULE OUT SOME SNOW MIXING IN OVER YUMA COUNTY COLORADO. SOUNDINGS ARE NOT ALL THAT SATURATED AT LOWER LEVELS SO PRECIPITATION MAY HAVE DIFFICULTY REACHING THE SURFACE. SUBSIDENCE TAKES OVER ACROSS THE ENTIRE FORECAST AREA THURSDAY NIGHT AND CONTINUES THROUGH SATURDAY. 850MB TEMPERATURES WILL KEEP MAX TEMPERATURES COOL IN THE UPPER 40S ON THURSDAY. TEMPERATURES WILL START MODERATING ON FRIDAY WITH ABOVE NORMAL READINGS NEAR 60 ON SATURDAY. MIN TEMPERATURES WILL FALL INTO THE UPPER 20S TO LOWER 30S TONIGHT THROUGH SATURDAY NIGHT. IN THE EXTENDED...DIFFERENCES STILL REMAIN BETWEEN THE GFS AND THE ECMWF. THE GFS IS MUCH WEAKER WITH THE SYSTEM THAN THE ECMWF. THE ECMWF DIVES SOUTH AND THEN COMES BACK NORTH ACROSS THE FORECAST AREA. DUE TO THE LACK OF AGREEMENT WILL CONTINUE SLIGHT CHANCE POPS FOR A RAIN/SNOW MIX FOR SUNDAY NIGHT THROUGH MONDAY NIGHT ESPECIALLY SINCE THE GFS HAS WEAK DYNAMICS. 850 TEMPERATURES FALL BELOW ZERO ON MONDAY AND STAY COLD THROUGH WEDNESDAY. MAX TEMPERATURES START IN THE LOWER 50S ON SUNDAY AND THEN COOL INTO THE MID 40S MONDAY THROUGH WEDNESDAY. MIN TEMPERATURES SHOULD FALL INTO THE MID/UPPER 20S. FS && .AVIATION... 432 PM MST WED NOV 5 2008 FOR THE 00Z TAF CYCLE...VFR CONDITIONS ARE EXPECTED TO REMAIN AT KGLD..ALTHOUGH CEILINGS WILL DROP TO NEAR MVFR CONDITIONS BY 12Z. FOR KMCK...MVFR CONDITIONS ARE EXPECTED AFTER 09Z. OF GREATEST CONCERN WILL BE THE WINDS TOMORROW. BETWEEN 09Z AND 12Z...EXPECT WINDS FROM THE NORTHWEST TO INCREASE TO THE 20G30KT RANGE. BY 15Z...WINDS ARE EXPECTED TO INCREASE YET AGAIN TO THE 30G45KT RANGE AND LAST THROUGH THE REMAINDER OF THE TAF PERIOD. LIGHT RAIN SHOWERS MAY OCCASIONALLY MIX WITH LIGHT SNOW...BUT DO NOT EXPECT ANY SIGNIFICANT ACCUMULATIONS. BLM && && .GLD WATCHES/WARNINGS/ADVISORIES... KS...HIGH WIND WARNING FROM 5 AM MST /6 AM CST/ TO 7 PM MST /8 PM CST/ THURSDAY FOR KSZ001>004-013>016. WIND ADVISORY FROM 5 AM MST /6 AM CST/ TO 7 PM MST /8 PM CST/ THURSDAY FOR KSZ027>029-041-042. NE...HIGH WIND WARNING FROM 5 AM MST /6 AM CST/ TO 7 PM MST /8 PM CST/ THURSDAY FOR NEZ079>081. CO...HIGH WIND WARNING FROM 5 AM TO 7 PM MST THURSDAY FOR COZ090-091. WIND ADVISORY FROM 5 AM TO 7 PM MST THURSDAY FOR COZ092. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 448 PM MST WED NOV 5 2008 .DISCUSSION...THE 20Z SURFACE ANALYSIS SHOWS A TROUGH EXTENDING FROM THE TEXAS PANHANDLE TO EASTERN SOUTH DAKOTA. WATER VAPOR IMAGERY SHOWING THE UPPER LOW OVER CENTRAL COLORADO. KGLD RADAR DETECTING SOME LIGHT SHOWERS OR SPRINKLES MAINLY OVER THE NORTHWEST AND FAR SOUTHERN ZONES. THE UPPER LOW IS PROGGED TO MOVE NORTHEAST INTO CENTRAL SOUTH DAKOTA TONIGHT. NORTHWEST FLOW WILL TAKE OVER ON THURSDAY AND CONTINUE THROUGH SATURDAY. SURFACE HIGH PRESSURE WILL BUILD EASTWARD INTO THE CENTRAL PLAINS BEHIND THE EXITING TROUGH. THE MAIN FORECAST ISSUES ARE WIND ON THURSDAY AND WHETHER ANY POPS WILL BE NEEDED FOR TONIGHT/THURSDAY. THE SURFACE PRESSURE GRADIENT TIGHTENS UP THURSDAY BEHIND THE EXITING LOW PRESSURE. LATEST GUIDANCE INDICATES THAT WINDS WILL SATISFY CRITERIA FOR A WIND ADVISORY ON THURSDAY OVER THE CWA. THE NAM AND GFS FORECAST SOUNDINGS INDICATE SUSTAINED WINDS OF 30+ KTS WITH POTENTIAL GUSTS TO 45KTS OVER MOST OF THE FORECAST AREA. THE RUC ALSO SUPPORTS THE WIND ADVISORY WITH SUSTAINED WINDS OF GREATER THAN 30KTS AND GUSTS GREATER THAN 40 KTS. BASED ON THIS HAVE ALREADY ISSUED A WIND ADVISORY FOR THE ENTIRE FORECAST AREA FOR THURSDAY...SEE DETAILS BELOW. FOR POPS...DYNAMICS MOVE TO THE SOUTHEAST AND NORTH THIS EVENING AND THEN TOWARD 12Z THURSDAY WRAPAROUND DYNAMICS START TO AFFECT THE NORTHEAST ZONES. THIS WILL CONTINUE THROUGH ABOUT 18Z THURSDAY. CONSEQUENTLY HAVE RELIED ON SLIGHT CHANCE POPS FOR THESE BASED UPON MARGINAL NATURE OF THIS SYSTEM SO FAR. HOWEVER EXPECT WRAPAROUND TO HAVE BETTER MOISTURE THURSDAY MORNING AND FOR THAT REASON HAVE INCREASE POPS TO CHANCE OVER THE MCK AREA. FORECAST SOUNDINGS INDICATE PRECIPITATION EAST OF COLORADO SHOULD BE LIQUID BUT CANNOT RULE OUT SOME SNOW MIXING IN OVER YUMA COUNTY COLORADO. SOUNDINGS ARE NOT ALL THAT SATURATED AT LOWER LEVELS SO PRECIPITATION MAY HAVE DIFFICULTY REACHING THE SURFACE. SUBSIDENCE TAKES OVER ACROSS THE ENTIRE FORECAST AREA THURSDAY NIGHT AND CONTINUES THROUGH SATURDAY. 850MB TEMPERATURES WILL KEEP MAX TEMPERATURES COOL IN THE UPPER 40S ON THURSDAY. TEMPERATURES WILL START MODERATING ON FRIDAY WITH ABOVE NORMAL READINGS NEAR 60 ON SATURDAY. MIN TEMPERATURES WILL FALL INTO THE UPPER 20S TO LOWER 30S TONIGHT THROUGH SATURDAY NIGHT. IN THE EXTENDED...DIFFERENCES STILL REMAIN BETWEEN THE GFS AND THE ECMWF. THE GFS IS MUCH WEAKER WITH THE SYSTEM THAN THE ECMWF. THE ECMWF DIVES SOUTH AND THEN COMES BACK NORTH ACROSS THE FORECAST AREA. DUE TO THE LACK OF AGREEMENT WILL CONTINUE SLIGHT CHANCE POPS FOR A RAIN/SNOW MIX FOR SUNDAY NIGHT THROUGH MONDAY NIGHT ESPECIALLY SINCE THE GFS HAS WEAK DYNAMICS. 850 TEMPERATURES FALL BELOW ZERO ON MONDAY AND STAY COLD THROUGH WEDNESDAY. MAX TEMPERATURES START IN THE LOWER 50S ON SUNDAY AND THEN COOL INTO THE MID 40S MONDAY THROUGH WEDNESDAY. MIN TEMPERATURES SHOULD FALL INTO THE MID/UPPER 20S. FS && .AVIATION... 432 PM MST WED NOV 5 2008 FOR THE 00Z TAF CYCLE...VFR CONDITIONS ARE EXPECTED TO REMAIN AT KGLD..ALTHOUGH CEILINGS WILL DROP TO NEAR MVFR CONDITIONS BY 12Z. FOR KMCK...MVFR CONDITIONS ARE EXPECTED AFTER 09Z. OF GREATEST CONCERN WILL BE THE WINDS TOMORROW. BETWEEN 09Z AND 12Z...EXPECT WINDS FROM THE NORTHWEST TO INCREASE TO THE 20G30KT RANGE. BY 15Z...WINDS ARE EXPECTED TO INCREASE YET AGAIN TO THE 30G45KT RANGE AND LAST THROUGH THE REMAINDER OF THE TAF PERIOD. LIGHT RAIN SHOWERS MAY OCCASIONALLY MIX WITH LIGHT SNOW...BUT DO NOT EXPECT ANY SIGNIFICANT ACCUMULATIONS. BLM && .GLD WATCHES/WARNINGS/ADVISORIES... KS...WIND ADVISORY FROM 5 AM MST /6 AM CST/ TO 7 PM MST /8 PM CST/ THURSDAY FOR KSZ001>004-013>016-027>029-041-042. NE...WIND ADVISORY FROM 5 AM MST /6 AM CST/ TO 7 PM MST /8 PM CST/ THURSDAY FOR NEZ079>081. CO...WIND ADVISORY FROM 5 AM TO 7 PM MST THURSDAY FOR COZ090>092. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 411 AM EST WED NOV 5 2008 .SYNOPSIS... LOW PRESSURE OFF THE SOUTHEAST COAST WILL TRACK SLOWLY N ALONG THE MID-ATLANTIC COAST. THE SYSTEM WILL SLOWLY LIFT NORTHEAST AWAY FROM OUR REGION TONIGHT AND THURSDAY. WEAK HIGH PRESSURE WILL BUILD ACROSS THE REGION FRIDAY. A COLD FRONT WILL PASS THROUGH SATURDAY. && .NEAR TERM /TODAY/... SOME SMALL VARIANCES IN THE MDL TRACK OF THE CSTL LOW...BUT THIS WOULD HV IMPLICATIONS ON WHICH AREAS RECEIVE ADTNL RAFL AND HOW MUCH. SREF KEEPS BULK OF PCPN FM DELMARVA EWD...WHILE RUC HRRR SPREADS PCPN INTO THE APLCHNS. BLV LKLY SCENARIO WL SHOW A TIGHT RAFL GRADIENT TDA...AND HV CAT POPS ALONG THE BAY. LKLY POPS BTWN I-81 TO THE BAY...DROPPING TO ISOLD IN THE HIGHLANDS. THESE WL DIMINISH FURTHER BY LATE AFTN. W/ XCPTN OF ALONG THE BAY ALL QPF`S WL BE LGT. TEMPS GNRLY REACHING L60S TDA...WHICH IS RIGHT ON CLIMO NORMS FOR ERLY NOV. && .SHORT TERM /TONIGHT/... LOW CONTINUES ITS SLOW TREK N MAINTAINING THE TIGHT PCPN STRIATION OVRNGT. LKLY POPS IN THE BAY...ISOLD POPS IN VCNTY I-81...CHC IN BTWN. LOW TEMPS IN 40S E OF I-95...L50S E. && .LONG TERM /THURSDAY THROUGH TUESDAY/... A WET MRNG ON THURS FOR LOCALES EAST OF I-95 ON INTO EARLY AFTN. THIS IS AN AREA WHERE THE NAM/GFS FINALLY IN AGREEMENT FOR THE SFC LOW HALTING IT/S N/WRD MOVEMENT...MEANDERING OFF THE MID ATLNC COAST THRU THE DAY ON THURS. THE LOW THEN SLIDES SLOWLY E/WRD ON FRIDAY AND REDEVELOPING ANOTHER SFC LOW OFF THE CAPE COD REGION BEFORE FINALLY BEING KICKED-OUT NE/WRD THIS WEEKEND. SO THE REMNANT RAIN BANDS FROM THE LOW WILL DISSIPATE GRADUALLY DRNG THE AFTN/EVNG HRS ON THURS...W/ MUCH OF CWA DRY BY EARLY FRIDAY. THE WEAK ONSHORE FLOW WILL KEEP THE BNDRY LAYER MOIST ACROSS THE PIEDMONT/COASTAL REGIONS. WEAK HIPRES RIDGING ON FRIDAY WILL TAKE THE CNTL PIEDMONT OF THE MID ATLNC BACK INTO A DRIER AND WARMER REGIME /JUST FOR THE DAY/...AS HIGHS CLIMB BACK INTO THE U60S/L70S. FRIDAY...THE TRANSITION DAY BTWN SYSTEMS W/ AN DISSIPATING COLD FRONT APRCHG THE REGION OVERNIGHT FRIDAY INTO EARLY SAT. THE GFS /THE MOST AGGRESSIVE IN PAST DAYS ON DEVELOPING A LEE TROF ACROSS THE MID ATLNC/ NOW MAKING A COMMON FRONTAL DISSIPATING OVER THE CNTL APLCHS AND A DRY SATURDAY ACROSS THE MID ATLNC. THE NAM/ECMWF WHICH TOOK LONGER INITIALLY W/ DEVELOPING PRECIP ON SAT ARE ALSO BACKING OFF AS WELL. DID NOT CHANGE POPS MUCH FOR THE WEEKEND...W/ A LIKELIHOOD OF SCTD -RA FROM THE PRE-FRONTAL FORCING AND INCRD MOIST S/RLY FLOW. ANOTHER NOTEWORTHY CHANGE IS THE DROP IN MAGNITUDE FOR WINDS BEHIND THE FRONT LATE SAT AND INTO EARLY NEXT WEEK. THE MAIN UPPER CLOSED LOW RESPONSIBLE FOR THE DYNAMICS OF THE GRT LKS SYSTEM THIS WEEKEND...WILL STALL OVER ERN QUEBEC...PUSHING A TRANSITIONAL ZONAL FLOW REGIME OVER THE MID ATLNC SUNDAY INTO MONDAY. WINDS WON/T BE AS STRONG...MAINLY IN THE 10-15MPH RANGE AND TEMPS WILL ALSO BE MODERATED INTO THE 50S FOR HIGHS. SUNDAY NIGHT WILL BE THE COLDEST NIGHT IN THE FORECAST W/ THE WRN HALF OF THE CWA NEAR FRZNG AND THE ERN HALF IN THE M/U30S. A VERY UNCERTAIN SPIN ON THE REMAINDER OF THE FORECAST...W/ MODELS GUESSING ON THE NEXT MIDWESTERN SYSTEM AND IT/S AFFECT ON THE MID ATLNC...PSBLY BY THE MIDDLE OF NEXT WEEK. && .AVIATION /TODAY THROUGH SUNDAY/... MAJOR AIRPORTS W/ IFR CIGS WL IMPROVE TO MVFR LATER THIS MRNG AND RMN THERE INTO THE NGT. THE COASTAL LOW PRES SYSTEM WILL KEEP A TIGHT AREA OF SHRA/IFR-MVFR CIGS NEAR THE COAST ON THURS...W/ LESSER EFFECTS WEST OF I-95. EARLY FRIDAY...THE LOW WILL DRIFT FAR OFF THE MID ATLNC COAST W/ HIGH PRES THRU LATE FRI. A WEAK COLD FRONT WILL SLIDE OVER REGION ON SAT...W/ LITTLE CONCERN OTHER THAN A FEW INTERMITTENT GUSTS AND AND ISLTD SHRA. BEHIND THE FRONT...HIGH PRES AND DRIER CONDS THRU THE MIDDLE OF NEXT WEEK. && .MARINE... LOW PRES ADVANCING UP THE COAST WILL CAUSE THE PRES GRAD TO TIGHTEN IN THE ERN PART OF THE CWA. THIS IN TURN WILL CREATE SCA WINDS ACROSS THE ENTIRE MARINE AREA TODAY AND TONIGHT. A COASTAL LOW PRES SYSTEM WILL MEANDER OFF THE MID ATLNC COAST ON THURS...KEEPING SCA CONDS THRU THE DAY AND GENERALLY SUBSIDING DRNG THE EVNG HRS. THE LOW WILL MOVE OFF TO THE NE ON FRIDAY... LEAVING THE REMAINDER OF THE FORECAST UNDER MUCH LESS DYNAMIC CONDS OUTSIDE OF A COLD FRONT FOR SAT AFTN/EVNG. THE REST OF THE WEEKEND NOT EXPTD TO BE AS WINDY BEHIND THE FRONT. HIGH PRES WILL INFLUENCE THE REGION OF EARLY NEXT WEEK. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THURSDAY FOR ANZ531>534- 537. SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 5 PM EST THURSDAY FOR ANZ530-535-536. && $$ PRODUCTS..WOODY!/GMS md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 645 PM EST THU NOV 6 2008 UPDATED FOR 00Z AVIATION DISCUSSION .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS SHOW A LARGE UPPER LOW ROTATING OVER THE CNTRL US. H500 LOW IS VERTICALLY STACKED OVER 997MB LOW OVER SE SD AND NE NEB...WHILE A SECOND LOW OF 994MB LOCATED OVER CNTRL MN. VERY STRONG PRESSURE GRADIENT BEHIND THE LOW IS PRODUCING VERY STRONG WINDS ACROSS WRN DAKOTAS PRODUCING BLIZZARD CONDITIONS...WITH NUMEROUS LOCATIONS GUSTING ABOVE 35KTS AND A COUPLE SITES NEAR THE BLACK HILLS GUSTING ABOVE 60KTS. CLOSER TO HOME...INITIAL PCPN WAVE STARTING TO MOVE INTO THE UP AS OF 19Z. THIS IS AHEAD OF COLD FRONT...AND ANOTHER LINE OF SHOWERS...THAT IS MOVING THROUGH SW WI. THERE IS DRY AIR IN PLACE ABOVE H850 ON 19Z KSAW AND 18Z KPLN TAMDAR SOUNDINGS...WHICH HAS BEEN PRODUCING PARTLY TO MOSTLY SUNNY SKIES ACROSS ERN UP. HIGH CIRRUS HAVE BEEN SLIDING NORTH OVER THE REST OF THE UP. && .SHORT TERM (TONIGHT AND FRIDAY)... UPPER TROUGH WILL CONTINUE TO DIG S ACROSS SRN PLAINS TONIGHT AND GRADUALLY MERGE WITH THE SUB TROPICAL JET LATER IN THE DAY ON FRI. WITH THE TROUGH DIGGING DEEP OVER THE CNTRL US...DUE TO H250 100KT JET MOVING SE OVER THE ROCKIES...IT PULLS THE UPPER SUPPORT JUST FAR ENOUGH AWAY FROM SFC LOW TO ALLOW IT TO GRADUALLY WEAKEN AND DRIFT NE THROUGH THE SHORT TERM PERIOD. EXPECT THE PCPN TO CONTINUE NORTH DURING THE LATE AFTN HRS. DRY AIR MENTIONED PREVIOUSLY SHOULD QUICKLY BE EATEN AWAY ACROSS THE REST OF THE CWA BY ABUNDANT H900 AND ABOVE MOISTURE MOVING IN FROM WI...AS SEEN ON WV IMAGERY AND CNTRL WI TAMDAR SOUNDINGS. HAVE LEFT MENTION OF ISOLATED THUNDER IN FOR THE LATE AFTN...AS STEEP LAPSE RATES ABOVE H850 WERE SEEN ON 18Z KCWA TAMDAR SOUNDING...BUT HAVE NOT SEEN ANY LIGHTING STRIKES IN NRN WI SO FAR. THIS MOISTURE IS SITUATED AHEAD OF SFC COLD/OCCLUDED FRONT THAT WILL PUSH N THROUGH CWA...MAINLY THIS EVENING. MOISTURE IS ABUNDANT FOR THIS TIME OF YEAR...WITH PWAT VALUES NEAR OR ABOVE AN INCH...WHICH IS 200-300 PERCENT OF NORMAL. SHOULD BE PLENTY OF FORCING ALONG THE FRONT...WITH 290-305K ISENTROPIC SFCS SHOWING WELL DEFINED BOUNDARY PUSHING NE THROUGH WRN HALF OF CWA BY 06Z AND THEN OVER THE FAR ERN CWA BY 12Z FRI...AND DECENT H850-500 Q VECTOR CONVERGENCE. THEREFORE...EXPECT NW TO SE ORIENTATED BAND OF SHOWERS TO TRANSITION FROM SW TO NE ACROSS THE CWA...WITH BEST PCPN CHANCES OVER THE WRN UP DURING THE EVENING AND ERN UP INTO THE OVERNIGHT HOURS. EXPECT THE WIDTH OF THE PCPN TO SHRINK TONIGHT...AS DRY AIR AHEAD OF THE FRONT AND DRY SLOT MOVING IN FROM BEHIND TO PINCH THE MOISTURE FIELD INTO FRI MORN. EXISTING FORECAST HAD PRETTY GOOD TIMING ON PCPN...SO DID NOT MAKE MANY ADJUSTMENTS. CONTINUED THE DECREASING CLOUDS OVERNIGHT FROM SW TO NE ACROSS THE CWA. SHOULD SEE A PERIOD OF PARTLY CLOUDY SKIES MOVING THROUGH THE CWA BEHIND THE FRONT...BEFORE UPPER LOW MOVES CLOSE ENOUGH TO MOVE H850-700 MOISTURE/CLOUDS OVER THE KIWD AREA LATE TONIGHT. LOW PRESSURE SYSTEM NEARLY BECOMES VERTICALLY STACKED DURING THE DAY ON FRI...AS IT DRIFTS TO THE SE. LOOKS LIKE THERE WILL BE A BROAD AREA OF CLOUDS AND SHOWERS ACROSS MN AND WI...AS COLD H850 TEMPS NEARLY WRAP ALL THE WAY AROUND THE LOW. BEST CHANCE OF PCPN TOMORROW LOOKS TO BE S AND W OF A LINE FROM KCMX TO KESC...MAINLY IN THE AFTN AS H850 COLD NOSE MOVES N INTO THE AREA AND SFC LOW MOVES TO JUST N OF KIWD. EXPECT A FEW SHOWERS TO DEVELOP THROUGH THE DAY. WITH COLD AIR ALOFT MOVING AROUND THE LOW...IT SHOULD PRODUCE FAIRLY STEEP LLVL LAPSE RATES BETWEEN SFC AND H750 INVERSION. THIS COMBINED WITH PLENTY OF MOISTURE BELOW THE INVERSION...SHOULD ALLOW SHOWERS TO DEVELOP ACROSS THE SW PART OF THE CWA AND GRADUALLY SHIFT NE. DID EXPAND THE CHANCE PCPN AREA FARTHER TO THE NE DURING THE AFTN...BUT LEFT THE FAR ERN CWA IN SLIGHT CHANCES DUE TO DRY SLOT STILL WORKING OUT OF THAT AREA. OVERALL...EXPECT THE SHOWERS TO BE HIT OR MISS...WITH QPF BEING LIGHT DUE TO LIMITED CLOUD DEPTH. ADDED SOME SLIGHT CHANCES OF SNOW ALONG THE WI BORDER AREA FOR LATE TOMORROW AFTN. H850 TEMPS DROP FROM -2C AT 18Z FRI TO AROUND -5-6C AT 0Z. SFC TEMPS SHOULD ALSO DROP DURING THE AFTN ALONG THE WI BORDER...WITH VALUES IN THE UPPER 30S BY 00Z. WBZ HEIGHTS WILL DROP BELOW 1.5KFT AGL BETWEEN 21-00Z ON NAM AND LOCAL HI-RES WRF-ARW. SO WOULD NOT BE SURPRISED IF PCPN MIXED WITH SNOW IN THE STRONGER SHOWERS LATE IN THE DAY FRI. LONGER TERM...00Z SAT ONWARD... NAM SHOWS THE CLOSED 500 MB LOW AND TROUGH AFFECTING THE UPPER GREAT LAKES 00Z SAT AND THEN SLOWLY TAKES THE LOW EAST WITH THE LOW CROSSING NORTHERN LAKE MICHIGAN ON SAT. MORE SHORTWAVE ENERGY DROPS DOWN THE BACKSIDE OF THE TROUGH SAT NIGHT AND SUN AND HELPS KEEP THE CLOSED 500 MB LOW FROM MOVING TO FAR TO THE EAST OF THE LAKE SUPERIOR REGION. NAM SHOWS SOME WEAK 850-500 MB Q-VECTOR CONVERGENCE PASSING ACROSS THE CWA FRI NIGHT WITH AMPLE MOISTURE AND THEN THE CONVERGENCE STAYS OVER THE NORTH AND EASTERN CWA ON SAT. NAM SHOWING SOME ISENTROPIC LIFT ON I280K-I295K SURFACES AND MOISTURE FRI NIGHT WITH LIFT MOVING OUT SAT NIGHT. SYSTEM IS REALLY WRAPPED UP ON THE ISENTROPIC SURFACES. COLD AIR WILL COME IN SLOWLY FROM THE SW FOR FRI NIGHT AND PUT IN SOME SNOW MIX FOR THE WEST HALF. BEST MOISTURE IS GONE THEN...BUT COULD STILL SEE UP TO 2 INCHES OF SNOW IN A FEW SPOTS FOR FRI NIGHT ANYWAY. COLD AIR SLOWLY MOVES EAST ON SAT...BUT DOES NOT GET INTO THE FAR EASTERN CWA UNTIL SAT EVENING. MOISTURE IS STILL NOT THAT PLENTIFUL ON SAT...BUT COULD SEE ANOTHER 2 INCHES ACROSS THE WEST. LAKE EFFECT REALLY GETS GOING THEN AS IT IS COLD ENOUGH AT 850 MB TO ADD SOME LAKE MOISTURE INTO THE EQUATION AS WINDS TURN TO THE NORTH DURING THE DAY. OVERALL...BESIDES MOVING THE COLD AIR IN QUICKER AND CHANGING THE PCPN OVER TO SNOW QUICKER OVER THE WEST...DID NOT MAKE MANY CHANGES TO THE GOING FORECAST. IN THE EXTENDED...GFS...ECMWF AND CANADIAN ALL SHOW A 500 MB TROUGH AND LOW ACROSS THE UPPER GREAT LAKES 00Z MON WITH TROUGHING REMAINING THROUGH 00Z TUE WHILE RIDGING BUILDS INTO THE NORTHERN PLAINS. THE RIDGE THEN MOVES IN FOR 00Z WED WITH ANOTHER TROUGH THEN FOR THU AFFECTING THE NORTHERN PLAINS. WILL KEEP LAKE EFFECT PCPN IN THROUGH TUE MORNING...THEN GO DRY THROUGH THE REST OF THE EXTENDED PERIOD. TEMPERATURES LOOK TO STAY NEAR NORMAL. DID NOT MAKE ANY HUGE CHANGES TO THE EXTENDED AS GOING FORECAST LOOKED PRETTY GOOD. && .AVIATION (FOR THE 00Z TAF ISSUANCE)... AN AREA OF SHOWERS WILL MOVE THROUGH WEST/CNTRL UPPER MI THIS EVENING WITH MAINLY IFR TO MVFR CIGS/VSBYS...BEFORE COMING TO AN END AFTER 06Z TONIGHT. KEPT LOWER VSBYS AND CIGS AFTER 06Z AT KSAW FOR A TIME...AS SE WINDS AND EXISTING MOISTURE SHOULD PRODUCE IFR TO LIFR CONDITIONS BELOW THE INVERSION AND DRY AIR ALOFT. BROUGHT THE CONDITIONS BACK UP TO VFR LATE TONIGHT AND TOMORROW MORNING AT BOTH SITES...AS DRIER AIR MOVES IN BEFORE ADDITIONAL SHOWERS LATER IN THE DAY. && .MARINE... SFC LOW OVER MN WILL SLOWLY DRIFT TO THE NE ACROSS THE UPPER GREAT LAKES THROUGH SATURDAY AFTN. EXPECT THE FEW NE GALE FORCE GUSTS NEAR THE ARROWHEAD OF MN TO DIMINISH THIS EVENING...BUT MAY SEE SOME GUSTS TO 30KTS EARLY AND SE GUSTS TO 30KTS ACROSS ERN SUPERIOR THROUGH THE NIGHT. AS THE LOW MOVES ACROSS THE AREA...WINDS SHOULD BE IN THE 15 TO 25 KNOTS RANGE...BEFORE STRENGTHENING ON THE BACK SIDE OF THE LOW. EXPECT GALE FORCE GUSTS ACROSS MOST OF LAKE SUPERIOR ON SAT AND SUN. THE LOW WILL EXIT THE REGION ON SUN...WITH HIGH PRESSURE MOVING OVER THE WRN GREAT LAKES FOR MON THROUGH THURS...KEEPING WINDS LESS THAN 25 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SYNOPSIS...SRF SHORT TERM...SRF LONG TERM...GM AVIATION...SRF MARINE...SRF mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 412 PM EST THU NOV 6 2008 .SYNOPSIS... WV IMAGERY AND RUC ANALYSIS SHOW A LARGE UPPER LOW ROTATING OVER THE CNTL US. H500 LOW IS VERTICALLY STACKED OVER 997MB LOW OVER SE SD AND NE NEB...WHILE A SECOND LOW OF 994MB LOCATED OVER CNTL MN. VERY STRONG PRESSURE GRADIENT BEHIND THE LOW IS PRODUCING VERY STRONG WINDS ACROSS WRN DAKOTAS PRODUCING BLIZZARD CONDITIONS...WITH NUMEROUS LOCATIONS GUSTING ABOVE 35KTS AND A COUPLE SITES NEAR THE BLACK HILLS GUSTING ABOVE 60KTS. CLOSER TO HOME...INITIAL PCPN WAVE STARTING TO MOVE INTO THE UP AS OF 19Z. THIS IS AHEAD OF COLD FRONT...AND ANOTHER LINE OF SHOWERS...THAT IS MOVING THROUGH SW WI. THERE IS DRY AIR IN PLACE ABOVE H850 ON 19Z KSAW AND 18Z KPLN TAMDAR SOUNDINGS...WHICH HAS BEEN PRODUCING PARTLY TO MOSTLY SUNNY SKIES ACROSS ERN UP. HIGH CIRRUS HAVE BEEN SLIDING NORTH OVER THE REST OF THE UP. && .SHORT TERM (TONIGHT AND FRIDAY)... UPPER TROUGH WILL CONTINUE TO DIG S ACROSS SRN PLAINS TONIGHT AND GRADUALLY MERGE WITH THE SUB TROPICAL JET LATER IN THE DAY ON FRI. WITH THE TROUGH DIGGING DEEP OVER THE CNTL US...DUE TO H250 100KT JET MOVING SE OVER THE ROCKIES...IT PULLS THE UPPER SUPPORT JUST FAR ENOUGH AWAY FROM SFC LOW TO ALLOW IT TO GRADUALLY WEAKEN AND DRIFT NE THROUGH THE SHORT TERM PERIOD. EXPECT THE PCPN TO CONTINUE NORTH DURING THE LATE AFTN HRS. DRY AIR MENTIONED PREVIOUSLY SHOULD QUICKLY BE EATEN AWAY ACROSS THE REST OF THE CWA BY ABUNDANT H900 AND ABOVE MOISTURE MOVING IN FROM WI...AS SEEN ON WV IMAGERY AND CNTL WI TAMDAR SOUNDINGS. HAVE LEFT MENTION OF ISOLATED THUNDER IN FOR THE LATE AFTN...AS STEEP LAPSE RATES ABOVE H850 WERE SEEN ON 18Z KCWA TAMDAR SOUNDING...BUT HAVE NOT SEEN ANY LIGHTING STRIKES IN NRN WI SO FAR. THIS MOISTURE IS SITUATED AHEAD OF SFC COLD/OCCLUDED FRONT THAT WILL PUSH N THROUGH CWA...MAINLY THIS EVENING. MOISTURE IS ABUNDANT FOR THIS TIME OF YEAR...WITH PWAT VALUES NEAR OR ABOVE AN INCH...WHICH IS 200-300 PERCENT OF NORMAL. SHOULD BE PLENTY OF FORCING ALONG THE FRONT...WITH 290-305K ISENTROPIC SFCS SHOWING WELL DEFINED BOUNDARY PUSHING NE THROUGH WRN HALF OF CWA BY 06Z AND THEN OVER THE FAR ERN CWA BY 12Z FRI...AND DECENT H850-500 Q VECTOR CONVERGENCE. THEREFORE...EXPECT NW TO SE ORIENTATED BAND OF SHOWERS TO TRANSITION FROM SW TO NE ACROSS THE CWA...WITH BEST PCPN CHANCES OVER THE WRN UP DURING THE EVENING AND ERN UP INTO THE OVERNIGHT HOURS. EXPECT THE WIDTH OF THE PCPN TO SHRINK TONIGHT...AS DRY AIR AHEAD OF THE FRONT AND DRY SLOT MOVING IN FROM BEHIND TO PINCH THE MOISTURE FIELD INTO FRI MORN. EXISTING FORECAST HAD PRETTY GOOD TIMING ON PCPN...SO DID NOT MAKE MANY ADJUSTMENTS. CONTINUED THE DECREASING CLOUDS OVERNIGHT FROM SW TO NE ACROSS THE CWA. SHOULD SEE A PERIOD OF PARTLY CLOUDY SKIES MOVING THROUGH THE CWA BEHIND THE FRONT...BEFORE UPPER LOW MOVES CLOSE ENOUGH TO MOVE H850-700 MOISTURE/CLOUDS OVER THE KIWD AREA LATE TONIGHT. LOW PRESSURE SYSTEM NEARLY BECOMES VERTICALLY STACKED DURING THE DAY ON FRI...AS IT DRIFTS TO THE SE. LOOKS LIKE THERE WILL BE A BROAD AREA OF CLOUDS AND SHOWERS ACROSS MN AND WI...AS COLD H850 TEMPS NEARLY WRAP ALL THE WAY AROUND THE LOW. BEST CHANCE OF PCPN TOMORROW LOOKS TO BE S AND W OF A LINE FROM KCMX TO KESC...MAINLY IN THE AFTN AS H850 COLD NOSE MOVES N INTO THE AREA AND SFC LOW MOVES TO JUST N OF KIWD. EXPECT A FEW SHOWERS TO DEVELOP THROUGH THE DAY. WITH COLD AIR ALOFT MOVING AROUND THE LOW...IT SHOULD PRODUCE FAIRLY STEEP LLVL LAPSE RATES BETWEEN SFC AND H750 INVERSION. THIS COMBINED WITH PLENTY OF MOISTURE BELOW THE INVERSION...SHOULD ALLOW SHOWERS TO DEVELOP ACROSS THE SW PART OF THE CWA AND GRADUALLY SHIFT NE. DID EXPAND THE CHANCE PCPN AREA FARTHER TO THE NE DURING THE AFTN...BUT LEFT THE FAR ERN CWA IN SLIGHT CHANCES DUE TO DRY SLOT STILL WORKING OUT OF THAT AREA. OVERALL...EXPECT THE SHOWERS TO BE HIT OR MISS...WITH QPF BEING LIGHT DUE TO LIMITED CLOUD DEPTH. ADDED SOME SLIGHT CHANCES OF SNOW ALONG THE WI BORDER AREA FOR LATE TOMORROW AFTN. H850 TEMPS DROP FROM -2C AT 18Z FRI TO AROUND -5-6C AT 0Z. SFC TEMPS SHOULD ALSO DROP DURING THE AFTN ALONG THE WI BORDER...WITH VALUES IN THE UPPER 30S BY 00Z. WBZ HEIGHTS WILL DROP BELOW 1.5KFT AGL BETWEEN 21-00Z ON NAM AND LOCAL HI-RES WRF-ARW. SO WOULD NOT BE SURPRISED IF PCPN MIXED WITH SNOW IN THE STRONGER SHOWERS LATE IN THE DAY FRI. LONGER TERM...00Z SAT ONWARD... NAM SHOWS THE CLOSED 500 MB LOW AND TROUGH AFFECTING THE UPPER GREAT LAKES 00Z SAT AND THEN SLOWLY TAKES THE LOW EAST WITH THE LOW CROSSING NORTHERN LAKE MICHIGAN ON SAT. MORE SHORTWAVE ENERGY DROPS DOWN THE BACKSIDE OF THE TROUGH SAT NIGHT AND SUN AND HELPS KEEP THE CLOSED 500 MB LOW FROM MOVING TO FAR TO THE EAST OF THE LAKE SUPERIOR REGION. NAM SHOWS SOME WEAK 850-500 MB Q-VECTOR CONVERGENCE PASSING ACROSS THE CWA FRI NIGHT WITH AMPLE MOISTURE AND THEN THE CONVERGENCE STAYS OVER THE NORTH AND EASTERN CWA ON SAT. NAM SHOWING SOME ISENTROPIC LIFT ON I280K-I295K SURFACES AND MOISTURE FRI NIGHT WITH LIFT MOVING OUT SAT NIGHT. SYSTEM IS REALLY WRAPPED UP ON THE ISENTROPIC SURFACES. COLD AIR WILL COME IN SLOWLY FROM THE SW FOR FRI NIGHT AND PUT IN SOME SNOW MIX FOR THE WEST HALF. BEST MOISTURE IS GONE THEN...BUT COULD STILL SEE UP TO 2 INCHES OF SNOW IN A FEW SPOTS FOR FRI NIGHT ANYWAY. COLD AIR SLOWLY MOVES EAST ON SAT...BUT DOES NOT GET INTO THE FAR EASTERN CWA UNTIL SAT EVENING. MOISTURE IS STILL NOT THAT PLENTIFUL ON SAT...BUT COULD SEE ANOTHER 2 INCHES ACROSS THE WEST. LAKE EFFECT REALLY GETS GOING THEN AS IT IS COLD ENOUGH AT 850 MB TO ADD SOME LAKE MOISTURE INTO THE EQUATION AS WINDS TURN TO THE NORTH DURING THE DAY. OVERALL...BESIDES MOVING THE COLD AIR IN QUICKER AND CHANGING THE PCPN OVER TO SNOW QUICKER OVER THE WEST...DID NOT MAKE MANY CHANGES TO THE GOING FORECAST. IN THE EXTENDED...GFS...ECMWF AND CANADIAN ALL SHOW A 500 MB TROUGH AND LOW ACROSS THE UPPER GREAT LAKES 00Z MON WITH TROUGHING REMAINING THROUGH 00Z TUE WHILE RIDGING BUILDS INTO THE NORTHERN PLAINS. THE RIDGE THEN MOVES IN FOR 00Z WED WITH ANOTHER TROUGH THEN FOR THU AFFECTING THE NORTHERN PLAINS. WILL KEEP LAKE EFFECT PCPN IN THROUGH TUE MORNING...THEN GO DRY THROUGH THE REST OF THE EXTENDED PERIOD. TEMPERATURES LOOK TO STAY NEAR NORMAL. DID NOT MAKE ANY HUGE CHANGES TO THE EXTENDED AS GOING FORECAST LOOKED PRETTY GOOD. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... A QUIET FIRST PART OF THE TAF PERIOD IS EXPECTED...AS CIRRUS MOVE OVER BOTH TAF SITES. AREA OF SHOWERS CURRENTLY STRETCHING FROM KDLH TO KRHI...TO KOSH...WILL CONTINUE TO ROTATE NORTH AND START AFFECTING THE TAF SITES AFTER 22Z. EXPECT THE PCPN TO CONTINUE OFF AND ON THROUGH THE EVENING HOURS...WITH MAINLY IFR TO MVFR CIGS/VSBYS...BEFORE COMING TO AN END AFTER 06Z TONIGHT. KEPT LOWER VSBYS AND CIGS AFTER 06Z AT KSAW FOR A TIME...AS SE WINDS AND EXISTING MOISTURE SHOULD PRODUCE IFR TO LIFR CONDITIONS BELOW THE INVERSION AND DRY AIR ALOFT. BROUGHT THE CONDITIONS BACK UP TO VFR LATE TONIGHT AND TOMORROW MORNING AT BOTH SITES...AS DRIER AIR MOVES IN BEFORE ADDITIONAL SHOWERS LATER IN THE DAY. ALSO KEPT THE MENTION OF WIND SHEAR IN LATE THIS EVENING AND INTO THE OVERNIGHT HOURS...AS STRONG JET ALOFT OF 35-45KTS SLIDE THROUGH. && .MARINE... SFC LOW OVER MN WILL SLOWLY DRIFT TO THE NE ACROSS THE UPPER GREAT LAKES THROUGH SATURDAY AFTN. EXPECT THE FEW NE GALE FORCE GUSTS NEAR THE ARROWHEAD OF MN TO DIMINISH THIS EVENING...BUT MAY SEE SOME GUSTS TO 30KTS EARLY AND SE GUSTS TO 30KTS ACROSS ERN SUPERIOR THROUGH THE NIGHT. AS THE LOW MOVES ACROSS THE AREA...WINDS SHOULD BE IN THE 15 TO 25 KNOTS RANGE...BEFORE STRENGTHENING ON THE BACK SIDE OF THE LOW. EXPECT GALE FORCE GUSTS ACROSS MOST OF LAKE SUPERIOR ON SAT AND SUN. THE LOW WILL EXIT THE REGION ON SUN...WITH HIGH PRESSURE MOVING OVER THE WRN GREAT LAKES FOR MON THROUGH THURS...KEEPING WINDS LESS THAN 25 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SYNOPSIS...SRF SHORT TERM...SRF LONG TERM...GM AVIATION...SRF MARINE...SRF mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1240 AM EST WED NOV 5 2008 UPDATED FOR 06Z AVIATION DISCUSSION .SYNOPSIS... WATER VAPOR IMAGERY AND RUC SHOWING A LOW CENTER EMBEDDED IN DEEP TROUGH OVER NORTHERN AND MIDDLE HIGH PLAINS. WEAK SHORTWAVES EJECTED OUT AHEAD OF THIS TROUGH ARE OVER CENTRAL MINNESOTA INTO CENTRAL ONTARIO. DEEPER SHORTWAVES ARE OVER WESTERN NEBRASKA. SURFACE ANALYSIS DEPICTS A CLOSED LOW NEAR KFSD. A FRONTAL SYSTEM EXTENDS NORTHEAST FROM THE LOW THROUGH NORTHERN MINNESOTA TO SOUTHERN TIP OF JAMES BAY...WHILE A COLD FRONT DRAPES SOUTH THE CENTRAL PLAINS. A STRONG SOUTHERLY FLOW AHEAD OF THE LOW CONTINUES TO DRAW WARM MOIST AIR INTO THE FORECAST AREA. ISENTROPIC ASCENT...SHORTWAVE ENERGY AND LOW LEVEL MOISTURE ARE GENERATE SOME THUNDERSTORMS OVER MINNESOTA AND IOWA THIS AFTERNOON. && .SHORT TERM (TONIGHT AND THURSDAY)... THE MID LEVEL WILL OVER WESTERN NEBRASKA WILL SHIFT EAST INTO EASTERN NEBRASKA. SHORTWAVE ENERGY WILL SHIFT THROUGH MINNESOTA AND WESTERN U.P. THIS AFTERNOON REACHING NORTHEAST NEBRASKA OVERNIGHT. THE SURFACE LOW WILL BECOME MORE FOCUSED OVER NORTHERN IOWA AND SOUTHERN MINNESOTA TONIGHT. A FRONTAL SYSTEM LEADING THIS LOW WILL CONTINUE TO STRETCH NORTHEAST BUT WILL START TO SETTLE SOUTH INTO WESTERN LAKE SUPERIOR OVERNIGHT. A TRAILING COLD FRONT WILL BE DRAPED SOUTH INTO MIDDLE AND LOWER MISSISSIPPI RIVER VALLEY. WARM MOIST AIR WILL CONTINUE TO BE LIFTED NORTH AHEAD OF THE FRONTAL SYSTEM. 850-500MB Q-VECTOR CONVERGENCE WILL BE CONFINED TO THE WESTERN U.P. THIS AFTERNOON AND TONIGHT. A 45 TO 50 KNOT LOW LEVEL JET EAST OF THE FRONT WILL CONTINUE TO DRAW MORE MOISTURE INTO THE AREA. AN UPPER LEVEL JET MAX WILL BE OVER JAMES BAY AND EASTERN NEBRASKA INTO SOUTHERN MINNESOTA. TOGETHER THESE ARE PRODUCING SOME UPPER LEVEL DIVERGENCE OF THE WESTERN U.P. TONIGHT. THUS WILL KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE WEST TONIGHT CLOSER TO THE FRONT AND LOW CENTER. THE MID LEVEL LOW WILL LIFT INTO SOUTHWEST MINNESOTA. THE WEAK SHORTWAVE EJECTED OUT OF THE BASE OF THE LOW WILL SWEEP INTO SOUTHEAST MINNESOTA AND EASTERN IOWA. THE SURFACE LOW WILL LIFT NORTH INTO CENTRAL MINNESOTA. THE COLD FRONT WILL LIFT OUT OF THE UPPER MISSISSIPPI RIVER VALLEY INTO NORTHEAST WISCONSIN ON THURSDAY. LOW LEVEL MOISTURE CONTINUE TO SHIFT OVERSPREAD THE AREA AHEAD OF THE FRONTAL BOUNDARY. THE STRONGEST Q-VECTORS CONVERGENCE AND ISENTROPIC ASCENT WILL BE OVER THE WESTERN U.P. TEMPTED TO DROP THE MENTION OF THUNDERSTORMS FOR THURSDAY AFTERNOON DUE TO THE EXPECTED LOW CAPE AND K-INDEX AND HIGH LIFTED INDEX READINGS. HOWEVER...THERE STILL DOES APPEAR TO BE SOME 300MB DIVERGENCE...MARGINAL 850-500MB LAPSE RATES AND STRONG ENOUGH LOW LEVEL WIND SHEAR TO AT LEAST KEEP A MENTION FOR NOW. .LONG TERM (THU NIGHT THROUGH NEXT WED)... THU NIGHT AND FRI...AT 00Z FRI...A NEARLY VERTICALLY STACKED LOW SHOULD BE SITUATED IN SW MN...WITH A 990S MB SFC LOW. THE ASSOCIATED UPPER TROUGH THE UPPER LOW IS IN LOOKS TO BE NEUTRAL OR POSSIBLY EVEN SOMEWHAT NEGATIVELY TILTED...STRETCHING SE INTO ILLINOIS. MAJORITY OF THE MODELS (EXCLUDING THE NAM) PROG THE UPPER LOW TO GRADUALLY PUSH EAST DURING THIS PERIOD WHILE THE NEGATIVELY TILTED PORTION LIFTS UP INTO UPPER MI. THE 500MB HEIGHT FALLS THU NIGHT ARE QUITE IMPRESSIVE...BETWEEN 100-120 DAM. THESE HEIGHT FALLS...COMBINED WITH A STREAM OF 1-1.25 INCH PRECIPITABLE WATER VALUES SHOULD BE ENOUGH TO SUPPORT A BAND OF SHOWERS TO MOVE SW TO NE ACROSS UPPER MICHIGAN THU NIGHT. WITH CONTINUED GOOD MODEL AGREEMENT ON QPF...RAISED POPS TO CATEGORICAL IN MOST AREAS. DRY SLOT COMES IN BEHIND THIS BAND OF SHOWERS...TAPERING OFF THE PCPN. STILL MAINTAINED SOME 20 POPS BEHIND THE PCPN...MOSTLY IF THE TIMING NEEDS TO BE ADJUSTED WITH LATER RUNS. HOWEVER...IT STILL SEEMS REASONABLE TO ASSUME THAT THE MAJORITY OF PCPN WILL FALL THU NIGHT. DID KEEP SOME LOWER CLOUD COVER...BUT DID NOT GO AS LOW AS MIGHT BE EXPECTED AS THE SOUNDINGS SUGGEST THE POSSIBILITY OF A LOW CLOUD DECK DEVELOPING IN THE WAKE OF THE RAIN (PER NAM/GFS SOUNDINGS). SOME WRAP-AROUND SHOWERS...ASSOCIATED WITH THE TROWAL...COULD WRAP BACK INTO WESTERN UPPER MICHIGAN ON THE NW SIDE OF THE UPPER LOW...PRIMARILY IN THE AFTERNOON...AND THEREFORE HAVE SOME HIGHER POPS THERE. BROUGHT LOW TEMPERATURES UP A BIT CLOSER TO MET GUIDANCE GIVEN PLENTY OF CLOUD COVER...RAIN AND HIGH DEWPOINTS. HIGHS ON FRIDAY WERE ALSO RAISED SLIGHTLY GIVEN POSSIBILITY FOR SOME SUN. HOWEVER...LATER FORECASTS MAY NEED TO ASSESS THE NEED FOR FOG. FRI NIGHT AND SAT...THE WARM DAYS WE HAVE HAD LOOK LIKE THEY ARE GOING TO COME TO AN END...AT LEAST FOR A WHILE. UPPER LOW SHOULD CONTINUE TO PUSH EAST DURING THIS PERIOD...REACHING SE ONTARIO BY 00Z. AS THE UPPER LOW CROSSES INTO WRN LOWER MI BY 12Z SAT...THE AREA BECOMES ENCOMPASSED BY THE TROWAL REGION. PCPN AMOUNTS DO NOT LOOK OVERLY IMPRESSIVE AT THIS TIME WITHIN THE TROWAL...ENOUGH TO WARRANT CHANCE TO LIKELY POPS. LIKELY POPS ARE MOSTLY CONFINED TO AREAS THAT CAN SEE SOME LAKE ENHANCEMENT OR UPSLOPE AS 850MB TEMPS FALL TO -2 TO -4C. OVERALL...PCPN TYPE WILL BE RAIN GIVEN THAT THE WET-BULB ZERO HEIGHTS ARE PROGGED TO STAY AT 2000-3000 FT OR EVEN HIGHER THROUGH THE NIGHT. HOWEVER...MORE COLD AIR IS INDICATED TO COME DOWN ON SAT AS THE UPPER LOW HEADS INTO ONTARIO...WITH 850MB TEMPS DROPPING TO -4 TO -8C BY 00Z SUN...COOLEST WEST. THE AIR SHOULD BE COLD ENOUGH TO TRANSITION THE PCPN TYPES FROM RAIN TO SNOW. NOT LOOKING FOR MUCH SNOW...THOUGH...DUE TO MOST OF THE VERTICAL MOTION OCCURRING AT TEMPS ABOVE -10C...SFC TEMPS WILL LIKELY BE AT LEAST IN THE MID 30S...AND THE WARM GROUND. ON THE OTHER HAND...ANY SNOW THAT DOES ACCUMULATE SHOULD BE WET GIVEN A FAVORABLE PROFILE FOR AGGREGATION. THEREFORE...SNOW TO WATER RATIOS ARE EXPECTED AT OR BELOW 10 TO 1. SAT SHOULD BE QUITE BREEZY AS WELL...ESPECIALLY IN THE AFTN AS THE SFC LOW HEADS OFF INTO NE ONTARIO. SAT NIGHT THROUGH WED...UPPER LEVEL PATTERN IS STILL FORECAST TO CHANGE TO SPLIT FLOW BY ALL EXTENDED MODELS...PRIMARILY AFTER THE UPPER TROUGH THAT IS OVER THE AREA COMPLETELY EJECTS OUT INTO QUEBEC AND NEW ENGLAND. THE TIMING OF THIS EJECTION VARIES SOMEWHAT...WITH INDICATIONS OF A FEW SHRTWVS ROTATING THROUGH THE UPPER MICHIGAN ON THE WESTERN SIDE OF THE TROUGH...WHICH SLOWS DOWN THE EJECTION. IN ANY EVENT...ALL OF THE MODELS INDICATE THAT BY TUE MORNING THE TROUGH IS OUT OF THE CWA...RIDGING BUILDS UP OVER THE NORTHERN PLAINS AND A FAIRLY LARGE HIGH BUILDS INTO THE AREA AT THE SURFACE. AFTER TUE...THE RIDGE IN THE NORTHERN PLAINS BUILDS INTO UPPER MI...WHILE SOME SHRTWV TROUGH CROSSES THE SOUTHERN PLAINS. NEW 12Z ECMWF/GFS AGREE WITH THE PREVIOUS RUNS...MAKING THE EXTENDED FORECAST A BIT MORE CONFIDENT. REGARDING DETAILS...SAT NIGHT THROUGH MON NIGHT WILL BE ON THE COOL SIDE THANKS TO NORTH TO NORTHWEST FLOW FROM THE SURFACE TO 500MB BRINGING COLD AIR DOWN FROM CENTRAL CANADA. 850MB TEMPS FROM THE 00Z ECMWF DROP TO -10 TO -12C BY 12Z SUN...AND THEN EVEN FALL FURTHER TO -12 TO -14C BY 12Z MON THANKS TO ONE OF THE SHRTWVS DROPPING SOUTH ON THE WEST SIDE OF THE UPPER TROUGH. READINGS THEN START CLIMBING UP MON NIGHT TO -8 TO -10C BY 12Z TUE. OVERALL...THE AIR IS PLENTY COLD ENOUGH TO PRODUCE LAKE EFFECT SNOW SHOWERS...AND SINCE THE WIND FLOW IS PRIMARILY OUT OF THE NW...THE NW FLOW AREAS OF THE WESTERN U.P. AND EAST OF MARQUETTE ARE FAVORED FOR PCPN. AFTER SAT NIGHT... THERE MAY NOT BE MUCH PCPN EITHER OVER THE SRN U.P. SINCE THE SHRTWVS DO NOT HAVE MOISTURE TO WORK WITH. THIS MOISTURE AVAILABILITY WILL ALSO AFFECT THE LAKE EFFECT AS WELL...AND GIVEN HOW COLD THE AIR IS COMPARED TO THE LAKE SFC...WOULD NOT BE SURPRISED TO SEE SOME HIGHER CLOUD BASES THAN USUAL. THEREFORE...AT LEAST RIGHT NOW...NO MAJOR ACCUMULATION IS EXPECTED. HAVE DECIDED TO CONTINUE SOME SLIGHT CHANCE POPS INTO TUE MORNING OVER THE EASTERN CWA UNTIL ENOUGH DRY AIR AND SUBSIDENCE ASSOCIATED WITH THE HIGH COMES IN. TUE SHOULD END UP WARMER AS WELL...BUT STILL ON THE COOL SIDE WITH 850MB TEMPS BTWN -6 AND -8C. NO PCPN EXPECTED FOR TUE NIGHT AND WED AS UPPER MI REMAINS UNDER THE INFLUENCE OF DRY AIR FROM THE SFC HIGH. GRADUAL WARMING WILL OCCUR ON WED AS UPPER MI GETS ON THE BACK SIDE OF THE HIGH. && .AVIATION (FOR THE 06Z TAF ISSUANCE)... AT KCMX...PERIODS OF -SHRA ARE EXPECTED WHICH ALONG WITH A RELATIVELY MOIST ESE FLOW SHOULD KEEP AT LEAST MVFR CONDITIONS GOING INTO THU. BY LATE THU INTO THU EVENING A PERIOD OF STEADY MODERATE RAIN IS EXPECTED TO RESULT IN IFR CONDITIONS. AT KSAW...MAINLY VFR CONDITIONS ARE EXPECTED OVERNIGHT AS SOME LIGHT SHOWERS OR SPRINKLES WILL NOT BE ENOUGH TO LOWER CIGS OR VSBY TOO MUCH. BY LATE THU OR THU EVENING...SHRA MOVING IN AHEAD OF A FRONT ALONG WITH MOIST SRLY FLOW WILL LOWER CONDITIONS INTO THE MVFR RANGE AND THEN INTO THE IFR RANGE BY LATE EVENING. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... STRONG WARM AIR ADVECTION AHEAD OF A SURFACE LOW OVR THE NORTHERN PLAINS WILL CONTINUE TO PRODUCE GUSTY SOUTH WINDS OVR THE EASTERN HALF OF LAKE SUPERIOR THROUGH THURSDAY. HIGH STABILITY WITH NEAR SFC BASED INVERSION AND UNFAVORABLE PRESSURE FALL PATTERN FOCUSED TO THE SOUTH SHOULD PREVENT ANY GALES. THE SURFACE LOW WILL LIFT TOWARD WESTERN LAKE SUPERIOR ON FRIDAY THEN ACROSS UPPER MICHIGAN INTO SATURDAY. NORTH WINDS ON BACK SIDE OF THE LOW OVER WESTERN LAKE SUPERIOR LATE FRIDAY NIGHT SHOULD REACH 30 KNOTS PRETTY EASILY WITH TIGHT PRESSURE GRADIENT AND COLD AIR ADVECTION ENHANCING MIXING. THE NORTHWEST WINDS TO 30 KNOTS WILL CONTINUE OVER THE REST OF LAKE SUPERIOR SATURDAY INTO SUNDAY...THEN DIMINISH ON MONDAY AS A SURFACE RIDGE SETTLES OVER THE NORTHERN PLAINS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/SHORT TERM...DLG LONG TERM...AJ AVIATION...JLB MARINE...DLG/AJ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 353 PM EST WED NOV 5 2008 .SYNOPSIS... WATER VAPOR IMAGERY AND RUC SHOWING A LOW CENTER EMBEDDED IN DEEP TROUGH OVER NORTHERN AND MIDDLE HIGH PLAINS. WEAK SHORTWAVES EJECTED OUT AHEAD OF THIS TROUGH ARE OVER CENTRAL MINNESOTA INTO CENTRAL ONTARIO. DEEPER SHORTWAVES ARE OVER WESTERN NEBRASKA. SURFACE ANALYSIS DEPICTS A CLOSED LOW NEAR KFSD. A FRONTAL SYSTEM EXTENDS NORTHEAST FROM THE LOW THROUGH NORTHERN MINNESOTA TO SOUTHERN TIP OF JAMES BAY...WHILE A COLD FRONT DRAPES SOUTH THE CENTRAL PLAINS. A STRONG SOUTHERLY FLOW AHEAD OF THE LOW CONTINUES TO DRAW WARM MOIST AIR INTO THE FORECAST AREA. ISENTROPIC ASCENT...SHORTWAVE ENERGY AND LOW LEVEL MOISTURE ARE GENERATE SOME THUNDERSTORMS OVER MINNESOTA AND IOWA THIS AFTERNOON. && .SHORT TERM (TONIGHT AND THURSDAY)... THE MID LEVEL WILL OVER WESTERN NEBRASKA WILL SHIFT EAST INTO EASTERN NEBRASKA. SHORTWAVE ENERGY WILL SHIFT THROUGH MINNESOTA AND WESTERN U.P. THIS AFTERNOON REACHING NORTHEAST NEBRASKA OVERNIGHT. THE SURFACE LOW WILL BECOME MORE FOCUSED OVER NORTHERN IOWA AND SOUTHERN MINNESOTA TONIGHT. A FRONTAL SYSTEM LEADING THIS LOW WILL CONTINUE TO STRETCH NORTHEAST BUT WILL START TO SETTLE SOUTH INTO WESTERN LAKE SUPERIOR OVERNIGHT. A TRAILING COLD FRONT WILL BE DRAPED SOUTH INTO MIDDLE AND LOWER MISSISSIPPI RIVER VALLEY. WARM MOIST AIR WILL CONTINUE TO BE LIFTED NORTH AHEAD OF THE FRONTAL SYSTEM. 850-500MB Q-VECTOR CONVERGENCE WILL BE CONFINED TO THE WESTERN U.P. THIS AFTERNOON AND TONIGHT. A 45 TO 50 KNOT LOW LEVEL JET EAST OF THE FRONT WILL CONTINUE TO DRAW MORE MOISTURE INTO THE AREA. AN UPPER LEVEL JET MAX WILL BE OVER JAMES BAY AND EASTERN NEBRASKA INTO SOUTHERN MINNESOTA. TOGETHER THESE ARE PRODUCING SOME UPPER LEVEL DIVERGENCE OF THE WESTERN U.P. TONIGHT. THUS WILL KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE WEST TONIGHT CLOSER TO THE FRONT AND LOW CENTER. THE MID LEVEL LOW WILL LIFT INTO SOUTHWEST MINNESOTA. THE WEAK SHORTWAVE EJECTED OUT OF THE BASE OF THE LOW WILL SWEEP INTO SOUTHEAST MINNESOTA AND EASTERN IOWA. THE SURFACE LOW WILL LIFT NORTH INTO CENTRAL MINNESOTA. THE COLD FRONT WILL LIFT OUT OF THE UPPER MISSISSIPPI RIVER VALLEY INTO NORTHEAST WISCONSIN ON THURSDAY. LOW LEVEL MOISTURE CONTINUE TO SHIFT OVERSPREAD THE AREA AHEAD OF THE FRONTAL BOUNDARY. THE STRONGEST Q-VECTORS CONVERGENCE AND ISENTROPIC ASCENT WILL BE OVER THE WESTERN U.P. TEMPTED TO DROP THE MENTION OF THUNDERSTORMS FOR THURSDAY AFTERNOON DUE TO THE EXPECTED LOW CAPE AND K-INDEX AND HIGH LIFTED INDEX READINGS. HOWEVER...THERE STILL DOES APPEAR TO BE SOME 300MB DIVERGENCE...MARGINAL 850-500MB LAPSE RATES AND STRONG ENOUGH LOW LEVEL WIND SHEAR TO AT LEAST KEEP A MENTION FOR NOW. .LONG TERM (THU NIGHT THROUGH NEXT WED)... THU NIGHT AND FRI...AT 00Z FRI...A NEARLY VERTICALLY STACKED LOW SHOULD BE SITUATED IN SW MN...WITH A 990S MB SFC LOW. THE ASSOCIATED UPPER TROUGH THE UPPER LOW IS IN LOOKS TO BE NEUTRAL OR POSSIBLY EVEN SOMEWHAT NEGATIVELY TILTED...STRETCHING SE INTO ILLINOIS. MAJORITY OF THE MODELS (EXCLUDING THE NAM) PROG THE UPPER LOW TO GRADUALLY PUSH EAST DURING THIS PERIOD WHILE THE NEGATIVELY TILTED PORTION LIFTS UP INTO UPPER MI. THE 500MB HEIGHT FALLS THU NIGHT ARE QUITE IMPRESSIVE...BETWEEN 100-120 DAM. THESE HEIGHT FALLS...COMBINED WITH A STREAM OF 1-1.25 INCH PRECIPITABLE WATER VALUES SHOULD BE ENOUGH TO SUPPORT A BAND OF SHOWERS TO MOVE SW TO NE ACROSS UPPER MICHIGAN THU NIGHT. WITH CONTINUED GOOD MODEL AGREEMENT ON QPF...RAISED POPS TO CATEGORICAL IN MOST AREAS. DRY SLOT COMES IN BEHIND THIS BAND OF SHOWERS...TAPERING OFF THE PCPN. STILL MAINTAINED SOME 20 POPS BEHIND THE PCPN...MOSTLY IF THE TIMING NEEDS TO BE ADJUSTED WITH LATER RUNS. HOWEVER...IT STILL SEEMS REASONABLE TO ASSUME THAT THE MAJORITY OF PCPN WILL FALL THU NIGHT. DID KEEP SOME LOWER CLOUD COVER...BUT DID NOT GO AS LOW AS MIGHT BE EXPECTED AS THE SOUNDINGS SUGGEST THE POSSIBILITY OF A LOW CLOUD DECK DEVELOPING IN THE WAKE OF THE RAIN (PER NAM/GFS SOUNDINGS). SOME WRAP-AROUND SHOWERS...ASSOCIATED WITH THE TROWAL...COULD WRAP BACK INTO WESTERN UPPER MICHIGAN ON THE NW SIDE OF THE UPPER LOW...PRIMARILY IN THE AFTERNOON...AND THEREFORE HAVE SOME HIGHER POPS THERE. BROUGHT LOW TEMPERATURES UP A BIT CLOSER TO MET GUIDANCE GIVEN PLENTY OF CLOUD COVER...RAIN AND HIGH DEWPOINTS. HIGHS ON FRIDAY WERE ALSO RAISED SLIGHTLY GIVEN POSSIBILITY FOR SOME SUN. HOWEVER...LATER FORECASTS MAY NEED TO ASSESS THE NEED FOR FOG. FRI NIGHT AND SAT...THE WARM DAYS WE HAVE HAD LOOK LIKE THEY ARE GOING TO COME TO AN END...AT LEAST FOR A WHILE. UPPER LOW SHOULD CONTINUE TO PUSH EAST DURING THIS PERIOD...REACHING SE ONTARIO BY 00Z. AS THE UPPER LOW CROSSES INTO WRN LOWER MI BY 12Z SAT...THE AREA BECOMES ENCOMPASSED BY THE TROWAL REGION. PCPN AMOUNTS DO NOT LOOK OVERLY IMPRESSIVE AT THIS TIME WITHIN THE TROWAL...ENOUGH TO WARRANT CHANCE TO LIKELY POPS. LIKELY POPS ARE MOSTLY CONFINED TO AREAS THAT CAN SEE SOME LAKE ENHANCEMENT OR UPSLOPE AS 850MB TEMPS FALL TO -2 TO -4C. OVERALL...PCPN TYPE WILL BE RAIN GIVEN THAT THE WET-BULB ZERO HEIGHTS ARE PROGGED TO STAY AT 2000-3000 FT OR EVEN HIGHER THROUGH THE NIGHT. HOWEVER...MORE COLD AIR IS INDICATED TO COME DOWN ON SAT AS THE UPPER LOW HEADS INTO ONTARIO...WITH 850MB TEMPS DROPPING TO -4 TO -8C BY 00Z SUN...COOLEST WEST. THE AIR SHOULD BE COLD ENOUGH TO TRANSITION THE PCPN TYPES FROM RAIN TO SNOW. NOT LOOKING FOR MUCH SNOW...THOUGH...DUE TO MOST OF THE VERTICAL MOTION OCCURRING AT TEMPS ABOVE -10C...SFC TEMPS WILL LIKELY BE AT LEAST IN THE MID 30S...AND THE WARM GROUND. ON THE OTHER HAND...ANY SNOW THAT DOES ACCUMULATE SHOULD BE WET GIVEN A FAVORABLE PROFILE FOR AGGREGATION. THEREFORE...SNOW TO WATER RATIOS ARE EXPECTED AT OR BELOW 10 TO 1. SAT SHOULD BE QUITE BREEZY AS WELL...ESPECIALLY IN THE AFTN AS THE SFC LOW HEADS OFF INTO NE ONTARIO. SAT NIGHT THROUGH WED...UPPER LEVEL PATTERN IS STILL FORECAST TO CHANGE TO SPLIT FLOW BY ALL EXTENDED MODELS...PRIMARILY AFTER THE UPPER TROUGH THAT IS OVER THE AREA COMPLETELY EJECTS OUT INTO QUEBEC AND NEW ENGLAND. THE TIMING OF THIS EJECTION VARIES SOMEWHAT...WITH INDICATIONS OF A FEW SHRTWVS ROTATING THROUGH THE UPPER MICHIGAN ON THE WESTERN SIDE OF THE TROUGH...WHICH SLOWS DOWN THE EJECTION. IN ANY EVENT...ALL OF THE MODELS INDICATE THAT BY TUE MORNING THE TROUGH IS OUT OF THE CWA...RIDGING BUILDS UP OVER THE NORTHERN PLAINS AND A FAIRLY LARGE HIGH BUILDS INTO THE AREA AT THE SURFACE. AFTER TUE...THE RIDGE IN THE NORTHERN PLAINS BUILDS INTO UPPER MI...WHILE SOME SHRTWV TROUGH CROSSES THE SOUTHERN PLAINS. NEW 12Z ECMWF/GFS AGREE WITH THE PREVIOUS RUNS...MAKING THE EXTENDED FORECAST A BIT MORE CONFIDENT. REGARDING DETAILS...SAT NIGHT THROUGH MON NIGHT WILL BE ON THE COOL SIDE THANKS TO NORTH TO NORTHWEST FLOW FROM THE SURFACE TO 500MB BRINGING COLD AIR DOWN FROM CENTRAL CANADA. 850MB TEMPS FROM THE 00Z ECMWF DROP TO -10 TO -12C BY 12Z SUN...AND THEN EVEN FALL FURTHER TO -12 TO -14C BY 12Z MON THANKS TO ONE OF THE SHRTWVS DROPPING SOUTH ON THE WEST SIDE OF THE UPPER TROUGH. READINGS THEN START CLIMBING UP MON NIGHT TO -8 TO -10C BY 12Z TUE. OVERALL...THE AIR IS PLENTY COLD ENOUGH TO PRODUCE LAKE EFFECT SNOW SHOWERS...AND SINCE THE WIND FLOW IS PRIMARILY OUT OF THE NW...THE NW FLOW AREAS OF THE WESTERN U.P. AND EAST OF MARQUETTE ARE FAVORED FOR PCPN. AFTER SAT NIGHT... THERE MAY NOT BE MUCH PCPN EITHER OVER THE SRN U.P. SINCE THE SHRTWVS DO NOT HAVE MOISTURE TO WORK WITH. THIS MOISTURE AVAILABILITY WILL ALSO AFFECT THE LAKE EFFECT AS WELL...AND GIVEN HOW COLD THE AIR IS COMPARED TO THE LAKE SFC...WOULD NOT BE SURPRISED TO SEE SOME HIGHER CLOUD BASES THAN USUAL. THEREFORE...AT LEAST RIGHT NOW...NO MAJOR ACCUMULATION IS EXPECTED. HAVE DECIDED TO CONTINUE SOME SLIGHT CHANCE POPS INTO TUE MORNING OVER THE EASTERN CWA UNTIL ENOUGH DRY AIR AND SUBSIDENCE ASSOCIATED WITH THE HIGH COMES IN. TUE SHOULD END UP WARMER AS WELL...BUT STILL ON THE COOL SIDE WITH 850MB TEMPS BTWN -6 AND -8C. NO PCPN EXPECTED FOR TUE NIGHT AND WED AS UPPER MI REMAINS UNDER THE INFLUENCE OF DRY AIR FROM THE SFC HIGH. GRADUAL WARMING WILL OCCUR ON WED AS UPPER MI GETS ON THE BACK SIDE OF THE HIGH. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... CMX...FOCUS IS ON FAIRLY WIDESPREAD AREA OF SHOWERS WITH QUITE A BIT OF THUNDER OVER EASTERN IOWA INTO SE MINNESOTA. STRONG MOISTURE ADVECTION GENERATING THE RAIN IS PROJECTED TO MAKE IT TO CMX LATE THIS AFTERNOON AND EVEN THOUGH IT IS NOVEMBER...INCREASING INSTABILITY ALOFT ALSO LEADS TO A GOOD CHANCE FOR SOME THUNDER. JUST INCLUDED A CB FOR NOW IN CASE THE PCPN DIMINISHES WITH LOSS OF LOW LEVEL JET MAX. HIGHEST CHANCES FOR SHRA/TSRA BTWN 20Z AND 00Z AS WEAK UPPER LEVEL DISTURBANCE MOVES THROUGH. MVFR CONDITIONS POSSIBLE WITH THE RAIN...ESPECIALLY IF IT PERSISTS FOR A FEW HOURS. SAW...A CLUSTER OF SHOWERS AND THUNDERSTORMS SHOULD MISS SAW TO THE WEST THIS AFTERNOON/EVENING. SO...ONLY VFR CONDITIONS ARE EXPECTED THROUGH TONIGHT. LLWS WILL CONTINUE THROUGH MUCH OF THIS AFTERNOON SHOULD ALLOW SOUTHERLY WIND GUSTS TO APPROACH 27 KNOTS. LLWS WILL CONTINUE THIS AFTERNOON AND EVENING TRAPPING STRONGER WINDS JUST ABOVE THE SURFACE. THE LOW LEVEL JET WILL SHIFT OUT OF THE AREA EARLY ON THURSDAY. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... STRONG WARM AIR ADVECTION AHEAD OF A SURFACE LOW OVR THE NORTHERN PLAINS WILL CONTINUE TO PRODUCE GUSTY SOUTH WINDS OVR THE EASTERN HALF OF LAKE SUPERIOR THROUGH THURSDAY. HIGH STABILITY WITH NEAR SFC BASED INVERSION AND UNFAVORABLE PRESSURE FALL PATTERN FOCUSED TO THE SOUTH SHOULD PREVENT ANY GALES. THE SURFACE LOW WILL LIFT TOWARD WESTERN LAKE SUPERIOR ON FRIDAY THEN ACROSS UPPER MICHIGAN INTO SATURDAY. NORTH WINDS ON BACK SIDE OF THE LOW OVER WESTERN LAKE SUPERIOR LATE FRIDAY NIGHT SHOULD REACH 30 KNOTS PRETTY EASILY WITH TIGHT PRESSURE GRADIENT AND COLD AIR ADVECTION ENHANCING MIXING. THE NORTHWEST WINDS TO 30 KNOTS WILL CONTINUE OVER THE REST OF LAKE SUPERIOR SATURDAY INTO SUNDAY...THEN DIMINISH ON MONDAY AS A SURFACE RIDGE SETTLES OVER THE NORTHERN PLAINS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/SHORT TERM...DLG LONG TERM...AJ AVIATION...DLG MARINE...DLG/AJ mi AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE MARQUETTE MI 1230 PM EST WED NOV 5 2008 .SYNOPSIS... WATER VAPOR IMAGERY AND RUC SHOWING A SLOW CENTER EMBEDDED IN DEEP TROUGH OVER NORTHERN AND MIDDLE HIGH PLAINS. WEAK SHORTWAVES ARE BEING EJECTED OUT AHEAD OF THIS TROUGH AND ARE OVER SOUTHERN MINNESOTA AND CENTRAL ONTARIO. OTHER SHORTWAVES ARE OVER WESTERN NEBRASKA. SURFACE ANALYSIS DEPICTS A CLOSED LOW OVER EASTERN SOUTH DAKOTA AND EASTERN NEBRASKA. A FRONTAL SYSTEM EXTENDS NORTHEAST FROM THE LOW THROUGH NORTHERN MINNESOTA TO JAMES BAY. A STRONG SOUTHERLY FLOW AHEAD OF THE LOW WILL CONTINUE TO DRAW WARM MOIST AIR INTO THE FORECAST AREA. ISENTROPIC ASCENT...SHORTWAVE ENERGY AND LOW LEVEL MOISTURE CONTINUES TO GENERATE SOME THUNDERSTORMS OVER MINNESOTA AND IOWA THIS MORNING. && .SHORT TERM...THIS AFTERNOON AND TONIGHT... THE MID LEVEL WILL LIFT INTO WESTERN NEBRASKA THIS AFTERNOON. SHORTWAVE ENERGY WILL SHIFT THROUGH MINNESOTA AND WESTERN U.P. THIS AFTERNOON REACHING NORTHEAST NEBRASKA OVERNIGHT. THE SURFACE LOW WILL BECOME MORE FOCUSED OVER EASTERN SOUTH DAKOTA THIS AFTERNOON BEFORE MOVING EAST INTO NORTHERN IOWA AND SOUTHERN MINNESOTA TONIGHT. A FRONTAL SYSTEM LEADING THIS LOW WILL CONTINUE TO STRETCH NORTHEAST BUT WILL START TO SETTLE SOUTH INTO NORTHERN LAKE SUPERIOR OVERNIGHT. A TRAILING COLD FRONT WILL BE DRAPED SOUTHWEST INTO MIDDLE AND LOWER MISSISSIPPI RIVER VALLEY. WARM MOIST AIR WILL CONTINUE TO BE LIFTED NORTH AHEAD OF THE FRONTAL SYSTEM. 850-500MB Q-VECTOR CONVERGENCE WILL BE CONFINED TO THE WESTERN U.P. THIS AFTERNOON AND TONIGHT. A 45 TO 50 KNOT LOW WILL JET WILL CONTINUE TO DRAW MORE MOISTURE INTO THE AREA. AN UPPER LEVEL JET MAX WILL BE OVER JAMES BAY AND EASTERN NEBRASKA INTO SOUTHERN MINNESOTA. TOGETHER THESE ARE PRODUCING SOME UPPER LEVEL DIVERGENCE OF THE WESTERN U.P. THIS AFTERNOON AND TONIGHT. THUS WILL KEEP A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE WEST THIS AFTERNOON AND TONIGHT CLOSER TO THE FRONT AND LOW CENTER. && .LONG TERM... AS THE LOW SHIFTS OUT OF MINNESOTA ON THURSDAY AND BEGINS TO OCCLUDE...MODELS ARE INDICATING THE FORMATION OF A TROWAL FEATURE...WHICH BY FRIDAY MORNING EXTENDS FROM NORTHERN MN ACROSS THE NORTH SHORE OF LAKE SUPERIOR BACK INTO THE LOWER GREAT LAKES. AS THIS HAPPENS DRY INTRUSION PER 850-500MB RH FIELD MOVES INTO FA FROM THE SOUTH. 00Z GFS RUN HAS TRENDED DRIER OVER THE WESTERN U.P. WITH THE INITIAL PUSH OF THE DRY SLOT. CAN/T JUSTIFY REMOVING POPS YET GIVEN LESS DRY EC SOLUTION...HOWEVER DID TREND POPS DOWN TO ACCOMMODATE PROGRESSION OF DRY SLOT ON FRIDAY. FOR FRIDAY NIGHT ATTENTION TURNS TO PROGGED LOW-LEVEL CONVERGENCE ASSOCIATED WITH TROWAL FEATURE MIGRATING SOUTH FROM NORTHERN LAKE SUPERIOR. NEED TO WATCH LAKE SUPERIOR SHORELINES ALONG WESTERN ZONES FOR HEAVY PRECIPITATION POTENTIAL. VERY STRONG CONVERGENCE SIGNAL NOTED IN MODEL DERIVED VERTICAL MOTION FIELDS. THOUGH THE OPPORTUNITY FOR HEAVY PRECIPITATION APPEARS BRIEF AS THE TROWAL FEATURE WEAKENS AND SHIFTS QUICKLY EAST ON FRIDAY WITH THE DEPARTING LOW. FOR NOW WILL INCREASE POPS A BIT OVER POTENTIAL UPSLOPE AREAS. AS THE LOW EXITS TO THE EAST...COLD AIR WILL SLOWLY FILTER IN ACROSS THE CWA. MADE SOME CHANGES TO WX GRIDS TO REFLECT CHANGE FROM RAIN TO SNOW...THOUGH THIS CHANGE WILL BE GRADUAL. PARTIAL THICKNESS PROGS WOULD SUGGEST AN ALL SNOW PRECIP. TYPE BY SOMETIME SUNDAY MORNING WHEN COLD AIR IS FIRMLY IN PLACE. UNTIL THEN...HAVE RAIN/SNOW MIX GRADUALLY SHIFTING EASTWARD THROUGHOUT SATURDAY INTO SUNDAY MORNING. CHANGE OVER TO SNOW IS FURTHER COMPLICATED BY PREVIOUSLY MENTIONED TONGUE OF WARM AIR ALOFT WHICH WILL ONLY DELAY THE P-TYPE CHANGE. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... CMX...FOCUS IS ON FAIRLY WIDESPREAD AREA OF SHOWERS WITH QUITE A BIT OF THUNDER OVER EASTERN IOWA INTO SE MINNESOTA. STRONG MOISTURE ADVECTION GENERATING THE RAIN IS PROJECTED TO MAKE IT TO CMX LATE THIS AFTERNOON AND EVEN THOUGH IT IS NOVEMBER...INCREASING INSTABILITY ALOFT ALSO LEADS TO A GOOD CHANCE FOR SOME THUNDER. JUST INCLUDED A CB FOR NOW IN CASE THE PCPN DIMINISHES WITH LOSS OF LOW LEVEL JET MAX. HIGHEST CHANCES FOR SHRA/TSRA BTWN 20Z AND 00Z AS WEAK UPPER LEVEL DISTURBANCE MOVES THROUGH. MVFR CONDITIONS POSSIBLE WITH THE RAIN...ESPECIALLY IF IT PERSISTS FOR A FEW HOURS. SAW...A CLUSTER OF SHOWERS AND THUNDERSTORMS SHOULD MISS SAW TO THE WEST THIS AFTERNOON/EVENING. SO...ONLY VFR CONDITIONS ARE EXPECTED THROUGH TONIGHT. LLWS WILL CONTINUE THROUGH MUCH OF THIS AFTERNOON SHOULD ALLOW SOUTHERLY WIND GUSTS TO APPROACH 27 KNOTS. LLWS WILL CONTINUE THIS AFTERNOON AND EVENING TRAPPING STRONGER WINDS JUST ABOVE THE SURFACE. THE LOW LEVEL JET WILL SHIFT OUT OF THE AREA EARLY ON THURSDAY. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... STRONG WARM AIR ADVECTION AHEAD OF A SFC LOW OVR THE NORTHERN PLAINS WILL CONTINUE TO PRODUCE GUSTY SOUTH WINDS OVR THE EASTERN HALF OF LAKE SUPERIOR THROUGH THURSDAY. HIGH STABILITY WITH NEAR SFC BASED INVERSION AND UNFAVORABLE PRESSURE FALL PATTERN FOCUSED TO THE SOUTH SHOULD PREVENT ANY GALES. SFC LOW LIFTS TOWARD WESTERN LAKE SUPERIOR ON FRIDAY THEN ACROSS UPPER MICHIGAN INTO SATURDAY. NORTH WINDS ON BACK SIDE OF THE LOW OVR WESTERN LAKE SUPERIOR FRIDAY NIGHT SHOULD REACH 30 KNOTS PRETTY EASILY WITH TIGHT PRESSURE GRADIENT AND COLD AIR ADVECTION ENHANCING MIXING. SOME LOW END GALE FORCE GUSTS TO 35 KNOTS WERE ALSO INCLUDED. NW WINDS TO 30 KNOTS EXPECTED OVR THE REST OF LK SUPERIOR SATURDAY INTO SATURDAY NIGHT WITH WINDS THEN DIMINISHING ON SUNDAY AS SFC LOW LIFTS AWAY FM THE REGION. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/SHORT TERM...DLG LONG TERM...PEARSON AVIATION...DLG MARINE...JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 1015 AM CST THU NOV 6 2008 .UPDATE...LARGE AREA OF RAIN WITH SOME EMBEDDED THUNDERSTORMS MOVING NORTH THROUGH FORECAST AREA. LITTLE CHANGE TO AFTERNOON FORECAST EXCEPT FOR TWEAKS FOR TEMPS. REST OF FCST UNCHANGED. STEWART && .PREV DISCUSSION... /ISSUED 338 AM CST THU NOV 6 2008/ DISCUSSION...SLOW MOVING CUT OFF SYSTEM IN THE DAKOTAS WILL DRIFT E OVER MN/IA TODAY...CENTERING OVER WIS AND THE WRN GREAT LAKES FRIDAY. ADJUSTED POPS DOWN IN ERN WIS ZONES TO CHC WITH SCT SHRA ISOLD TSRA WORDING THIS MORNING BASED ON CURRENT RADAR TREND AND 06Z MODEL RUNS KEEPING THE WIS ZONES DRY THROUGH 18Z. ELSEWHERE THIS MORNING...AND ALL ZONES THIS AFTERNOON...CONTINUED DEF POPS AND ISOLD TSTMS. NO SEVERE WEATHER IS EXPECTED ATTM. AT 09Z THE SFC LOW PRESSURE WAS 992 MB...DEEPER THAN THE GFS/NAM/SHEF/RUC WERE SUGGESTING FOR THIS HR. INCREASED WIND SPEEDS TODAY. IF THE CURRENT PRESSURE CAN BE MAINTAINED AS LOW APPROACHES WIND SPEEDS WILL NEED TO BE INCREASED EVEN FURTHER. WITH 3 FT WAVES ALREADY BEING REPORTED AT THE DULUTH ENTRY AT 3 AM...ISSUED A SMALL CRAFT ADVISORY. REFER TO NSH/WSW FOR ADDITIONAL MARINE DETAILS. FCST CHALLENGES CONCERNING TIMING AND PLACEMENT OF DRY SLOT WRAPPING INTO THE SYSTEM OVER THE SRN AND ERN ZONES TONIGHT/FRIDAY. MINOR ADJUSTMENTS TO POP/QPF GRIDS DURING THIS TIME...MAINLY TO DECREASE POPS IN FAR EAST. UNCERTAINTY REMAINS IN TIMING AND STRENGTH OF CAA WITH PHASE TRANSITION FRIDAY/SAT. BUFR SOUNDINGS SHOW RA/SN TRANSITION IN THE WRN FA...INL TO BRD...TAKES PLACE LATE FRI AFTRN/EARLY EVENING. ELSEWHERE...PROFILE SUPPORTS ALL RA FRIDAY. CHANGE OVER TO SN FROM WEST TO EAST EXPECTED THROUGH FRIDAY NIGHT INTO SAT. ATTM...ALL SN EXPECTED SAT NIGHT/SUN. SNOW ACCUMULATIONS ARE EXPECTED TO REMAIN LIGHT...A DUSTING UP TO AN INCH OR TWO TOTAL. THE GREATEST ACCUMULATIONS...A FEW INCHES...EXPECTED ALONG THE SOUTH SHORE OF LAKE SUPERIOR SATURDAY NIGHT INTO SUNDAY. AVIATION...MVFR TO IFR CONDITIONS WILL BE WIDESPREAD THROUGH AT LEAST 18Z TODAY AS DEEP MOISTURE FLOWS NORTH AHEAD OF A DEEPENING LOW PRESSURE SYSTEM. RAIN SHOWERS AND EMBEDDED THUNDERSTORMS...AND AREAS OF FOG...WILL BECOME MORE NUMEROUS EARLY THIS MORNING WHILE GRADUALLY SPREADING NORTH AND WEST...WITH THE POOREST CEILINGS AND VISIBILITIES LIKELY TO OCCUR FROM 12Z-16Z. AS A COLD FRONT DRAWS CLOSER TO THE REGION BY THE LATE AFTERNOON AND EARLY EVENING...CEILINGS MAY LIFT SOMEWHAT AS DRIER AIR IS TEMPORARILY ADVECTED INTO THE REGION. TOWARD THE END OF THE TAF PERIOD...BY 06Z FRIDAY...CEILINGS WILL LOWER ONCE AGAIN...WITH A CONTINUED CHANCE FOR SHOWERS AS LOW PRESSURE SLUGGISHLY PUSHES EAST OF THE AREA. && POINT TEMPS/POPS... DLH 56 41 45 29 / 90 70 70 50 INL 53 36 40 28 / 90 80 70 40 BRD 54 39 43 30 / 90 70 70 40 HYR 59 43 47 33 / 90 40 70 60 ASX 58 43 47 34 / 90 70 70 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 10 PM CST THIS EVENING FOR LSZ121- LSZ144-LSZ145-LSZ146-LSZ147-LSZ148. SMALL CRAFT ADVISORY UNTIL 9 AM CST FRIDAY FOR LSZ140-LSZ141- LSZ142-LSZ143. $$ STEWART/DAP mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 338 AM CST THU NOV 6 2008 .DISCUSSION...SLOW MOVING CUT OFF SYSTEM IN THE DAKOTAS WILL DRIFT E OVER MN/IA TODAY...CENTERING OVER WIS AND THE WRN GREAT LAKES FRIDAY. ADJUSTED POPS DOWN IN ERN WIS ZONES TO CHC WITH SCT SHRA ISOLD TSRA WORDING THIS MORNING BASED ON CURRENT RADAR TREND AND 06Z MODEL RUNS KEEPING THE WIS ZONES DRY THROUGH 18Z. ELSEWHERE THIS MORNING...AND ALL ZONES THIS AFTERNOON...CONTINUED DEF POPS AND ISOLD TSTMS. NO SEVERE WEATHER IS EXPECTED ATTM. AT 09Z THE SFC LOW PRESSURE WAS 992 MB...DEEPER THAN THE GFS/NAM/SHEF/RUC WERE SUGGESTING FOR THIS HR. INCREASED WIND SPEEDS TODAY. IF THE CURRENT PRESSURE CAN BE MAINTAINED AS LOW APPROACHES WIND SPEEDS WILL NEED TO BE INCREASED EVEN FURTHER. WITH 3 FT WAVES ALREADY BEING REPORTED AT THE DULUTH ENTRY AT 3 AM...ISSUED A SMALL CRAFT ADVISORY. REFER TO NSH/WSW FOR ADDITIONAL MARINE DETAILS. FCST CHALLENGES CONCERNING TIMING AND PLACEMENT OF DRY SLOT WRAPPING INTO THE SYSTEM OVER THE SRN AND ERN ZONES TONIGHT/FRIDAY. MINOR ADJUSTMENTS TO POP/QPF GRIDS DURING THIS TIME...MAINLY TO DECREASE POPS IN FAR EAST. UNCERTAINTY REMAINS IN TIMING AND STRENGTH OF CAA WITH PHASE TRANSITION FRIDAY/SAT. BUFR SOUNDINGS SHOW RA/SN TRANSITION IN THE WRN FA...INL TO BRD...TAKES PLACE LATE FRI AFTRN/EARLY EVENING. ELSEWHERE...PROFILE SUPPORTS ALL RA FRIDAY. CHANGE OVER TO SN FROM WEST TO EAST EXPECTED THROUGH FRIDAY NIGHT INTO SAT. ATTM...ALL SN EXPECTED SAT NIGHT/SUN. SNOW ACCUMULATIONS ARE EXPECTED TO REMAIN LIGHT...A DUSTING UP TO AN INCH OR TWO TOTAL. THE GREATEST ACCUMULATIONS...A FEW INCHES...EXPECTED ALONG THE SOUTH SHORE OF LAKE SUPERIOR SATURDAY NIGHT INTO SUNDAY. && .AVIATION...MVFR TO IFR CONDITIONS WILL BE WIDESPREAD THROUGH AT LEAST 18Z TODAY AS DEEP MOISTURE FLOWS NORTH AHEAD OF A DEEPENING LOW PRESSURE SYSTEM. RAIN SHOWERS AND EMBEDDED THUNDERSTORMS...AND AREAS OF FOG...WILL BECOME MORE NUMEROUS EARLY THIS MORNING WHILE GRADUALLY SPREADING NORTH AND WEST...WITH THE POOREST CEILINGS AND VISIBILITIES LIKELY TO OCCUR FROM 12Z-16Z. AS A COLD FRONT DRAWS CLOSER TO THE REGION BY THE LATE AFTERNOON AND EARLY EVENING...CEILINGS MAY LIFT SOMEWHAT AS DRIER AIR IS TEMPORARILY ADVECTED INTO THE REGION. TOWARD THE END OF THE TAF PERIOD...BY 06Z FRIDAY...CEILINGS WILL LOWER ONCE AGAIN...WITH A CONTINUED CHANCE FOR SHOWERS AS LOW PRESSURE SLUGGISHLY PUSHES EAST OF THE AREA. && POINT TEMPS/POPS... DLH 56 41 45 29 / 90 70 70 50 INL 53 36 40 28 / 80 80 70 40 BRD 52 39 43 30 / 90 70 70 40 HYR 59 43 47 33 / 90 40 70 60 ASX 58 43 47 34 / 90 70 70 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...SMALL CRAFT ADVISORY UNTIL 10 PM CST THIS EVENING FOR LSZ121- LSZ144-LSZ145-LSZ146-LSZ147-LSZ148. SMALL CRAFT ADVISORY UNTIL 9 AM CST FRIDAY FOR LSZ140-LSZ141- LSZ142-LSZ143. $$ GRANING/GSF/BETTWY mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 1139 PM CST WED NOV 5 2008 .AVIATION... /06Z TAF ISSUANCE/ MOISTURE TRANSPORT WELL UNDERWAY ACROSS EASTERN MN AND WESTERN WI ATTM. SURFACE LOW KS/MO BORDER AREA EXPECTED TO DEEPEN AS IT MOVES NORTH INTO THE CWA ON THURSDAY AS STRONG COUPLED JET APPROACHES FROM THE CENTRAL PLAINS. EXPECT SHOWERS TO EXPAND WESTWARD OVERNIGHT AND THURSDAY MORNING ACROSS THE FA WITH CEILINGS AND VISIBILITIES DETERIORATING TO IFR FOR THE WESTERN TAFS AND MVFR FOR THE EASTERN SITES. THERE SHOULD BE SOME IMPROVEMENT FROM SW TO NE DURING THE AFTERNOON AS A COLD FRONT PUSHES EASTWARD ACROSS THE AREA AND SOMEWHAT DRIER AIR WORKS IN FOR A TIME. THE TREND WILL BE BACK DOWN BY EVENING IN THE WEST WITH DRIZZLE AND FOG AS LOW LEVEL MOISTURE PROFILES SATURATE ON THE BACKSIDE OF THE LOW PRESSURE SYSTEM. && .DISCUSSION... /ISSUED 307 PM CST WED NOV 5 2008/ GOES WV LOOP SHOWING A STRONG UPPER JET DIGGING AROUND THE BASE OF THE LONG WAVE TROUGH POISED OVER THE IMMEDIATE LEE OF THE ROCKIES. THIS MAXIMA WILL EXPAND NORTH NORTHEAST THIS EVENING...OVERRIDING A DEEP AND MOIST WARM SECTOR. SFC LOW AT 993MB IN SE SD THIS AFTN WITH BREEZY SOUTHERLY WINDS CONTINUING AHEAD OF THIS. SFC CAPE EXISTS UP TO THE CENTER OF THE LOW ACCORDING TO DIAGNOSTIC ANALYSIS. THIS LOW PRESSURE WILL GRADUALLY WORK INTO SWRN MN OVERNIGHT TONIGHT. AS UPPER SPEED MAX APPROACHES WITHIN DIFFLUENT MID AND UPPER FLOW PATTERN AND LOW LEVEL JET STRENGTHENS...AREAL COVERAGE OF SHOWERS SHOULD INCREASE THIS EVENING BEGINNING IN SRN MN. THOUGH SFC CAPE UNLIKELY TO BE REALIZED IN OUR FORECAST AREA...ELEVATED INSTABILITY FROM THAT REGION WILL ADVECT NORTH NORTHEAST INTO THE FORECAST AREA THIS EVE AND EARLY OVERNIGHT. MUCAPE VALUES FROM THE 18Z RUC AND NAM RUNS ARE ON THE ORDER OF 200-600 J/KG. SIMILAR ELEVATED CAPE EXISTED THIS MORNING...AND A FEW STORMS WERE ABLE TO HAVE VIGOROUS ENOUGH UPDRAFTS TO HAVE BRIEF SEVERE HAIL. THUNDERSTORMS IN GENERAL WERE FAIRLY PLENTIFUL AND HAVE CONTINUED AT THIS LATITUDE OR NORTH IN ADJACENT AREAS TODAY. WHILE THE LAPSE RATES ASSOCIATED WITH THE INSTABILITY TONIGHT ARE NOT PROJECTED TO BE AS STEEP AS THIS MORNING...DEEP LAYER SHEAR VALUES WILL BE LARGE. SO THIS MAY HELP TO CREATE A FEW SEVERE STORMS...AND IF SO LIKELY THE LAST FEW OF THE YEAR. OVERNIGHT IS LIKELY TO SEE MORE RAIN COVERAGE ESPECIALLY IN ERN MN AND WRN WI UNDER TONGUE OF DEEPER OMEGA AND MOISTURE. SREF PROBABILITIES INDICATE THE POSSIBILITY OF A HALF INCH IN 6 HOURS OR GREATER INCREASING TO ABOVE 50 PERCENT IN SOUTHEAST FORECAST AREA. WITH SOME TRAINING AND HIGH PRECIP EFFICIENCY...A HALF INCH OR MORE MAY INDEED BE REALIZED IN SOME COMMUNITIES OVERNIGHT. FLOOD THREAT LOOKS MINIMAL THOUGH AS ANY HEAVY RAIN CORES SHOULD BE QUICKLY MOVING. BACK IN WRN MN...AS LOW MOVES OVER THE AREA TONIGHT BOTH FOG AND DRIZZLE ARE MORE LIKELY THAN RAIN SHOWERS. AND ONE MORE NIGHT OF MIN TEMPS ABOVE AVG MAX TEMPS FOR EARLY NOV. THE BEST ISENTROPIC ASCENT SHIFTS NORTH OF OUR AREA BY THURSDAY AFTERNOON... AND IS APPEARS THAT A DECENT DRY SLOT WILL OVERSPREAD MUCH OF THE SOUTHERN FORECAST AREA. HOWEVER... THERE IS A FAIR AMOUNT OF SPREAD IN THE SREF AND SOME DISAGREEMENT BETWEEN THE NAM AND GFS ON THE DEPTH OF MOISTURE WHICH WILL LINGER BENEATH THE DRY SLOT. SO... ALTHOUGH THE BEST CHANCE FOR PCPN APPEARS TO BE IN THE MORNING HOURS... WILL KEEP POPS GOING THROUGH THE DAY... PARTICULARLY OVER THE NORTH AND WEST. THE SIGNIFICANT ACTION WITH THIS SYSTEM WILL CONTINUE TO OUR WEST THURSDAY NIGHT... WITH ALL OF THE GUIDANCE SHOWING AN IMPRESSIVE TROWAL FEATURE AROUND THE NORTHERN AND WESTERN PERIPHERY OF THE UPPER PV ANOMALY. THE MAIN AXIS OF FRONTOGENESIS WILL BE CORRELATED WITH THIS FEATURE... REMAINING TO OUR WEST THROUGHOUT THE TIME PERIOD. OVER OUR AREA... SOME Q-VECTOR CONVERGENCE IS ADVERTISED THURSDAY NIGHT THROUGH FRIDAY OWING TO THE PRESENCE OF THE UPPER LOW. DEEP MOISTURE WILL MOVE BACK INTO THE AREA... WHICH WILL COMBINE WITH THE FORCING TO PRODUCE OCCASIONAL LIGHT PCPN. THE TRANSITION FROM RAIN TO SNOW WILL OCCUR FROM SOUTHWEST TO NORTHEAST FROM LATE THURSDAY EVENING THROUGH THE DAY ON FRIDAY... WITH PRIMARILY SNOW ANTICIPATED BY FRIDAY NIGHT. FORECAST SOUNDINGS DO NOT SHOW AN ELEVATED WARM LAYER IMPACTED OUR AREA... WHICH IS REASONABLE GIVEN THE PRIMARY WARM ADVECTION AND FRONTOGENETICAL ZONE TO OUR NORTHWEST... SO THE RAIN/SNOW LINE WILL BE DEPENDENT UPON TEMPERATURES IN THE 1000-850MB LAYER. GENERALLY FOLLOWED A BLEND OF THE 1000-850MB 1300M THICKNESSES AND SREF PROBABILITY OF SNOW PROGS TO TRY AND TIME THE TRANSITION FROM RAIN TO SNOW... ALTHOUGH ALSO TRIED TO TAKE INTO ACCOUNT FORECAST SURFACE TEMPERATURES DURING THE DAYTIME HOURS. THE STRONGEST FORCING OVER OUR AREA... ALONG THE WESTERN EDGE OF THE PV ANOMALY... LOOKS TO BE OVER THE WEST AND SOUTHWEST... SO SOME ACCUMULATING SNOW IS POSSIBLE THERE... BUT AT THIS POINT DO NOT ANTICIPATE ANYTHING MORE THAN LIGHT AMOUNTS. TRACE AMOUNTS ARE EXPECTED TO THE NORTH AND EAST. FORCING WILL CONTINUE TO WANE FRIDAY NIGHT THROUGH SATURDAY AS THE SYSTEM SLOWLY FILLS AND EVENTUALLY SLIDE OFF TO THE EAST... WITH THE DEEP MOISTURE DEPARTING WITH IT. WILL LOWER POPS STEADILY FROM WEST TO EAST THROUGH THIS TIME PERIOD. THE EXTENDED PERIOD OF THE FORECAST... SUNDAY THROUGH WEDNESDAY... CONTINUES TO LOOK FAIRLY BENIGN ACROSS THE AREA. THE MEDIUM RANGE DETERMINISTIC SOLUTIONS HAVE SOME SPREAD IN THEIR HANDLING OF FEATURES... WITH THE PRIMARY FEATURE OF INTEREST BEING A WAVE IN THE SOUTHERN STREAM WHICH SCOOTS BY TO OUR SOUTH MONDAY THEN LIFTS NORTHEAST TOWARD THE OHIO VALLEY TUESDAY INTO WEDNESDAY. OUR AREA IS GENERALLY IN BAGGY MID-UPPER LEVEL FLOW WITH THIS WAVE TO OUR SOUTH AND UPPER RIDGING ACROSS SOUTH CENTRAL CANADA. WILL FOLLOW THE HPC GUIDANCE... WHICH IS VERY SIMILAR TO THE GFS ENSEMBLE MEAN FROM 00Z. WITH THAT SAID... HIGH PRESSURE WILL BUILD SOUTH FROM CANADA ON SUNDAY... BRINGING SEASONABLY COOL AND DRY WEATHER. THIS AREA OF HIGH PRESSURE LOOKS TO HOLD ON ACROSS THE REGION ON MONDAY... AS LOW PRESSURE ORGANIZES OVER THE SOUTHERN PLAINS. THERE IS SOME POSSIBILITY THAT SOME PCPN COULD SNEAK INTO THE SOUTHERN CWFA IF THIS SYSTEM WINDS UP FARTHER NORTH... BUT THE TREND HAS BEEN FOR IT TO STAY SOUTH... SO WILL MAINTAIN THE DRY FORECAST. THE SURFACE LOW LIFTS NORTHEAST FROM THE SOUTHERN PLAINS INTO THE WESTERN OHIO VALLEY ON TUESDAY... WITH RIDGING HOLDING ON ACROSS OUR REGION. ONCE AGAIN... ANY NORTHWARD ADJUSTMENT COULD BRING PCPN INTO THE SOUTHERN/SOUTHEASTERN COUNTIES... BUT WILL BANK ON RIDGING AND DRY AIR KEEPING THINGS PCPN-FREE OVER OUR AREA. BY WEDNESDAY... THE RIDGE WILL SLIDE FARTHER SOUTH ACROSS OUR AREA AS LOW PRESSURE OVER THE OHIO VALLEY LIFTS TOWARD THE EASTERN GREAT LAKES. FAIR AND COOL CONDITIONS SHOULD PERSIST OVER OUR AREA. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ RAH/TRH mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 558 PM CST WED NOV 5 2008 .UPDATE... UPDATED FOR AVIATION DISCUSSION BELOW. && .DISCUSSION... /ISSUED 307 PM CST WED NOV 5 2008/ GOES WV LOOP SHOWING A STRONG UPPER JET DIGGING AROUND THE BASE OF THE LONG WAVE TROUGH POISED OVER THE IMMEDIATE LEE OF THE ROCKIES. THIS MAXIMA WILL EXPAND NORTH NORTHEAST THIS EVENING...OVERRIDING A DEEP AND MOIST WARM SECTOR. SFC LOW AT 993MB IN SE SD THIS AFTN WITH BREEZY SOUTHERLY WINDS CONTINUING AHEAD OF THIS. SFC CAPE EXISTS UP TO THE CENTER OF THE LOW ACCORDING TO DIAGNOSTIC ANALYSIS. THIS LOW PRESSURE WILL GRADUALLY WORK INTO SWRN MN OVERNIGHT TONIGHT. AS UPPER SPEED MAX APPROACHES WITHIN DIFFLUENT MID AND UPPER FLOW PATTERN AND LOW LEVEL JET STRENGTHENS...AREAL COVERAGE OF SHOWERS SHOULD INCREASE THIS EVENING BEGINNING IN SRN MN. THOUGH SFC CAPE UNLIKELY TO BE REALIZED IN OUR FORECAST AREA...ELEVATED INSTABILITY FROM THAT REGION WILL ADVECT NORTH NORTHEAST INTO THE FORECAST AREA THIS EVE AND EARLY OVERNIGHT. MUCAPE VALUES FROM THE 18Z RUC AND NAM RUNS ARE ON THE ORDER OF 200-600 J/KG. SIMILAR ELEVATED CAPE EXISTED THIS MORNING...AND A FEW STORMS WERE ABLE TO HAVE VIGOROUS ENOUGH UPDRAFTS TO HAVE BRIEF SEVERE HAIL. THUNDERSTORMS IN GENERAL WERE FAIRLY PLENTIFUL AND HAVE CONTINUED AT THIS LATITUDE OR NORTH IN ADJACENT AREAS TODAY. WHILE THE LAPSE RATES ASSOCIATED WITH THE INSTABILITY TONIGHT ARE NOT PROJECTED TO BE AS STEEP AS THIS MORNING...DEEP LAYER SHEAR VALUES WILL BE LARGE. SO THIS MAY HELP TO CREATE A FEW SEVERE STORMS...AND IF SO LIKELY THE LAST FEW OF THE YEAR. OVERNIGHT IS LIKELY TO SEE MORE RAIN COVERAGE ESPECIALLY IN ERN MN AND WRN WI UNDER TONGUE OF DEEPER OMEGA AND MOISTURE. SREF PROBABILITIES INDICATE THE POSSIBILITY OF A HALF INCH IN 6 HOURS OR GREATER INCREASING TO ABOVE 50 PERCENT IN SOUTHEAST FORECAST AREA. WITH SOME TRAINING AND HIGH PRECIP EFFICIENCY...A HALF INCH OR MORE MAY INDEED BE REALIZED IN SOME COMMUNITIES OVERNIGHT. FLOOD THREAT LOOKS MINIMAL THOUGH AS ANY HEAVY RAIN CORES SHOULD BE QUICKLY MOVING. BACK IN WRN MN...AS LOW MOVES OVER THE AREA TONIGHT BOTH FOG AND DRIZZLE ARE MORE LIKELY THAN RAIN SHOWERS. AND ONE MORE NIGHT OF MIN TEMPS ABOVE AVG MAX TEMPS FOR EARLY NOV. THE BEST ISENTROPIC ASCENT SHIFTS NORTH OF OUR AREA BY THURSDAY AFTERNOON... AND IS APPEARS THAT A DECENT DRY SLOT WILL OVERSPREAD MUCH OF THE SOUTHERN FORECAST AREA. HOWEVER... THERE IS A FAIR AMOUNT OF SPREAD IN THE SREF AND SOME DISAGREEMENT BETWEEN THE NAM AND GFS ON THE DEPTH OF MOISTURE WHICH WILL LINGER BENEATH THE DRY SLOT. SO... ALTHOUGH THE BEST CHANCE FOR PCPN APPEARS TO BE IN THE MORNING HOURS... WILL KEEP POPS GOING THROUGH THE DAY... PARTICULARLY OVER THE NORTH AND WEST. THE SIGNIFICANT ACTION WITH THIS SYSTEM WILL CONTINUE TO OUR WEST THURSDAY NIGHT... WITH ALL OF THE GUIDANCE SHOWING AN IMPRESSIVE TROWAL FEATURE AROUND THE NORTHERN AND WESTERN PERIPHERY OF THE UPPER PV ANOMALY. THE MAIN AXIS OF FRONTOGENESIS WILL BE CORRELATED WITH THIS FEATURE... REMAINING TO OUR WEST THROUGHOUT THE TIME PERIOD. OVER OUR AREA... SOME Q-VECTOR CONVERGENCE IS ADVERTISED THURSDAY NIGHT THROUGH FRIDAY OWING TO THE PRESENCE OF THE UPPER LOW. DEEP MOISTURE WILL MOVE BACK INTO THE AREA... WHICH WILL COMBINE WITH THE FORCING TO PRODUCE OCCASIONAL LIGHT PCPN. THE TRANSITION FROM RAIN TO SNOW WILL OCCUR FROM SOUTHWEST TO NORTHEAST FROM LATE THURSDAY EVENING THROUGH THE DAY ON FRIDAY... WITH PRIMARILY SNOW ANTICIPATED BY FRIDAY NIGHT. FORECAST SOUNDINGS DO NOT SHOW AN ELEVATED WARM LAYER IMPACTED OUR AREA... WHICH IS REASONABLE GIVEN THE PRIMARY WARM ADVECTION AND FRONTOGENETICAL ZONE TO OUR NORTHWEST... SO THE RAIN/SNOW LINE WILL BE DEPENDENT UPON TEMPERATURES IN THE 1000-850MB LAYER. GENERALLY FOLLOWED A BLEND OF THE 1000-850MB 1300M THICKNESSES AND SREF PROBABILITY OF SNOW PROGS TO TRY AND TIME THE TRANSITION FROM RAIN TO SNOW... ALTHOUGH ALSO TRIED TO TAKE INTO ACCOUNT FORECAST SURFACE TEMPERATURES DURING THE DAYTIME HOURS. THE STRONGEST FORCING OVER OUR AREA... ALONG THE WESTERN EDGE OF THE PV ANOMALY... LOOKS TO BE OVER THE WEST AND SOUTHWEST... SO SOME ACCUMULATING SNOW IS POSSIBLE THERE... BUT AT THIS POINT DO NOT ANTICIPATE ANYTHING MORE THAN LIGHT AMOUNTS. TRACE AMOUNTS ARE EXPECTED TO THE NORTH AND EAST. FORCING WILL CONTINUE TO WANE FRIDAY NIGHT THROUGH SATURDAY AS THE SYSTEM SLOWLY FILLS AND EVENTUALLY SLIDE OFF TO THE EAST... WITH THE DEEP MOISTURE DEPARTING WITH IT. WILL LOWER POPS STEADILY FROM WEST TO EAST THROUGH THIS TIME PERIOD. THE EXTENDED PERIOD OF THE FORECAST... SUNDAY THROUGH WEDNESDAY... CONTINUES TO LOOK FAIRLY BENIGN ACROSS THE AREA. THE MEDIUM RANGE DETERMINISTIC SOLUTIONS HAVE SOME SPREAD IN THEIR HANDLING OF FEATURES... WITH THE PRIMARY FEATURE OF INTEREST BEING A WAVE IN THE SOUTHERN STREAM WHICH SCOOTS BY TO OUR SOUTH MONDAY THEN LIFTS NORTHEAST TOWARD THE OHIO VALLEY TUESDAY INTO WEDNESDAY. OUR AREA IS GENERALLY IN BAGGY MID-UPPER LEVEL FLOW WITH THIS WAVE TO OUR SOUTH AND UPPER RIDGING ACROSS SOUTH CENTRAL CANADA. WILL FOLLOW THE HPC GUIDANCE... WHICH IS VERY SIMILAR TO THE GFS ENSEMBLE MEAN FROM 00Z. WITH THAT SAID... HIGH PRESSURE WILL BUILD SOUTH FROM CANADA ON SUNDAY... BRINGING SEASONABLY COOL AND DRY WEATHER. THIS AREA OF HIGH PRESSURE LOOKS TO HOLD ON ACROSS THE REGION ON MONDAY... AS LOW PRESSURE ORGANIZES OVER THE SOUTHERN PLAINS. THERE IS SOME POSSIBILITY THAT SOME PCPN COULD SNEAK INTO THE SOUTHERN CWFA IF THIS SYSTEM WINDS UP FARTHER NORTH... BUT THE TREND HAS BEEN FOR IT TO STAY SOUTH... SO WILL MAINTAIN THE DRY FORECAST. THE SURFACE LOW LIFTS NORTHEAST FROM THE SOUTHERN PLAINS INTO THE WESTERN OHIO VALLEY ON TUESDAY... WITH RIDGING HOLDING ON ACROSS OUR REGION. ONCE AGAIN... ANY NORTHWARD ADJUSTMENT COULD BRING PCPN INTO THE SOUTHERN/SOUTHEASTERN COUNTIES... BUT WILL BANK ON RIDGING AND DRY AIR KEEPING THINGS PCPN-FREE OVER OUR AREA. BY WEDNESDAY... THE RIDGE WILL SLIDE FARTHER SOUTH ACROSS OUR AREA AS LOW PRESSURE OVER THE OHIO VALLEY LIFTS TOWARD THE EASTERN GREAT LAKES. FAIR AND COOL CONDITIONS SHOULD PERSIST OVER OUR AREA. && .AVIATION.../00Z TAF ISSUANCE/ LINE OF STORMS ATTM FROM EXTREME SW MN SOUTHWARD THROUGH WRN IA AND INTO SERN NEBRASKA. 18Z NAM DID THE BEST AT FLAGGING THIS AREA AHEAD OF TIME. BEST INSTABILITY WITH THIS LIFTS NNE TOWARD RWF/STC/AXN...WHICH MAKES SENSE IN LIGHT OF UPPER AIR PATTERN. WILL MENTION TWO OR THREE HOURS OF THUNDER LATER THIS EVENING FOR THESE SITES. LINE SHOULD ARC AND/OR DEVELOP EASTWARD INTO MSP AND MAYBE RNH BUT WILL ONLY MENTION SHOWERS DUE TO MISSING OUT ON THE BETTER INSTABILITY. THEREAFTER...CIGS AND VISBYS WILL GRADUALLY BE ON THEIR WAY DOWN TONIGHT WITH THE AMPLE LOW LEVEL MOISTURE. WILL CONTINUE FORECAST OF IFR CONDITIONS TOWARD 12Z AND INTO THURSDAY MORNING...ESPECIALLY AT SITES WHERE MID-LEVEL DRY SLOT MOVES IN. HOWEVER...AMPLE LOW LEVEL MOISTURE REMAINING IN PLACE AND SOME LIFT SUGGESTS LIGHT RAIN OR DRIZZLE MUCH OF THURSDAY DURING THE DAY. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ TRH/TDK mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 307 PM CST WED NOV 5 2008 .DISCUSSION... CORRECTED TO INCLUDE UPDATED FIRST PERIOD DISCUSSION. GOES WV LOOP SHOWING A STRONG UPPER JET DIGGING AROUND THE BASE OF THE LONG WAVE TROUGH POISED OVER THE IMMEDIATE LEE OF THE ROCKIES. THIS MAXIMA WILL EXPAND NORTH NORTHEAST THIS EVENING...OVERRIDING A DEEP AND MOIST WARM SECTOR. SFC LOW AT 993MB IN SE SD THIS AFTN WITH BREEZY SOUTHERLY WINDS CONTINUING AHEAD OF THIS. SFC CAPE EXISTS UP TO THE CENTER OF THE LOW ACCORDING TO DIAGNOSTIC ANALYSIS. THIS LOW PRESSURE WILL GRADUALLY WORK INTO SWRN MN OVERNIGHT TONIGHT. AS UPPER SPEED MAX APPROACHES WITHIN DIFFLUENT MID AND UPPER FLOW PATTERN AND LOW LEVEL JET STRENGTHENS...AREAL COVERAGE OF SHOWERS SHOULD INCREASE THIS EVENING BEGINNING IN SRN MN. THOUGH SFC CAPE UNLIKELY TO BE REALIZED IN OUR FORECAST AREA...ELEVATED INSTABILITY FROM THAT REGION WILL ADVECT NORTH NORTHEAST INTO THE FORECAST AREA THIS EVE AND EARLY OVERNIGHT. MUCAPE VALUES FROM THE 18Z RUC AND NAM RUNS ARE ON THE ORDER OF 200-600 J/KG. SIMILAR ELEVATED CAPE EXISTED THIS MORNING...AND A FEW STORMS WERE ABLE TO HAVE VIGOROUS ENOUGH UPDRAFTS TO HAVE BRIEF SEVERE HAIL. THUNDERSTORMS IN GENERAL WERE FAIRLY PLENTIFUL AND HAVE CONTINUED AT THIS LATITUDE OR NORTH IN ADJACENT AREAS TODAY. WHILE THE LAPSE RATES ASSOCIATED WITH THE INSTABILITY TONIGHT ARE NOT PROJECTED TO BE AS STEEP AS THIS MORNING...DEEP LAYER SHEAR VALUES WILL BE LARGE. SO THIS MAY HELP TO CREATE A FEW SEVERE STORMS...AND IF SO LIKELY THE LAST FEW OF THE YEAR. OVERNIGHT IS LIKELY TO SEE MORE RAIN COVERAGE ESPECIALLY IN ERN MN AND WRN WI UNDER TONGUE OF DEEPER OMEGA AND MOISTURE. SREF PROBABILITIES INDICATE THE POSSIBILITY OF A HALF INCH IN 6 HOURS OR GREATER INCREASING TO ABOVE 50 PERCENT IN SOUTHEAST FORECAST AREA. WITH SOME TRAINING AND HIGH PRECIP EFFICIENCY...A HALF INCH OR MORE MAY INDEED BE REALIZED IN SOME COMMUNITIES OVERNIGHT. FLOOD THREAT LOOKS MINIMAL THOUGH AS ANY HEAVY RAIN CORES SHOULD BE QUICKLY MOVING. BACK IN WRN MN...AS LOW MOVES OVER THE AREA TONIGHT BOTH FOG AND DRIZZLE ARE MORE LIKELY THAN RAIN SHOWERS. AND ONE MORE NIGHT OF MIN TEMPS ABOVE AVG MAX TEMPS FOR EARLY NOV. THE BEST ISENTROPIC ASCENT SHIFTS NORTH OF OUR AREA BY THURSDAY AFTERNOON... AND IS APPEARS THAT A DECENT DRY SLOT WILL OVERSPREAD MUCH OF THE SOUTHERN FORECAST AREA. HOWEVER... THERE IS A FAIR AMOUNT OF SPREAD IN THE SREF AND SOME DISAGREEMENT BETWEEN THE NAM AND GFS ON THE DEPTH OF MOISTURE WHICH WILL LINGER BENEATH THE DRY SLOT. SO... ALTHOUGH THE BEST CHANCE FOR PCPN APPEARS TO BE IN THE MORNING HOURS... WILL KEEP POPS GOING THROUGH THE DAY... PARTICULARLY OVER THE NORTH AND WEST. THE SIGNIFICANT ACTION WITH THIS SYSTEM WILL CONTINUE TO OUR WEST THURSDAY NIGHT... WITH ALL OF THE GUIDANCE SHOWING AN IMPRESSIVE TROWAL FEATURE AROUND THE NORTHERN AND WESTERN PERIPHERY OF THE UPPER PV ANOMALY. THE MAIN AXIS OF FRONTOGENESIS WILL BE CORRELATED WITH THIS FEATURE... REMAINING TO OUR WEST THROUGHOUT THE TIME PERIOD. OVER OUR AREA... SOME Q-VECTOR CONVERGENCE IS ADVERTISED THURSDAY NIGHT THROUGH FRIDAY OWING TO THE PRESENCE OF THE UPPER LOW. DEEP MOISTURE WILL MOVE BACK INTO THE AREA... WHICH WILL COMBINE WITH THE FORCING TO PRODUCE OCCASIONAL LIGHT PCPN. THE TRANSITION FROM RAIN TO SNOW WILL OCCUR FROM SOUTHWEST TO NORTHEAST FROM LATE THURSDAY EVENING THROUGH THE DAY ON FRIDAY... WITH PRIMARILY SNOW ANTICIPATED BY FRIDAY NIGHT. FORECAST SOUNDINGS DO NOT SHOW AN ELEVATED WARM LAYER IMPACTED OUR AREA... WHICH IS REASONABLE GIVEN THE PRIMARY WARM ADVECTION AND FRONTOGENETICAL ZONE TO OUR NORTHWEST... SO THE RAIN/SNOW LINE WILL BE DEPENDENT UPON TEMPERATURES IN THE 1000-850MB LAYER. GENERALLY FOLLOWED A BLEND OF THE 1000-850MB 1300M THICKNESSES AND SREF PROBABILITY OF SNOW PROGS TO TRY AND TIME THE TRANSITION FROM RAIN TO SNOW... ALTHOUGH ALSO TRIED TO TAKE INTO ACCOUNT FORECAST SURFACE TEMPERATURES DURING THE DAYTIME HOURS. THE STRONGEST FORCING OVER OUR AREA... ALONG THE WESTERN EDGE OF THE PV ANOMALY... LOOKS TO BE OVER THE WEST AND SOUTHWEST... SO SOME ACCUMULATING SNOW IS POSSIBLE THERE... BUT AT THIS POINT DO NOT ANTICIPATE ANYTHING MORE THAN LIGHT AMOUNTS. TRACE AMOUNTS ARE EXPECTED TO THE NORTH AND EAST. FORCING WILL CONTINUE TO WANE FRIDAY NIGHT THROUGH SATURDAY AS THE SYSTEM SLOWLY FILLS AND EVENTUALLY SLIDE OFF TO THE EAST... WITH THE DEEP MOISTURE DEPARTING WITH IT. WILL LOWER POPS STEADILY FROM WEST TO EAST THROUGH THIS TIME PERIOD. THE EXTENDED PERIOD OF THE FORECAST... SUNDAY THROUGH WEDNESDAY... CONTINUES TO LOOK FAIRLY BENIGN ACROSS THE AREA. THE MEDIUM RANGE DETERMINISTIC SOLUTIONS HAVE SOME SPREAD IN THEIR HANDLING OF FEATURES... WITH THE PRIMARY FEATURE OF INTEREST BEING A WAVE IN THE SOUTHERN STREAM WHICH SCOOTS BY TO OUR SOUTH MONDAY THEN LIFTS NORTHEAST TOWARD THE OHIO VALLEY TUESDAY INTO WEDNESDAY. OUR AREA IS GENERALLY IN BAGGY MID-UPPER LEVEL FLOW WITH THIS WAVE TO OUR SOUTH AND UPPER RIDGING ACROSS SOUTH CENTRAL CANADA. WILL FOLLOW THE HPC GUIDANCE... WHICH IS VERY SIMILAR TO THE GFS ENSEMBLE MEAN FROM 00Z. WITH THAT SAID... HIGH PRESSURE WILL BUILD SOUTH FROM CANADA ON SUNDAY... BRINGING SEASONABLY COOL AND DRY WEATHER. THIS AREA OF HIGH PRESSURE LOOKS TO HOLD ON ACROSS THE REGION ON MONDAY... AS LOW PRESSURE ORGANIZES OVER THE SOUTHERN PLAINS. THERE IS SOME POSSIBILITY THAT SOME PCPN COULD SNEAK INTO THE SOUTHERN CWFA IF THIS SYSTEM WINDS UP FARTHER NORTH... BUT THE TREND HAS BEEN FOR IT TO STAY SOUTH... SO WILL MAINTAIN THE DRY FORECAST. THE SURFACE LOW LIFTS NORTHEAST FROM THE SOUTHERN PLAINS INTO THE WESTERN OHIO VALLEY ON TUESDAY... WITH RIDGING HOLDING ON ACROSS OUR REGION. ONCE AGAIN... ANY NORTHWARD ADJUSTMENT COULD BRING PCPN INTO THE SOUTHERN/SOUTHEASTERN COUNTIES... BUT WILL BANK ON RIDGING AND DRY AIR KEEPING THINGS PCPN-FREE OVER OUR AREA. BY WEDNESDAY... THE RIDGE WILL SLIDE FARTHER SOUTH ACROSS OUR AREA AS LOW PRESSURE OVER THE OHIO VALLEY LIFTS TOWARD THE EASTERN GREAT LAKES. FAIR AND COOL CONDITIONS SHOULD PERSIST OVER OUR AREA. && .AVIATION.../18Z TAF ISSUANCE/ CHALLENGING AVIATION FORECAST THROUGH THE NEXT 24 TO 30 HOURS. DEEP SYSTEM SLOWING MOVING EAST OUT OF THE ROCKIES WITH CONTINUED WARM BUT MOISTENING AIR OVER THE REGION. FOR THE FIRST HALF OF THIS AFTN...LACK OF FOCUS FOR WARM AIR ADVECTION WILL KEEP ANY SHOWERS WIDELY ISOLATED. THEN MORE OF A CONCENTRATION IS EXPECTED BY LATE AFTN AND ESPECIALLY THIS EVENING AS DEEPER LIFT MOVES ATOP THE REGION. POTENTIAL FOR THUNDER WILL REMAIN THROUGH MUCH OF TONIGHT AS MODELS CONTINUE TO INDICATE INSTABILITY VALUES SIMILAR TO THIS MORNING WHEN ALMOST ALL SHOWERS HAD SOME CLOUD-TO-GROUND LIGHTNING. CIGS AND VISBYS WILL GRADUALLY BE ON THEIR WAY DOWN TONIGHT WITH THE AMPLE LOW LEVEL MOISTURE AND THE ASSISTANCE OF PRECIPITATION. IFR CONDITIONS STILL EXPECTED NEAR MORNING...ESPECIALLY AT SITES WHERE LIGHTER WINDS DEVELOP. THESE WILL BE SEEN MOST NOTABLY AT AXN...STC...AND RWF AS SFC TROUGH GRADUALLY EXPANDS INTO WRN MN. PRIMARY RAIN/SHOWER AREA TO ROTATE SLOWLY NORTHWARD ACROSS ERN MN AND WRN WI THU MORNING AS MID-LEVEL DRY SLOT ADVECTS AROUND SYSTEM AND INTO SRN MN. THOUGH THE MID- LEVELS ARE DRY WITH THIS...WITH THE SFC LOW OVER CTRL/SRN MN AND REMAINING HIGH DEW POINTS...LOW CLOUDS ARE THOUGH TO REMAIN MUCH OF THU. THE THOUGH IS IFR CONDITIONS IN THE EARLY-MID MORNING GIVING WAY TO PREVAILING MVFR BY NOON. DRIZZLE IS EXPECTED TO BE MORE COMMON THAN RAIN. BEYOND TAF PERIOD...BACKSIDE PRECIPITATION WITH THIS SYSTEM AND STRONGER WINDS ARE EXPECTED TO START IN WRN MN THU NIGHT. THERE IS POTENTIAL FOR THIS CHANGE TO SNOW AT AXN AND RWF DURING THAT TIME WITH AT LEAST SOME SNOW AND BLOWING SNOW LIKELY DURING FRI. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ TRH/MTF mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 303 PM CST WED NOV 5 2008 .DISCUSSION... WEATHER OVER THE NEXT FEW DAYS WILL BE QUITE BUSY AND VARIED... ALTHOUGH THE MOST SIGNIFICANT ACTIVITY APPEARS AS THOUGH IT WILL MISS OUR AREA... BOTH WITH RESPECT TO HEAVY RAINS AND CONVECTIVE ACTIVITY OVER THE NEXT 12-24 HOURS AND THE TRANSITION TO SNOW AND WIND. LATEST WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSES SHOW A HIGHLY AMPLIFIED MID-UPPER PATTERN ACROSS THE CONUS... WITH A DEEP TROUGH CARVED OUT OVER THE EASTERN ROCKIES WITH IMPRESSIVE DOWNSTREAM RIDGING OVER THE GREAT LAKES AND EASTERN US... ALTHOUGH A CUTOFF LOW WAS PERSISTING OFF THE MID-ATLANTIC COAST. A LEAD SHORTWAVE COULD BE SEEN LIFTING INTO EASTERN SOUTH DAKOTA... WITH THE MAIN SHORTWAVE AND SIGNIFICANT UPPER LEVEL PV ANOMALY ROUNDING THE BASE OF THE UPPER TROUGH NEAR THE COLORADO/NEW MEXICO BORDER. THIS FEATURE WILL LIFT UP THE EASTERN SIDE OF THE UPPER TROUGH HELPING IT TO BECOME NEGATIVELY TILTED WHILE THE SURFACE LOW NEAR THE SOUTH DAKOTA/NEBRASKA BORDER DEEPENS OVER THE NEXT 24 HOURS BEFORE BECOMING VERTICALLY STACKED OVER MINNESOTA. THE SYSTEM WILL THEN SLOWLY FILL AS IT LINGERS OVER OUR AREA FOR A TIME BEFORE LIFTING NORTHEAST INTO THE GREAT LAKES AND ONTARIO. THE 12Z NAM AND GFS ARE REASONABLY SIMILAR WITH THE LARGE SCALE MASS FIELDS... ALTHOUGH DO EXHIBIT SOME SUBSTANTIVE DIFFERENCES IN THE HANDLING OF THE UPPER AND SURFACE LOWS BEYOND 30 HOURS ONCE THE SYSTEM OCCLUDES AND MEANDERS. WILL GENERALLY FOLLOW A BLEND OF THE SREF MEAN AND GFS FOR THE OVERALL HANDLING OF FEATURES... ALTHOUGH WILL PUT SOME WEIGHT ON THE NAM THROUGH THE FIRST 24 TO 36 HOURS. MOISTURE TRANSPORT INCREASES OVER THE AREA TONIGHT... PARTICULARLY OVER THE SOUTH AND EAST LATE TONIGHT INTO THURSDAY MORNING. WILL GENERALLY GO WITH INCREASING POPS FROM SOUTH TO NORTH... FOCUSING THE HIGHER POPS OVER THE SOUTH AND EAST LATE TONIGHT INTO THURSDAY MORNING. ELEVATED POTENTIAL INSTABILITY REMAINS IN PLACE OVER MUCH OF THE AREA THROUGH THURSDAY MORNING... BEFORE SLOWLY SLIDING EASTWARD THROUGH THE AFTERNOON... SO WILL CONTINUE TO INCLUDE A MENTION OF THUNDER IN THE FORECAST. THE BEST CHANCES FOR SEVERE WEATHER WILL BE SOUTH OF OUR AREA WHERE THERE IS A BETTER CHANCE FOR CONVECTION ROOTED IN THE BOUNDARY LAYER... BUT INCREASING DEEP LAYER SHEAR AND ELEVATED INSTABILITY WILL KEEP SOME POTENTIAL FOR LARGE HAIL OVER THE SOUTHERN AND SOUTHWESTERN PORTION OF THE CWFA THROUGH THIS EVENING. THE BEST ISENTROPIC ASCENT SHIFTS NORTH OF OUR AREA THURSDAY AFTERNOON... AND IS APPEARS THAT A DECENT DRY SLOT WILL OVERSPREAD MUCH OF THE SOUTHERN FORECAST AREA. HOWEVER... THERE IS A FAIR AMOUNT OF SPREAD IN THE SREF AND SOME DISAGREEMENT BETWEEN THE NAM AND GFS ON THE DEPTH OF MOISTURE WHICH WILL LINGER BENEATH THE DRY SLOT. SO... ALTHOUGH THE BEST CHANCE FOR PCPN APPEARS TO BE IN THE MORNING HOURS... WILL KEEP POPS GOING THROUGH THE DAY... PARTICULARLY OVER THE NORTH AND WEST. THE SIGNIFICANT ACTION WITH THIS SYSTEM WILL CONTINUE TO OUR WEST THURSDAY NIGHT... WITH ALL OF THE GUIDANCE SHOWING AN IMPRESSIVE TROWAL FEATURE AROUND THE NORTHERN AND WESTERN PERIPHERY OF THE UPPER PV ANOMALY. THE MAIN AXIS OF FRONTOGENESIS WILL BE CORRELATED WITH THIS FEATURE... REMAINING TO OUR WEST THROUGHOUT THE TIME PERIOD. OVER OUR AREA... SOME Q-VECTOR CONVERGENCE IS ADVERTISED THURSDAY NIGHT THROUGH FRIDAY OWING TO THE PRESENCE OF THE UPPER LOW. DEEP MOISTURE WILL MOVE BACK INTO THE AREA... WHICH WILL COMBINE WITH THE FORCING TO PRODUCE OCCASIONAL LIGHT PCPN. THE TRANSITION FROM RAIN TO SNOW WILL OCCUR FROM SOUTHWEST TO NORTHEAST FROM LATE THURSDAY EVENING THROUGH THE DAY ON FRIDAY... WITH PRIMARILY SNOW ANTICIPATED BY FRIDAY NIGHT. FORECAST SOUNDINGS DO NOT SHOW AN ELEVATED WARM LAYER IMPACTED OUR AREA... WHICH IS REASONABLE GIVEN THE PRIMARY WARM ADVECTION AND FRONTOGENETICAL ZONE TO OUR NORTHWEST... SO THE RAIN/SNOW LINE WILL BE DEPENDENT UPON TEMPERATURES IN THE 1000-850MB LAYER. GENERALLY FOLLOWED A BLEND OF THE 1000-850MB 1300M THICKNESSES AND SREF PROBABILITY OF SNOW PROGS TO TRY AND TIME THE TRANSITION FROM RAIN TO SNOW... ALTHOUGH ALSO TRIED TO TAKE INTO ACCOUNT FORECAST SURFACE TEMPERATURES DURING THE DAYTIME HOURS. THE STRONGEST FORCING OVER OUR AREA... ALONG THE WESTERN EDGE OF THE PV ANOMALY... LOOKS TO BE OVER THE WEST AND SOUTHWEST... SO SOME ACCUMULATING SNOW IS POSSIBLE THERE... BUT AT THIS POINT DO NOT ANTICIPATE ANYTHING MORE THAN LIGHT AMOUNTS. TRACE AMOUNTS ARE EXPECTED TO THE NORTH AND EAST. FORCING WILL CONTINUE TO WANE FRIDAY NIGHT THROUGH SATURDAY AS THE SYSTEM SLOWLY FILLS AND EVENTUALLY SLIDE OFF TO THE EAST... WITH THE DEEP MOISTURE DEPARTING WITH IT. WILL LOWER POPS STEADILY FROM WEST TO EAST THROUGH THIS TIME PERIOD. THE EXTENDED PERIOD OF THE FORECAST... SUNDAY THROUGH WEDNESDAY... CONTINUES TO LOOK FAIRLY BENIGN ACROSS THE AREA. THE MEDIUM RANGE DETERMINISTIC SOLUTIONS HAVE SOME SPREAD IN THEIR HANDLING OF FEATURES... WITH THE PRIMARY FEATURE OF INTEREST BEING A WAVE IN THE SOUTHERN STREAM WHICH SCOOTS BY TO OUR SOUTH MONDAY THEN LIFTS NORTHEAST TOWARD THE OHIO VALLEY TUESDAY INTO WEDNESDAY. OUR AREA IS GENERALLY IN BAGGY MID-UPPER LEVEL FLOW WITH THIS WAVE TO OUR SOUTH AND UPPER RIDGING ACROSS SOUTH CENTRAL CANADA. WILL FOLLOW THE HPC GUIDANCE... WHICH IS VERY SIMILAR TO THE GFS ENSEMBLE MEAN FROM 00Z. WITH THAT SAID... HIGH PRESSURE WILL BUILD SOUTH FROM CANADA ON SUNDAY... BRINGING SEASONABLY COOL AND DRY WEATHER. THIS AREA OF HIGH PRESSURE LOOKS TO HOLD ON ACROSS THE REGION ON MONDAY... AS LOW PRESSURE ORGANIZES OVER THE SOUTHERN PLAINS. THERE IS SOME POSSIBILITY THAT SOME PCPN COULD SNEAK INTO THE SOUTHERN CWFA IF THIS SYSTEM WINDS UP FARTHER NORTH... BUT THE TREND HAS BEEN FOR IT TO STAY SOUTH... SO WILL MAINTAIN THE DRY FORECAST. THE SURFACE LOW LIFTS NORTHEAST FROM THE SOUTHERN PLAINS INTO THE WESTERN OHIO VALLEY ON TUESDAY... WITH RIDGING HOLDING ON ACROSS OUR REGION. ONCE AGAIN... ANY NORTHWARD ADJUSTMENT COULD BRING PCPN INTO THE SOUTHERN/SOUTHEASTERN COUNTIES... BUT WILL BANK ON RIDGING AND DRY AIR KEEPING THINGS PCPN-FREE OVER OUR AREA. BY WEDNESDAY... THE RIDGE WILL SLIDE FARTHER SOUTH ACROSS OUR AREA AS LOW PRESSURE OVER THE OHIO VALLEY LIFTS TOWARD THE EASTERN GREAT LAKES. FAIR AND COOL CONDITIONS SHOULD PERSIST OVER OUR AREA. && .AVIATION.../18Z TAF ISSUANCE/ CHALLENGING AVIATION FORECAST THROUGH THE NEXT 24 TO 30 HOURS. DEEP SYSTEM SLOWING MOVING EAST OUT OF THE ROCKIES WITH CONTINUED WARM BUT MOISTENING AIR OVER THE REGION. FOR THE FIRST HALF OF THIS AFTN...LACK OF FOCUS FOR WARM AIR ADVECTION WILL KEEP ANY SHOWERS WIDELY ISOLATED. THEN MORE OF A CONCENTRATION IS EXPECTED BY LATE AFTN AND ESPECIALLY THIS EVENING AS DEEPER LIFT MOVES ATOP THE REGION. POTENTIAL FOR THUNDER WILL REMAIN THROUGH MUCH OF TONIGHT AS MODELS CONTINUE TO INDICATE INSTABILITY VALUES SIMILAR TO THIS MORNING WHEN ALMOST ALL SHOWERS HAD SOME CLOUD-TO-GROUND LIGHTNING. CIGS AND VISBYS WILL GRADUALLY BE ON THEIR WAY DOWN TONIGHT WITH THE AMPLE LOW LEVEL MOISTURE AND THE ASSISTANCE OF PRECIPITATION. IFR CONDITIONS STILL EXPECTED NEAR MORNING...ESPECIALLY AT SITES WHERE LIGHTER WINDS DEVELOP. THESE WILL BE SEEN MOST NOTABLY AT AXN...STC...AND RWF AS SFC TROUGH GRADUALLY EXPANDS INTO WRN MN. PRIMARY RAIN/SHOWER AREA TO ROTATE SLOWLY NORTHWARD ACROSS ERN MN AND WRN WI THU MORNING AS MID-LEVEL DRY SLOT ADVECTS AROUND SYSTEM AND INTO SRN MN. THOUGH THE MID- LEVELS ARE DRY WITH THIS...WITH THE SFC LOW OVER CTRL/SRN MN AND REMAINING HIGH DEW POINTS...LOW CLOUDS ARE THOUGH TO REMAIN MUCH OF THU. THE THOUGH IS IFR CONDITIONS IN THE EARLY-MID MORNING GIVING WAY TO PREVAILING MVFR BY NOON. DRIZZLE IS EXPECTED TO BE MORE COMMON THAN RAIN. BEYOND TAF PERIOD...BACKSIDE PRECIPITATION WITH THIS SYSTEM AND STRONGER WINDS ARE EXPECTED TO START IN WRN MN THU NIGHT. THERE IS POTENTIAL FOR THIS CHANGE TO SNOW AT AXN AND RWF DURING THAT TIME WITH AT LEAST SOME SNOW AND BLOWING SNOW LIKELY DURING FRI. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ TRH/MTF mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DULUTH MN 1244 PM CST WED NOV 5 2008 .UPDATE... WE STRESSED PRECIPITATION...INCREAING POPS RIGHT THROUGH SATURDAY. WE ALSO STRESSED THUNDER BY PUTTING IT AT THE SCATTERED LEVEL THROUGH THURSDAY. WE HELD OFF ON SNOW...NOT BRINGING ANY MIX EAST OF OUR WESTERN MARGIN UNTIL FRIDAY NIGHT. ON FRIDAY NIGHT...WE KEPT ALL RAIN ALONG LAKE SUPERIOR AND ACROSS NORTHWEST WISCONSIN AND WENT WITH A WINTRY MIX FURTHER WEST. WE WENT TO ALL SNOW FRIDAY NIGHT WEST OF ST LOUIS COUNTY. ON SATURDAY...WE WENT WITH ALL SNOW ACROSS NORTHEAST MINNESOTA AND KEPT A MIX ACROSS NORTHWEST WISCONSIN. && .DISCUSSION... DEEP SURFACE LOW OVER BUFFALO RIDGE IS BRINGING DEW POINTS IN THE 10C TO 13C RANGE NORTHWARD...ALONG WITH UNSEASONABLY WARM AIR UP ACROSS OUR AREA. THE LOW IS XPCD TO STALL OVER BUFFALO RIDGE INTO FRIDAY MORNING...AS THE UPPER TROUGH CATCHES UP TO IT AND CUTS OFF. THE UPPER LOW THAT STACKS OVER IT HAS NINE CLOSED CIRCLES WHICH REMOVES IT FROM THE PREVAILING FLOW AND SETS IT UP AS AN OMEGA BLOCK OF ITS VERY OWN. SURFACE PRESSURES FALLING TO AOB 990 MB WITH THE SORT OF WARM ADVECTION POURING INTO IT SETS IT UP FOR THIS BAROCLINIC-TYPE TRANSITIONING AND EVEOLUTION. SO WE LINGER THE WARM AIR OVER US...ALONG WITH THUNDER...RIGHT THROUGH THURSDAY AND WE MAY NEED TO EVENTUALLY PUSH THUNDER OUT FURTHER. DRAMATIC COOLING REMAINS WEST AND SOUTH OF THIS SYSTEM...AND WEST AND SOUTH OF OUR AREA. AGAIN...WE DON/T FEEL THAT THIS SYSTEM IS GOING TO BE VERY PROGRESSIVE AT ALL...SO WE AGREE WITH ALL THE MODELS PREFERENCE OF LAGGING EASTWARD OR NORTHWARD PROGRESSION OF COLD AIR. WE HOLD ANY CHANGE-OVER TO SNOW TO FRIDAY NIGHT...WHICH WILL BE DIFFICULT ANYWAY WITH THE WARMTH OF THE GROUND AND ESPECIALLY THE LAKE AND ALSO WITH THE LACK OF A TRUE INTRUSION OF ACTUALLY COLD CANADIAN AIR. WE DON/T GO TO ALL SNOW ACROSS ALL OF NORTHEAST MN UNTIL SATURDAY AND ACROSS NORTHWEST WISCONSIN UNTIL LATE SATURDAY. PRIND THE SYSTEM FINALLY BECOMES PROGRESSIVE ENOUGH TO START PULLING COLD AIR DOWN INTO OUR AREA AFTER THINGS BEGIN TO DRY OUT EARLY SUNDAY. WE WILL NEED TO EXAMINE THE 12Z EUROPEAN A LITTLE MORE TO GET A BETTER MODEL CONSENSUS ON WHEN THE COLD AIR BEGINS TO SETTLE INTO OUR AREA. && .PREV DISCUSSION... /ISSUED 359 AM CST WED NOV 5 2008/ DISCUSSION... INITIAL BAND OF ELEVATED CONVECTION... ASSOCIATED WITH LLJ IMPINGING ON EAST/WEST THERMAL BDRY...HAS SHIFTED NORTH OF CWA. CWA REMAINS UNDER INFLUENCE OF RRQ OF UPPER JET OVER ONTARIO EARLY THIS MORNING. LATEST RUC13 SHOWS MAGNITUDE OF LLJ IS DECREASING AS FIRST SHORTWAVE HAS MOVED NE OF AREA. 70/50 LAPSE RATES HAVE INCREASED TO 6/7C/KM SO INSTABILITY WILL NOW ALLOW ADDITIONAL GROWTH OF SPORADIC CONVECTION. TODAY/TONIGHT...MAJOR CHANGES UNDERWAY OVER WESTERN CONUS WITH AMPLIFICATION OF PROGRESSIVE UPPER TROF. INTENSIFICATION OF SFC LOW IS OCCURRING AS INITIAL 30H JET MAX SPREADS INTO PLAINS EARLY THIS MORNING. STRONGEST JET CORE ON WEST SIDE OF TROF SO AMPLIFICATION OF UPPER TROF WILL CONTINUE WITH EVENTUAL CLOSING/CAPTURING OF MID/SFC LOWS BY 12Z THUR OVER NEBRASKA VICINITY. THIS LEAVES NWRN CORNER OF CWA UNDERNEATH A DEVELOPING COUPLED JET TODAY WITH LEFT EXIT REGION OF PLAINS JET INTERACTING WITH RRQ OF ONTARIO JET CORE. AN AREA OF COOLING CLOUD TOPS IS OCCURRING JUST NW OF CWA AS LARGE SCALE ASCENT INCREASES. HAVE KEPT HIGHEST POPS OVER WRN CWA THROUGH 18Z...THEN SPREAD HIGHER POPS EAST TOWARDS TWIN PORTS THIS AFTERNOON. LATEST 4KM NMM/WRF SIM REFL PRODUCT SUGGESTS INCREASING CORRIDOR OF CONVECTION ALONG ST CROIX VALLEY TO NORTH SHORE. PRECIP SHOULD EXPAND TONIGHT AS AREA COMES UNDER INCREASING DIFFLUENCE OF MID LVL TROF. MARINE LAYER WILL DEEPEN ALONG SUPERIOR AS ONSHORE WINDS UNDERCUT WARM MOIST AIR ALOFT. THURSDAY...MID LVL CLOSED LOW DEEPENS AS MAIN JET CORE SWINGS OUT OF ROCKIES. WELL DEFINED DRY SLOT/TROWAL ROTATES NE TOWARDS CWA BY LATE IN THE DAY. MDLS HAVE TIMING DIFFERENCES SO TOUGH TO BE TOO SPECIFIC ON MAIN CONVEYOR BELT OF MSTR. WILL NEED TO MONITOR SVR POTENTIAL AS MDL SUGGESTS LOW CAPE/MDT 0-6KM BULK SHEAR ENVIRONMENT WILL DEVELOP. EXTENDED...FRID THRU SUN...FCST STILL RELATIVELY UNCHANGED WITH RAIN TO SNOW TRANSITION DEVELOPING FRIDAY ACROSS WRN CWA. SOME CONCERN THAT INTENSITY OF MID LVL LOW MAY PROMOTE ENOUGH COOLING OF DEEP LAYER THERMAL FIELD TO MIX SNOW WITH RAIN OVER PARTS OF SRN/SERN CWA EARLIER THAN EXPECTED. GIVEN UNCERTAINTY OF MID LVL PLACEMENT/STRENGTH WILL LEAVE JUST LIQUID FOR NOW. COLD AIR RUSHES IN FRIDAY EVENING ENSURING CHANGEOVER TO SNOW. SOME ACCUMULATION POSSIBLE AND WILL DETAIL IN LATER FCSTS. AVIATION... VFR CIGS WILL GRADUALLY GIVE WAY TO MVFR CIGS WITH THE ONSET OF THE NEXT ROUND OF PCPN LATER TODAY. VSBYS MAY OCCASIONALLY DROP INTO THE MVFR RANGE IN THE VICINITY OF TSRA. GUSTY SFC WINDS MAY ALSO ACCOMPANY THE STRONGER STORMS. && POINT TEMPS/POPS... DLH 61 53 56 41 / 70 80 80 60 INL 56 48 53 37 / 70 80 80 80 BRD 60 52 52 36 / 60 80 80 60 HYR 66 55 59 43 / 70 80 80 60 ASX 64 54 58 43 / 70 80 80 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ EOM/DAP mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 359 AM CST WED NOV 5 2008 .DISCUSSION... INITIAL BAND OF ELEVATED CONVECTION... ASSOCIATED WITH LLJ IMPINGING ON EAST/WEST THERMAL BDRY...HAS SHIFTED NORTH OF CWA. CWA REMAINS UNDER INFLUENCE OF RRQ OF UPPER JET OVER ONTARIO EARLY THIS MORNING. LATEST RUC13 SHOWS MAGNITUDE OF LLJ IS DECREASING AS FIRST SHORTWAVE HAS MOVED NE OF AREA. 70/50 LAPSE RATES HAVE INCREASED TO 6/7C/KM SO INSTABILITY WILL NOW ALLOW ADDITIONAL GROWTH OF SPORADIC CONVECTION. TODAY/TONIGHT...MAJOR CHANGES UNDERWAY OVER WESTERN CONUS WITH AMPLIFICATION OF PROGRESSIVE UPPER TROF. INTENSIFICATION OF SFC LOW IS OCCURRING AS INITIAL 30H JET MAX SPREADS INTO PLAINS EARLY THIS MORNING. STRONGEST JET CORE ON WEST SIDE OF TROF SO AMPLIFICATION OF UPPER TROF WILL CONTINUE WITH EVENTUAL CLOSING/CAPTURING OF MID/SFC LOWS BY 12Z THUR OVER NEBRASKA VICINITY. THIS LEAVES NWRN CORNER OF CWA UNDERNEATH A DEVELOPING COUPLED JET TODAY WITH LEFT EXIT REGION OF PLAINS JET INTERACTING WITH RRQ OF ONTARIO JET CORE. AN AREA OF COOLING CLOUD TOPS IS OCCURRING JUST NW OF CWA AS LARGE SCALE ASCENT INCREASES. HAVE KEPT HIGHEST POPS OVER WRN CWA THROUGH 18Z...THEN SPREAD HIGHER POPS EAST TOWARDS TWIN PORTS THIS AFTERNOON. LATEST 4KM NMM/WRF SIM REFL PRODUCT SUGGESTS INCREASING CORRIDOR OF CONVECTION ALONG ST CROIX VALLEY TO NORTH SHORE. PRECIP SHOULD EXPAND TONIGHT AS AREA COMES UNDER INCREASING DIFFLUENCE OF MID LVL TROF. MARINE LAYER WILL DEEPEN ALONG SUPERIOR AS ONSHORE WINDS UNDERCUT WARM MOIST AIR ALOFT. THURSDAY...MID LVL CLOSED LOW DEEPENS AS MAIN JET CORE SWINGS OUT OF ROCKIES. WELL DEFINED DRY SLOT/TROWAL ROTATES NE TOWARDS CWA BY LATE IN THE DAY. MDLS HAVE TIMING DIFFERENCES SO TOUGH TO BE TOO SPECIFIC ON MAIN CONVEYOR BELT OF MSTR. WILL NEED TO MONITOR SVR POTENTIAL AS MDL SUGGESTS LOW CAPE/MDT 0-6KM BULK SHEAR ENVIRONMENT WILL DEVELOP. EXTENDED...FRID THRU SUN...FCST STILL RELATIVELY UNCHANGED WITH RAIN TO SNOW TRANSITION DEVELOPING FRIDAY ACROSS WRN CWA. SOME CONCERN THAT INTENSITY OF MID LVL LOW MAY PROMOTE ENOUGH COOLING OF DEEP LAYER THERMAL FIELD TO MIX SNOW WITH RAIN OVER PARTS OF SRN/SERN CWA EARLIER THAN EXPECTED. GIVEN UNCERTAINTY OF MID LVL PLACEMENT/STRENGTH WILL LEAVE JUST LIQUID FOR NOW. COLD AIR RUSHES IN FRIDAY EVENING ENSURING CHANGEOVER TO SNOW. SOME ACCUMULATION POSSIBLE AND WILL DETAIL IN LATER FCSTS. && .AVIATION... VFR CIGS WILL GRADUALLY GIVE WAY TO MVFR CIGS WITH THE ONSET OF THE NEXT ROUND OF PCPN LATER TODAY. VSBYS MAY OCCASIONALLY DROP INTO THE MVFR RANGE IN THE VICINITY OF TSRA. GUSTY SFC WINDS MAY ALSO ACCOMPANY THE STRONGER STORMS. && POINT TEMPS/POPS... DLH 61 50 52 41 / 70 80 80 60 INL 56 48 48 37 / 70 80 80 70 BRD 63 51 51 36 / 70 80 80 60 HYR 65 53 57 41 / 50 80 80 60 ASX 64 51 57 43 / 50 80 80 60 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ CANNON/GSF mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 354 PM CST THU NOV 6 2008 .SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT. THE MSAS HAS A WEAK LOW OVER NORTH CENTRAL LOUISIANA. MODELS SHOW THE DISTURBANCE TRACKING ACROSS THE NORTHERN ZONES. THE LINE OF SHOWERS AND OCCASIONAL THUNDERSTORMS WAS STRUGGLING...BUT ISOLATED CELLS WERE STARTING TO DEVELOP ALONG AND AHEAD OF THE LINE...WILL MAINTAIN STRONG-SEVERE WORDING IN THE HWO. CLOUDS HAVE BEEN SLOW TO MOVE INTO THE SOUTHEAST...MAY STILL BE SOME BREAKS IN THE CLOUDS OVERNIGHT...SO LEFT MENTION OF PATCHY FOG IN THE HWO ALSO. THERE WAS ABOUT 25KTS OF SOUTHWESTERLY LOW AROUND 850MB. THE LLJ WAS NOT IMPRESSIVE...BUT SHOULD BE ENOUGH TO STEER ACTIVITY AND MAINTAIN THUNDERSTORMS THROUGH THE EVENING. IT WAS WARMEST ALONG THE RIVER...WITH TVR BEING AROUND 80. RUC ALSO HAS THE BETTER INSTABILITY ALONG THE RIVER. EXPECTING THERE TO BE MOSTLY RAIN AFTER SUNSET WITH THE LOSS OF HEATING. THE LINE DID SLOW DOWN TREMENDOUSLY...SO BELIEVE RAIN WILL BE LINGERING INTO THE AFTERNOON FOR THE EASTERN ZONES. ADDED SLIGHT CHANCE VALUES BACK TO THE METRO AREA ALSO. LATE FRIDAY NIGHT THROUGH SUNDAY...FAIR WEATHER RETURNS. IT SHOULD BE CLEAR AND COOL FOR THE WEEKEND. MADE A FEW ADJUSTMENTS TO GUIDANCE TEMPS. LOWERED VALUES SEVERAL DEGREES NEARLY EACH DAY OF THE SHORT TERM. LOOKING AT 850 TEMPS AND CLIMO...GUIDANCE SEEMED A LITTLE WARM. KEPT POPS FROM PREVIOUS FORECAST...NEW GUIDANCE VALUES WERE NOT DRAMATICALLY DIFFERENT. OVERALL...NO REAL CHANGES TO THE FORECAST. .LONG TERM...SUNDAY THROUGH THURSDAY. PREVIOUS DISCUSSION...CONDITIONS WILL BEGIN TO WARM AND SLIGHTLY MOISTEN ON MONDAY AS THE UPPER LEVEL PATTERN FLATTENS OUT AND THE LOW LEVEL FLOW BECOMES MORE FROM THE SOUTHEAST. CONFIDENCE IN HOW THE FORECAST WILL PAN OUT REALLY DROPS OFF AFTER MONDAY. BOTH THE GFS AND THE EUROPEAN ARE AT LEAST BRINGING OUR NEXT SYSTEM INTO THE FORECAST AREA ON TUESDAY. HOWEVER...THAT`S ABOUT THE ONLY AGREEMENT BETWEEN THE TWO. THE GFS IS THE MORE PROGRESSIVE OF THE TWO MODELS WITH PUSHING THE SURFACE LOW AND ASSOCIATED COLD FRONT THROUGH THE FORECAST AREA BY TUESDAY NIGHT AND ESSENTIALLY DRYING US OUT THROUGH MUCH OF WEDNESDAY. IT THEN BRINGS THE NEXT DISTURBANCE INTO AND THROUGH THE AREA THROUGH THE DAY THURSDAY. THE EUROPEAN ON THE OTHER HAND STALLS THE BOUNDARY ASSOCIATED WITH TUESDAY`S SYSTEM OVER THE CWA...THEN DEVELOPS AND SENDS A SERIES OF UPPER LEVEL DISTURBANCES THROUGH THE FORECAST WEDNESDAY AND AGAIN THURSDAY NIGHT. GIVEN THESE DISCREPANCIES IN THE MODELS DURING THE LATTER HALF OF THE FORECAST PERIOD...I`LL STICK CLOSE TO GUIDANCE NUMBERS. /19/ && .AVIATION...VFR CONDITIONS WILL PREVAIL AT JAN/GTR/MEI/PIB THROUGH MOST OF THE EVENING WITH CLOUD LAYERS GENERALLY ABOVE 4000 FEET. SCATTERED SHOWERS/TSTMS CONTAINING MVFR/IFR CIGS/VSBYS WILL AFFECT GLH TO GWO AS WE GO INTO THE LATE AFTN AND EVENING...THEN JAN/GTR AFTER 06Z...AND MEI AND PIB AFTER 09Z. VFR CONDITIONS WILL RETURN TO GLH/GWO/JAN FOR FRIDAY MORNING AS THE FRONT MOVES EWD WITH IFR TO MVFR CONDITIONS AND RAINFALL ENDING AT MEI AND PIB BY EARLY AFTERNOON. /EC/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 61 71 41 72 / 88 61 7 0 MERIDIAN 60 71 41 71 / 68 73 16 0 VICKSBURG 58 69 41 72 / 89 37 3 0 HATTIESBURG 63 74 46 73 / 40 71 17 0 NATCHEZ 59 69 42 73 / 89 58 3 0 GREENVILLE 55 67 40 68 / 80 11 4 0 GREENWOOD 57 67 40 67 / 89 29 4 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 7/EC ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 1022 AM CST THU NOV 6 2008 .UPDATE...A FEW SHOWERS WERE POPPING UP IN NORTHEAST LOUISIANA AND WESTERN MISSISSIPPI AHEAD OF THE APPROACHING COLD FRONT. ADJUSTED POPS TO INCLUDE THE SOUTHWEST ZONES THIS MORNING. OTHERWISE THE FORECAST WAS GOOD. AIR REMAINS PRETTY STABLE OVER THE CWA AT THIS TIME. HOWEVER...THUNDERSTORMS CONTINUE TO DEVELOP ALONG THE TAIL END OF THE LINE AND THE RUC SHOWS INSTABILITY ALONG AND JUST AHEAD OF THE BOUNDARY. WILL MAINTAIN ISOLATED SEVERE/STRONG WORDING THE HWO FOR THE WESTERN ZONES. && .AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THE AFTERNOON WITH CLOUD LAYERS GENERALLY ABOVE 4K FEET. INITIAL SHOWER DEVELOPMENT LATE THIS MORNING INTO THE EARLY AFTERNOON OVER NORTHEAST LOUISIANA AND SOUTHWEST MISSISSIPPI WILL MISS THE TAF SITES. LINE OF SHOWERS/TSTMS CONTAINING MVFR/IFR CIGS/VSBYS WILL AFFECT GLH AFTER 23Z...GWO AFTER 02Z...JAN AFTER 04Z...AND MEI AND PIB AFTER 06Z. VFR CONDITIONS WILL RETURN TO GLH/GWO/JAN FOR FRIDAY MORNING AS THE FRONT MOVES EWD WITH IFR TO MVFR CONDITIONS EXPECTED AT MEI AND PIB. /EC/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 80 59 67 44 / 35 88 61 12 MERIDIAN 80 57 68 40 / 13 68 73 23 VICKSBURG 80 57 68 44 / 55 89 37 9 HATTIESBURG 80 61 70 46 / 11 40 71 27 NATCHEZ 80 59 69 46 / 51 89 58 10 GREENVILLE 76 52 70 43 / 78 80 11 8 GREENWOOD 76 55 68 43 / 66 89 29 9 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 7/EC ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 410 AM CST THU NOV 6 2008 .DISCUSSION...TODAY THROUGH FRIDAY...SURFACE PRESSURE GRADIENT STARTING TO TIGHTEN UP OVER WRN PORTIONS OF CWFA WITH STRATUS EXPANDING ON LATEST LOW CLOUD SATELLITE IMAGERY. WE ALSO ARE SEEING LOW CLOUDS/FOG FORMING OVER SERN MS WHERE A FEW LOCATIONS GETTING SOCKED IN. WILL HANDLE THE FOG WITH NOWJAN BUT MAY NEED A DENSE FOG ADVSY IF CONDS SPREAD TOO MUCH. THESE AREAS SHOULD IMPROVE RATHER QUICKLY AFTER SUNRISE AS MIXING PICKS UP LEADING TO PARTLY CLOUDY CONDITIONS FOR MUCH OF TODAY AHEAD OF A MODERATE COLD FRONT HEADING OUR WAY. TEMPERATURES HAVE REMAINED QUITE MILD OVERNIGHT IN THE 45-60F RANGE AND WE SHOULD SEE WIDESPREAD MIDDLE 70S TO AROUND 80F AGAIN THIS AFTERNOON. THE DAYLIGHT HOURS BEING MUCH SHORTER NOW...ANY LINGERING CLOUDS OVER ONE AREA COULD INHIBIT READINGS FROM HEATING UP COMPLETELY. OTHERWISE...THERE SHOULD BE ENOUGH PERIODS OF SUNSHINE AHEAD OF SHRA/TSRA DEVELOPMENT. LOCAL WRF...GFS AND NAM12 RUNS BRING FIRST BATCH OF RAIN INTO NERN LA...SERN AR AND THE DELTA REGION BETWEEN 18-21Z. BEST 0-3KM VEERING WIND SHEAR CROSSES THE REGION THIS MORNING WITH DECREASING LOW LEVEL FLOW BY THE AFTERNOON HOURS. HOWEVER...THERE SHOULD BE ENOUGH MOISTURE(RUC DEWPOINTS APPEAR TO BE RUNNING TOO LOW AT THE MOMENT) AND INSTABILITY WITH POCKETS OF 300-600J/KG MLCAPES FOR NUMEROUS SHRA/SCATTERED TSRA TO DEVELOP IN THE PRE-FRONTAL CONVERGENCE ZONE. DEWPOINTS WILL APPROACH THE REACH LOWER TO MIDDLE 60S AS DEEPER MOISTURE WILL BE ON THE INCREASE BY MID AFTERNOON WITH PWATS NEAR 1.7 INCHES. THE BULK OF THE FRONTAL FORCING REMAINS TO OUR NW AND N DURING THE DAYLIGHT AND WIND FIELDS BECOME MORE UNIDIRECTIONAL THE LATER IN THE DAY WE GET. THE RISK FOR SEVERE WEATHER STILL REMAINS IN THE SLIGHT CATEGORY OR LOWER AND CONFINED TO THE NWRN THIRD OF THE CWFA AS LACKING INSTABILITY AND THE NIGHT TIME FRONTAL PASSAGE SEEMS TO KEEP THIS SYSTEM IN CHECK. WILL KEEP MENTION IN THE HWOJAN OF A FEW STRONG AND POSSIBLY A SVR STORM OR TWO JUST AHEAD OF THE FRONT. THE BEST TIMING FOR THIS WILL BE FROM ABOUT 20Z-02Z ACROSS THE NWRN PORTIONS. BY TONIGHT...THE SLOWING FRONT AND DIMINSHING INSTABILITY SHOULD YIELD A BAND OF SHRA/ISOLATED TSRA STEADILY CROSSING THE AREA FROM NW TO SE. THE MAIN AXIS OF PRECIPITATION SHOULD LIE ALONG THE NATCHEZ TRACE CORRIDOR BY ABOUT MIDNIGHT AND SHIFT TO THE SERN COUNTIES CLOSE TO DAYBREAK. QPF AMOUNTS OF ONE HALF TO ONE INCH APPEAR TO BE MOST LIKELY WITH THIS SYSTEM AS THE FRONT REACHES NEAR A MERIDIAN-BROOKHAVEN ARE BY 18Z FRIDAY. EXPECT BROKEN AREA OF SHRA/TSRA EARLY FRIDAY AFTERNOON OVER SERN MS WHILE CLEARING RETURNS TO THE DELTA REGION. RATHER WEAK CAA SHOULD PUT MOST HIGHS FRIDAY IN THE 65-70F RANGE. /40/ FRIDAY NIGHT THROUGH NEXT THURSDAY...THE COLD FRONT WILL CONTINUE TO EXIT THE FORECAST AREA TO THE EAST FRIDAY NIGHT. SOME LIGHT SHOWER ACTIVITY COULD HOLD ON ACROSS EAST AND SOUTHEAST MISSISSIPPI EARLY IN THE PERIOD...BUT BY MIDNIGHT ALL OF THE RAIN SHOULD BE OFF TO THE EAST AND OUT OF THE AREA. MEANWHILE...AS THE FRONT EXITS STAGE EAST...A COOLER DRIER AIRMASS WILL BEGIN TO FILTER INTO THE FORECAST AREA AS HIGH PRESSURE TO THE NORTHWEST BUILDS SOUTHEAST INTO THE LOWER MISSISSIPPI RIVER VALLEY. THIS WILL IN TURN PROVIDE US WITH VERY PLEASANT AUTUMN CONDITIONS THROUGHOUT THE UPCOMING WEEKEND. CONDITIONS WILL THEN BEGIN TO WARM AND SLIGHTLY MOISTEN ON MONDAY AS THE UPPER LEVEL PATTERN FLATTENS OUT AND THE LOW LEVEL FLOW BECOMES MORE FROM THE SOUTHEAST. CONFIDENCE IN HOW THE FORECAST WILL PAN OUT REALLY DROPS OFF AFTER MONDAY. BOTH THE GFS AND THE EUROPEAN ARE AT LEAST BRINGING OUR NEXT SYSTEM INTO THE FORECAST AREA ON TUESDAY. HOWEVER...THAT`S ABOUT THE ONLY AGREEMENT BETWEEN THE TWO. THE GFS IS THE MORE PROGRESSIVE OF THE TWO MODELS WITH PUSHING THE SURFACE LOW AND ASSOCIATED COLD FRONT THROUGH THE FORECAST AREA BY TUESDAY NIGHT AND ESSENTIALLY DRYING US OUT THROUGH MUCH OF WEDNESDAY. IT THEN BRINGS THE NEXT DISTURBANCE INTO AND THROUGH THE AREA THROUGH THE DAY THURSDAY. THE EUROPEAN ON THE OTHER HAND STALLS THE BOUNDARY ASSOCIATED WITH TUESDAY`S SYSTEM OVER THE CWA...THEN DEVELOPS AND SENDS A SERIES OF UPPER LEVEL DISTURBANCES THROUGH THE FORECAST WEDNESDAY AND AGAIN THURSDAY NIGHT. GIVEN THESE DISCREPANCIES IN THE MODELS DURING THE LATTER HALF OF THE FORECAST PERIOD...I`LL STICK CLOSE TO GUIDANCE NUMBERS. /19/ && .AVIATION...LOCATIONS ACROSS CNTRL...ERN...AND SERN MS WILL DEAL WITH PATCHY LIFR FOG/LOW CLOUDS BEFORE 14Z THIS MORNING. OTHERWISE INCREASING STRATUS DECK OF NEAR 2K FEET OVER WRN HALF OF THE CWFA WILL SPREAD EWD THROUGH MIDDAY. ONCE THE SUN IS UP FOR A FEW HRS EVERYONE SHOULD BE VFR BY 17Z WITH CLOUD LAYERS GENERALLY ABOVE 4K FEET UNTIL SCATTERED SHRA/TSRA DEVELOP 18-21Z W OF THE MS RIVER. THE PRECIPITATION SHOULD SPREAD EWD BY 00-03Z REACHING ABOUT THE NWRN HALF OF THE CWFA. MOST TAF LOCATIONS WILL DROP TO MVFR CEILINGS AND VSBYS BY 06Z TONIGHT LASTING THROUGH 18Z FRIDAY. /40/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 80 59 67 45 / 35 88 61 12 MERIDIAN 80 57 68 40 / 13 68 73 23 VICKSBURG 80 57 68 45 / 55 89 37 9 HATTIESBURG 80 61 70 46 / 11 40 71 27 NATCHEZ 80 59 69 46 / 51 89 58 10 GREENVILLE 76 52 70 44 / 78 80 11 8 GREENWOOD 76 55 68 44 / 66 89 29 9 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 40/19 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 1205 AM CST THU NOV 6 2008 .AVIATION...06Z KGRI TAF. A STRONG UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE IMPACTING THE CENTRAL PLAINS THROUGH THIS TAF PERIOD...BRINGING A ROUND OF MVFR CEILINGS...LIGHT PRECIPITATION...AND PLENTY OF WIND. ALTHOUGH CONFIDENCE IN THE TIMING OF THE ONSET OF LOW CEILINGS IS SOMEWHAT LOW...AN OVERCAST DECK BETWEEN 1K AND 3K FT SHOULD PREVAIL THROUGH MUCH OF THURSDAY AND THURSDAY EVENING. LIGHT RAIN/SNOW SHOWERS WRAPPING IN BEHIND THE UPPER LOW ARE ALSO LIKELY...ESPECIALLY FROM MID MORNING THROUGH MID AFTERNOON. SOME OF THIS PRECIPITATION COULD LINGER LATER INTO THE EVENING...BUT WILL DEFER TO LATER FORECASTS TO REFINE THIS MATTER. ONE CERTAINTY IS THAT STRONG WEST/NORTHWEST WINDS GUSTING TO OVER 35 KTS WILL BE AROUND FOR THE MAJORITY OF THE PERIOD. && .PREV DISCUSSION... /ISSUED 317 PM CST WED NOV 5 2008/ SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...COLD FRONT HAS SLIPPED EAST FASTER THAN EARLIER PREDICTED...THEREFORE PULLED THE RUG OUT FROM POPS IN THE EAST CWA. WRAP AROUND WILL EVENTUALLY WORK IN TONIGHT...THURSDAY AND LINGER THROUGH THURSDAY NIGHT. DOES NOT LOOK LIKE VERY MUCH PRECIPITATION AND SNOW AMOUNTS WILL BE LOW. MODELS WERE A BIT ALARMING FROM 06Z RUNS IN REGARD TO POSSIBLE WIND SPEEDS...BUT 12Z RUNS HAVE SHOWN ABOUT A 10 KT REDUCTION...FITTING MORE COMFORTABLY INTO A WIND ADVISORY SCENARIO FOR THURSDAY/THURSDAY NIGHT...INSTEAD OF A HIGH WIND WATCH. FOR PRECIPITATION CHANCES...LOOKS SIMILAR TO THE PREVIOUS FORECAST...BUT DID EXTEND LOW CHANCES A BIT FARTHER TO THE SOUTH. RE0RIENTED THE SNOW GRIDS A TAD. LOWERED TEMPERATURES A BIT MORE FOR THURSDAY HIGHS. HIGHS WILL NOT GO ANYWHERE ON THURSDAY WITH STRONG COLD AIR ADVECTION AND PLENTY OF SKY COVER. MAY BE TEMPORARY BOUTS OF REDUCED VISIBILITY WITH SCATTERED SNOW SHOWERS THURSDAY AND THURSDAY NIGHT...BUT FOR NOW IT DOES NOT LOOK LIKE IT WILL BE ENOUGH OF A FACTOR TO INTRODUCE A WINTER WEATHER PRODUCT AT THIS TIME. THE MAIN HAZARD WILL BE THE WIND FROM THE NORTHWEST. COULD BE A BIT STRONG EXTENDING INTO FRIDAY MORNING...BUT WE CAN VISIT THIS LATER AS WE BECOME MORE CONFIDENT. I TENDED TO LIKE THE RUC FOR THIS EVENING...THEN LEAN MORE TOWARD A NAM SCENARIO FOR THE PRECIP FIELD FOR THURSDAY INTO THURSDAY NIGHT. LONG TERM...FRIDAY THROUGH WEDNESDAY. THE CENTER OF THE POTENT UPPER LOW PRESSURE SYSTEM WILL BE LOCATED NEAR THE MINNESOTA AND IOWA BORDER ON FRIDAY MORNING. MODELS DIFFER ON WHETHER OR NOT WRAPAROUND SNOW SHOWERS OR FLURRIES WILL CONTINUE FRIDAY MORNING WITH THE GFS MORE ROBUST WITH THIS THAN THE NAM...BUT HAVE CONTINUED TO MENTION THE POTENTIAL IN OUR NORTHEAST CWA FOR THE MORNING. LITTLE IF ANY SNOW ACCUMULATION IS EXPECTED FRIDAY MORNING. WINDS WILL STILL REMAIN STRONG FROM THE NORTHWEST THROUGH AT LEAST THE FIRST HALF OF THE DAY IN A STILL TIGHT SURFACE GRADIENT...UNTIL THE SYSTEM LIFTS FARTHER TO THE NORTHEAST AND THE GRADIENT RELAXES. HIGH PRESSURE BUILDS IN BEHIND THE FRONT ON SATURDAY AND A COOL AIRMASS REMAINS IN PLACE. MODELS DIVERGE OVER THE WEEKEND AND INTO NEXT WEEK WITH THE NEXT COUPLE OF SYSTEMS. THE GFS BACKS IN COLDER AIR AND DEVELOPS A FRONTOGENETIC BAND OF PRECIPITATION POSSIBLY BEGINNING AS EARLY AS SATURDAY NIGHT...BUT MORE SO INTO THE SUNDAY PERIOD. THE GFS TEMPERATURE PROFILE IS MUCH COOLER THAN THE ECMWF AND SUGGESTS POTENTIAL FOR SOME SNOW. THE 00Z ECMWF DEVELOPS THE PCPN SATURDAY NIGHT TO OUR WEST IN THE HIGH PLAINS IN THE UPSLOPE FLOW CONDITIONS...WITH AN OVERALL WARMER/LIQUID TEMPERATURE PROFILE. THE GEM ALSO SUGGESTS THE POTENTIAL FOR PCPN ON SUNDAY AND FEEL BEST BET IS TO MAINTAIN THE STATUS QUO OF LOW POPS FOR NOW UNTIL MODELS COME INTO MORE AGREEMENT. AND NOW...THE 12Z ECMWF SOLUTION HAS COME AROUND TO MORE OF THE GFS/GEM SOLUTIONS...BUT HOLDS ONTO A WARMER TEMP PROFILE. ON MONDAY OF NEXT WEEK...A CLOSED LOW PRESSURE SYSTEM IS PROGGED TO MOVE EAST ALONG THE SOUTHERN TIER STATES AND LIFT ACROSS OKLAHOMA AND KANSAS THRU MONDAY NIGHT. THE ECMWF FAVORS A STRONGER SOLUTION VS THE GFS WHICH FILLS THE SYSTEM AS IT MOVES INTO THE PLAINS. THE GFS IS ALSO COLDER WITH ITS TEMP PROFILE SUGGESTING THE POTENTIAL FOR MIXED PCPN OR SNOW...WHEREAS THE ECMWF SUGGESTS MORE OF A RAINFALL EVENT. HAVE MAINTAINED POPS FOR MONDAY AND MONDAY NIGHT WITH THE INCREASING ISENTROPIC LIFT AND POTENTIAL FOR DEFORMATION PCPN. HAVE KEPT PCPN AS RAIN INITIALLY WITH A R/S MIX AS TEMPS COOL ON THE BACK SIDE OF THE SYSTEM MONDAY NIGHT. THE 12Z ECMWF NOW HAS A MORE SOUTHERN TRACK THAN ITS PREVIOUS RUN WHICH SUGGESTS EVEN LESSER OF A CHC FOR PCPN IN OUR CWA...BUT WILL NEED TO WATCH. THE FORECAST DRIES FOR THE TUESDAY AND WEDNESDAY PERIODS. OVERALL TEMPERATURES THROUGH THE EXTENDED HAVE SWUNG TOWARD THE COLDER DIRECTION WITH READINGS BELOW SEASONAL NORMALS. && .GID WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY FROM 6 AM THURSDAY TO 6 AM CST FRIDAY FOR NEZ039>041-046>049-060>064-072>077-082>087. KS...WIND ADVISORY FROM 6 AM THURSDAY TO 6 AM CST FRIDAY FOR KSZ005>007-017>019. && $$ AVIATION...PFANNKUCH ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 611 PM CST WED NOV 5 2008 .AVIATION...00Z TAF. KGRI AREA WILL BE INFLUENCED BY STRONG UPPER LEVEL LOW PRESSURE THROUGH THE FORECAST PERIOD...WITH MVFR CIGS AND VSBYS DEVELOPING BY THURSDAY MORNING AND CONTINUING THROUGH THE DAY. FEW SHOWERS WEST OF KEAR ATTM...APPEAR AS THOUGH THEY WON/T BE AN ISSUE FOR THE KGRI AREA THIS EVENING...SO I LEFT THE TAF DRY. KGRI AREA WILL EXPERIENCE VFR CIGS TONIGHT...BUT DO EXPECT LOWER MVFR CIGS TO SPREAD SOUTHEAST DURING THE DAY THURSDAY AS THE WRAP AROUND PRECIPITATION MOVES INTO THE AREA. STRONG WEST/NORTHWEST WINDS WILL BE STEADY TONIGHT...BUT PICK UP AGAIN BY MID MORNING THURSDAY AS SHOWERY PRECIPITATION OVERTAKES THE AREA. WINDS WILL RANGE FROM 25 TO 35KTS THROUGHOUT THE DAY. && .PREV DISCUSSION... /ISSUED 317 PM CST WED NOV 5 2008/ SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...COLD FRONT HAS SLIPPED EAST FASTER THAN EARLIER PREDICTED...THEREFORE PULLED THE RUG OUT FROM POPS IN THE EAST CWA. WRAP AROUND WILL EVENTUALLY WORK IN TONIGHT...THURSDAY AND LINGER THROUGH THURSDAY NIGHT. DOES NOT LOOK LIKE VERY MUCH PRECIPITATION AND SNOW AMOUNTS WILL BE LOW. MODELS WERE A BIT ALARMING FROM 06Z RUNS IN REGARD TO POSSIBLE WIND SPEEDS...BUT 12Z RUNS HAVE SHOWN ABOUT A 10 KT REDUCTION...FITTING MORE COMFORTABLY INTO A WIND ADVISORY SCENARIO FOR THURSDAY/THURSDAY NIGHT...INSTEAD OF A HIGH WIND WATCH. FOR PRECIPITATION CHANCES...LOOKS SIMILAR TO THE PREVIOUS FORECAST...BUT DID EXTEND LOW CHANCES A BIT FARTHER TO THE SOUTH. RE0RIENTED THE SNOW GRIDS A TAD. LOWERED TEMPERATURES A BIT MORE FOR THURSDAY HIGHS. HIGHS WILL NOT GO ANYWHERE ON THURSDAY WITH STRONG COLD AIR ADVECTION AND PLENTY OF SKY COVER. MAY BE TEMPORARY BOUTS OF REDUCED VISIBILITY WITH SCATTERED SNOW SHOWERS THURSDAY AND THURSDAY NIGHT...BUT FOR NOW IT DOES NOT LOOK LIKE IT WILL BE ENOUGH OF A FACTOR TO INTRODUCE A WINTER WEATHER PRODUCT AT THIS TIME. THE MAIN HAZARD WILL BE THE WIND FROM THE NORTHWEST. COULD BE A BIT STRONG EXTENDING INTO FRIDAY MORNING...BUT WE CAN VISIT THIS LATER AS WE BECOME MORE CONFIDENT. I TENDED TO LIKE THE RUC FOR THIS EVENING...THEN LEAN MORE TOWARD A NAM SCENARIO FOR THE PRECIP FIELD FOR THURSDAY INTO THURSDAY NIGHT. LONG TERM...FRIDAY THROUGH WEDNESDAY. THE CENTER OF THE POTENT UPPER LOW PRESSURE SYSTEM WILL BE LOCATED NEAR THE MINNESOTA AND IOWA BORDER ON FRIDAY MORNING. MODELS DIFFER ON WHETHER OR NOT WRAPAROUND SNOW SHOWERS OR FLURRIES WILL CONTINUE FRIDAY MORNING WITH THE GFS MORE ROBUST WITH THIS THAN THE NAM...BUT HAVE CONTINUED TO MENTION THE POTENTIAL IN OUR NORTHEAST CWA FOR THE MORNING. LITTLE IF ANY SNOW ACCUMULATION IS EXPECTED FRIDAY MORNING. WINDS WILL STILL REMAIN STRONG FROM THE NORTHWEST THROUGH AT LEAST THE FIRST HALF OF THE DAY IN A STILL TIGHT SURFACE GRADIENT...UNTIL THE SYSTEM LIFTS FARTHER TO THE NORTHEAST AND THE GRADIENT RELAXES. HIGH PRESSURE BUILDS IN BEHIND THE FRONT ON SATURDAY AND A COOL AIRMASS REMAINS IN PLACE. MODELS DIVERGE OVER THE WEEKEND AND INTO NEXT WEEK WITH THE NEXT COUPLE OF SYSTEMS. THE GFS BACKS IN COLDER AIR AND DEVELOPS A FRONTOGENETIC BAND OF PRECIPITATION POSSIBLY BEGINNING AS EARLY AS SATURDAY NIGHT...BUT MORE SO INTO THE SUNDAY PERIOD. THE GFS TEMPERATURE PROFILE IS MUCH COOLER THAN THE ECMWF AND SUGGESTS POTENTIAL FOR SOME SNOW. THE 00Z ECMWF DEVELOPS THE PCPN SATURDAY NIGHT TO OUR WEST IN THE HIGH PLAINS IN THE UPSLOPE FLOW CONDITIONS...WITH AN OVERALL WARMER/LIQUID TEMPERATURE PROFILE. THE GEM ALSO SUGGESTS THE POTENTIAL FOR PCPN ON SUNDAY AND FEEL BEST BET IS TO MAINTAIN THE STATUS QUO OF LOW POPS FOR NOW UNTIL MODELS COME INTO MORE AGREEMENT. AND NOW...THE 12Z ECMWF SOLUTION HAS COME AROUND TO MORE OF THE GFS/GEM SOLUTIONS...BUT HOLDS ONTO A WARMER TEMP PROFILE. ON MONDAY OF NEXT WEEK...A CLOSED LOW PRESSURE SYSTEM IS PROGGED TO MOVE EAST ALONG THE SOUTHERN TIER STATES AND LIFT ACROSS OKLAHOMA AND KANSAS THRU MONDAY NIGHT. THE ECMWF FAVORS A STRONGER SOLUTION VS THE GFS WHICH FILLS THE SYSTEM AS IT MOVES INTO THE PLAINS. THE GFS IS ALSO COLDER WITH ITS TEMP PROFILE SUGGESTING THE POTENTIAL FOR MIXED PCPN OR SNOW...WHEREAS THE ECMWF SUGGESTS MORE OF A RAINFALL EVENT. HAVE MAINTAINED POPS FOR MONDAY AND MONDAY NIGHT WITH THE INCREASING ISENTROPIC LIFT AND POTENTIAL FOR DEFORMATION PCPN. HAVE KEPT PCPN AS RAIN INITIALLY WITH A R/S MIX AS TEMPS COOL ON THE BACK SIDE OF THE SYSTEM MONDAY NIGHT. THE 12Z ECMWF NOW HAS A MORE SOUTHERN TRACK THAN ITS PREVIOUS RUN WHICH SUGGESTS EVEN LESSER OF A CHC FOR PCPN IN OUR CWA...BUT WILL NEED TO WATCH. THE FORECAST DRIES FOR THE TUESDAY AND WEDNESDAY PERIODS. OVERALL TEMPERATURES THROUGH THE EXTENDED HAVE SWUNG TOWARD THE COLDER DIRECTION WITH READINGS BELOW SEASONAL NORMALS. PREV DISCUSSION... /ISSUED 1246 PM CST WED NOV 5 2008/ AVIATION...18Z KGRI TAF. COLD FRONT IS IN THE PROCESS OF MOVING THROUGH THE AREA AND SHOULD KEEP THUNDERSTORM DEVELOPMENT OFF TO THE EAST OF THE TERMINAL. LOWER CEILINGS ASSOCIATED WITH WRAP AROUND MOISTURE LOOKS LIKE IT IS ON ITS WAY LATER ON THIS AFTERNOON/TONIGHT. MAY BE A REDUCTION IN VISIBILITY TO MVFR VERY LATE IN THE FORECAST IF PRECIPITATION PICKS UP A BIT MORE...BUT LEFT OUT OF THE FORECAST SINCE TIMING WOULD BE DIFFICULT. WIND SHOULD REACH ADVISORY LEVEL DURING THE MORNING OUT OF THE WEST NORTHWEST. PREV DISCUSSION... /ISSUED 412 AM CST WED NOV 5 2008/ DISCUSSION...DEFINITELY NOT A QUIET FORECAST FOR THE SHORT TERM PERIOD THROUGH FRIDAY...AS PRECIPITATION CHANCES MAKE A RETURN. THIS IS CAUSED BY AN UPPER LEVEL TROUGH/LOW PRESSURE SYSTEM...WHICH 00Z UPPER AIR OBSERVATION DATA AND CURRENT SATELLITE IMAGERY SHOW OVER THE ROCKIES. AHEAD OF THIS TROUGH AT THE SURFACE...CURRENT ANALYSIS SHOWS LOW PRESSURE/TROUGH DRAPED ACROSS THE HIGH PLAINS. AS EXPECTED...A FEW SHOWERS HAVE DEVELOPED IN ASSOCIATION WITH 40-55KT SOUTHERLY LOW LEVEL NOSING INTO THE AREA...AND HAVE STAYED TO THE NORTH/EAST OF THE CWA. LITTLE HAS CHANGED LOOKING INTO THE REST OF TODAY...AND MODELS ARE IN MUCH BETTER AGREEMENT THAN A FEW DAYS AGO. AS THE DAYTIME HOURS PASS...THE MAIN UPPER LEVEL SYSTEM BECOMES BETTER ORGANIZED AS IT SHIFTS EAST...AND BY THIS EVENING IS CENTERED OVER THE PANHANDLE OF NEBRASKA. MEANWHILE AT THE SURFACE...THE AREA OF LOW PRESSURE GETS PUSHED EAST ACROSS THE CWA...ALONG WITH ITS ACCOMPANYING COLD FRONT. AHEAD OF THIS FRONT...WHILE STILL BREEZY...SOUTHERLY WINDS EXPECTED TO STAY IN THE 15 TO 25 MPH RANGE. WITH THE FRONT PASSING THROUGH DURING THE AFTERNOON HOURS...THIS LEAVES A GRADIENT WITH HIGH TEMPERATURES ACROSS THE CWA...WITH WESTERN AREAS EXPECTED TO PEAK IN THE LOWER 60S...AND AREAS AHEAD OF THE FRONT IN THE EAST IN THE LOWER 70S. THE FRONT IS ALSO THE FOCUS FOR THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND EVENING...BUT UNCERTAINTIES REMAIN AS TO JUST HOW MUCH OF OUR CWA ACTUALLY SEES ANY ACTION. MODEL CONTINUE TO BE IN GOOD AGREEMENT SHOWING THE FRONT AT 00Z TONIGHT RIGHT ON THE EASTERN BORDER OF THE CWA. UPPED POPS A BIT...BUT DIDN/T EXPAND VERY FAR WEST...MAINLY AREAS EAST OF HIGHWAY 281. THERE CONTINUES TO BE THE POSSIBILITY THAT SOME THUNDERSTORMS MAY BECOME STRONG/SEVERE...AS MODELS SHOW GOOD SHEAR AND INSTABILITY NEAR 1000 J/KG. DURING THE EVENING HOURS...TAPERED BACK POPS A BIT AS ANYTHING THAT DEVELOPS IS EXPECTED TO QUICKLY MOVE OFF TO THE EAST. LOOKING TO OVERNIGHT TONIGHT THROUGH THURSDAY...ANY CHANCES OF PRECIPITATION THE CWA SEES WILL COME WITH ANY LINGERING SHOWERS/THUNDER EARLY ON...WITH THE SOURCE LATER TONIGHT AND INTO THURSDAY BEING WITH MOISTURE WRAPPING AROUND THE BACKSIDE OF THE LOW PRESSURE SYSTEM. MODELS IN GOOD AGREEMENT WITH THE PATH OF THE LOW...WHICH CROSSES THROUGH NORTHERN NEBRASKA. THIS PATH LIMITS THE AREAL EXTENT OF PRECIPITATION IN OUR CWA...WITH CHANCES DROPPING SIGNIFICANTLY HEADING SOUTH OF INTERSTATE 80. FELT INHERITED POPS HAD A GOOD HANDLE ON THE PROGRESSION AND ONLY MINOR ADJUSTMENTS WERE MADE. AS THE SYSTEM MOVES EAST...ALONG WITH MOISTURE GETTING PULLED SOUTH INTO THE CWA...SO DOES COLDER AIR. EVEN STARTING LATER TONIGHT/EARLY THURSDAY MORNING...NORTHERN AREAS COULD SEE A RAIN/SNOW MIX...WHICH WILL EXPAND A BIT FURTHER SOUTH DURING THE DAY AS MORE COLD ARE BUILDS IN. NOT EXPECTING SIGNIFICANT ACCUMULATIONS...AS BEST MOISTURE/FORCING REMAINS TO THE NORTH...BUT A DUSTING TO NEAR A HALF INCH IS POSSIBLE ACROSS NORTHERN AREAS. BIG CONCERN FOR THURSDAY LIES WITH WINDS. AS THE STORM SYSTEM SHIFTS EAST...NORTHWESTERLY WINDS ON THE BACKSIDE GET CRANKED UP AS THE PRESSURE GRADIENT TIGHTENS UP AND MIXING IMPROVES. HIGHEST WINDS LOOK TO REMAIN TO OUR WEST...BUT THERE LOOKS TO BE A GOOD CHANCE FOR SOLID ADV LEVEL WINDS...WITH GUSTS NEAR 50 MPH NOT OUT OF THE QUESTION. WITH THIS BEING IN THE THIRD PERIOD AND WITH AGREEMENT AMONG SURROUNDING OFFICES...WILL CONTINUE MENTION IN HWO AND LET DAY SHIFT GET ANOTHER MODEL RUN TO LOOK AT TO NAIL DOWN THE EXACT LOCATION/TIME. WITH THE STRONG WINDS...AND POSSIBILITY OF LIGHT SNOW...COULD CAUSE REDUCED VISIBILITIES IN THE NORTH. SNOW DOESN/T LOOK TO BE HEAVY ENOUGH AT THIS TIME TO CAUSE SIGNIFICANT PROBLEMS...BUT THE AREA WILL BE CLOSELY WATCHED. THINGS START TO REALLY WIND DOWN THURSDAY NIGHT...WITH LITTLE/NOTHING EXPECTED BY FRIDAY MORNING...WITH THE REST OF FRIDAY AND INTO THE FIRST PART OF THE WEEKEND REMAINING DRY. AS FAR AS TEMPERATURES GO...THUR/FRI HIGHS EXPECTED TO RANGE FROM RIGHT AROUND 40 NORTH TO NEAR 50 SOUTH...WITH SAT A DEGREE OR TWO WARMER. && .GID WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY FROM 6 AM THURSDAY TO 6 AM CST FRIDAY FOR NEZ039>041-046>049-060>064-072>077-082>087. KS...WIND ADVISORY FROM 6 AM THURSDAY TO 6 AM CST FRIDAY FOR KSZ005>007-017>019. && $$ ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HASTINGS NE 317 PM CST WED NOV 5 2008 .SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...COLD FRONT HAS SLIPPED EAST FASTER THAN EARLIER PREDICTED...THEREFORE PULLED THE RUG OUT FROM POPS IN THE EAST CWA. WRAP AROUND WILL EVENTUALLY WORK IN TONIGHT...THURSDAY AND LINGER THROUGH THURSDAY NIGHT. DOES NOT LOOK LIKE VERY MUCH PRECIPITATION AND SNOW AMOUNTS WILL BE LOW. MODELS WERE A BIT ALARMING FROM 06Z RUNS IN REGARD TO POSSIBLE WIND SPEEDS...BUT 12Z RUNS HAVE SHOWN ABOUT A 10 KT REDUCTION...FITTING MORE COMFORTABLY INTO A WIND ADVISORY SCENARIO FOR THURSDAY/THURSDAY NIGHT...INSTEAD OF A HIGH WIND WATCH. FOR PRECIPITATION CHANCES...LOOKS SIMILAR TO THE PREVIOUS FORECAST...BUT DID EXTEND LOW CHANCES A BIT FARTHER TO THE SOUTH. RE0RIENTED THE SNOW GRIDS A TAD. LOWERED TEMPERATURES A BIT MORE FOR THURSDAY HIGHS. HIGHS WILL NOT GO ANYWHERE ON THURSDAY WITH STRONG COLD AIR ADVECTION AND PLENTY OF SKY COVER. MAY BE TEMPORARY BOUTS OF REDUCED VISIBILITY WITH SCATTERED SNOW SHOWERS THURSDAY AND THURSDAY NIGHT...BUT FOR NOW IT DOES NOT LOOK LIKE IT WILL BE ENOUGH OF A FACTOR TO INTRODUCE A WINTER WEATHER PRODUCT AT THIS TIME. THE MAIN HAZARD WILL BE THE WIND FROM THE NORTHWEST. COULD BE A BIT STRONG EXTENDING INTO FRIDAY MORNING...BUT WE CAN VISIT THIS LATER AS WE BECOME MORE CONFIDENT. I TENDED TO LIKE THE RUC FOR THIS EVENING...THEN LEAN MORE TOWARD A NAM SCENARIO FOR THE PRECIP FIELD FOR THURSDAY INTO THURSDAY NIGHT. .LONG TERM...FRIDAY THROUGH WEDNESDAY. THE CENTER OF THE POTENT UPPER LOW PRESSURE SYSTEM WILL BE LOCATED NEAR THE MINNESOTA AND IOWA BORDER ON FRIDAY MORNING. MODELS DIFFER ON WHETHER OR NOT WRAPAROUND SNOW SHOWERS OR FLURRIES WILL CONTINUE FRIDAY MORNING WITH THE GFS MORE ROBUST WITH THIS THAN THE NAM...BUT HAVE CONTINUED TO MENTION THE POTENTIAL IN OUR NORTHEAST CWA FOR THE MORNING. LITTLE IF ANY SNOW ACCUMULATION IS EXPECTED FRIDAY MORNING. WINDS WILL STILL REMAIN STRONG FROM THE NORTHWEST THROUGH AT LEAST THE FIRST HALF OF THE DAY IN A STILL TIGHT SURFACE GRADIENT...UNTIL THE SYSTEM LIFTS FARTHER TO THE NORTHEAST AND THE GRADIENT RELAXES. HIGH PRESSURE BUILDS IN BEHIND THE FRONT ON SATURDAY AND A COOL AIRMASS REMAINS IN PLACE. MODELS DIVERGE OVER THE WEEKEND AND INTO NEXT WEEK WITH THE NEXT COUPLE OF SYSTEMS. THE GFS BACKS IN COLDER AIR AND DEVELOPS A FRONTOGENETIC BAND OF PRECIPITATION POSSIBLY BEGINNING AS EARLY AS SATURDAY NIGHT...BUT MORE SO INTO THE SUNDAY PERIOD. THE GFS TEMPERATURE PROFILE IS MUCH COOLER THAN THE ECMWF AND SUGGESTS POTENTIAL FOR SOME SNOW. THE 00Z ECMWF DEVELOPS THE PCPN SATURDAY NIGHT TO OUR WEST IN THE HIGH PLAINS IN THE UPSLOPE FLOW CONDITIONS...WITH AN OVERALL WARMER/LIQUID TEMPERATURE PROFILE. THE GEM ALSO SUGGESTS THE POTENTIAL FOR PCPN ON SUNDAY AND FEEL BEST BET IS TO MAINTAIN THE STATUS QUO OF LOW POPS FOR NOW UNTIL MODELS COME INTO MORE AGREEMENT. AND NOW...THE 12Z ECMWF SOLUTION HAS COME AROUND TO MORE OF THE GFS/GEM SOLUTIONS...BUT HOLDS ONTO A WARMER TEMP PROFILE. ON MONDAY OF NEXT WEEK...A CLOSED LOW PRESSURE SYSTEM IS PROGGED TO MOVE EAST ALONG THE SOUTHERN TIER STATES AND LIFT ACROSS OKLAHOMA AND KANSAS THRU MONDAY NIGHT. THE ECMWF FAVORS A STRONGER SOLUTION VS THE GFS WHICH FILLS THE SYSTEM AS IT MOVES INTO THE PLAINS. THE GFS IS ALSO COLDER WITH ITS TEMP PROFILE SUGGESTING THE POTENTIAL FOR MIXED PCPN OR SNOW...WHEREAS THE ECMWF SUGGESTS MORE OF A RAINFALL EVENT. HAVE MAINTAINED POPS FOR MONDAY AND MONDAY NIGHT WITH THE INCREASING ISENTROPIC LIFT AND POTENTIAL FOR DEFORMATION PCPN. HAVE KEPT PCPN AS RAIN INITIALLY WITH A R/S MIX AS TEMPS COOL ON THE BACK SIDE OF THE SYSTEM MONDAY NIGHT. THE 12Z ECMWF NOW HAS A MORE SOUTHERN TRACK THAN ITS PREVIOUS RUN WHICH SUGGESTS EVEN LESSER OF A CHC FOR PCPN IN OUR CWA...BUT WILL NEED TO WATCH. THE FORECAST DRIES FOR THE TUESDAY AND WEDNESDAY PERIODS. OVERALL TEMPERATURES THROUGH THE EXTENDED HAVE SWUNG TOWARD THE COLDER DIRECTION WITH READINGS BELOW SEASONAL NORMALS. && .PREV DISCUSSION... /ISSUED 1246 PM CST WED NOV 5 2008/ AVIATION...18Z KGRI TAF. COLD FRONT IS IN THE PROCESS OF MOVING THROUGH THE AREA AND SHOULD KEEP THUNDERSTORM DEVELOPMENT OFF TO THE EAST OF THE TERMINAL. LOWER CEILINGS ASSOCIATED WITH WRAP AROUND MOISTURE LOOKS LIKE IT IS ON ITS WAY LATER ON THIS AFTERNOON/TONIGHT. MAY BE A REDUCTION IN VISIBILITY TO MVFR VERY LATE IN THE FORECAST IF PRECIPITATION PICKS UP A BIT MORE...BUT LEFT OUT OF THE FORECAST SINCE TIMING WOULD BE DIFFICULT. WIND SHOULD REACH ADVISORY LEVEL DURING THE MORNING OUT OF THE WEST NORTHWEST. PREV DISCUSSION... /ISSUED 412 AM CST WED NOV 5 2008/ DISCUSSION...DEFINITELY NOT A QUIET FORECAST FOR THE SHORT TERM PERIOD THROUGH FRIDAY...AS PRECIPITATION CHANCES MAKE A RETURN. THIS IS CAUSED BY AN UPPER LEVEL TROUGH/LOW PRESSURE SYSTEM...WHICH 00Z UPPER AIR OBSERVATION DATA AND CURRENT SATELLITE IMAGERY SHOW OVER THE ROCKIES. AHEAD OF THIS TROUGH AT THE SURFACE...CURRENT ANALYSIS SHOWS LOW PRESSURE/TROUGH DRAPED ACROSS THE HIGH PLAINS. AS EXPECTED...A FEW SHOWERS HAVE DEVELOPED IN ASSOCIATION WITH 40-55KT SOUTHERLY LOW LEVEL NOSING INTO THE AREA...AND HAVE STAYED TO THE NORTH/EAST OF THE CWA. LITTLE HAS CHANGED LOOKING INTO THE REST OF TODAY...AND MODELS ARE IN MUCH BETTER AGREEMENT THAN A FEW DAYS AGO. AS THE DAYTIME HOURS PASS...THE MAIN UPPER LEVEL SYSTEM BECOMES BETTER ORGANIZED AS IT SHIFTS EAST...AND BY THIS EVENING IS CENTERED OVER THE PANHANDLE OF NEBRASKA. MEANWHILE AT THE SURFACE...THE AREA OF LOW PRESSURE GETS PUSHED EAST ACROSS THE CWA...ALONG WITH ITS ACCOMPANYING COLD FRONT. AHEAD OF THIS FRONT...WHILE STILL BREEZY...SOUTHERLY WINDS EXPECTED TO STAY IN THE 15 TO 25 MPH RANGE. WITH THE FRONT PASSING THROUGH DURING THE AFTERNOON HOURS...THIS LEAVES A GRADIENT WITH HIGH TEMPERATURES ACROSS THE CWA...WITH WESTERN AREAS EXPECTED TO PEAK IN THE LOWER 60S...AND AREAS AHEAD OF THE FRONT IN THE EAST IN THE LOWER 70S. THE FRONT IS ALSO THE FOCUS FOR THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND EVENING...BUT UNCERTAINTIES REMAIN AS TO JUST HOW MUCH OF OUR CWA ACTUALLY SEES ANY ACTION. MODEL CONTINUE TO BE IN GOOD AGREEMENT SHOWING THE FRONT AT 00Z TONIGHT RIGHT ON THE EASTERN BORDER OF THE CWA. UPPED POPS A BIT...BUT DIDN/T EXPAND VERY FAR WEST...MAINLY AREAS EAST OF HIGHWAY 281. THERE CONTINUES TO BE THE POSSIBILITY THAT SOME THUNDERSTORMS MAY BECOME STRONG/SEVERE...AS MODELS SHOW GOOD SHEAR AND INSTABILITY NEAR 1000 J/KG. DURING THE EVENING HOURS...TAPERED BACK POPS A BIT AS ANYTHING THAT DEVELOPS IS EXPECTED TO QUICKLY MOVE OFF TO THE EAST. LOOKING TO OVERNIGHT TONIGHT THROUGH THURSDAY...ANY CHANCES OF PRECIPITATION THE CWA SEES WILL COME WITH ANY LINGERING SHOWERS/THUNDER EARLY ON...WITH THE SOURCE LATER TONIGHT AND INTO THURSDAY BEING WITH MOISTURE WRAPPING AROUND THE BACKSIDE OF THE LOW PRESSURE SYSTEM. MODELS IN GOOD AGREEMENT WITH THE PATH OF THE LOW...WHICH CROSSES THROUGH NORTHERN NEBRASKA. THIS PATH LIMITS THE AREAL EXTENT OF PRECIPITATION IN OUR CWA...WITH CHANCES DROPPING SIGNIFICANTLY HEADING SOUTH OF INTERSTATE 80. FELT INHERITED POPS HAD A GOOD HANDLE ON THE PROGRESSION AND ONLY MINOR ADJUSTMENTS WERE MADE. AS THE SYSTEM MOVES EAST...ALONG WITH MOISTURE GETTING PULLED SOUTH INTO THE CWA...SO DOES COLDER AIR. EVEN STARTING LATER TONIGHT/EARLY THURSDAY MORNING...NORTHERN AREAS COULD SEE A RAIN/SNOW MIX...WHICH WILL EXPAND A BIT FURTHER SOUTH DURING THE DAY AS MORE COLD ARE BUILDS IN. NOT EXPECTING SIGNIFICANT ACCUMULATIONS...AS BEST MOISTURE/FORCING REMAINS TO THE NORTH...BUT A DUSTING TO NEAR A HALF INCH IS POSSIBLE ACROSS NORTHERN AREAS. BIG CONCERN FOR THURSDAY LIES WITH WINDS. AS THE STORM SYSTEM SHIFTS EAST...NORTHWESTERLY WINDS ON THE BACKSIDE GET CRANKED UP AS THE PRESSURE GRADIENT TIGHTENS UP AND MIXING IMPROVES. HIGHEST WINDS LOOK TO REMAIN TO OUR WEST...BUT THERE LOOKS TO BE A GOOD CHANCE FOR SOLID ADV LEVEL WINDS...WITH GUSTS NEAR 50 MPH NOT OUT OF THE QUESTION. WITH THIS BEING IN THE THIRD PERIOD AND WITH AGREEMENT AMONG SURROUNDING OFFICES...WILL CONTINUE MENTION IN HWO AND LET DAY SHIFT GET ANOTHER MODEL RUN TO LOOK AT TO NAIL DOWN THE EXACT LOCATION/TIME. WITH THE STRONG WINDS...AND POSSIBILITY OF LIGHT SNOW...COULD CAUSE REDUCED VISIBILITIES IN THE NORTH. SNOW DOESN/T LOOK TO BE HEAVY ENOUGH AT THIS TIME TO CAUSE SIGNIFICANT PROBLEMS...BUT THE AREA WILL BE CLOSELY WATCHED. THINGS START TO REALLY WIND DOWN THURSDAY NIGHT...WITH LITTLE/NOTHING EXPECTED BY FRIDAY MORNING...WITH THE REST OF FRIDAY AND INTO THE FIRST PART OF THE WEEKEND REMAINING DRY. AS FAR AS TEMPERATURES GO...THUR/FRI HIGHS EXPECTED TO RANGE FROM RIGHT AROUND 40 NORTH TO NEAR 50 SOUTH...WITH SAT A DEGREE OR TWO WARMER. && .GID WATCHES/WARNINGS/ADVISORIES... NE...WIND ADVISORY FROM 6 AM THURSDAY TO 6 AM CST FRIDAY FOR NEZ039>041-046>049-060>064-072>077-082>087. KS...WIND ADVISORY FROM 6 AM THURSDAY TO 6 AM CST FRIDAY FOR KSZ005>007-017>019. && $$ HEINLEIN/FAY ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 144 PM CST WED NOV 5 2008 .UPDATE... SENT EARLY AFTERNOON UPDATE TO ACCOUNT FOR SFC LOW FARTHERN NORTH AND DRIER AIR INTO THE NW CWA AND WARMER TEMPS THERE. && .DISCUSSION... 18Z SOUNDING IS IN AN SHOWS A STRONG CAPPING INVERSION AT 822MB. THIS CAP IS FCST TO WEAKEN AS WE HEAD TOWARD THE SECOND HALF OF THE AFTERNOON. WHILE THE WRN CWA WILL BEGIN TO SEE THE DRIER DEWPOINTS PUSH IN...THERE WILL BE A WINDOW FOR STORMS TO FORM BEFORE THE DRIER AIR MOVES IN. THE GREATER RISK FOR SVR WX CONTINUES TO BE OVR KS AND OK...HOWEVER...SVR WX IS STILL POSSIBLE OVR ERN NEB AND WRN IA UNTIL THAT MOISTURE IS PUSHED EAST. && .PREV DISCUSSION... /ISSUED 1058 AM CST WED NOV 5 2008/ UPDATE... UPDATED GRIDS AND PRODUCTS FOR LATEST RADAR TREND AND FORECAST CONDITIONS. DISCUSSION... LATEST SFC ANALYSIS HAS THE CNTR OF LOW PRES OVR SCNTRL SD WITH A SECONDARY AREA OF LOW PRES FM SW KS INTO SE CO. SHOWERS HAVE BEEN NOTED ON RADAR OVR PARTS OF ERN NEB AND SW IA. SFC DEWPOINTS ARE IN THE 50S. WITH DEEPER MOISTURE IN PLACE AHEAD OF THE SFC FRONT AND CONTINUED H7 WAA ISO TO SCT SHOWER AND TSRA ACTIVITY WILL CONTINUE. AS A STRONG UPR LEVEL JET SWINGS THRU ALONG WITH INCREASED MID LEVEL DYNAMICS AND DESTABILIZATION...THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AHEAD OF THE CDFNT THIS AFTERNOON AND THIS EVENING. SWODY1 STILL HAS US IN THE SLIGHT RISK FOR SVR STORMS WITH SUPERCELLS MORE LIKELY IN KS AND MORE LINEAR DEVELOPMENT WITH THE FNT FOR ERN NEB AND SW IA. WILL CONTINUE TO MONITOR THIS AFTERNOON DUE TO HIGH SHEAR ENVIRONMENT AND CONTINUED DESTABILIZATION. PREV DISCUSSION... /ISSUED 246 AM CST WED NOV 5 2008/ DISCUSSION... TIMING AND EXTENT OF CONVECTION TODAY WILL BE THE MAIN CONCERN INITIALLY... THEN TEMPERATURES AND PRECIP TRANSITION LATE TONIGHT INTO FRIDAY. NARROW BAND OF ELEVATED CONVECTION HAD DEVELOPED OVER THE SOUTHEAST CORNER OF THE CWA AFTER MIDNIGHT AND WAS MOVING OUT OF THE SW CORNER OF IOWA AT 08Z. THIS AREA CORRELATES WELL WITH MID LEVEL INSTABILITY POCKET SHOWN BY 06Z RUC WHICH CONTINUES TO SHIFT EAST OF THE AREA INTO CENTRAL IOWA THROUGH 12Z. LATEST MODEL DATA SUGGEST CONVECTION MAY BE SLOW TO START IN THE AREA TODAY WITH FORECAST SOUNDINGS FROM THE GFS...NAM AND RUC EACH SHOWING PROMINANT CAP IN PLACE THRU 18Z AND LIMITED INSTABILITY IN THE MID LEVELS ABOVE THE CAP. POPS ON THE LOW END FOR THIS TIME PERIOD AS A RESULT. CAP ERODES DURING THE AFTERNOON WITH THE APPROACH OF THE FRONT BUT CAPE VALUES FROM FORECAST SOUNDINGS NOT THAT IMPRESSIVE. WILL CONTINUE TO CARRY BEST POPS FOR STORMS FROM THE AFTERNOON INTO THE EVENING IN ASSOCIATION WITH THE FRONTAL PASSAGE. COLD AIR SURGES IN BEHIND THE FRONT TONIGHT WITH AREA DRY SLOTTED FOR A TIME BEFORE THE WRAP AROUND PRECIP MOVES IN. MODELS VARY IN THEIR DEPICTION OF THE SOUTHERN EXTENT OF PRECIP SO HAVE CONTINUED WITH A NORTH SOUTH GRADIENT FOR POPS ON THURSDAY INTO EARLY FRIDAY. SOME LIGHT SNOW ACCUMULATION UP TO AN INCH INDICATED ACROSS NORTHERN PARTS OF THE CWA IN NORTHEAST NEBRASKA BEFORE ENDING FRIDAY AFTERNOON. EXPECT WINDS TODAY TO STAY BELOW ADVISORY LEVELS BASED ON FORECAST SOUNDINGS BUT MORE STRONG WINDS BEHIND THE FRONT ON THURSDAY WILL HAVE TO BE CONSIDERED IN LATER FORECASTS. NO CHANGES TO THE EXTENDED PERIOD AT THIS TIME. AVIATION... FOR TAF SITES KOFK/KOMA/KLNK THROUGH 06/12Z. MAINLY VFR CONDITIONS EXPECTED THROUGH WEDNESDAY AFTERNOON WITH STRONG SOUTH WINDS OF 15 TO 30KTS. LOW LEVEL WIND SHEAR IS ALSO LIKELY THROUGH 15Z AS 2000FT WINDS AVERAGE 50KTS. SCATTERED SHOWERS OR THUNDERSTORMS ARE POSSIBLE THROUGH 00Z...BUT MORE FOCUSED CHANCES WILL COME BETWEEN 00Z AND 06Z AS A COLD FRONT PUSHES THROUGH EASTERN NEBRASKA. ASSOCIATED MVFR/IFR CIGS/VSBYS IN THUNDERSTORMS SHOULD BE REPLACED BY VFR CIGS AFTER 06Z AS SURFACE WINDS BECOME WESTERLY AFTER FRONTAL PASSAGE. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ ZAPOTOCNY ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 1058 AM CST WED NOV 5 2008 .UPDATE... UPDATED GRIDS AND PRODUCTS FOR LATEST RADAR TREND AND FORECAST CONDITIONS. && .DISCUSSION... LATEST SFC ANALYSIS HAS THE CNTR OF LOW PRES OVR SCNTRL SD WITH A SECONDARY AREA OF LOW PRES FM SW KS INTO SE CO. SHOWERS HAVE BEEN NOTED ON RADAR OVR PARTS OF ERN NEB AND SW IA. SFC DEWPOINTS ARE IN THE 50S. WITH DEEPER MOISTURE IN PLACE AHEAD OF THE SFC FRONT AND CONTINUED H7 WAA ISO TO SCT SHOWER AND TSRA ACTIVITY WILL CONTINUE. AS A STRONG UPR LEVEL JET SWINGS THRU ALONG WITH INCREASED MID LEVEL DYNAMICS AND DESTABILIZATION...THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AHEAD OF THE CDFNT THIS AFTERNOON AND THIS EVENING. SWODY1 STILL HAS US IN THE SLIGHT RISK FOR SVR STORMS WITH SUPERCELLS MORE LIKELY IN KS AND MORE LINEAR DEVELOPMENT WITH THE FNT FOR ERN NEB AND SW IA. WILL CONTINUE TO MONITOR THIS AFTERNOON DUE TO HIGH SHEAR ENVIRONMENT AND CONTINUED DESTABILIZATION. && .PREV DISCUSSION... /ISSUED 246 AM CST WED NOV 5 2008/ DISCUSSION... TIMING AND EXTENT OF CONVECTION TODAY WILL BE THE MAIN CONCERN INITIALLY... THEN TEMPERATURES AND PRECIP TRANSITION LATE TONIGHT INTO FRIDAY. NARROW BAND OF ELEVATED CONVECTION HAD DEVELOPED OVER THE SOUTHEAST CORNER OF THE CWA AFTER MIDNIGHT AND WAS MOVING OUT OF THE SW CORNER OF IOWA AT 08Z. THIS AREA CORRELATES WELL WITH MID LEVEL INSTABILITY POCKET SHOWN BY 06Z RUC WHICH CONTINUES TO SHIFT EAST OF THE AREA INTO CENTRAL IOWA THROUGH 12Z. LATEST MODEL DATA SUGGEST CONVECTION MAY BE SLOW TO START IN THE AREA TODAY WITH FORECAST SOUNDINGS FROM THE GFS...NAM AND RUC EACH SHOWING PROMINANT CAP IN PLACE THRU 18Z AND LIMITED INSTABILITY IN THE MID LEVELS ABOVE THE CAP. POPS ON THE LOW END FOR THIS TIME PERIOD AS A RESULT. CAP ERODES DURING THE AFTERNOON WITH THE APPROACH OF THE FRONT BUT CAPE VALUES FROM FORECAST SOUNDINGS NOT THAT IMPRESSIVE. WILL CONTINUE TO CARRY BEST POPS FOR STORMS FROM THE AFTERNOON INTO THE EVENING IN ASSOCIATION WITH THE FRONTAL PASSAGE. COLD AIR SURGES IN BEHIND THE FRONT TONIGHT WITH AREA DRY SLOTTED FOR A TIME BEFORE THE WRAP AROUND PRECIP MOVES IN. MODELS VARY IN THEIR DEPICTION OF THE SOUTHERN EXTENT OF PRECIP SO HAVE CONTINUED WITH A NORTH SOUTH GRADIENT FOR POPS ON THURSDAY INTO EARLY FRIDAY. SOME LIGHT SNOW ACCUMULATION UP TO AN INCH INDICATED ACROSS NORTHERN PARTS OF THE CWA IN NORTHEAST NEBRASKA BEFORE ENDING FRIDAY AFTERNOON. EXPECT WINDS TODAY TO STAY BELOW ADVISORY LEVELS BASED ON FORECAST SOUNDINGS BUT MORE STRONG WINDS BEHIND THE FRONT ON THURSDAY WILL HAVE TO BE CONSIDERED IN LATER FORECASTS. NO CHANGES TO THE EXTENDED PERIOD AT THIS TIME. AVIATION... FOR TAF SITES KOFK/KOMA/KLNK THROUGH 06/12Z. MAINLY VFR CONDITIONS EXPECTED THROUGH WEDNESDAY AFTERNOON WITH STRONG SOUTH WINDS OF 15 TO 30KTS. LOW LEVEL WIND SHEAR IS ALSO LIKELY THROUGH 15Z AS 2000FT WINDS AVERAGE 50KTS. SCATTERED SHOWERS OR THUNDERSTORMS ARE POSSIBLE THROUGH 00Z...BUT MORE FOCUSED CHANCES WILL COME BETWEEN 00Z AND 06Z AS A COLD FRONT PUSHES THROUGH EASTERN NEBRASKA. ASSOCIATED MVFR/IFR CIGS/VSBYS IN THUNDERSTORMS SHOULD BE REPLACED BY VFR CIGS AFTER 06Z AS SURFACE WINDS BECOME WESTERLY AFTER FRONTAL PASSAGE. FOBERT/DERGAN && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ ZAPOTOCNY ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 246 AM CST WED NOV 5 2008 .DISCUSSION... TIMING AND EXTENT OF CONVECTION TODAY WILL BE THE MAIN CONCERN INITIALLY... THEN TEMPERATURES AND PRECIP TRANSITION LATE TONIGHT INTO FRIDAY. NARROW BAND OF ELEVATED CONVECTION HAD DEVELOPED OVER THE SOUTHEAST CORNER OF THE CWA AFTER MIDNIGHT AND WAS MOVING OUT OF THE SW CORNER OF IOWA AT 08Z. THIS AREA CORRELATES WELL WITH MID LEVEL INSTABILITY POCKET SHOWN BY 06Z RUC WHICH CONTINUES TO SHIFT EAST OF THE AREA INTO CENTRAL IOWA THROUGH 12Z. LATEST MODEL DATA SUGGEST CONVECTION MAY BE SLOW TO START IN THE AREA TODAY WITH FORECAST SOUNDINGS FROM THE GFS...NAM AND RUC EACH SHOWING PROMINANT CAP IN PLACE THRU 18Z AND LIMITED INSTABILITY IN THE MID LEVELS ABOVE THE CAP. POPS ON THE LOW END FOR THIS TIME PERIOD AS A RESULT. CAP ERODES DURING THE AFTERNOON WITH THE APPROACH OF THE FRONT BUT CAPE VALUES FROM FORECAST SOUNDINGS NOT THAT IMPRESSIVE. WILL CONTINUE TO CARRY BEST POPS FOR STORMS FROM THE AFTERNOON INTO THE EVENING IN ASSOCIATION WITH THE FRONTAL PASSAGE. COLD AIR SURGES IN BEHIND THE FRONT TONIGHT WITH AREA DRY SLOTTED FOR A TIME BEFORE THE WRAP AROUND PRECIP MOVES IN. MODELS VARY IN THEIR DEPICTION OF THE SOUTHERN EXTENT OF PRECIP SO HAVE CONTINUED WITH A NORTH SOUTH GRADIENT FOR POPS ON THURSDAY INTO EARLY FRIDAY. SOME LIGHT SNOW ACCUMULATION UP TO AN INCH INDICATED ACROSS NORTHERN PARTS OF THE CWA IN NORTHEAST NEBRASKA BEFORE ENDING FRIDAY AFTERNOON. EXPECT WINDS TODAY TO STAY BELOW ADVISORY LEVELS BASED ON FORECAST SOUNDINGS BUT MORE STRONG WINDS BEHIND THE FRONT ON THURSDAY WILL HAVE TO BE CONSIDERED IN LATER FORECASTS. NO CHANGES TO THE EXTENDED PERIOD AT THIS TIME. && .AVIATION... FOR TAF SITES KOFK/KOMA/KLNK THROUGH 06/12Z. MAINLY VFR CONDITIONS EXPECTED THROUGH WEDNESDAY AFTERNOON WITH STRONG SOUTH WINDS OF 15 TO 30KTS. LOW LEVEL WIND SHEAR IS ALSO LIKELY THROUGH 15Z AS 2000FT WINDS AVERAGE 50KTS. SCATTERED SHOWERS OR THUNDERSTORMS ARE POSSIBLE THROUGH 00Z...BUT MORE FOCUSED CHANCES WILL COME BETWEEN 00Z AND 06Z AS A COLD FRONT PUSHES THROUGH EASTERN NEBRASKA. ASSOCIATED MVFR/IFR CIGS/VSBYS IN THUNDERSTORMS SHOULD BE REPLACED BY VFR CIGS AFTER 06Z AS SURFACE WINDS BECOME WESTERLY AFTER FRONTAL PASSAGE. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ FOBERT/DERGAN ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1230 AM EST THU NOV 6 2008 .SYNOPSIS... DEEP LOW PRESSURE OFFSHORE FROM THE VIRGINIA CAPES WILL MOVE SLOWLY NORTHEAST OVERNIGHT AND THURSDAY...AWAY FROM NORTH CAROLINA. WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA LATE TONIGHT AND PERSIST THROUGH FRIDAY. A COLD FRONT MOVING WEST TO EAST...WILL CROSS THE CAROLINAS SATURDAY. HIGH PRESSURE FROM THE PLAINS STATES WILL RIDGE ACROSS THE AREA LATE SATURDAY THROUGH EARLY NEXT WEEK. ANOTHER STORM SYSTEM WILL APPROACH FROM THE WEST BY MID-WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM WEDNESDAY...BAROTROPIC LOW OFFSHORE FROM THE VA CAPES...TO SLOWLY LIFT NE OVERNIGHT AND THURSDAY. ITS CIRCULATION ACROSS THE AREA INVOLVING WINDS AND CLOUDS WILL LIKELY COME TO AN END OVERNIGHT...WITH THE COASTAL SE NC THE LAST TO OBSERVE THE CLOUDS AND WINDS. MAIN DILEMMA TONIGHT WILL BE THE POSSIBILITY OF FOG AND HOW MUCH OF IT. AT 1ST GLANCE...PROCEDURES USING RUC MODEL DATA INDICATE AREAS OF FOG WEST OF A LINE FROM ELIZABETHTOWN...WHITEVILLE...AYNOR TO KINGSTREE. PATCHY FOG EAST OF THIS LINE TO THE WESTERN COUNTY BOUNDARIES OF PENDER...NEW HANOVER AND BRUNSWICK COUNTIES. THE FOG STABILITY INDEX INDICATES DENSE FOG IS A GOOD POSSIBILITY FOR THOSE INLAND COUNTIES...IE WEST OF A LINE FROM LUMBERTON...MARION TO KINGSTREE. THE NAMBUFR SOUNDINGS FOR FLO AND LBT ARE MORE REPRESENTATIVE OF A FOG/DENSE FOG OCCURRENCE FOR THURSDAY MORNING. ONLY TWEAKED AROUND WITH THE MINS SINCE 1/3RD OF THE AREAS LATEST TEMPS HAD REACHED THEIR DEWPOINTS ALREADY...AND DONT SEE MUCH IN THE WAY OF CAA TO LOWER THEM TOO MUCH FURTHER. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 PM WEDNESDAY...500 MB HEIGHT RISES WILL OCCUR DURING THURSDAY AS THE UPPER LOW CONTINUES TO LIFT AWAY FROM THE REGION. THE H5 RIDGE AXIS WILL PASS OVERHEAD THURSDAY NIGHT...THEN OFF THE COAST FRIDAY AS A LARGE UPPER LOW TRANSLATES FROM THE MID-WEST TOWARD THE OH VALLEY. CLOSER TO HOME...WEAK DOWNSLOPE FLOW WILL DEVELOP DURING THURSDAY WHICH WILL HELP TO SCOUR OUT ANY LINGER SCT LOW CLOUDS IN THE WAKE OF THE DEPARTING LOW. LOW-LEVEL THICKNESSES WILL INCREASE IN THE SHORT TERM TRANSLATING INTO A PERIOD OF ABOVE NORMAL TEMPERATURES. HIGHS THURSDAY AND FRIDAY WILL GENERALLY BE IN THE MID 70S. CLOUDS WILL BE ON THE INCREASE FROM W-E DURING FRIDAY NIGHT AS THE NEXT COLD FRONT APPROACHES. LOW CONFIDENCE IN REGARDS TO POPS WITH THIS FEATURE...WITH ONLY SLIGHT CHANCES MAINLY FOR THE WESTERN ZONES LATE FRIDAY NIGHT. ANY SHOWER ACTIVITY ASSOCIATED WITH THIS SYSTEM WILL MORE THAN LIKELY BE FOCUSED RIGHT ALONG THE FRONT COMING INTO PLAY EARLY ON IN THE EXTENDED PERIOD. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 3 PM WEDNESDAY...THE EXTENDED WILL BE HIGHLIGHTED BY THE PASSAGE OF A COLD FRONT SATURDAY FOLLOWED BY HIGH PRESSURE WITH YET ANOTHER SYSTEM AT THE END OF THE PERIOD. THIS...ALL IN ASSOCIATION WITH A PROGRESSIVE PATTERN AT THE MID LEVELS. THE GFS IS MORE BULLISH IN DEVELOPING AN AREA OF RAIN ACROSS THE AREA SATURDAY MORNING MOST LIKELY IN DUE TO INCREASED OMEGA VIA THE LEFT EXIT REGION OF THE 200MB JET. MOISTURE REMAINS MARGINAL AND IS WITH ALMOST IDENTICAL PRECIPITABLE WATER VALUES WHEN COMPARED TO YESTERDAYS MODEL RUNS. TWEAKED POPS A BIT TO REPRESENT BETTER CHANCES ACROSS THE NORTHEASTERN COUNTIES WHERE THE BEST OMEGA RESIDES...OTHERWISE NO CHANGES WITH THIS SYSTEM. A FAST MOVING SHORTWAVE APPROACHES THE AREA TUESDAY AND WEDNESDAY AT THE END OF THE PERIOD AND HAVE MAINTAINED THE LOW CHANCE POPS FOR THIS TIME. OBVIOUSLY WITH THE SYSTEM TIMED FOR THE END OF THE PERIOD PLUS THE FACT IT APPEARS TO BE EMBEDDED IN A FAST WESTERLY FLOW CONFIDENCE IS LOW. SUNDAY AND MONDAY SHOULD BE DRY. NO CHANGE TO TEMPERATURE FORECAST AS IT APPEARS READINGS WILL NOT STRAY A DEGREE OR TWO FROM CLIMATOLOGY. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... SKIES ARE CLEAR AT ALL TERMINALS EARLY THIS MORNING. WINDS HAVE BECOME CALM IN PLACES AND AS A RESULT FOG HAS DEVELOPED AND HAS BECOME BRIEFLY DENSE AT TIMES. THIS WILL BE AN ISSUE AT THESE TERMINALS THROUGH SUNRISE WITH IFR/LIFR VISIBILITIES LIKELY TO OCCUR...ALTHOUGH 15-20 KT WINDS JUST 1000 FT UP SHOULD KEEP VISIBILITIES JUMPING UP AND DOWN THROUGH THE NIGHT. DUE TO STRONGER WIND SPEEDS IN THE BOUNDARY LAYER FOG DEVELOPMENT IS LESS LIKELY AT THE COASTAL TERMINALS...EXCEPT AT CRE WHERE LOCAL EFFECTS WILL ALLOW FOR PREDOMINATE MVFR VISIBILITIES WITH TEMPO IFR VISIBILITIES. VFR/CLEAR SKIES EXPECTED ALL TERMINALS AFTER 13Z-14Z WITH NORTHWEST WINDS AROUND 10 KNOTS BECOMING SOUTHWEST AT THE COASTAL TERMINALS BY AFTERNOON. OUTLOOK THROUGH MONDAY...VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM WEDNESDAY...SCEC WAS RAISED ACROSS THE SAME AMZ ZONES THAT A SCA EXPIRED AT 7 PM. ONLY HAD TO TWEAK WINDS UP 1 TO 3 KNOTS FOR THE OVERNITE GIVEN LATEST READINGS...TRENDS...MODEL DATA. THE SEAS HAVE BEEN ALSO BEEN TWEAKED A FOOT OR 2 HIER...MAINLY ACROSS THE NEAR SHORE. THE MAIN REASON IS THAT THE ESE SWELL AT 11 SECOND PERIODS CONTINUES TO PUSH 3 TO 5 FOOT SEAS ACROSS THE ILM COASTAL WATERS. WITH ONLY A WEAK OFFSHORE WIND AFFECTING IT THROUGH THURSDAY...THE SWELL WILL BE SLOWER TO DETERIORATE. IN ADDITION... SURF REPORTS FROM WRIGHTSVILLE BEACH LATE THIS AFTERNOON INDICATED 4 TO 5 FOOT...AND AS MUCH AS 6 FOOT AT TIMES. WITH AN ESE SWELL...BASICALLY THE ENTIRE CWA COASTAL WATERS IS APT TO OBSERVE ALL OR PORTION OF THIS SWELL...WITH THE EXCEPTION OF THE SHADOW EFFECTS FROM FRYING PAN SHOALS. IF IT WAS A TRUE SE SWELL...THEN THE SHADOW EFFECTS COULD BE NEGATED. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 PM WEDNESDAY...WINDS/SEAS WILL DIMINISH/SUBSIDE THROUGH THE FIRST HALF OF THE SHORT TERM PERIOD...THEN BEGIN TO INCREASE/BUILD FRIDAY NIGHT AHEAD OF THE NEXT COLD FRONT. SEAS ARE EXPECTED TO RANGE FROM 4 FT AWAY FROM THE COAST TO 2 FT OR LESS INSHORE THURSDAY...SUBSIDING TO 1-3 FT BY THURSDAY NIGHT. RETURN FLOW FRIDAY WILL CREATE A SOUTHWESTERLY FETCH ALLOWING SEAS TO BUILD BACK TO AROUND 4 FT BY FRIDAY NIGHT. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 3 PM WEDNESDAY...LITTLE CHANGE TO THE EXTENDED COASTAL WATERS FORECAST THIS AFTERNOON AS VERY MODEST SOUTHWEST FLOW WILL PREVAIL SATURDAY TRANSITIONING TO A WEAK WEST TO NORTHWEST FLOW BY SUNDAY AFTERNOON. THIS IS THE ONLY CHANGE TO THE FORECAST AS THE PUSH BEHIND THE FRONT NOW APPEARS TO BE WEAKER THAN ADVERTISED. LOOK FOR RANGES OF 10-15 KNOTS BUT MORE REALISTICALLY NEAR 10 KNOTS. WAVE SPECTRUM WILL BE COMPRISED OF A WEAK SWELL COMPONENT FROM THE EAST/SOUTHEAST AND A WEAK WIND WAVE. THIS EQUATES TO THE STANDARD 2-4 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ250-252. && $$ SYNOPSIS...HOEHLER NEAR TERM...HOEHLER SHORT TERM...PFAFF LONG TERM...KEEBLER AVIATION...ROSS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1000 PM EST WED NOV 5 2008 .SYNOPSIS... DEEP LOW PRESSURE OFFSHORE FROM THE VIRGINIA CAPES...WILL MOVE SLOWLY NORTHEAST OVERNIGHT AND THURSDAY...AWAY FROM NORTH CAROLINA. WEAK HIGH PRESSURE WILL BUILD ACROSS THE AREA LATE TONIGHT AND PERSIST THROUGH FRIDAY. A COLD FRONT MOVING WEST TO EAST...WILL CROSS THE CAROLINAS SATURDAY. HIGH PRESSURE FROM THE PLAINS STATES WILL RIDGE ACROSS THE AREA LATE SATURDAY THROUGH EARLY NEXT WEEK. ANOTHER STORM SYSTEM WILL APPROACH FROM THE WEST BY MID-WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM WEDNESDAY...BAROTROPIC LOW OFFSHORE FROM THE VA CAPES...TO SLOWLY LIFT NE OVERNIGHT AND THURSDAY. ITS CIRCULATION ACROSS THE AREA INVOLVING WINDS AND CLOUDS WILL LIKELY COME TO AN END OVERNIGHT...WITH THE COASTAL SE NC THE LAST TO OBSERVE THE CLOUDS AND WINDS. MAIN DILEMMA TONIGHT WILL BE THE POSSIBILITY OF FOG AND HOW MUCH OF IT. AT 1ST GLANCE...PROCEDURES USING RUC MODEL DATA INDICATE AREAS OF FOG WEST OF A LINE FROM ELIZABETHTOWN...WHITEVILLE...AYNOR TO KINGSTREE. PATCHY FOG EAST OF THIS LINE TO THE WESTERN COUNTY BOUNDARIES OF PENDER...NEW HANOVER AND BRUNSWICK COUNTIES. THE FOG STABILITY INDEX INDICATES DENSE FOG IS A GOOD POSSIBILITY FOR THOSE INLAND COUNTIES...IE WEST OF A LINE FROM LUMBERTON...MARION TO KINGSTREE. THE NAMBUFR SOUNDINGS FOR FLO AND LBT ARE MORE REPRESENTATIVE OF A FOG/DENSE FOG OCCURRENCE FOR THURSDAY MORNING. ONLY TWEAKED AROUND WITH THE MINS SINCE 1/3RD OF THE AREAS LATEST TEMPS HAD REACHED THEIR DEWPOINTS ALREADY...AND DONT SEE MUCH IN THE WAY OF CAA TO LOWER THEM TOO MUCH FURTHER. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 PM WEDNESDAY...500 MB HEIGHT RISES WILL OCCUR DURING THURSDAY AS THE UPPER LOW CONTINUES TO LIFT AWAY FROM THE REGION. THE H5 RIDGE AXIS WILL PASS OVERHEAD THURSDAY NIGHT...THEN OFF THE COAST FRIDAY AS A LARGE UPPER LOW TRANSLATES FROM THE MID-WEST TOWARD THE OH VALLEY. CLOSER TO HOME...WEAK DOWNSLOPE FLOW WILL DEVELOP DURING THURSDAY WHICH WILL HELP TO SCOUR OUT ANY LINGER SCT LOW CLOUDS IN THE WAKE OF THE DEPARTING LOW. LOW-LEVEL THICKNESSES WILL INCREASE IN THE SHORT TERM TRANSLATING INTO A PERIOD OF ABOVE NORMAL TEMPERATURES. HIGHS THURSDAY AND FRIDAY WILL GENERALLY BE IN THE MID 70S. CLOUDS WILL BE ON THE INCREASE FROM W-E DURING FRIDAY NIGHT AS THE NEXT COLD FRONT APPROACHES. LOW CONFIDENCE IN REGARDS TO POPS WITH THIS FEATURE...WITH ONLY SLIGHT CHANCES MAINLY FOR THE WESTERN ZONES LATE FRIDAY NIGHT. ANY SHOWER ACTIVITY ASSOCIATED WITH THIS SYSTEM WILL MORE THAN LIKELY BE FOCUSED RIGHT ALONG THE FRONT COMING INTO PLAY EARLY ON IN THE EXTENDED PERIOD. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 3 PM WEDNESDAY...THE EXTENDED WILL BE HIGHLIGHTED BY THE PASSAGE OF A COLD FRONT SATURDAY FOLLOWED BY HIGH PRESSURE WITH YET ANOTHER SYSTEM AT THE END OF THE PERIOD. THIS...ALL IN ASSOCIATION WITH A PROGRESSIVE PATTERN AT THE MID LEVELS. THE GFS IS MORE BULLISH IN DEVELOPING AN AREA OF RAIN ACROSS THE AREA SATURDAY MORNING MOST LIKELY IN DUE TO INCREASED OMEGA VIA THE LEFT EXIT REGION OF THE 200MB JET. MOISTURE REMAINS MARGINAL AND IS WITH ALMOST IDENTICAL PRECIPITABLE WATER VALUES WHEN COMPARED TO YESTERDAYS MODEL RUNS. TWEAKED POPS A BIT TO REPRESENT BETTER CHANCES ACROSS THE NORTHEASTERN COUNTIES WHERE THE BEST OMEGA RESIDES...OTHERWISE NO CHANGES WITH THIS SYSTEM. A FAST MOVING SHORTWAVE APPROACHES THE AREA TUESDAY AND WEDNESDAY AT THE END OF THE PERIOD AND HAVE MAINTAINED THE LOW CHANCE POPS FOR THIS TIME. OBVIOUSLY WITH THE SYSTEM TIMED FOR THE END OF THE PERIOD PLUS THE FACT IT APPEARS TO BE EMBEDDED IN A FAST WESTERLY FLOW CONFIDENCE IS LOW. SUNDAY AND MONDAY SHOULD BE DRY. NO CHANGE TO TEMPERATURE FORECAST AS IT APPEARS READINGS WILL NOT STRAY A DEGREE OR TWO FROM CLIMATOLOGY. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... LOW CLOUDS 4K-6K WRAPPING AROUND A SURFACE LOW WELL NORTHEAST OF THE TERMINALS STILL AFFECTING ILM AT 02Z. SKIES AT THE REMAINING TERMINALS ARE CLEAR. EXPECT CLOUDS TO SCATTER OUT OF THE ILM TERMINAL BY 04Z. CLEAR SKIES HAVE ALLOWED FOR PATCHY FOG TO DEVELOP. VISIBILITIES AT FLO HAVE VARIED FROM P6SM TO A HALF MILE OVER THE PAST COUPLE OF HOURS WITH A 3 KNOT WESTERLY WIND HELPING TO DISPERSE THE FOG. VISIBILITIES AT LBT HAVE VARIED FROM 4SM TO P6SM AND THE TERMINAL ALSO HAS THE SAME 3 KNOT WESTERLY WIND HELPING DISPERSE THE FOG. WINDS AT CRE HAVE BECOME CALM OVER THE PAST HOUR OR TWO AND VISIBILITIES HAVE BEGUN TO DROP THERE BUT ARE STILL P6SM. WITH THE SURFACE LOW FORECAST TO MOVE FURTHER AWAY FROM THE TERMINALS OVERNIGHT CAN ONLY EXPECT CURRENT WIND SPEEDS TO DECREASE WHICH SHOULD ALLOW FOR FURTHER FOG DEVELOPMENT. WILL FORECAST PREDOMINATELY MVFR VISIBILITIES WITH IFR POSSIBLE AFTER 09Z AT FLO/LBT. SINCE THE COASTAL TERMINALS SHOULD HAVE A BIT STRONGER WINDS IN THE BOUNDARY LAYER WILL FORECAST TEMPO MVFR VISIBILITIES AT ILM AND MYR AFTER 09Z. BUT AT CRE DUE TO LOCAL EFFECTS WILL SHOW PREDOMINATE MVFR VISIBILITIES WITH TEMPO IFR AFTER 09Z. VFR/CLEAR SKIES EXPECTED ALL TERMINALS AFTER 13Z-14Z WITH NORTHWEST WINDS AROUND 10 KNOTS BECOMING SOUTHWEST AT THE COASTAL TERMINALS BY AFTERNOON. OUTLOOK THROUGH MONDAY...VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM WEDNESDAY...SCEC WAS RAISED ACROSS THE SAME AMZ ZONES THAT A SCA EXPIRED AT 7 PM. ONLY HAD TO TWEAK WINDS UP 1 TO 3 KNOTS FOR THE OVERNITE GIVEN LATEST READINGS...TRENDS...MODEL DATA. THE SEAS HAVE BEEN ALSO BEEN TWEAKED A FOOT OR 2 HIER...MAINLY ACROSS THE NEAR SHORE. THE MAIN REASON IS THAT THE ESE SWELL AT 11 SECOND PERIODS CONTINUES TO PUSH 3 TO 5 FOOT SEAS ACROSS THE ILM COASTAL WATERS. WITH ONLY A WEAK OFFSHORE WIND AFFECTING IT THROUGH THURSDAY...THE SWELL WILL BE SLOWER TO DETERIORATE. IN ADDITION... SURF REPORTS FROM WRIGHTSVILLE BEACH LATE THIS AFTERNOON INDICATED 4 TO 5 FOOT...AND AS MUCH AS 6 FOOT AT TIMES. WITH AN ESE SWELL...BASICALLY THE ENTIRE CWA COASTAL WATERS IS APT TO OBSERVE ALL OR PORTION OF THIS SWELL...WITH THE EXCEPTION OF THE SHADOW EFFECTS FROM FRYING PAN SHOALS. IF IT WAS A TRUE SE SWELL...THEN THE SHADOW EFFECTS COULD BE NEGATED. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 PM WEDNESDAY...WINDS/SEAS WILL DIMINISH/SUBSIDE THROUGH THE FIRST HALF OF THE SHORT TERM PERIOD...THEN BEGIN TO INCREASE/BUILD FRIDAY NIGHT AHEAD OF THE NEXT COLD FRONT. SEAS ARE EXPECTED TO RANGE FROM 4 FT AWAY FROM THE COAST TO 2 FT OR LESS INSHORE THURSDAY...SUBSIDING TO 1-3 FT BY THURSDAY NIGHT. RETURN FLOW FRIDAY WILL CREATE A SOUTHWESTERLY FETCH ALLOWING SEAS TO BUILD BACK TO AROUND 4 FT BY FRIDAY NIGHT. LONG TERM /SATURDAY THROUGH MONDAY/... AS OF 3 PM WEDNESDAY...LITTLE CHANGE TO THE EXTENDED COASTAL WATERS FORECAST THIS AFTERNOON AS VERY MODEST SOUTHWEST FLOW WILL PREVAIL SATURDAY TRANSITIONING TO A WEAK WEST TO NORTHWEST FLOW BY SUNDAY AFTERNOON. THIS IS THE ONLY CHANGE TO THE FORECAST AS THE PUSH BEHIND THE FRONT NOW APPEARS TO BE WEAKER THAN ADVERTISED. LOOK FOR RANGES OF 10-15 KNOTS BUT MORE REALISTICALLY NEAR 10 KNOTS. WAVE SPECTRUM WILL BE COMPRISED OF A WEAK SWELL COMPONENT FROM THE EAST/SOUTHEAST AND A WEAK WIND WAVE. THIS EQUATES TO THE STANDARD 2-4 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ250-252. && $$ SYNOPSIS...HOEHLER NEAR TERM...HOEHLER SHORT TERM...PFAFF LONG TERM...KEEBLER AVIATION...ROSS nc AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 917 PM CST WED NOV 5 2008 .DISCUSSION...NO MAJOR UPDATED NEEDED AT THIS POINT. PREVIOUS FORECAST THINKING REMAINS VALID (SEE BELOW). ALL CURRENT HEADLINES ON TRACK. CURRENT RAIN AREA LOCATED ALONG AND NORTH OF A COOPERSTOWN-GRAND FORKS-ROSEAU LINE (STRONGEST 850MB WARM AIR ADVECTION). THIS AREA OF RAIN WILL REMAIN MAINLY ACROSS THE DVL BASIN THROUGH 12Z THUR. SE FA WILL PROBABLY BE MAINLY DRY DURING THIS TIME (CURRENT FORECAST DOES SHOW LOWER POPS ACROSS THIS AREA). LEADING EDGE OF NEXT SLUG OF MOISTURE SEEN ON RADAR IMAGERY ACROSS IOWA/S MN. THIS WILL PROPAGATE INTO THE FA TOMORROW MORNING. THINK CURRENT QPF FORECAST ON TRACK GIVEN THE ABOVE. BIGGEST QUESTION MARK WITH THIS EVENT LOOKS TO BE P-TYPE...ESPECIALLY ACROSS THE DVL BASIN TONIGHT INTO THURSDAY. CURRENTLY TEMPS ARE NEAR FREEZING (32F-34F). WARM GROUND TEMPS PREVENTING FZRA ATTM...WHICH SHOULD PREVENT ICE ON ROADS THROUGH TONIGHT (WILL MONITOR THOUGH). TOMORROW EVEN TRICKIER...AND 00Z NAM STRONGER/NW WITH SFC LOW INDICATING CHANGEOVER TO SNOW WILL BE DELAYED. WILL AWAIT ALL 00Z GUIDANCE AND ALLOW MID-SHIFT TO ASSESS THE SITUATION. COMPLEX TO SAY THE LEAST. && .AVIATION...IFR CIGS FOR MOST TAF SITES TODAY THROUGH ABOUT FRIDAY...AS A LOW PRESSURE SYSTEM BRINGS A SIG RAIN EVENT...WHICH WILL LIKELY TURN TO SNOW THU NIGHT. COULD SEE SOME TEMPO CONDS WHERE CIGS BECOME MVFR AND MAYBE VFR...BUT PREDOMINANT CONDS BY LATE THIS EVENING SHOULD BE IFR. && .PREV DISCUSSION... /ISSUED 624 PM CST WED NOV 5 2008/ UPDATE...WIND SPEEDS ACROSS THE DEVILS LAKE BASIN CURRENTLY SUSTAINED AOA 30MPH. 21Z RUC SHOWS 925MB WINDS AROUND 40KNTS AND REMAIN OR SLIGHTLY INCREASE THROUGH THE NIGHT. SOUNDINGS SHOW UNIDIRECTIONAL UP TO 900MB. THUS...DO NOT SEE WIND SPEEDS DECREASING THROUGH THE NIGHT. WILL ISSUE WIND ADVISORY FOR THIS AREA UNTIL 12Z THUR. WINDS WILL REMAIN STRONG INTO TOMORROW...BUT WINTER STORM WARNING TAKES AFFECT. WILL NEED TO MONITOR LOCATIONS TO THE EAST FOR POSSIBLE WIND ADVISORY...AND WILL ADDRESS ON ACTUAL EVENING UPDATE (@830PM). PREV DISCUSSION... /ISSUED 330 PM CST WED NOV 5 2008/ SHORT TERM... LOTS OF ISSUES TODAY. ATTM LEANING TOWARD 12Z GFS SOLN WHICH MATCHES VERY WELL WITH 12Z CANADIAN AS WELL IN KEEPING A BIT WARMER 925-850 MB LAYER FURTHER WEST INTO THE RED RIVER VALLEY TIL LATE THURSDAY AFTN/NIGHT THAN THE 12Z NAM DOES. CURRENTLY...SFC LOW DEEPENING BTWN ABERDEEN AND PIERRE WITH PRESSURE FALLS JUST WEST OF ABERDEEN. UPPER LOW AND VORT MOVING INTO WRN NEBRASKA/SW SD ATTM WITH TSTMS DEVELOPING ON NOSE OF DRY SLOT ALOFT OVER SE ND MOVING NORTH AND NORTHWEST. RUC SHOWS CONTINUED DESTABILIZATION AS 850 MB JET INCREASES LATE THIS AFTN/EVE OVER ERN ND WITH STRONG UPPER LEVEL DIVERGENCE DEVELOPING OVER THE AREA LEADING TO EXPANDING PCPN FIELD. SFC BOUNDARY EXTENDS FROM SFC LOW IN SOUTH DAKOTA TO JUST SOUTH OF FARGO TO NEAR WASKISH MN AND WILL MOVE LITTLE THRU 12Z THU AS SFC LOW MOVES ONLY SLOWLY ENE ALONG IT. AREA OF DEEPER LAYER MOISTURE SEEN ON WATER VAPOR FROM OKLA INTO KS/IA/SRN MN WILL GET ABSORBED INTO SYSTEM AND GET DRAGGED NORTH AND THEN WEST TO THE NORTH OF THE UPPER LOW INTO ERN ND LATE TONIGHT INTO THURSDAY SETTING THE STAGE FOR A WIDESPREAD HEAVY RAINFALL AND SNOWFALL EVENT FOR CNTR/ERN ND AND NW MN. SFC LOW WILL MOVE TO NR A WHEATON/ALEXANDRIA AREA BY 00Z FRI WITH PCPN CONTINUING TO WRAP AROUND THE SYSTEM OVER ERN/CNTRL ND. CRITICAL THICKNESSES SHOW TRANSITION TO SNOW WITH BRIEF MIX OF SLEET/FZRA PSBL FROM WEST TO EAST THRU ERN ND ON THURSDAY. DVL BASIN TO SEE MOSTLY SNOW EVENT AFTER 12Z THURSDAY INTO THU NIGHT AND AGREE WITH HPC THINKING OF 6-10 INCHES NR LANGDON TO DVL AREA SOUTHWESTWARD SO UPGRADED TO WINTER STORM WARNING IN THAT AREA. WENT WITH WINTER STORM WATCH FOR AREAS EASTWARD TO HALLOCK-GRAND FORKS-VALLEY CITY-LISBON AS RAIN CHANGES TO SNOW LATE THU AFTN. RAIN TO SNOW WILL TRANSITION EASTWARD THU NIGHT BUT PCPN TO DIMINISH IN INTENSITY SO THREAT FOR HVY SNOW DIMINISHES FOR AREAS EAST OF A ROSEAU TO CROOKSTON TO FARGO AND WAHPETON LINE. WIND TO BE AN ISSUE WITH 40-50KTS AT 850 MB OVER DVL BASIN AND THE JAMES RIVER BASIN THURSDAY-THU NIGHT SO NR BLIZZARD CONDITIONS VERY PSBL. SYSTEM WILL FILL ON FRIDAY WITH PCPN WINDING DOWN AND WIND DIMINISHING. LONG TERM... /WED THROUGH SAT/ LONG TERM MODELS IN GENERAL AGREEMENT WITH A CANADIAN HIGH SITTING OVER MY FA IN THE LONG TERM. HOWEVER...CANADIAN/ECMWF BOTH SHOW A LOW EJECT OUT OF SWRN US TUE INTO WED...WITH THE TRACK BRING MORE PRECIP INTO THE GRT LKS STATES. GFS DOES NOT SHOW A CLOSED LOW WITH THIS SYSTEM. NOT A FACTOR FOR OUR FA UNLESS THE TRACK STARTS SHIFTING FURTHER WEST...OTHERWISE LOOK FOR A DRY LONG TERM. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR NDZ008-016-026>030- 038-039-049-052>054. WIND ADVISORY UNTIL 6 AM CST THURSDAY FOR NDZ006-007-014-015-024. WINTER STORM WARNING FROM 6 AM THURSDAY TO 12 PM CST FRIDAY FOR NDZ006-007-014-015-024. WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY MORNING FOR NDZ008-016-026>029-038-049-052-054. MN...FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR MNZ001>005-007-008- 013>015-022-027-029-030-040. WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY MORNING FOR MNZ004-007. && $$ TG nd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 624 PM CST WED NOV 5 2008 .UPDATE...WIND SPEEDS ACROSS THE DEVILS LAKE BASIN CURRENTLY SUSTAINED AOA 30MPH. 21Z RUC SHOWS 925MB WINDS AROUND 40KNTS AND REMAIN OR SLIGHTLY INCREASE THROUGH THE NIGHT. SOUNDINGS SHOW UNIDIRECTIONAL UP TO 900MB. THUS...DO NOT SEE WIND SPEEDS DECREASING THROUGH THE NIGHT. WILL ISSUE WIND ADVISORY FOR THIS AREA UNTIL 12Z THUR. WINDS WILL REMAIN STRONG INTO TOMORROW...BUT WINTER STORM WARNING TAKES AFFECT. WILL NEED TO MONITOR LOCATIONS TO THE EAST FOR POSSIBLE WIND ADVISORY...AND WILL ADDRESS ON ACTUAL EVENING UPDATE (@830PM). && .AVIATION...IFR CIGS FOR MOST TAF SITES TODAY THROUGH ABOUT FRIDAY...AS A LOW PRESSURE SYSTEM BRINGS A SIG RAIN EVENT...WHICH WILL LIKELY TURN TO SNOW THU NIGHT. COULD SEE SOME TEMPO CONDS WHERE CIGS BECOME MVFR AND MAYBE VFR...BUT PREDOMINANT CONDS BY LATE THIS EVENING SHOULD BE IFR. && .PREV DISCUSSION... /ISSUED 330 PM CST WED NOV 5 2008/ SHORT TERM... LOTS OF ISSUES TODAY. ATTM LEANING TOWARD 12Z GFS SOLN WHICH MATCHES VERY WELL WITH 12Z CANADIAN AS WELL IN KEEPING A BIT WARMER 925-850 MB LAYER FURTHER WEST INTO THE RED RIVER VALLEY TIL LATE THURSDAY AFTN/NIGHT THAN THE 12Z NAM DOES. CURRENTLY...SFC LOW DEEPENING BTWN ABERDEEN AND PIERRE WITH PRESSURE FALLS JUST WEST OF ABERDEEN. UPPER LOW AND VORT MOVING INTO WRN NEBRASKA/SW SD ATTM WITH TSTMS DEVELOPING ON NOSE OF DRY SLOT ALOFT OVER SE ND MOVING NORTH AND NORTHWEST. RUC SHOWS CONTINUED DESTABILIZATION AS 850 MB JET INCREASES LATE THIS AFTN/EVE OVER ERN ND WITH STRONG UPPER LEVEL DIVERGENCE DEVELOPING OVER THE AREA LEADING TO EXPANDING PCPN FIELD. SFC BOUNDARY EXTENDS FROM SFC LOW IN SOUTH DAKOTA TO JUST SOUTH OF FARGO TO NEAR WASKISH MN AND WILL MOVE LITTLE THRU 12Z THU AS SFC LOW MOVES ONLY SLOWLY ENE ALONG IT. AREA OF DEEPER LAYER MOISTURE SEEN ON WATER VAPOR FROM OKLA INTO KS/IA/SRN MN WILL GET ABSORBED INTO SYSTEM AND GET DRAGGED NORTH AND THEN WEST TO THE NORTH OF THE UPPER LOW INTO ERN ND LATE TONIGHT INTO THURSDAY SETTING THE STAGE FOR A WIDESPREAD HEAVY RAINFALL AND SNOWFALL EVENT FOR CNTR/ERN ND AND NW MN. SFC LOW WILL MOVE TO NR A WHEATON/ALEXANDRIA AREA BY 00Z FRI WITH PCPN CONTINUING TO WRAP AROUND THE SYSTEM OVER ERN/CNTRL ND. CRITICAL THICKNESSES SHOW TRANSITION TO SNOW WITH BRIEF MIX OF SLEET/FZRA PSBL FROM WEST TO EAST THRU ERN ND ON THURSDAY. DVL BASIN TO SEE MOSTLY SNOW EVENT AFTER 12Z THURSDAY INTO THU NIGHT AND AGREE WITH HPC THINKING OF 6-10 INCHES NR LANGDON TO DVL AREA SOUTHWESTWARD SO UPGRADED TO WINTER STORM WARNING IN THAT AREA. WENT WITH WINTER STORM WATCH FOR AREAS EASTWARD TO HALLOCK-GRAND FORKS-VALLEY CITY-LISBON AS RAIN CHANGES TO SNOW LATE THU AFTN. RAIN TO SNOW WILL TRANSITION EASTWARD THU NIGHT BUT PCPN TO DIMINISH IN INTENSITY SO THREAT FOR HVY SNOW DIMINISHES FOR AREAS EAST OF A ROSEAU TO CROOKSTON TO FARGO AND WAHPETON LINE. WIND TO BE AN ISSUE WITH 40-50KTS AT 850 MB OVER DVL BASIN AND THE JAMES RIVER BASIN THURSDAY-THU NIGHT SO NR BLIZZARD CONDITIONS VERY PSBL. SYSTEM WILL FILL ON FRIDAY WITH PCPN WINDING DOWN AND WIND DIMINISHING. LONG TERM... /WED THROUGH SAT/ LONG TERM MODELS IN GENERAL AGREEMENT WITH A CANADIAN HIGH SITTING OVER MY FA IN THE LONG TERM. HOWEVER...CANADIAN/ECMWF BOTH SHOW A LOW EJECT OUT OF SWRN US TUE INTO WED...WITH THE TRACK BRING MORE PRECIP INTO THE GRT LKS STATES. GFS DOES NOT SHOW A CLOSED LOW WITH THIS SYSTEM. NOT A FACTOR FOR OUR FA UNLESS THE TRACK STARTS SHIFTING FURTHER WEST...OTHERWISE LOOK FOR A DRY LONG TERM. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR NDZ008-016-026>030- 038-039-049-052>054. WIND ADVISORY UNTIL 6 AM CST THURSDAY FOR NDZ006-007-014-015-024. WINTER STORM WARNING FROM 6 AM THURSDAY TO 12 PM CST FRIDAY FOR NDZ006-007-014-015-024. WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY MORNING FOR NDZ008-016-026>029-038-049-052-054. MN...FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR MNZ001>005-007-008- 013>015-022-027-029-030-040. WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY MORNING FOR MNZ004-007. && $$ TG nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 330 PM CST WED NOV 5 2008 .SHORT TERM... LOTS OF ISSUES TODAY. ATTM LEANING TOWARD 12Z GFS SOLN WHICH MATCHES VERY WELL WITH 12Z CANADIAN AS WELL IN KEEPING A BIT WARMER 925-850 MB LAYER FURTHER WEST INTO THE RED RIVER VALLEY TIL LATE THURSDAY AFTN/NIGHT THAN THE 12Z NAM DOES. CURRENTLY...SFC LOW DEEPENING BTWN ABERDEEN AND PIERRE WITH PRESSURE FALLS JUST WEST OF ABERDEEN. UPPER LOW AND VORT MOVING INTO WRN NEBRASKA/SW SD ATTM WITH TSTMS DEVELOPING ON NOSE OF DRY SLOT ALOFT OVER SE ND MOVING NORTH AND NORTHWEST. RUC SHOWS CONTINUED DESTABLIZATION AS 850 MB JET INCREASES LATE THIS AFTN/EVE OVER ERN ND WITH STRONG UPPER LEVEL DIVERGENCE DEVELOPING OVER THE AREA LEADING TO EXPANDING PCPN FIELD. SFC BOUNDARY EXTENDS FROM SFC LOW IN SOUTH DAKOTA TO JUST SOUTH OF FARGO TO NEAR WASKISH MN AND WILL MOVE LITTLE THRU 12Z THU AS SFC LOW MOVES ONLY SLOWLY ENE ALONG IT. AREA OF DEEPER LAYER MOISTURE SEEN ON WATER VAPOR FROM OKLA INTO KS/IA/SRN MN WILL GET ABSORBED INTO SYSTEM AND GET DRAGGED NORTH AND THEN WEST TO THE NORTH OF THE UPPER LOW INTO ERN ND LATE TONIGHT INTO THURSDAY SETTING THE STAGE FOR A WIDESPREAD HEAVY RAINFALL AND SNOWFALL EVENT FOR CNTR/ERN ND AND NW MN. SFC LOW WILL MOVE TO NR A WHEATON/ALEXANDRIA AREA BY 00Z FRI WITH PCPN CONTINUING TO WRAP AROUND THE SYSTEM OVER ERN/CNTRL ND. CRITICAL THICKENSSES SHOW TRANSITION TO SNOW WITH BRIEF MIX OF SLEET/FZRA PSBL FROM WEST TO EAST THRU ERN ND ON THURSDAY. DVL BASIN TO SEE MOSTLY SNOW EVENT AFTER 12Z THURSDAY INTO THU NIGHT AND AGREE WITH HPC THINKING OF 6-10 INCHES NR LANGDON TO DVL AREA SOUTHWESTWARD SO UPGRADED TO WINTER STORM WARNING IN THAT AREA. WENT WITH WINTER STORM WATCH FOR AREAS EASTWARD TO HALLOCK-GRAND FORKS-VALLEY CITY-LISBON AS RAIN CHANGES TO SNOW LATE THU AFTN. RAIN TO SNOW WILL TRANSITION EASTWARD THU NIGHT BUT PCPN TO DIMINISH IN INTENSITY SO THREAT FOR HVY SNOW DIMINISHES FOR AREAS EAST OF A ROSEAU TO CROOKSTON TO FARGO AND WAHPETON LINE. WIND TO BE AN ISSUE WITH 40-50KTS AT 850 MB OVER DVL BASIN AND THE JAMES RIVER BASIN THURSDAY-THU NIGHT SO NR BLIZZARD CONDITIONS VERY PSBL. SYSTEM WILL FILL ON FRIDAY WITH PCPN WINDING DOWN AND WIND DIMINISHING. .LONG TERM... /WED THROUGH SAT/ LONG TERM MODELS IN GENERAL AGREEMENT WITH A CANADIAN HIGH SITTING OVER MY FA IN THE LONG TERM. HOWEVER...CANADIAN/ECMWF BOTH SHOW A LOW EJECT OUT OF SWRN US TUE INTO WED...WITH THE TRACK BRING MORE PRECIP INTO THE GRT LKS STATES. GFS DOES NOT SHOW A CLOSED LOW WITH THIS SYSTEM. NOT A FACTOR FOR OUR FA UNLESS THE TRACK STARTS SHIFTING FURTHER WEST...OTHERWISE LOOK FOR A DRY LONG TERM. && .AVIATION IFR CIGS FOR MOST TAF SITES TODAY THROUGH ABOUT FRIDAY...AS A LOW PRESSURE SYSTEM BRINGS A SIG RAIN EVENT...WHICH WILL LIKELY TURN TO SNOW THU NIGHT. COULD SEE SOME TEMPO CONDS WHERE CIGS BECOME MVFR AND MAYBE VFR...BUT PREDOMINANT CONDS BY LATE THIS EVENING SHOULD BE IFR. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR NDZ008-016-026>030- 038-039-049-052>054. WINTER STORM WARNING FROM 6 AM THURSDAY TO 12 PM CST FRIDAY FOR NDZ006-007-014-015-024. WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY MORNING FOR NDZ008-016-026>029-038-049-052-054. MN...FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR MNZ001>005-007-008- 013>015-022-027-029-030-040. WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH FRIDAY MORNING FOR MNZ004-007. && $$ RIDDLE/SPEICHER nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OH 1005 PM EST THU NOV 6 2008 .SYNOPSIS... STRONG CENTER OF LOW PRESSURE WILL SLOWLY MOVE TOWARD NORTHERN OHIO AND NORTHWESTERN PENNSYLVANIA TONIGHT INTO FRIDAY. AS THE LOW APPROACHES ON FRIDAY A COLD FRONT WILL BE PUSHED ACROSS THE REGION. A SECONDARY SURGE OF COLDER AIR WILL ARRIVE ON SATURDAY WHICH MAY CHANGE ANY REMAINING RAIN SHOWERS OVER TO SOME LIGHT SNOW FOR LATE IN THE WEEKEND INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... MOSTLY COSMETIC CHANGES TO CURRENT FORECAST/GRAPHICS. WILL TRY TO TIME THE ONSET OF SHOWERS A LITTLE BETTER. USING EXTRAPOLATION THE SHOWERS WOULD REACH THE TOLEDO AREA ABOUT 3 AM BUT MORE LIKELY 6 AM BASED ON THE LATEST RUC AND OTHER MODELS. ALL MODELS INDICATE THAT THE OCCLUDED FRONT WILL CONTINUE TO WEAKEN AND THE SHOWERS WILL ALSO WEAKEN FRI MORN. SHOWERS WILL THEN PUSH EAST AND WEAK WAVE TO DEVELOP ON THE FRONT AND SHOWERS WILL REDEVELOP ACROSS NE OH/NW PA. UPPER LEVEL LOW CONTINUES TO SPIN OVER THE NORTHERN PLAINS STATES AND IS PUSHING A COLD FRONT SLOWLY CLOSER TO WESTERN OHIO. A FEW SHOWERS/THUNDERSTORMS HAVE DEVELOPED ALONG THIS BOUNDARY OVER ILLINOIS AND WESTERN INDIANA. THESE SHOWERS MAY MOVE INTO WESTERN OHIO AFTER MIDNIGHT. CLOUD COVER WILL GRADUALLY INCREASE THROUGH THE EVENING...ESPECIALLY OUT WEST. THESE CLOUDS SHOULD KEEP THE WESTERN AREAS WARMER THAN THE LAST COUPLE OF NIGHTS. BELIEVE THAT IT WILL STILL RADIATE WELL OUT EAST WHERE SKIES WILL REMAIN CLEAR THE LONGEST. THIS WILL SET UP A DECENT GRADIENT IN TEMPERATURES FROM WEST TO EAST OVERNIGHT WITH LOWS NEAR 50 OUT WEST AND INTO THE UPPER 30S FOR THE INLAND VALLEYS. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/... FRONT SHOULD BE MOVING ACROSS NORTHERN OHIO ON FRIDAY AND INTO NORTHWESTERN PA FOR FRIDAY EVENING. MADE VERY FEW CHANGES TO THE CHANCES OF THE SHOWERS AND THUNDERSTORMS ALONG THE FRONT. HOWEVER AM GROWING MORE CONCERNED THAT THE LINE OF SHOWERS/THUNDERSTORMS THAT DEVELOPS MAY END UP BEING A SCATTERED LINE THAT MOVES EASTWARD ACROSS THE CWA AS THE DRY SLOT SURGES ACROSS NORTHERN OHIO. THIS MAY LEAD TO SOME DECENT BREAKS AND SOME BREEZY CONDITIONS ACROSS NORTHWESTERN OHIO. LATER SHIFTS WILL NEED TO MONITOR THIS HIGHER WIND POSSIBILITY. TEMPERATURES WILL BE COOLER ON FRIDAY WITH THE ADDED CLOUD COVER BUT SHOULD STILL REMAIN A GOOD 10 TO 15 DEGREES ABOVE AVERAGE. A SECONDARY SURGE OF COLD ARI WILL SPILL INTO THE AREA ON SATURDAY AS THE UPPER LEVEL LOW MOVES INTO SOUTHERN ONTARIO. WILL KEEP CHANCE POPS IN THE FORECAST THROUGH THE WEEKEND WITH THE UPPER LEVEL LOW IN THE VICINITY. BEST RAIN CHANCES WILL BE THE SNOWBELT AREAS ACROSS NORTHEAST OHIO AND NORTHWEST PA. TEMPERATURES MAY BE COLD ENOUGH FOR A FEW SNOWFLAKES SATURDAY NIGHT. BETTER CHANCES OF SNOW ARRIVE BY SUNDAY NIGHT AS THE ENTIRE COLUMN COOLS. EXPECT MUCH COOLER CONDITIONS FOR SATURDAY AND SUNDAY WITH HIGHS BACK INTO THE 40S. && .LONG TERM /MONDAY THROUGH THURSDAY/... NOT TOO MANY CHANGES TO THE EXTENDED FORECAST TODAY WITH LITTLE CHANGE NOTED IN THE LONG RANGE GUIDANCE. CYCLONIC FLOW WILL BE UNDERWAY MONDAY MORNING AND I CONTINUED WITH A RAIN/SNOW MIX IN THE SNOWBELT COUNTIES. BY MONDAY NIGHT HOWEVER WEAK RIDGING AT THE SURFACE AND ALOFT SHOULD ACT TO DRY OUT ANY LINGERING RAIN/SNOW SHOWERS AND I DRIED THINGS OUT BY TUESDAY MORNING. SOME MODEL DISCREPANCIES CONTINUE TO REVEAL THEMSELVES FROM TUESDAY AND BEYOND. THE GFS AND GEM MODELS ARE QUITE FAST BRINGING PRECIP UP THE OHIO VALLEY ON TUESDAY WHILE THE EURO IS A BIT MORE CONSERVATIVE. THE NEW EURO IS STARTING TO LOOK MORE AND MORE LIKE THE GFS/GEM SO I DECIDED TO SPLIT THE DIFFERENCE AND BRING RAIN INTO THE SOUTHERN HALF OF THE FORECAST AREA TUESDAY AFTERNOON. THE PERIOD FROM TUESDAY NIGHT THROUGH THURSDAY LOOKS TO BE QUITE ACTIVE AS ONE WAVE MOVES SOUTH OF THE AREA WEDNESDAY...FOLLOWED BY BRIEF HIGH PRESSURE WEDNESDAY NIGHT AND ANOTHER SOUTHERN STREAM LOW ON THURSDAY. LOW CHANCE POPS IN EACH PERIOD LOOKS REASONABLE...HARD TO PIN DOWN ANY SORT OF TIMING THOUGH. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... THE FIRST HALF OF THE TAF PERIOD WILL BE QUIET BUT PRECIP CHANCES WILL INCREASE FRI AM. COLD FRONT STILL ON TRACK TO MOVE INTO NW PA TOWARD END OF TAF PERIOD. CURRENTLY A BAND OF SHRA/TSRA OVER INDIANA. THIS BAND WILL CONTINUE TO MAKE ONLY VERY SLOW PROGRESS E OVERNIGHT WHILE ALSO SLOWLY DISSIPATING. WILL START PRECIP AS EARLY AS 09Z AT KTOL BUT PRECIP SHOULD BE VERY LIGHT. BETTER CHANCES FOR PRECIP WILL COME FRI AFTERNOON AS FRONT MOVES THROUGH. LOCATIONS E OF I-71 CORRIDOR WILL SEE GOOD CHANCES FOR CONVECTION FRI AFTERNOON. THUNDER WILL BE A POSSIBILITY BUT FOR NOW WILL ONLY MENTION CB IN TAFS. HEAVIER SHOWERS COULD DROP VSBYS AND CIGS TO MVFR. LOCATIONS BEHIND FRONT WILL BE DRY SLOTTED AND EXPECT KTOL AND KFDY TO BE DRY ONCE INITIAL BAND OF SHOWERS MOVES THROUGH LATE TONIGHT. LIGHT SE TO S FLOW WILL BECOME SW AND GUSTY ON FRI. OUTLOOK...ANOTHER ROUND OF MVFR CONDITIONS SATURDAY AS A SECONDARY FRONT MOVES THROUGH. THE MVFR CONDITIONS WILL LAST INTO SUNDAY. HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION MONDAY WITH VFR CONDITIONS TRYING TO RETURN TO MUCH OF THE FORECAST AREA. && .MARINE... LAKE BREEZE WILL QUICKLY SHIFT BACK TO A MORE SOUTHERLY FLOW BY LATE THIS EVENING AS WINDS LINE UP OUT OF THE SOUTH AHEAD OF A COLD FRONT THAT WILL MOVE EAST ACROSS THE LAKE FRIDAY. WITH THE PASSAGE OF THE COLD FRONT WINDS WILL KICK UP OUT OF THE SW TO 10 TO 20 KNOTS FRIDAY NIGHT AND 15 TO 25 KNOTS SATURDAY AS THE FLOW TURN A LITTLE MORE TOWARD THE WEST. THIS WILL MEAN SMALL CRAFT CONDITIONS FOR THE NEARSHORE FOR SATURDAY WHICH PROBABLY WILL CONTINUE INTO EARLY MONDAY IN THE EAST HALF. WEAK HIGH PRESSURE RIDGING IS EXPECTED OVER LAKE ERIE MONDAY NIGHT AND TUESDAY WHICH SHOULD MEAN LIGHT AND VARIABLE FLOW. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. MARINE...NONE. && $$ SYNOPSIS...MULLEN NEAR TERM...KOSARIK SHORT TERM...MULLEN LONG TERM...LEINS AVIATION...KUBINA MARINE...ADAMS/GARNET oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 853 PM EST THU NOV 6 2008 .SYNOPSIS... A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT AND PUSH THROUGH THE REGION FRIDAY MORNING. THIS WILL BRING A CHANCE OF SHOWERS TONIGHT INTO FRIDAY...ALONG WITH MUCH COOLER TEMPERATURES FOR THE WEEKEND. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... THE LATEST RUC SFC ANALYSIS INDICATES A 994 MB LOW ACROSS SRN MINNESOTA...WITH A COLD FRONT EXTENDING FROM THE LOW ACROSS CENTRAL ILLINOIS. AHEAD OF THE COLD FRONT THE LEADING EDGE OF AN AXIS OF MOISTURE CURRENTLY EXTENDS ALONG THE INDIANA/OHIO BORDER...WITH WARMER TDS ADVECTING INTO THE WRN CWA. ALONG THIS AXIS...A LAYER OF LOW TO MID LEVEL CU ALONG WITH ISOLD SHOWERS CONTINUE TO DECREASE IN COVERAGE AS THEY MOVE CLOSER TO THE CWA. OVERNIGHT...A FEW LIGHT SHOWERS OR SPRINKLES WILL WORK THEIR WAY INTO THE CWA. WITH TDS AND CLOUD COVERAGE INCREASING...LOW TEMPS FOR MUCH OF THE AREA WILL BE THE WARMEST YET THIS MONTH. AS THE H5 RIDGE EXITS EAST OF THE CWA...THE ERN THIRD OF THE CWA SHOULD SHOULD HAVE SOME RADIATIONAL COOLING WITH CLEAR SKIES BEFORE GIVING WAY TO CLOUD COVERAGE DURING THE EARLY MORNING HRS. LOWS OVERNIGHT WILL RANGE FROM THE MID 40S ACROSS THE ERN THIRD OF THE CWA TO THE LOW 50S FOR THE WRN TWO THIRDS. MINOR UPDATE TO THE GRIDS TO ACCOUNT FOR THE LATEST TRENDS. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... UPPER LEVEL LOW FORECAST TO ROTATE ACROSS THE UPPER GREAT LAKES FRIDAY INTO SATURDAY...WHILE COLD FRONT MOVES THROUGH OUR AREA DURING THE DAY ON FRIDAY. AS WE GET INTO A MORE FAVORABLE TIME OF DAY EXPECT PCPN TO BECOME MORE WIDESPREAD ACROSS OUR EAST THROUGH LATE MORNING AND ON INTO FRIDAY AFTERNOON. SOME VERY LIMITED ELEVATED INSTABILITY DEVELOPS THROUGH EARLY AFTERNOON ACROSS THE EAST AND THIS MAY BE ENOUGH FOR AN ISOLATED THUNDERSTORM OR TWO...BUT PREFER TO LEAVE MENTION OUT OF FORECAST AT THIS POINT DUE TO LOW PROBABILITY. WE SHOULD SEE DRY SLOT SLOWLY PUSH INTO THE WEST THROUGH THE DAY AND WOULD NOT BE SURPRISED TO SEE SOME DECENT SUNSHINE IN THE AFTERNOON ACROSS PARTS OF THE WEST. HAVE TRIED TO INDICATE THIS IN THE GRIDS...BUT WILL JUST HAVE PARTLY SUNNY TYPE WORDING IN THE ZONES. WITH SOME UNCERTAINTY IN CLOUD COVER AND BETTER CAA HOLDING OFF UNTIL FRIDAY NIGHT...WILL NOT DEVIATE TOO MUCH FROM GUIDANCE FOR HIGHS ON FRIDAY. CYCLONIC LOW LEVEL FLOW WILL THEN PERSIST ACROSS THE REGION THROUGH THE REMAINDER OF THE SHORT TERM PERIOD. THIS MAY BE ENOUGH TO SQUEEZE OUT A FEW SHOWERS...PARTICULARLY ACROSS OUR NORTH WHERE MOISTURE IS A LITTLE BETTER. BEST CHANCE FOR ANY SHOWER ACTIVITY WILL PROBABLY BE DURING THE MORE DIURNALLY FAVORABLE AFTERNOON HOURS. AND WILL PLAY FORECAST ACCORDINGLY. && .LONG TERM /SUNDAY THROUGH THURSDAY/... UNCERTAINTY REMAINS SIGNIFICANT THROUGH THIS PERIOD WITH LARGE DIFFERENCES BETWEEN MODEL RUNS SHOWING UP BY MONDAY NIGHT. WHAT IS CERTAIN IS THAT A LARGE UPPER TROUGH WILL BE IN PLACE ACROSS THE REGION TO START OFF THE PERIOD. WITH CYCLONIC FLOW ACROSS THE GREAT LAKES...EXPECT BELOW AVG TEMPS AND MOSTLY CLOUDY CONDITIONS TO START OFF THE WEEK. MAY SEE A FEW LIGHT RAIN OR SNOW SHOWERS ACROSS THE NORTHERN CWA ON SUNDAY AS EMBEDDED ENERGY ROTATES AROUND THE UPPER LOW. AFTER THIS...THE LARGE SCALE PATTERN WILL SHIFT TO A BROAD UPPER TROUGH OVER THE WESTERN U.S. WITH SOUTHWESTERLY FLOW ACROSS THE OHIO VALLEY. TIMING OF DISTURBANCES IN THIS FLOW PATTERN IS DIFFICULT TO DETERMINE SO MODEL SPREAD IS LARGE. BOTH ECMWF AND GFS SEND ENERGY OUT OF THE SOUTHWEST INTO THE OHIO VALLEY EARLY TO MID WEEK...BUT TIMING DIFFERENCES ARE SIGNIFICANT. GFS SEEMS MUCH TOO FAST WITH THIS SYSTEM AND THE 00Z ECMWF TOO DEEP. WENT MUCH CLOSER TO A 00Z GFS ENSEMBLE MEAN SOLUTION...WITHOUT MUCH DETAIL IN TIMING OF POPS NEXT WEEK DUE TO THE HIGH UNCERTAINTY. FOR NOW...EXPECT RAIN CHANCES TO SPREAD IN FROM THE SOUTHWEST TUES AND WEDS...BUT COVERAGE AND TIMING ARE TOO HARD TO PIN DOWN AT THIS POINT. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... SCATTERED SHOWERS ASSOCIATED WITH A COLD FRONT WILL AFFECT TAF SITES...ESPECIALLY FROM 09Z TO 15Z WHEN VISIBILITIES MAY FALL TO MVFR AT TIMES. EXPECT CEILINGS TO STAY BARELY IN THE VFR CATEGORY AT 3500 FT. SOUTHEAST WINDS WILL SHIFT TO SOUTHWEST AROUND 15Z WITH SPEEDS UP TO 12 KNOTS POSSIBLE. OUTLOOK...MVFR CEILINGS ARE POSSIBLE SATURDAY THROUGH SUNDAY. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. KY...NONE. IN...NONE. && $$ SYNOPSIS...JGL NEAR TERM...WOODRUM SHORT TERM...JGL LONG TERM...HAWBLITZEL AVIATION...CONIGLIO oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 721 PM CST THU NOV 6 2008 .UPDATE... UPGRADED PART OF NORTHEAST SD WINTER WEATHER ADVISORY TO A WINTER STORM WARNING DUE TO THE PRESENT ACCUMULATIONS IN THE AREA OF 2 TO 3 INCHES AND SNOW CONTINUING FOR SEVERAL HOURS YET. OTHERWISE...REST OF FORECAST WILL NOT CHANGE AS SNOW CONTINUES TO WRAP AROUND UPPER LOW AND WINDS CONTINUE VERY STRONG CREATING WIDESPREAD BLOWING SNOW AND LOW VISIBILITIES. && .PREV DISCUSSION... .SHORT TERM...TONIGHT THROUGH SATURDAY FORECAST FOCUS ON BLIZZARD CONDITIONS THIS EVENING AND TONIGHT. AFTER MUCH HOOPLA...WELL ADVERTISED WINTER STORM FINALLY TAKEN SHAPE OVER NORTH-CENTRAL AND NORTHEASTERN SOUTH DAKOTA. CURRENT WATER VAPOR IMAGERY SHOWING WELL DEFINED UPPER LOW CENTERED NEAR SIOUX FALLS...WITH DRY SLOT CURRENTLY WRAPPING N/NWWD INTO SRN MN. MSAS SURFACE ANALYSIS SHOWING PRIMARY LOW PRESSURE CENTER NOW CONSOLIDATING OVER SRN MN AS IMPRESSIVE 130M HEIGHT FALLS AT H5 OVERSPREAD THE AREA. AS SUCH...VERY TIGHT PRESSURE GRADIENT RESIDING OVER THE DAKOTAS WITH CURRENT WIND GUSTS IN THE 30 TO 50 MPH OVER THE WESTERN HALF OF SD WHERE BLIZZARD CONDITIONS CONTINUE. CLOSER TO HOME...AREA RADARS CURRENTLY SHOWING A PRONOUNCED INCREASE IN PRECIP COVERAGE AS NEXT SLUG OF MOISTURE ASSOCIATED WITH WARM CONVEYOR BELT ROTATES INTO THE AREA FROM THE E/NE. INITIAL FORECAST PROBLEM THIS EVENING WILL BE TIMING DEVELOPMENT AND/OR CHANGEOVER TO SNOW. NAM/GFS/RUC THERMAL PROGS AND SOUNDINGS INDICATE THAT AREAS WEST OF THE JAMES VALLEY WILL SEE A QUICKER CHANGEOVER TO SNOW DUE TO COLDER SFC TEMPS /LIKELY BY 4PM CST/. FURTHER EAST...18Z SOUNDING AT KABR SHOWED WARMER BOUNDARY LAYER TEMPS WHICH WILL TAKE SOME TIME TO DIABATICALLY COOL...PROBABLY DELAYING ONSET OF ACCUMULATING SNOW TO AROUND 4 OR 5PM AT ABERDEEN...AND POSSIBILITY AS LATE AS 6PM ALONG I-29 NEAR SISSETON. ONCE SNOW BEGINS...BELIEVE WE WILL SEE SOME RATHER IMPRESSIVE SNOWFALL RATES AND REDUCTIONS IN VISIBILITY DUE TO COMBINATION OF PLENTIFUL MOISTURE /4 TO 5 G/KG/...STRONG LIFT THROUGH THE DENDRITIC ZONE...AND LOW STATIC STABILITY. SNOWFALL RATES OF AN INCH OR TWO PER HOUR WILL BE POSSIBLE IN HEAVIER BANDS. VISIBILITIES ARE STILL FORECAST TO DROP BELOW 1/4 MILE AT TIMES DUE TO FALLING/BLOWING SNOW...RESULTING IN OCCASIONAL BLIZZARD CONDITIONS. GFS/NAM AND LOCAL HIRES WRF-ARW MODELS INDICATE THAT THE HEAVIEST SNOW SHOULD GENERALLY FALL BETWEEN 00Z AND 09Z...WITH A GRADUALLY DECREASE IN THE PRECIP INTENSITY/COVERAGE BY FRIDAY MORNING AS ANOTHER SURGE OF DRY AIR WRAPS INTO THE AREA. TOTAL SNOWFALL AMOUNTS REMAIN SOMEWHAT PROBLEMATIC DUE TO BANDING POTENTIAL...BUT BELIEVE A FEW LOCATIONS COULD SEE 4 TO 8 INCHES BY FRIDAY AFTERNOON...WITH LOCALLY HIGHER AMOUNTS WITHIN M0RE PERSISTENT BANDS. OF COURSE WITH 40+ MPH WINDS...MEASURING SNOW WITH ANY ACCURACY IS ALWAYS A TREAT. COULD ALSO SEE ANOTHER PERIOD OF LIGHT FREEZING RAIN/DRIZZLE ON FRIDAY AS MODEL SOUNDINGS SHOW A LOSS OF ICE IN THE CLOUDS. LOW PRESSURE SYSTEM WILL GRADUALLY SLIDE OFF THE EAST ON FRIDAY NIGHT AND SATURDAY ENDING ANY AND ALL PRECIP. WITH EXPECTED SNOWCOVER...BELIEVE TEMPS WILL BE RATHER CHILLY FRIDAY NIGHT /20S OR TEENS/ AND SATURDAY /LOW 30S/. .LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY FAIR AGREEMENT BETWEEN MEDIUM RANGE MODELS. HPC GUIDANCE AND MODELS CONTINUE TO POINT TO A DRY PERIOD THROUGH THE EXTENDED PERIOD. STAYED WITH THE IDEA OF TEMPERATURES BELOW CLIMATOLOGICAL NORMALS EXPECTING AFFECTS OF NEW SNOW FIELD TO HOLD VALUES LOW. OTHERWISE MADE FEW ADJUSTMENTS TO GOING GRIDS THAT APPEAR TO BE IN GOOD SHAPE. && .AVIATION... SNOW AND BLOWING SNOW ALONG WITH MVFR/IFR CEILINGS AND VISIBILITIES WILL CONTINUE THROUGH THE NIGHT AT ALL TAF SITES. EXPECT IMPROVEMENT IN VISIBILITIES AND CEILINGS ON FRIDAY AS THE SNOW DECREASES AND WINDS DECREASE. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...BLIZZARD WARNING UNTIL 12 PM CST /11 AM MST/ FRIDAY FOR BROWN- BUFFALO-CAMPBELL-CLARK-CORSON-DAY-DEWEY-EDMUNDS-FAULK-HAND- HUGHES-HYDE-JONES-LYMAN-MARSHALL-MCPHERSON-POTTER-SPINK- STANLEY-SULLY-WALWORTH. WINTER WEATHER ADVISORY UNTIL 12 PM CST FRIDAY FOR ROBERTS. WINTER STORM WARNING UNTIL 12 PM CST FRIDAY FOR CODINGTON-DEUEL- GRANT-HAMLIN. MN...WINTER WEATHER ADVISORY UNTIL 12 PM CST FRIDAY FOR BIG STONE- TRAVERSE. && $$ UPDATE...MOHR SHORT TERM...FOWLE LONG TERM...KEEFE AVIATION...MOHR WEATHER.GOV/ABERDEEN sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 322 PM CST THU NOV 6 2008 .SHORT TERM...TONIGHT THROUGH SATURDAY FORECAST FOCUS ON BLIZZARD CONDITIONS THIS EVENING AND TONIGHT. AFTER MUCH HOOPLA...WELL ADVERTISED WINTER STORM FINALLY TAKEN SHAPE OVER NORTH-CENTRAL AND NORTHEASTERN SOUTH DAKOTA. CURRENT WATER VAPOR IMAGERY SHOWING WELL DEFINED UPPER LOW CENTERED NEAR SIOUX FALLS...WITH DRY SLOT CURRENTLY WRAPPING N/NWWD INTO SRN MN. MSAS SURFACE ANALYSIS SHOWING PRIMARY LOW PRESSURE CENTER NOW CONSOLIDATING OVER SRN MN AS IMPRESSIVE 130M HEIGHT FALLS AT H5 OVERSPREAD THE AREA. AS SUCH...VERY TIGHT PRESSURE GRADIENT RESIDING OVER THE DAKOTAS WITH CURRENT WIND GUSTS IN THE 30 TO 50 MPH OVER THE WESTERN HALF OF SD WHERE BLIZZARD CONDITIONS CONTINUE. CLOSER TO HOME...AREA RADARS CURRENTLY SHOWING A PRONOUNCED INCREASE IN PRECIP COVERAGE AS NEXT SLUG OF MOISTURE ASSOCIATED WITH WARM CONVEYOR BELT ROTATES INTO THE AREA FROM THE E/NE. INITIAL FORECAST PROBLEM THIS EVENING WILL BE TIMING DEVELOPMENT AND/OR CHANGEOVER TO SNOW. NAM/GFS/RUC THERMAL PROGS AND SOUNDINGS INDICATE THAT AREAS WEST OF THE JAMES VALLEY WILL SEE A QUICKER CHANGEOVER TO SNOW DUE TO COLDER SFC TEMPS /LIKELY BY 4PM CST/. FURTHER EAST...18Z SOUNDING AT KABR SHOWED WARMER BOUNDARY LAYER TEMPS WHICH WILL TAKE SOME TIME TO DIABATICALLY COOL...PROBABLY DELAYING ONSET OF ACCUMULATING SNOW TO AROUND 4 OR 5PM AT ABERDEEN...AND POSSIBILITY AS LATE AS 6PM ALONG I-29 NEAR SISSETON. ONCE SNOW BEGINS...BELIEVE WE WILL SEE SOME RATHER IMPRESSIVE SNOWFALL RATES AND REDUCTIONS IN VISIBILITY DUE TO COMBINATION OF PLENTIFUL MOISTURE /4 TO 5 G/KG/...STRONG LIFT THROUGH THE DENDRITIC ZONE...AND LOW STATIC STABILITY. SNOWFALL RATES OF AN INCH OR TWO PER HOUR WILL BE POSSIBLE IN HEAVIER BANDS. VISIBILITIES ARE STILL FORECAST TO DROP BELOW 1/4 MILE AT TIMES DUE TO FALLING/BLOWING SNOW...RESULTING IN OCCASIONAL BLIZZARD CONDITIONS. GFS/NAM AND LOCAL HIRES WRF-ARW MODELS INDICATE THAT THE HEAVIEST SNOW SHOULD GENERALLY FALL BETWEEN 00Z AND 09Z...WITH A GRADUALLY DECREASE IN THE PRECIP INTENSITY/COVERAGE BY FRIDAY MORNING AS ANOTHER SURGE OF DRY AIR WRAPS INTO THE AREA. TOTAL SNOWFALL AMOUNTS REMAIN SOMEWHAT PROBLEMATIC DUE TO BANDING POTENTIAL...BUT BELIEVE A FEW LOCATIONS COULD SEE 4 TO 8 INCHES BY FRIDAY AFTERNOON...WITH LOCALLY HIGHER AMOUNTS WITHIN M0RE PERSISTENT BANDS. OF COURSE WITH 40+ MPH WINDS...MEASURING SNOW WITH ANY ACCURACY IS ALWAYS A TREAT. COULD ALSO SEE ANOTHER PERIOD OF LIGHT FREEZING RAIN/DRIZZLE ON FRIDAY AS MODEL SOUNDINGS SHOW A LOSS OF ICE IN THE CLOUDS. LOW PRESSURE SYSTEM WILL GRADUALLY SLIDE OFF THE EAST ON FRIDAY NIGHT AND SATURDAY ENDING ANY AND ALL PRECIP. WITH EXPECTED SNOWCOVER...BELIEVE TEMPS WILL BE RATHER CHILLY FRIDAY NIGHT /20S OR TEENS/ AND SATURDAY /LOW 30S/. .LONG TERM...SATURDAY THROUGH WEDNESDAY FAIR AGREEMENT BETWEEN MEDIUM RANGE MODELS. HPC GUIDANCE AND MODELS CONTINUE TO POINT TO A DRY PERIOD THROUGH THE EXTENDED PERIOD. STAYED WITH THE IDEA OF TEMPERATURES BELOW CLIMATOLOGICAL NORMALS EXPECTING AFFECTS OF NEW SNOW FIELD TO HOLD VALUES LOW. OTHERWISE MADE FEW ADJUSTMENTS TO GOING GRIDS THAT APPEAR TO BE IN GOOD SHAPE. && .AVIATION... A WINTER STORM IS SPOOLING UP OVER THE AREA. VERY STRONG NORTHWEST SURFACE WINDS WILL BE THE RULE ACROSS THE AREA WITH GUSTS APPROACHING 50 KTS. FREEZING RAIN IS COMMON WEST OF THE MISSOURI RIVER AND IS SPREADING EAST. AS TEMPERATURES CONTINUE TO FALL THE FREEZING PRECIPITATION WILL CHANGE OVER TO SNOW AND BE HEAVY AT TIMES. CEILINGS AND VISIBILITY WILL IMPROVE AT TIMES TO NEAR MVFR BUT IFR WILL BE MORE COMMON THROUGH TOMORROW MORNING. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...BLIZZARD WARNING UNTIL 12 PM CST /11 AM MST/ FRIDAY FOR BROWN- BUFFALO-CAMPBELL-CLARK-CORSON-DAY-DEWEY-EDMUNDS-FAULK-HAND- HUGHES-HYDE-JONES-LYMAN-MARSHALL-MCPHERSON-POTTER-SPINK- STANLEY-SULLY-WALWORTH. WINTER WEATHER ADVISORY UNTIL 12 PM CST FRIDAY FOR CODINGTON- DEUEL-GRANT-HAMLIN-ROBERTS. MN...WINTER WEATHER ADVISORY UNTIL 12 PM CST FRIDAY FOR BIG STONE- TRAVERSE. && $$ SHORT TERM...FOWLE LONG TERM...KEEFE AVIATION...KEEFE WEATHER.GOV/ABERDEEN sd AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MIDLAND/ODESSA TX 705 PM CST WED NOV 5 2008 .UPDATE... WE HAVE UPDATED TO REMOVE MENTION OF THE WIND ADVISORY FOR THE SOUTHEAST NEW MEXICO PLAINS...PORTIONS OF THE NORTHERN PERMIAN BASIN...UPPER TRANS PECOS AND MARFA PLATEAU. THE HIGH WIND WARNING FOR THE DAVIS MOUNTAINS ABOVE 6000 FEET HAS ALSO BEEN ALLOWED TO EXPIRE. THE HIGH WIND WARNING FOR THE GUADALUPE MOUNTAINS REMAINS IN EFFECT. MINOR CHANGES HAVE ALSO BEEN MADE TO THIS EVENING/S WINDS AND DEW POINTS. && .DISCUSSION... AREA OBSERVATIONS SHOW WINDS GENERALLY ON THE DECREASE ACROSS WEST TEXAS AND SOUTHEASTERN NEW MEXICO. WINDS ACROSS THE GUADALUPES REMAIN AT OR VERY CLOSE TO HIGH WIND LEVELS...SO THE HIGH WIND WARNING WILL REMAIN INTACT THERE UNTIL 8 PM MST. ELSEWHERE...A COLD FRONT IS CURRENTLY LOCATED JUST NORTH OF ARTESIA TO LOVINGTON. WINDS BEHIND THE FRONT HAVE BEEN SUSTAINED NEAR 20KTS WITH GUSTS AROUND 30KTS. THE LATEST RUC13 AGREES FAIRLY WELL WITH THE CURRENT OBSERVATIONS...SO WE HAVE USED IT/S SOLUTION TO UPDATE WINDS THIS EVENING. ALL PRODUCTS HAVE BEEN SENT. && .PREV DISCUSSION... /ISSUED 559 PM CST WED NOV 5 2008/ DISCUSSION... 00Z AVIATION FORECAST DISCUSSION BELOW. AVIATION... WESTERLY WIND SPEEDS ARE GRADUALLY COMING DOWN ACROSS THE REGION... ALTHOUGH SPEEDS BETWEEN 15 AND 20 KNOTS...WITH A FEW GUSTS OVER 25 KNOTS ARE EXPECTED TO PERSIST AT KCNM AND KHOB THROUGH 03Z. A COLD FRONT WILL MOVE ACROSS THE REGION LATER THIS EVENING...AND WINDS WILL BECOME NORTHWESTERLY FOLLOWING FRONTAL PASSAGE. WIND SPEEDS SHOULD GENERALLY REMAIN BETWEEN 10 AND 15 KNOTS BEHIND THE FRONT...ALTHOUGH SLIGHTLY HIGHER SPEEDS MAY AFFECT THE KHOB TERMINAL UNTIL AROUND 08Z. OTHERWISE...LOOK FOR VFR CONDITIONS THROUGH THE NEXT 24 HOURS. A BAND OF HIGH CLOUDS ACROSS THE REGION SHOULD GRADUALLY DIMINISH BY LATE EVENING...WITH CLEAR SKIES EXPECTED OVERNIGHT THROUGH MUCH OF THE DAY THURSDAY. 21 PREV DISCUSSION... /ISSUED 229 PM CST WED NOV 5 2008/ DISCUSSION... RELATIVELY TYPICAL WIND EVENT TODAY DUE TO AN UPPER LEVEL LOW MOVING NORTH OF THE AREA. HAVE CONTINUED THE HIGH WIND WARNING AND ADVISORY ACROSS THE AREA AS WINDS ARE EXPECTED TO CONTINUE INTO THE EVENING. SOME LOCATIONS... MOST NOTABLY THE NORTHERN PERMIAN BASIN...HAVE NOT YET COME UP TO ADVISORY CRITERIA...BUT THINKING IS THAT THEY STILL COULD OVER THE NEXT HANDFUL OF HOURS...GIVEN THAT MANY LOCATIONS HAVE COME CLOSE. OTHERWISE...WINDS WILL BEGIN TO LAY DOWN TOMORROW AS THE UPPER LEVEL SYSTEM CLEARS THE AREA AND GO TO LIGHT AND VARIABLE INTO THE WEEKEND. AS THE PACIFIC FRONT CONTINUES MOVING THROUGH THE AREA A DRIER AIRMASS WILL BEGIN FILTERING INTO THE AREA EARLY TOMORROW. DEWPOINTS WILL BEGIN TO DROP AND BE INTO THE SINGLE DIGITS/TEENS ACROSS THE AREA BY THURSDAY NIGHT. THIS...ALONG WITH LIGHTER WINDS...WILL ALLOW OVERNIGHT TEMPS TO DROP DOWN QUITE A BIT. BE ON THE WATCH FOR FREEZE WARNINGS POSSIBLY THURSDAY OR FRIDAY NIGHT AS SOME LOCATIONS COULD HIT THE 32F MARK THAT DIDN/T WITH OUR LAST STRONG COLD FRONT. IN ADDITION...GIVEN THE DRY CONDITIONS...FIRE WEATHER CONCERNS WILL BE ON THE INCREASE /SEE FIRE WX DISCO BELOW/. EXPECT ANOTHER ROUND OF WINDS...SIMILAR TO TODAY/S AROUND MONDAY OF NEXT WEEK AS THE NEXT BIG SYSTEM WINDS UP TO MOVE NORTH OF THE AREA. MODELS HINT THAT A SHORT WAVE SYSTEM WILL QUICKLY FOLLOW BEHIND IT DURING MID WEEK THAT COULD KEEP WINDS UP ACROSS SOME PARTS OF THE AREA. RAINFALL CHANCES CONTINUE TO LOOK SLIM THROUGH MUCH OF THE WEEK...ALTHOUGH SOME RETURN FLOW LATE NEXT WEEK COULD BRING SOME MUCH NEEDED MOISTURE WITH THAT MID WEEK SYSTEM. CROSS YOUR FINGERS IF YOU/RE WANTING RAIN.../13/. FIRE WEATHER... STRONG WESTERLY WINDS AND MINIMUM AFTERNOON RH/S NEAR 15 PERCENT WILL COMBINE TO CREATE NEAR CRITICAL FIRE WEATHER CONDITIONS OVER PORTIONS OF THE SOUTHEAST NEW MEXICO PLAINS THIS AFTERNOON. ALTHOUGH WEST WINDS WILL DECREASE IN THE 05/23Z TO 06/03Z TIME FRAME...CONDITIONS WILL IMPROVE ONLY SLOWLY TONIGHT AS A COLD FRONT PUSHES SOUTH THROUGH THE AREA TONIGHT. MUCH DRIER AIR WILL FILTER INTO THE AREA BEHIND THE FRONT WHICH WILL RESULT IN POOR TO FAIR RECOVERY OVERNIGHT MOST LOCATIONS. IN ADDITION...NORTHWEST TO NORTH WINDS WILL BE 15 TO 20 MPH FOR A PERIOD OF TIME BEHIND THE FRONT. DO NOT EXPECT CRITICAL FIRE WEATHER CONDITIONS FOR THREE HOURS OR LONGER THOUGH...SO WILL NOT ISSUE A RED FLAG WARNING. DESPITE COOLER TEMPERATURES AREAWIDE THURSDAY AND FRIDAY...MINIMUM AFTERNOON RH/S WILL DIP TO 10 TO 20 PERCENT MOST LOCATIONS AS THE DRY AIR REMAINS ENTRENCHED OVER THE AREA. HOWEVER...WIND SPEEDS WILL GENERALLY BE LESS THAN 15 MPH BOTH DAYS. RECOVERY THURSDAY AND FRIDAY NIGHT WILL BE POOR TO FAIR. THE NEXT UPPER STORM SYSTEM WILL AFFECT THE REGION SUNDAY NIGHT AND MONDAY. AT THIS TIME...IT APPEARS CRITICAL FIRE WEATHER CONDITIONS WILL NOT BE MET SUNDAY AFTERNOON DESPITE INCREASING SOUTHWESTERLY WINDS. /67/ && .PRELIMINARY POINT TEMPS/POPS... BIG SPRING TX 42 65 33 66 / 0 0 0 0 CARLSBAD NM 42 66 32 66 / 0 0 0 0 DRYDEN TX 52 71 42 70 / 0 0 0 0 FORT STOCKTON TX 42 67 33 67 / 0 0 0 0 GUADALUPE PASS TX 40 60 33 60 / 0 0 0 0 HOBBS NM 41 61 32 63 / 0 0 0 0 MARFA TX 37 64 27 63 / 0 0 0 0 MIDLAND INTL AIRPORT TX 41 65 32 67 / 0 0 0 0 ODESSA TX 41 65 32 67 / 0 0 0 0 WINK TX 42 67 34 68 / 0 0 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...HIGH WIND WARNING UNTIL 8 PM MST THIS EVENING FOR THE FOLLOWING ZONES... GUADALUPE MOUNTAINS OF EDDY COUNTY. TX...HIGH WIND WARNING UNTIL 8 PM MST THIS EVENING FOR THE FOLLOWING ZONES... GUADALUPE MOUNTAINS. && $$ 21/06 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 816 PM CST WED NOV 5 2008 .UPDATE...EVENING SURFACE ANALYSIS HAD LOW PRESSURE LOCATED OVER CENTRAL SOUTH DAKOTA...WITH COLD FRONT TRAILING SOUTHWARD ACROSS MISSOURI RIVER VALLEY. WATER VAPOR IMAGERY INDICATED MID LEVEL CIRCULATION SITUATED ALONG THE NEBRASKA/SOUTH DAKOTA BORDER. SHORT WAVES EVIDENT MOVING THROUGH EASTERN DAKOTAS...WITH ANOTHER VIGOROUS WAVE ADVANCING ACROSS TX/OK PANHANDLE AREA. 850MB MOISTURE TRANSPORT POINTED INTO THE UPPER MISSISSIPPI VALLEY...AS EVIDENCED BY STRONG LOW LEVEL WINDS OF 45-55KT IN PROFILER DATA. IN ADDITION...THERMODYNAMIC PROFILES SHOWED MUCAPE OF 500J/KG ELEVATED ATOP MLCIN VALUES OF 250J/KG. BASED ON LATEST RUC...AS WELL AS SREF DATA...RAIN PROBABILITIES EXPECTED TO INCREASE TONIGHT...ESPECIALLY WEST OF THE MISSISSIPPI RIVER. THIS DUE IN PART TO STRONGLY FORCED LOW LEVEL ENVIRONMENT ASSOCIATED WITH APPROACHING COLD FRONT...ALONG WITH UPPER LEVEL DIVERGENCE. CURRENT FORECAST APPEARS TO HANDLE SCENARIO WELL. ONLY CHANGES NECESSARY WILL BE TO SIMPLY ADJUST TRENDS FOR EVOLVING PRECIPITATION...AS INDICATED BY LATEST RADAR AND FORECAST GUIDANCE. AN UPDATED ZONE FORECAST PRODUCT SHOULD BE ISSUED BY 06.0330Z THIS EVENING. THOMPSON && .PREV DISCUSSION... /ISSUED 245 PM CST WED NOV 5 2008/ SHORT TERM...TODAY THROUGH SATURDAY NIGHT FORECAST CONCERNS FOCUS ON THE PCPN CHANCES/TIMING FOR TONIGHT AND THURSDAY...FOLLOWED BY THE AMOUNT OF COLD AIR AND THEN SNOW CHANCES. CURRENTLY...500 MB TROUGH AND ASSOCIATED SHORTWAVE ENERGY DRIVING EAST ACROSS THE NORTHERN/CENTRAL PLAINS. AN ASSOCIATED SFC LOW WAS LOCATED IN THE SD/NEB VICINITY...WITH A COLD FRONT RUNNING SOUTH OF THERE. LATEST 88-D RADAR IMAGERY POINTED TO SCT PCPN ALONG AND AHEAD OF THIS FRONT...MOSTLY ASSOCIATED WITH BROAD LOW LEVEL MOISTURE TRANSPORT AND THE LOW LEVEL JET. THE 05.12Z NMM AND NAM12 CONTINUE THIS SCT ACTIVITY THIS EVENING...BUT START TO SHIFT THE MAIN PCPN FOCUS TO THE WEST...WHERE THE BETTER UPPER LEVEL DYNAMICS OF THE 500 MB SHORTWAVE TROUGH AND 300 MB JET WILL LIE. THE 05.12Z GFS SUPPORTS THIS. STRONG...CURVED UPPER LEVEL JET PROGGED TO ENHANCE ANY CONVECTION OVER MN/IA...ESPECIALLY BETWEEN 06-12Z. FEEL THE ENHANCED QPF SIGNALS IN THE MODELS IN DIRECT RELATION TO THIS STRONG JET. MEANWHILE...THE LOW LEVEL THERMODYNAMICS/MOISTURE WOULD SEEM TO SUPPORT PCPN CHANCES A BIT MORE EAST. BOTH THE GFS AND NAM POINT A STRONG 850 MB JET AND MOISTURE TRANSPORT INTO THE FORECAST AREA BY 12Z THU. IN ADDITION...GOOD ISENTROPIC UPGLIDE IS INDICATED IN THE 295-305 K LAYER IN THIS AREA...ALONG WITH SOME 850-700 MB QG CONVERGENCE. HOWEVER...AS MENTIONED...THE GFS AND NAM SEEM TO KEEP THEIR QPF ASSOCIATED WITH THE UPPER LEVEL FORCING. THE 05.12Z ARXMESOWRF CHOOSES TO PLACES IT QPF MORE WITH THE LOW LEVEL FORCING. THIS HAS A DIRECT BEARING ON THE POPS FOR TONIGHT...AS THE MAJORITY OF THE LATEST MODEL RUNS WOULD HOLD OFF ON THE BEST CHANCES UNTIL AFTER 12Z...AND THE MODELS HAVE BEEN TRENDING SLOWER OVER THEIR PAST COUPLE RUNS. HOWEVER...OTHER THAN THE MESOWRF...FEEL THE MODELS AREN/T CAPTURING THE PCPN POTENTIAL WITH THE LOW LEVEL FORCING. WILL LIKELY TRIM BACK POPS A BIT FOR THIS EVENING...WITH BETTER CHANCES //MORE WIDESPREAD// OVERNIGHT...BUT CONTINUE THESE CHANCES FARTHER EAST THAN THE 12Z RUNS WOULD INDICATE. ONLY A HINT OF SOME MUCAPE BETWEEN 06-18Z...BUT WITH THE STRENGTH OF THE LOW LEVEL JET...PROBABLY ENOUGH FOR ISOLATED THUNDER POTENTIAL. THE FRONT WILL SWING NORTHEAST THROUGH THE REGION ON THU...WHILE THE SYSTEM ITSELF BECOMES VERTICALLY STACKED FOR A SHORT WHILE. THE BETTER LOW LEVEL FORCING WILL ALSO SHIFT NORTHEAST THROUGH THE DAY AS A RESULT...WITH THE SHORTWAVE ENERGY ALSO ON ITS HEELS. THIS SHOULD BRING THE BEST RAIN THREAT WEST OF THE MISSISSIPPI RIVER IN THE MORNING...AND THEN EAST FOR THE AFTERNOON. GOOD ENTRAINMENT OF DRY AIR POST THE SFC FRONT...PER TIME/HEIGHT X-SECTIONS...AND WILL SERVE TO CUTOFF THE PCPN...BUT DON/T EXPECT MUCH CLEARING AT THE MOMENT. THE SYSTEM WILL MOVE OVER THE REGION ON FRI...WITH MILD/MOIST AIR WRAPPING WELL AROUND THE LOW CENTER. THIS WILL LEAD TO MORE PCPN FOR FRI AND SAT...WITH THE SYSTEM EXITING INTO SOUTHEAST CANADA LATE IN THE WEEKEND. HOWEVER...COLDER AIR WILL FLOW IN BEHIND THE LOW...AND WILL CHANGE THE PCPN CHANCES FROM RAIN TO RAIN/SNOW OR JUST SNOW. AS FOR ACCUMULATIONS...RECENT WARMTH SHOULD KEEP MOST ROADS JUST WET...BUT GRASSY SFCS COULD HOLD SOME SNOW. THE 12Z COBB OUTPUT VIA THE GFS AND NAM WOULD DROP 1-3 INCHES AT RST FROM LATE FRI NIGHT THROUGH SAT. LOOKING AT PREVIOUS COBB OUTPUT...THE TREND IS TO START ACCUMULATIONS SOONER WITH THE 12Z RUN COMPARED TO PREVIOUS RUNS...THUS LEADING TO A BIT MORE SNOW ACCUMULATION. FEEL THIS IS OVERDONE AT THE MOMENT...ESPECIALLY THE 3 INCH AMOUNT...BUT AGAIN...SOME SNOW ON GRASSY SURFACES ISN/T OUT OF THE QUESTION. BETTER CHANCES LIKELY TO THE WEST...WHERE THE COLDER AIR AND BEST FORCING/MOISTURE WILL BE TOGETHER LONGER. THE STRETCH OF MILD DAYS WILL COME TO AN END ON FRIDAY...AS THE COLD AIR WITH THE LOW FULLY SPREADS ACROSS THE REGION. HIGHS IN THE 40S WILL RETURN...WITH THIS RETURN TO COLDER TEMPERATURES CONTINUING INTO NEXT WEEK. LONG TERM...SUNDAY THROUGH WEDNESDAY WHILE THE OVERALL UPPER LEVEL PATTERN IS SIMILAR BETWEEN THE GFS AND ECMWF...THE DETAILS ON WHERE VARIOUS PACKETS OF SHORTWAVE ENERGY WILL TRACK...TIMING/PLACEMENT...ARE QUITE VARIABLE. THEY DO AGREE UPON PUSHING THE 500 MB TROUGH/LOW FROM THE EASTERN GREAT LAKES THIS WEEKEND INTO SOUTHEAST CANADA FOR EARLY NEXT WEEK. THIS ALLOWS FOR SOME WEAK RIDGING TO BUILD IN FROM THE NORTHERN PLAINS...WHILE A SHORTWAVE TROUGH MOVES EAST ACROSS THE SOUTHERN PLAINS INTO THE MO RIVER VALLEY. AT THE SFC...BOTH THE ECMWF AND GFS DROP A CANADIAN HIGH ACROSS THE UPPER MISSISSIPPI RIVER VALLEY FOR THE START OF THE NEW WORK WEEK...WHICH WOULD HELP TO KEEP THAT SOUTHERN SHORTWAVE TO THE SOUTH. SO...SENSIBLE WEATHER-WISE...THE MODEL DIFFERENCES MAY NOT HAVE A BIG IMPACT LOCALLY. THE GFS/ECMWF DO AGREE THAT THE COLDER TEMPS WILL SETTLE IN...WITH HIGHS ONLY IN THE 40S THROUGH AT LEAST THE MIDDLE PART OF NEXT WEEK. && AVIATION... LARGE STORM SYSTEM OVER SOUTH DAKOTA WILL EDGE EAST TOWARD THE AREA THROUGH 18Z THURSDAY. BIGGEST QUESTION WITH THIS SYSTEM IS WHEN WILL THE ASSOCIATED PRECIPITATION IMPACT THE TAF SITES. THE NEW 05.12Z NAM AND NMMWRF MODELS NOW SUGGEST THAT THE GREATEST CONCENTRATION OF SHOWERS AND THUNDERSTORMS SHOULD OCCUR TO THE SOUTH OF THE TAF SITES THROUGH 12Z THURSDAY AS THE MAIN SHORT WAVE TROUGH ROTATES AROUND THE BASE OF THE UPPER LEVEL LOW AND INTERSECTS THE LOW LEVEL JET TO PRODUCE WIDESPREAD RAINS ACROSS CENTRAL IOWA AND POINTS SOUTH. THE MAIN BRANCH OF LOW LEVEL JET DOES NOT GET INTO THE AREA UNTIL LATE TONIGHT SO HAVE PUSHED BACK THE TIMING OF THE CATEGORICAL RAIN AND MVFR VISIBILITY UNTIL THE 12 TO 15Z TIME FRAME. THERE IS ENOUGH MOISTURE TRANSPORT INTO THE AREA AFTER 06Z TO MOST LIKELY PRODUCE SOME SCATTERED ACTIVITY AND WILL HAVE VICINITY SHOWERS TO COVER THIS. SOME ELEVATED INSTABILITY IS PRESENT BUT CONFIDENCE ON WHEN AND WHERE ANY THUNDERSTORMS WILL DEVELOP IS TOO LOW TO INCLUDE ANYTHING MORE THAN A CB QUALIFIER AT THIS POINT. ONCE THE RAIN BEGINS EXPECT BOTH MVFR CEILINGS AND VISIBILITY TO BE PRESENT. 04 && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ RIECK wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN 342 AM CST FRI NOV 7 2008 .DISCUSSION...SATELLITE IMAGERY SHOWING AN IMPRESSIVE SYSTEM WOBBLING OVER SW MN. MSAS SFC PRESSURE MINIMUM HOLDING AT 997 MB OVERNIGHT. THE NAM/GFS/RUC ALL SUGGEST THE SFC LOW CIRCULATION BROADENS OVER EC MN AS THE CEN PRESSURE INCREASES TO 1003 MB BY 15Z. ATTM...THIS APPEARS TOO AGGRESSIVE IN FILLING THE LOW AND EXPECTING A SLIGHTLY SLOWER EWRD TRACK THAN MODELS SHOW. BANDS OF RAIN WILL CONTINUE TO LIFT NORTH AND WEST AROUND THE SYSTEM AND OVER THE FA TODAY...KEPT LIKELY TO DEF POPS FOR MOST AREAS...WITH SCT SHRA IN THE TIP OF THE MN ARROWHEAD. FORECAST CHALLENGE IN PCPN TYPE THIS AFTRN THROUGH SATURDAY AFTRN. THE COLD CORE ALOFT AND ASSOCIATED LOWEST THICKNESSES ARE FOUND TO THE SOUTH OF THE SFC LOW AS RELATIVELY WARMER AIR HAS WRAPPED AROUND THE NRN SIDE OF THE SYSTEM...OVER THE WRN GRT LAKES REGION. THICKNESS FALLS...AND SUB-ZERO 850 TEMPS FOUND ON THE BACK SIDE OF THE SYSTEM ARE PROGGED TO SHIFT EAST INTO THE WRN THIRD OF THE FA THIS AFTERNOON AS SYSTEM PROGRESSES SLOWLY E. THIS WILL RESULT IN A PERIOD OF SN MIXING WITH THE RA IN THE WRN AREAS...BEFORE THE LOW LVLS COOL ENOUGH TO SUPPORT ALL SN. HOWEVER...SOME UNCERTAINTY IN SPECIFIC TIMING OF RA TO SN TRANSITION. SUSPECT MODELS ARE ADVANCING SYSTEM E TO QUICKLY. IF SO...RA/SN PHASE CHANGE WILL BE LATER INTO THE EVENING FOR THE WRN AREAS. OVERNIGHT...MOST MN LOCATIONS CAN EXPECT TO SEE RA IN THE EVENING...TRANSITIONING TO A RA/SN MIX OR ALL SN AFTER 06Z. AREAS NEAR LAKE SUPERIOR AND IN NW WIS EXPECTED TO REMAIN WARM ENOUGH FOR RA THROUGH MUCH OF THE NIGHT...POSSIBLY MIXING WITH A FEW SNOW FLAKES AROUND DAY BREAK SAT. AREAS ALONG THE SOUTH SHORE WILL TRANSITIONING TO SN SAT AFTRN...WITH A FEW INCHES OF ACCUMULATION POSSIBLE LATE SAT INTO EARLY SUN. ELSEWHERE...SN ACCUMULATION THROUGH THIS WEEKEND WILL BE MINIMAL. MOST AREAS CAN EXPECT A DUSTING...TO AROUND AN INCH. && .AVIATION...MAINLY MVFR-VFR CONDITIONS EARLY THIS MORNING WILL DETERIORATE TO PRIMARILY IFR-MVFR BY 12Z...AND THEN PERSIST THROUGH MUCH OF THE DAY AS AN INTENSE AREA OF LOW PRESSURE SLOWLY PUSHES EAST ACROSS MINNESOTA. AREAS OF DRIZZLE AND ASSOCIATED LOW STRATUS WILL BE POSSIBLE...ESPECIALLY FROM KDLH AND POINTS NORTH...ALONG THE NORTH SHORE THROUGH THIS MORNING. AREAS OF RAIN WILL THEN BECOME MORE COMMON...FROM WEST TO EAST...BETWEEN 12Z-18Z. CEILINGS AND VSBYS MAY ONCE AGAIN LIFT A BIT DURING THE EARLY AND MID AFTERNOON...BEFORE LOWERING AGAIN DURING THE EVENING. RAIN COULD BECOME MIXED WITH SNOW AS EARLY AS 18Z FROM KINL SOUTH TO KBRD...BUT WILL LIKELY REMAIN ALL LIQUID THROUGH AT LEAST 06Z SATURDAY SOUTH AND EAST OF KDLH. WINDS WILL SHIFT TO THE NORTH AND NORTHWEST BY FRIDAY AFTERNOON...WITH SOME INCREASE IN SURFACE WIND SPEEDS...ALTHOUGH THE STRONGEST WINDS WILL REMAIN JUST SOUTH OF OUR AREA. && POINT TEMPS/POPS... DLH 45 31 37 21 / 70 70 40 10 INL 43 27 31 19 / 80 60 30 10 BRD 43 29 33 22 / 80 60 30 10 HYR 47 34 37 22 / 70 70 60 10 ASX 48 37 37 25 / 70 70 70 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ GRANING/GSF/BETTWY mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTH PLATTE NE 305 AM CST FRI NOV 7 2008 .DISCUSSION... WATER VAPOR SHOWING STRONG DARKENING ROTATING AROUND LOW OVER EASTERN DAKOTA OVER PAST 6 HOURS. MOST LIKELY PV LOBE HAS ALLOWED TROP FOLD TO BRING STRATO AIR DOWN TO AS FAR AS H7 ACCORDING TO LATEST RUC DATA. HOWEVER LOW...IT HAS INDUCED ADDITIONAL CYCLOGENESIS AS SFC ANALYSIS HAS SHOWN A 2MB DROP TO AROUND 994 AS CENTER OF CIRCULATION HAS WOBBLED FROM NEAR FAR TO NEAR ATY. NAM/GFS DID NOT HAVE THIS INCLUDED. AS LOW HAS ROTATED SOUTHWARD...GRAD TIGHTENED ACROSS NORTHEAST CWA AND EXPECT SOME CONVECTIVE MIXING GOING ON AS WELL...BUT WIND GUSTS EXCEEDING 50KT HAVE OCCURRED RECENTLY. CALLS TO NORTHERN CHERRY COUNTY WHERE PERSISTANT BAND OF SNOW ASSOC WITH TROWAL/MOSITURE WRAPPING AROUND LOW IS KEEPING VSBYS UNDER A MILE NEAR KVTN AND 30-40 MILES WEST ALONG HIGHWAY 20. SNOW NOT REALLY SIGNIFICANT AND LIMITED TO THAT AREA SO NO HEADLINES PLANNED AND CONDITIONS SHOULD IMPROVE AFTER SUNRISE AS SUBSIDENCE AND DRIER AIR GET THROWN INTO THE PICTURE. WINDS SHOULD STAY UP TODAY AND WILL KEEP ADV MOSTLY AS INHERITED...BUT ADD SHERIDAN COUNTY PER LATEST OBS AND START EARLIER IN THE WEST. COLD AIR WILL CONTINUE TO WRAP AROUND CYCLONE INTO EASTERN CWA AND TEMPS WILL STRUGGLE TO REACH INTO MID 30S. LACK OF SNOW COVER AND DOWNSLOPE AND MAYBE SOME AFTERNOON SUN WILL HELP FAR SW REACH LOWER 50S. UPPER JET AND SOME ELEVATED MOISTURE WILL DROP DOWN FRONT OF S/W RIDGE OVER N.ROCKIES THIS EVENING AS NEXT SYSTEM APPROACHES PAC NW. THIS COULD TRIGGER SOME LIGHT SNOW SHOWERS BUT MOST LIKELY NON MEASURABLE FLURRIES SIMILAR TO WHAT IS HAPPENING UPSTREAM ATTM SO WILL LEAVE OUT ATTM WITH LOW CONFIDENCE...HOWEVER THIS UPPER LIFT IS MOVING OVHD A LLVL THERMAL BOUNDARY. CHANNELIZED VORT ENERGY DROPPING DOWN IN STRONG NW FLOW LOOKS TO REINFORCE THE COLD AIR THROUGH SAT ON BACK SIDE OF JET AND AGAIN LOOKS LIKE BIG CONTRAST BETWEEN LOWER 30S NE TO LOWER 50S IN THE FAR SW. THE ARCTIC FRONT LOOKS TO PROGRESS WESTWARD AFTER SUNSET AND MOVING INTO WESTER CWA. SOUNDINGS STILL SHOW SOME POTENTIAL FOR FREEZING PCPN WITH DRY DENDRTIC LAYER...AND HAVE KEPT MENTION OF FZDZ...OR LIGHT SNOW WHICH SEEMS UNLIKELY AS LIFT IS MINIMAL AT BEST. AFTER THIS PERIOD MODELS BEGIN TO DIVERGE IN VARIOUS DIRECTIONS. NAM MOST AGGRESSIVE BRINGING ARCTIC SHOT IN FOR SUNDAY AS IT HAS THE FARTHER WEST SOLN OF THE STRONGER WAVE ROTATING AROUND GREAT LAKES VORTEX AND BRING MUCH COLDER AIR INTO NORTHEAST CWA AND BACKS IT INTO WELL INTO WESTERN CWA. GFS/EURO/CAN IN BETTER AGGREEMENT WITH THIS WAVE NOT PUSHING COLD AIR INTO AREA UNTIL SUN NITE...WHICH WILL BRING COLD START TO NEXT WEEK. GFS BECOMES OUTLIER WITH NEXT SYSTEM MOVING OUT OF ROCKIES AND CLOSING OVER THE PLAINS MONDAY INTO TUESDAY. EURO SEEMS GOOD COMPROMISE ATTM WITH BEST PCPN CHANCES OVER SOUTHERN CWA AND MADE A FEW TWEAKS. && .AVIATION... STRONG LOW PRESSURE SYSTEM CONTINUES TO SLOWLY PUSH NORTHEAST ACROSS SOUTHERN MINNESOTA. NORTHWEST WINDS WILL REMAIN GUSTY TODAY AT BOTH TERMINAL SITES...KLBF AND KVTN. AT KVTN...LIGHT SNOW SHOWERS WITH OCCASIONAL MVFR CIGS AND MVFR/IFR VSBY TO EXPECTED THIS MORNING. SLOWLY CONDITIONS TO IMPROVE TO VFR BY AFTERNOON ACROSS THE STATE. WINDS NOT EXPECTED TO DIMINISH MUCH BEFORE SUNSET. OVERNIGHT DECREASING CLOUDS AND LIGHT WINDS EXPECTED TO DEVELOP. && .LBF WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS AFTERNOON FOR NEZ004>010-022>029-035>038-056>059-069>071-094. && $$ 13/MASEK ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 915 AM EST FRI NOV 7 2008 .SYNOPSIS... 14Z WATER VAPOR AND H4 RUC ANALYSIS SHOWING AN AMPLIFIED UPPER LEVEL PATTERN ACROSS NORTH AMERICA THIS MORNING. THE FEATURE THAT IMMEDIATELY DRAWS ATTENTION IS THE DEEP LONGWAVE TROUGH OVER THE CENTRAL PORTION OF THE CONTINENT ANCHORED BY A STRONG 535DM UPPER LEVEL LOW SPINNING OVER THE UPPER MISSISSIPPI VALLEY. THIS LARGE SYSTEM ACROSS THE MID-SECTION OF THE COUNTRY IS CURRENTLY FLANKED ON BOTH SIDES BY UPPER LEVEL RIDING ALONG BOTH COASTS. THE UPPER LEVEL RIDGE IS NOW IN FIRM CONTROL FOR TODAY ALONG THE EAST COAST AS THE OLD UPPER LOW THAT HAD BEEN SPINNING OFF THE MID-ATLANTIC STATES FINALLY BEGINS TO FILL AND MOVE OFF TOWARD THE CANADIAN MARITIMES. STRONG SHORTWAVE EMBEDDED WITHIN THE MAIN TROUGH OVER THE CENTRAL PLAINS IS EXTENDING SOUTHWARD INTO THE SOUTHERN PLAINS AS IT ROTATES AROUND THE MAIN UPPER LOW. IT WILL BE THIS FEATURE THAT HELPS PROPEL THE SURFACE COLD FRONT EASTWARD ACROSS THE FORECAST AREA OVER THE NEXT 24 HOURS. AT THE SURFACE...1019MB HIGH PRESSURE IS IN CONTROL OF THE FORECAST AREAS THIS MORNING CENTERED AROUND VALDOSTA. HOWEVER...CHANGES ARE ON THE WAY AS WE NOW SEE TONIGHT`S COLD FRONT ALIGNED FROM THE CENTRAL TN VALLEY SOUTHWEST INTO NORTHERN AL AND SOUTHERN MS. REGIONAL RADARS SHOWING A SCATTERING OF SHOWERS ALONG AND AHEAD OF THIS FRONT STILL WELL TO THE WEST OF OUR ZONES...HOWEVER THE MAIN CLOUD SHIELD IS JUST BEGINNING TO ENTER OUR SE AL/PANHANDLE ZONES. && .DISCUSSION/UPDATE...(TODAY THROUGH SATURDAY). MID-LEVEL SHORTWAVE DISCUSSED ABOVE NOW APPROACHING THE SOUTHERN MS VALLEY WILL CONTINUE TO HELP PUSH THE COLD FRONT EASTWARD INTO THIS EVENING. AHEAD OF THIS FRONTS PROGRESS...WILL SEE A STEADY INCREASE IN CLOUDS WEST OF A LINE FROM AROUND ALBANY TO PANAMA CITY INTO THE AFTERNOON HOURS. SHOWER ACTIVITY WILL HOLD OFF FOR THE TIME BEING BUT MAY SEE SCT SHOWERS BEGIN TO IMPACT PORTIONS OF SE AL LATE IN THE AFTERNOON AND MORE LIKELY TOWARD AND AFTER SUNSET. ANOTHER WARM DAY FOR EARLY NOVEMBER UPCOMING WITH UPPER 70S TO PERHAPS 80 EAST OF A LINE FROM ALBANY TO TALLAHASSEE WHERE MOSTLY TO PARTLY SUNNY SKIES WILL BE THE RULE. FURTHER WEST WHERE CLOUDS WILL BE MORE ON THE INCREASE HIGH TEMPS WILL BE HELD IN THE MIDDLE 70S...BUT STILL NOT BAD FOR THIS TIME OF YEAR. COLD FRONT ENTERS THE WESTERN FORECAST AREA DURING THE MIDDLE TO LATER EVENING HOURS AND CONTINUES A FAIRLY STEADY EASTWARD PROGRESSION THROUGH THE NIGHT. BEST CHANCES FOR SCT SHOWERS AND PERHAPS AND ISOLATED THUNDERSTORM OVER THE NORTHWEST HALF OF THE AREA WILL GENERALLY FALL BEFORE 2 TO 3 AM. THE CHANCES FOR THUNDER DO APPEAR RATHER SMALL AT THIS TIME AS THE LARGE SCALE FORCING ASSOCIATED WITH THE SHORTWAVE IS PROGGED TO WEAKEN AND SHEAR OFF TO THE NORTHEAST AS IT ENTERS THE REGION. IN ADDITION INSTABILITY IS LIMITED AT BEST. IN FACT LATEST SREF PROBABILITIES FOR 500 J/KG (EVEN OVER THE WESTERN ZONES) IS LESS THAN 10% AND LI`S ASSOCIATED WITH THE PRE-FRONTAL ENVIRONMENT RISE RAPIDLY TO BETWEEN +2 AND +5 AFTER SUNSET. EITHER WAY THE BAND OF SHOWERS PROGRESSING EASTWARD AHEAD OF THE FRONT SHOULD BE THIN WITH ANY RAINFALL BEING BRIEF IN NATURE. THEREFORE ALTHOUGH MOST LOCATIONS WILL SEE A BRIEF SHOWER AND HENCE POPS ARE ON THE HIGH SIDE...THE OVERALL IMPACT WILL BE LOW AS RAINFALL AMOUNTS ARE ANTICIPATED TO BE LIGHT. COLD FRONT CROSSES THROUGH THE VALDOSTA TO TALLAHASSEE AND APALACHICOLA VICINITY AFTER MIDNIGHT IN THE PRE-DAWN HOURS WITH JUST A BRIEF SHOWER POSSIBLE. COLD FRONT LOOKS TO EXIT THE EASTERN PART OF THE CWA IN THE FIRST FEW DAYLIGHT HOURS SATURDAY MORNING WITH RAPID CLEARING ARRIVING FROM THE WEST AS HIGH PRESSURE BUILDS ALONG THE NORTHERN GULF COAST. MUCH DRIER LOW LEVEL AIR WILL ARRIVE DURING THE DAY ON SATURDAY...HOWEVER THE AIRMASS IMMEDIATELY BEHIND THE FRONT IS NOT ALL THAT MUCH COLDER AND SHOULD STILL ALLOW AFTERNOON HIGH TEMPERATURES TO REACH THE LOWER AND MIDDLE 70S. ANY LINGERING MORNING CLOUDS ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA SHOULD BE EXITING BY EARLY AFTERNOON WITH PARTLY TO MOSTLY SUNNY SKIES AREA-WIDE. && .MARINE...VERY LIGHT WINDS AND SEAS ONGOING THIS MORNING. STILL EXPECTING A SLOW INCREASE OUT OF THE SOUTH THIS AFTERNOON... ESPECIALLY ACROSS THE WESTERN LEGS AS THE COLD FRONT APPROACHES. HOWEVER...WINDS WILL NOT INCREASE ABOVE 15 KNOTS UNTIL THE OVERNIGHT HOURS WHEN THE COLD FRONT PASSES AND WINDS TURN TO THE NORTHWEST. IT IS LOOKING MORE LIKELY THAT WE WILL SEE A PERIOD OF CAUTIONARY CONDITIONS BEHIND THE FRONTAL PASSAGE WITH THE POTENTIAL FOR A BRIEF PERIOD OF NEAR ADVISORY WINDS OVER THE WESTERN LEGS. HOWEVER...THE SHORT DURATION OF 15 TO 20 KNOT WINDS AND A LIMITED FETCH LENGTH WILL KEEP SEAS EVEN WELL OFFSHORE ONLY AROUND 5 FEET. WINDS AND SEAS WILL DIMINISH ONCE AGAIN THROUGH THE REMAINDER OF THE WEEKEND AS HIGH PRESSURE BUILDS ALONG THE NORTHERN GULF COAST. ANOTHER INCREASE IN WINDS WILL BE LIKELY BY TUESDAY AS HIGH PRESSURE BUILDS OFF THE MID ATLANTIC COAST AND CREATES A TIGHT PRESSURE GRADIENT ACROSS OUR WATERS BETWEEN THIS RIDGE TO THE NORTHEAST AND PALOMA (IN EITHER TROPICAL OR SUBTROPICAL FORM) TO OUR EAST. && .AVIATION... PATCHES OF DENSE FOG WITH VIS BETWEEN 1/4 AND 1/2 MILE WHICH FORMED ACROSS THE REGION OVERNIGHT ARE LINGERING AT MOST OF THE TAF SITES AFTER SUNRISE THIS MORNING...WITH PFN OUR ONLY LOCATION AT VFR AS OF 8 AM EST. FORTUNATELY...IT APPEARS THAT THIS FOG IS VERY SHALLOW...AND MANY LOCATIONS ARE IMPROVING QUITE QUICKLY BETWEEN 8 AND 9 AM...WITH ONLY TLH HANGING ON TO 1/4 MILE VIS. ONCE THIS FOG COMPLETELY LIFTS...EXPECT PARTLY CLOUDY VFR SKIES TO BE THE RULE..WITH INCREASING MID LEVEL CLOUDS FROM WEST TO EAST FOR THE REMAINDER OF THE DAY. BY LATE AFTERNOON...MAY SEE A FEW SHOWERS APPROACH DHN. ON THE NEXT FULL TAF PACKAGE EARLY THIS AFTERNOON... WILL LIKELY ELIMINATE THUNDER FROM THE FCST FOR TONIGHT...AS IT NOW APPEARS FAIRLY CLEAR THAT INSTABILITY WILL BE INSUFFICIENT BY THE TIME THE LINE OF SHOWERS REACHES THE CWA. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 79 52 74 41 74 / 0 40 0 0 0 PANAMA CITY 76 56 73 51 73 / 10 50 0 0 0 DOTHAN 77 48 73 45 72 / 20 60 0 0 0 ALBANY 79 50 73 40 71 / 0 50 0 0 0 VALDOSTA 79 52 74 42 73 / 0 40 05 0 0 CROSS CITY 80 52 75 42 77 / 0 20 10 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...FIRE WEATHER WATCH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES: BAY...CALHOUN...DIXIE...FRANKLIN...GADSDEN...GULF...HOLMES... INLAND WALTON...JACKSON...JEFFERSON...LAFAYETTE...LEON... LIBERTY...MADISON...TAYLOR...WAKULLA...WASHINGTON. GM...NONE. && $$ AVIATION...GOULD MARINE...MROCZKA/GODSEY SYNOPSIS/UPDATE...MROCZKA fl AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 703 AM EST FRI NOV 7 2008 UPDATED FOR 12Z AVIATION DISCUSSION .SYNOPSIS... 09Z WV IMAGERY AND RUC ANALYSIS SHOW A LARGE UPPER LOW ROTATING OVER SW MN WITH A FAIRLY BROAD UPSTREAM RIDGE OVER THE WRN CONUS. STACKED LOW PRESSURE RESULTING IN 998 MB SFC LOW PRES OVER SW MN. TIGHTLY PACKED PRESSURE GRADIENT BEHIND THE LOW IS STILL PRODUCING VERY STRONG NW WINDS (GUSTS OVER 40 MPH AT SOME LOCATIONS) ACROSS DAKOTAS AND BLIZZARD CONDITIONS OVER CENTRAL SD. OVER OUR AREA...THE INITIAL BAND OF WAA RAIN AHEAD OF THE LOW HAS GENERALLY EXITED ALL EXCEPT FAR ERN COUNTIES OF UPR MI. DRY SLOT AS DEPICTED ON FCST SNDGS AND NOTED ON WATER VAPOR LOOP IS MOVING ACROSS MUCH OF THE U.P EARLY THIS MORNING. THE DRY SLOT HAS EITHER ENDED THE RAIN OR DIMINISHED PCPN TO -DZ. && .DISCUSSION... GIVEN THE DRY SLOT MOVING OVER THE AREA AND THE SLOWER ADVANCE OF THE UPR LOW TODAY TOWARD THE GREAT LAKES AS DEPICTED BY THE 00Z MODELS...HAVE DECIDED TO TRIM BACK COVERAGE OF SHRA TO ISOLD FOR ALL BUT THE FAR SW FCST AREA FOR LATE IN THE AFTERNOON. AS THE UPPER LOW SLOWLY SLIDES SOUTH OF THE FCST AREA LATE TONIGHT LOOK FOR PCPN IN DEFORMATION ZONE/COMMA HEAD OF UPR LOW TO WRAP BACK TOWARD THE WRN FCST AREA ESPECIALLY TOWARD 12Z SAT WHEN MODELS SHOW INCREASING ISENTROPIC ASCENT ON THE 290-295K SFC. THUS...HAVE KEPT LIKELY POPS OVER THE FAR WEST BUT HAVE TRIMMED BACK POPS TO AROUND 40 PCT OVER THE FAR EAST DUE TO LACK OF DEEP MOISTURE AND ABSENCE OF GOOD ISENTROPIC ASCENT. GIVEN DEGREE OF WARM AIR AT 850 MB (-1 TO -2C TEMPS) THAT`S WRAPPING BEHIND THE LOW LOOK FOR PCPN TYPE TO BE MOSTLY RAIN TONIGHT. AS DEFORMATION ZONE WITH SYSTEM AND IMPRESSIVE 290-295K ISENTROPIC ASCENT SPREADS EAST SAT AFTERNOON INTO SAT NIGHT...GRADUALLY UPPED POPS TO CATEGORICAL ACROSS THE NRN AND ERN TIER. COLDER 850 MB TEMPS OF -8 TO -11C FLOODING ACROSS THE AREA LATE SAT INTO SAT NIGHT WILL ENSURE CHANGEOVER FROM LAKE ENHANCED RAIN TO LAKE ENHANCED SNOW. GIVEN THE IMPRESSIVE DYNAMICS LATE SAT INTO SAT NIGHT...WOULD EXPECT THE POTENTIAL FOR SOME HEAVY WET SNOW OVER WRN AND NCNTRL PORTIONS OF THE CWA IN NNW FLOW. ONLY LIMITATION FOR SNOW AMOUNTS IS EXPECTED LOW 10/1 SNOW/WATER RATIO AS MODEL SNDGS INDICATE BETTER MODEL OMEGA OCCURRING BELOW FAVORABLE DENDRITIC SNOW GROWTH REGION. THUS...AT THIS POINT...WOULD NOT ANTIPICATE WARNING SNOW AMOUNTS TO JUSTIFY A WATCH BUT I`M PRETTY CONFIDENT THAT ADVISORIES WILL BE NEEDED FOR SOME WRN AND PERHAPS NCNTRL COUNTIES. WILL ISSUE A SPS TO HIGHLIGHT POTENTIAL FOR SOME HEAVIER WET SNOW LATE SATURDAY INTO SUNDAY. ALTHOUGH PLAINS UPR LOW WILL BE PULLING EAST BY SUN...ANOTHER SHORTWAVE DIVING SOUTH THROUGH THE NRN PLAINS COULD PROVIDE ADDITIONAL ENHANCEMENT FOR LES AND THIS WILL NEED TO BE WATCHED ON LATER MODEL RUNS. LINGERING 850 MB TEMPS OF -9 TO -11C AND DEEP CYCLONIC NWRLY FLOW WILL STILL WARRANT LIKELY POPS FOR THE NW SNOWBELTS DOWNWIND OF LAKE SUPERIOR WITH CHC POPS OVER SRN COUNTIES. && .AVIATION (FOR THE 12Z TAF ISSUANCE)... OTHER THAN LIGHT PATCHY FOG EARLY ON AT BOTH SITES...VFR CONDITIONS PREDOMINATE TODAY AS DRIER AIR SHIFTS IN FM THE SOUTH. EVENTUALLY ...WRAP AROUND MOISTURE AND PCPN CURRENTLY PUSHING ACROSS SE MN...PIVOTS INTO UPR MI FM THE SOUTH THIS EVENING. THE ARRIVAL OF THIS MOISTURE WILL LOWER CIGS TO MVFR LATE THIS EVENING THROUGH THE OVERNIGHT HOURS TONIGHT AND ALSO BRING A BETTER CHANCE OF RAIN SHOWERS. BASED ON LOW LEVEL THICKNESSES AND UPSTREAM OBS...SNOW MAY BEGIN MIX IN WITH THE RAIN AT SAW BY SUNRISE ON SATURDAY. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... SFC LOW OVER SOUTHERN MN DRIFTS NORTHEAST ACROSS THE UPPER GREAT LAKES THROUGH SATURDAY AFTN. LIGHT PRESSURE GRADIENT WITH THE LOW CENTER LEADS TO WINDS STAYING BLO 25 KNOTS INTO THIS EVENING. THEN...AS THE LOW BEGINS TO SHIFT EAST OF LAKE SUPERIOR ON SATURDAY...WINDS INCREASE FROM WEST TO EAST ACROSS LAKE SUPERIOR. COLD AIR FLOWING OVR THE WARMER LAKE LEADS TO UNSTABLE LOW LEVELS AND GOOD MIXING. THE BETTER MIXING AND TIGHT PRESSURE GRADIENT SHOULD RESULT IN 30 KNOT WINDS WITH POTENTIAL FOR A FEW GALE FORCE GUSTS TO 35 KNOTS SATURDAY AFTERNOON/EVENING BEHIND THE COLD FRONT. HIGH PRESSURE SLIDING ACROSS THE UPR GREAT LAKES LATER MONDAY THROUGH THURSDAY WILL KEEP WINDS LESS THAN 25 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/DISCUSSION...VOSS AVIATION...JLA MARINE...JLA mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE DULUTH MN 1004 AM CST FRI NOV 7 2008 .UPDATE... FOCUS FOR THIS MORNING UPDATE IS ON PRECIPITATION CHANGEOVER FROM RAIN TO SNOW OVER THE NEXT 24 HOURS. A FEW BANDS OF PRECIPIATIION CONTINUE TO MOVE NORTHWEST THROUGH THE NORTHERN TIER...WHILE ADDITIONAL BANDS SCOOT NORTH IN WISCONSIN AHEAD OF THE SURFACE LOW. TEMPERATURES IN THE FORECAST AREA STILL REMAIN WARM ENOUGH TO SUPPORT RAIN THROUGH THE MORNING AND EARLY AFTERNOON HOURS. WE ARE CONTINUING TO MONITOR AREAS IN NORTHWEST WISCONSIN...ALONG THE SOUTHERN TIER OF BURNETT..WASHBURN...AND SAWYER COUNTIES...AS LOCATIONS JUST TO THE SOUTH...INCLUDING EAU CLAIRE AND UP TO RICE LAKE HAVE BEEN WAFFLING BACK AND FORTH BETWEEN RAIN AND SNOW. COLDER TEMPERATURES ARE WRAPPING AROUND THE DEEP LOW PRESSURE SYSTEM IN SOUTHERN MINNESOTA. BUT...WINDS ARE EXPECTED TO REMAIN EASTERLY IN THESE ABOVE MENTIONED COUNTIES...WHICH WILL KEEP THE COOLER AIR TO THE SOUTH...UNTIL WINDS TAKE ON A MORE SOUTHERLY TRAJECTORY. THIS APPREARS TO OCCUR AFTER 2100 UTC/300 PM CST...AND SO WE HAVE INTRODUCED OCCASIONAL SNOW IN THESE AREAS IN THE LATE AFTERNOON...WITH THE PREDOMINANT PRECIP TYPE AS RAIN...UNTIL AFTER 0000 UTC. CONCERNING AREAS FURTHER WEST...BEMIDJI HAS ALSO BEEN TOGGLING BETWEEN RAIN/DRIZZLE/SNOW THIS MORNING...AND THIS IS THE SECOND AREA THAT WILL SEE A CHANGEOVER TO SNOW THIS AFTERNOON. WE HAVE UPDATED THE ZONES TO INDICATE A POTENTIAL CHANGEOEVER IN THE INTERNATIONAL FALLS VICINITY AFTER 1800 UTC...WITH WINDS EXPECTED TO BECOME NORTHERLY...AND COMMENCING COLD AIR ADVECTION. FORECAST SOUNDINGS INDICATE THAT MUCH OF THE WESTERN TIER OF THE AREA...FROM THE BRAINERD LAKES NORTH TO GRAND RAPIDS WILL REMAIN RAIN THROUGH 0000 UTC/600 PM CST...THOUGH A FEW SNOW FLAKES DURING THE EVENING COMMUTE ARE NOT OUT OF THE QUESTION WITH 850/925 TEMPS BEING COLD ENOUGH. WINDS WILL ALSO BECOME RATHER GUSTY ON THE BACK SIDE OF THE LOW PRESSURE...WHICH WILL REDUCE VISIBILITIES IN AREAS OF SNOW...EVEN THOUGH SNOW IS EXPECTED TO BE LIGHT. REST OF THE FCST UNCHANGED FOR NOW. && .PREV DISCUSSION... /ISSUED 342 AM CST FRI NOV 7 2008/ DISCUSSION...SATELLITE IMAGERY SHOWING AN IMPRESSIVE SYSTEM WOBBLING OVER SW MN. MSAS SFC PRESSURE MINIMUM HOLDING AT 997 MB OVERNIGHT. THE NAM/GFS/RUC ALL SUGGEST THE SFC LOW CIRCULATION BROADENS OVER EC MN AS THE CEN PRESSURE INCREASES TO 1003 MB BY 15Z. ATTM...THIS APPEARS TOO AGGRESSIVE IN FILLING THE LOW AND EXPECTING A SLIGHTLY SLOWER EWRD TRACK THAN MODELS SHOW. BANDS OF RAIN WILL CONTINUE TO LIFT NORTH AND WEST AROUND THE SYSTEM AND OVER THE FA TODAY...KEPT LIKELY TO DEF POPS FOR MOST AREAS...WITH SCT SHRA IN THE TIP OF THE MN ARROWHEAD. FORECAST CHALLENGE IN PCPN TYPE THIS AFTRN THROUGH SATURDAY AFTRN. THE COLD CORE ALOFT AND ASSOCIATED LOWEST THICKNESSES ARE FOUND TO THE SOUTH OF THE SFC LOW AS RELATIVELY WARMER AIR HAS WRAPPED AROUND THE NRN SIDE OF THE SYSTEM...OVER THE WRN GRT LAKES REGION. THICKNESS FALLS...AND SUB-ZERO 850 TEMPS FOUND ON THE BACK SIDE OF THE SYSTEM ARE PROGGED TO SHIFT EAST INTO THE WRN THIRD OF THE FA THIS AFTERNOON AS SYSTEM PROGRESSES SLOWLY E. THIS WILL RESULT IN A PERIOD OF SN MIXING WITH THE RA IN THE WRN AREAS...BEFORE THE LOW LVLS COOL ENOUGH TO SUPPORT ALL SN. HOWEVER...SOME UNCERTAINTY IN SPECIFIC TIMING OF RA TO SN TRANSITION. SUSPECT MODELS ARE ADVANCING SYSTEM E TO QUICKLY. IF SO...RA/SN PHASE CHANGE WILL BE LATER INTO THE EVENING FOR THE WRN AREAS. OVERNIGHT...MOST MN LOCATIONS CAN EXPECT TO SEE RA IN THE EVENING...TRANSITIONING TO A RA/SN MIX OR ALL SN AFTER 06Z. AREAS NEAR LAKE SUPERIOR AND IN NW WIS EXPECTED TO REMAIN WARM ENOUGH FOR RA THROUGH MUCH OF THE NIGHT...POSSIBLY MIXING WITH A FEW SNOW FLAKES AROUND DAY BREAK SAT. AREAS ALONG THE SOUTH SHORE WILL TRANSITIONING TO SN SAT AFTRN...WITH A FEW INCHES OF ACCUMULATION POSSIBLE LATE SAT INTO EARLY SUN. ELSEWHERE...SN ACCUMULATION THROUGH THIS WEEKEND WILL BE MINIMAL. MOST AREAS CAN EXPECT A DUSTING...TO AROUND AN INCH. AVIATION...MAINLY MVFR-VFR CONDITIONS EARLY THIS MORNING WILL DETERIORATE TO PRIMARILY IFR-MVFR BY 12Z...AND THEN PERSIST THROUGH MUCH OF THE DAY AS AN INTENSE AREA OF LOW PRESSURE SLOWLY PUSHES EAST ACROSS MINNESOTA. AREAS OF DRIZZLE AND ASSOCIATED LOW STRATUS WILL BE POSSIBLE...ESPECIALLY FROM KDLH AND POINTS NORTH...ALONG THE NORTH SHORE THROUGH THIS MORNING. AREAS OF RAIN WILL THEN BECOME MORE COMMON...FROM WEST TO EAST...BETWEEN 12Z-18Z. CEILINGS AND VSBYS MAY ONCE AGAIN LIFT A BIT DURING THE EARLY AND MID AFTERNOON...BEFORE LOWERING AGAIN DURING THE EVENING. RAIN COULD BECOME MIXED WITH SNOW AS EARLY AS 18Z FROM KINL SOUTH TO KBRD...BUT WILL LIKELY REMAIN ALL LIQUID THROUGH AT LEAST 06Z SATURDAY SOUTH AND EAST OF KDLH. WINDS WILL SHIFT TO THE NORTH AND NORTHWEST BY FRIDAY AFTERNOON...WITH SOME INCREASE IN SURFACE WIND SPEEDS...ALTHOUGH THE STRONGEST WINDS WILL REMAIN JUST SOUTH OF OUR AREA. && POINT TEMPS/POPS... DLH 44 31 37 21 / 70 70 40 10 INL 39 27 31 19 / 80 60 30 10 BRD 42 29 33 22 / 80 60 30 10 HYR 46 33 37 22 / 70 70 60 10 ASX 46 35 37 25 / 70 70 70 40 && .DLH WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. LS...NONE. $$ DONOFRIO/EOM mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GRAND FORKS ND 1030 AM CST FRI NOV 7 2008 .DISCUSSION... IMPRESSIVE STORM SNOW TOTALS THUS FAR FROM MORNING REPORTS. FAR WESTERN FORECAST AREA WAS HIT HARDEST WITH 12 TO 14 INCHES REPORTED ACROSS WESTERN BENSON AND TOWNER COUNTIES...8 INCHES IN LANGDON... 3 TO 5 INCHES IN DEVILS LAKE...AND 2 INCHES NEAR GRAFTON. MOST AREAS ALONG AND EAST OF THE RED RIVER VALLEY HAVE REMAINED ALL LIQUID WITH SURFACE TEMPERATURES SLIGHTLY ABOVE FREEZING. 16 UTC RADAR IMAGERY SHOWS TWO REMAINING PRECIPITATION BANDS. THE FIRST IS ALL SNOW AND LOCATED FROM JUST WEST OF LANGDON TO CANDO/DEVILS LAKE AND SOUTHWESTWARD TO JUST WEST OF JAMESTOWN. THE SECOND BAND IS STILL A MIX OF SNOW...SLEET AND RAIN AND IS LOCATED FROM THIEF RIVER FALLS THROUGH CROOKSTON TO JUST NORTH OF FARGO. THIS SECONDARY PRECIPITATION BAND FOLLOWS THE SURFACE FREEZING LINE QUITE WELL. LOW PRESSURE SYSTEM WILL CONTINUE TO WEAKEN AND SLOWLY MOVE EASTWARD TODAY. WATER VAPOR AND GFS MODEL CROSS SECTION ANALYSIS SHOWS MID-LEVEL DEFORMATION ZONE AND TROWAL WEAKENING THROUGH THE DAY WITH DECREASING MOISTURE. AS SUCH...CURRENT PRECIPITATION EXPECTED TO WEAKEN TODAY AS IT MOVES EASTWARD...BUT THERE STILL SHOULD EXIST A NARROW AREA OF MIXED PRECIPITATION AS RAIN CHANGES TO SNOW ACROSS WEST-CENTRAL AND NORTHWEST MINNESOTA. THE DEVILS LAKE BASIN COULD PICK UP ANOTHER 1 TO 2 INCHES OF SNOW THIS MORNING AND UP TO 1 INCH ELSEWHERE THROUGH 00 UTC THIS EVENING. NORTH WINDS WILL REMAIN STRONG THROUGH THE MORNING...ESPECIALLY WEST OF THE RED RIVER VALLEY...BUT DECREASE THROUGH THE DAY. AS A RESULT...BLOWING SNOW WILL REMAIN A PROBLEM IN AREAS THAT RECEIVED SIGNIFICANT ACCUMULATIONS CREATING HAZARDOUS DRIVING CONDITIONS. WINTER STORM WARNING WILL BE ALLOWED TO EXPIRE AT 18 UTC. WILL SEND OUT UPDATED MORNING GRIDS/FORECAST AT THIS TIME TO COORDINATE WITH EXPIRATION STATEMENT. MAIN CONCERN THEREAFTER WILL BE FALLING TEMPERATURES IN THE WAKE OF THE LOW REGION-WIDE. HIGH TEMPERATURES SATURDAY WILL ONLY BE IN THE UPPER 20S. && .AVIATION... RIBBON OF IFR CIGS OVER NW MN THROUGH VALLEY REGION. ADJACENT TO THIS BAND SEEING MVFR CIGS WITH VFR PUSHING INTO DVL BASIN. WILL CONTINUE TO SEE SOME LIGHT MIXED PCPN WHICH SHOULD GRADUALLY TRANSITION OVER TO -SN THIS AFTERNOON. RESTRICTIONS TO VSBY WILL BE MINOR WITH CIGS SLOWLY IMPROVING DURING DAY BUT MAIN MVFR FROM VALLEY EAST. && .PREV DISCUSSION... /ISSUED 438 AM CST FRI NOV 7 2008/ SHORT TERM...TODAY THROUGH SUNDAY NIGHT. WATER VAPOR LOOP SHOWS LARGE UPPER LOW WAS LOCATED OVER THE SD MN BORDER. MODELS WERE A LITTLE FARTHER EAST. SAME BIAS NOTED WITH THE MODELS AND THE SURFACE LOW. RUC WAS BEST WITH SURFACE AND UPPER AIR FEATURES. HOWEVER GFS HAS BEST MOISTURE FIELD CONTINUITY. WILL USE THE GFS. WARM CONVEYOR BELT EXTENDED FROM LOWER MI INTO ONTARIO AND WILL CONTINUE TO SHIFT EAST. MODELS DROPPING PRECIPITATION UNDER 700 THETA-E RIDGE. 700 TO 850 CRITICAL THICKNESS WAS FARTHER EAST AND WILL DROP BELOW FREEZING PRECIP CRITERIA THIS MORNING IN NORTHWEST ZONES. CRITICAL THICKNESS AT 1000-850 HPA ALSO SLOWLY LOWERS TODAY AS COLDER AIR SHIFTS EAST. WILL KEEP WINTER STORM WARNING GOING THIS MORNING FOR WINDS AND EXPECTED SNOWS. WATER VAPOR LOOP ALSO SHOWING A SHORT WAVE OVER THE BC/AB BORDER WILL MOVE THROUGH THE WEST DAKOTAS SAT MORNING. ANOTHER SHORT WAVE OVER NORTHERN SK WILL MOVE INTO NORTHERN MN SAT NIGHT. SHORT WAVE MAY BRING LOW CLOUDS AND LIGHT SNOW IN EASTERN ZONES SAT NIGHT AND SUN. WILL KEEP THE EASTERN ZONES RELATIVELY MILD. LONG TERM...MONDAY AND TUESDAY. UPPER LEVEL LOW MOVES OFF INTO EASTERN CANADA HOWEVER A TROUGH AXIS HANGS BACK OVER THE NORTHERN PLAINS MON. SHORT WAVELENGTH UPPER RIDGE TO MOVE OVER THE AREA TUE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER STORM WARNING UNTIL NOON CST TODAY FOR NDZ006>008-014>016- 024-026>029-038-049-052-054. MN...WINTER STORM WARNING UNTIL NOON CST TODAY FOR MNZ004-007. && $$ ROGERS/VOELKER/HOPPES nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 438 AM CST FRI NOV 7 2008 .SHORT TERM...TODAY THROUGH SUNDAY NIGHT. WATER VAPOR LOOP SHOWS LARGE UPPER LOW WAS LOCATED OVER THE SD MN BORDER. MODELS WERE A LITTLE FARTHER EAST. SAME BIAS NOTED WITH THE MODELS AND THE SURFACE LOW. RUC WAS BEST WITH SURFACE AND UPPER AIR FEATURES. HOWEVER GFS HAS BEST MOISTURE FIELD CONTINUITY. WILL USE THE GFS. WARM CONVEYOR BELT EXTENDED FROM LOWER MI INTO ONTARIO AND WILL CONTINUE TO SHIFT EAST. MODELS DROPPING PRECIPITATION UNDER 700 THETA-E RIDGE. 700 TO 850 CRITICAL THICKNESS WAS FARTHER EAST AND WILL DROP BELOW FREEZING PRECIP CRITERIA THIS MORNING IN NORTHWEST ZONES. CRITICAL THICKNESS AT 1000-850 HPA ALSO SLOWLY LOWERS TODAY AS COLDER AIR SHIFTS EAST. WILL KEEP WINTER STORM WARNING GOING THIS MORNING FOR WINDS AND EXPECTED SNOWS. WATER VAPOR LOOP ALSO SHOWING A SHORT WAVE OVER THE BC/AB BORDER WILL MOVE THROUGH THE WEST DAKOTAS SAT MORNING. ANOTHER SHORT WAVE OVER NORTHERN SK WILL MOVE INTO NORTHERN MN SAT NIGHT. SHORT WAVE MAY BRING LOW CLOUDS AND LIGHT SNOW IN EASTERN ZONES SAT NIGHT AND SUN. WILL KEEP THE EASTERN ZONES RELATIVELY MILD. .LONG TERM...MONDAY AND TUESDAY. UPPER LEVEL LOW MOVES OFF INTO EASTERN CANADA HOWEVER A TROUGH AXIS HANGS BACK OVER THE NORTHERN PLAINS MON. SHORT WAVELENGTH UPPER RIDGE TO MOVE OVER THE AREA TUE. && .AVIATION... BAND OF IFR CONDITIONS WERE GENERALLY OVER THE NORTHWEST HALF OF THE AREA. EXPECTED IFR BAND TO SHIFT SOUTHEAST TODAY. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...WINTER STORM WARNING UNTIL NOON CST TODAY FOR NDZ006>008- 014>016-024-026>029-038-049-052-054. MN...WINTER STORM WARNING UNTIL NOON CST TODAY FOR MNZ004-007. && $$ HOPPES nd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 235 PM EST FRI NOV 7 2008 .SYNOPSIS... 18Z WATER VAPOR AND H4 RUC ANALYSIS CONTINUE TO SHOW AN AMPLIFIED UPPER LEVEL PATTERN ACROSS NORTH AMERICA. THE FEATURE THAT IMMEDIATELY DRAWS ATTENTION IS THE DEEP LONGWAVE TROUGH OVER THE CENTRAL PORTION OF THE CONTINENT ANCHORED BY A STRONG 534DM UPPER LOW SPINNING OVER THE UPPER MS VALLEY. THIS LARGE SYSTEM ACROSS THE MID-SECTION OF THE COUNTRY IS FLANKED ON BOTH SIDES BY UPPER LEVEL RIDING ALONG THE COASTS. THE UPPER LEVEL RIDGE IS NOW IN FIRM CONTROL ALONG THE EAST COAST AS THE OLD UPPER LOW THAT HAD BEEN SPINNING OFF THE MID-ATLANTIC STATES FINALLY FILLS AND MOVE OFF TOWARD THE CANADIAN MARITIMES. STRONG SHORTWAVE ROTATING AROUND THE MAIN UPPER LOW IS EXTENDING SOUTHWARD INTO THE SOUTHERN PLAINS AND APPROACHING THE SOUTHERN/CENTRAL MS VALLEY. IT WILL BE THIS FEATURE THAT HELPS PROPEL THE SURFACE COLD FRONT EASTWARD ACROSS THE FORECAST AREA OVER THE NEXT 12 TO 18 HOURS. AT THE SURFACE...1018MB HIGH PRESSURE IS IN CONTROL OF THE EASTERN HALF OF THE FORECAST AREAS THIS AFTERNOON BUT IS BEGINNING TO WEAKEN AND MOVE EAST. THIS HIGH IS ON THE MOVE AS TONIGHT`S COLD FRONT CURRENTLY ALIGNED FROM THE EASTERN TN VALLEY SOUTHWEST INTO EASTERN AND SOUTHERN AL APPROACHES THE AREA. REGIONAL RADARS SHOWING A FAIRLY SOLID LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS ALONG AND AHEAD OF THIS FRONT APPROACHING THE WESTERN ZONES FROM THE WEST. THE CLOUD SHIELD IS ALSO OVERSPREADING THE FORECAST AREA FROM WEST TO EAST. && .DISCUSSION/UPDATE...(TONIGHT THROUGH SUNDAY NIGHT). MID-LEVEL SHORTWAVE DISCUSSED ABOVE NOW APPROACHING THE SOUTHERN MS VALLEY WILL CONTINUE TO HELP PUSH THE SURFACE COLD FRONT EASTWARD INTO THIS EVENING. AHEAD OF THIS FRONTS PROGRESS...WILL SEE A STEADY INCREASE IN CLOUDS THIS EVENING WEST OF A LINE FROM AROUND TIFTON TO TALLAHASSEE AND APALACHICOLA. SHOWER ACTIVITY STILL CURRENTLY HOLDING OFF TO THE WEST BUT WILL SEE THE CHANCES FOR SCT SHOWERS AND STORMS BEGIN INCREASING EARLY THIS EVENING ACROSS OUR SE AL ZONES AND DOWN TOWARD WALTON COUNTY IN THE EASTERN FL PANHANDLE. COLD FRONT ENTERS THE WESTERN FORECAST AREA DURING THE MIDDLE TO LATER EVENING HOURS AND CONTINUES A FAIRLY STEADY EASTWARD PROGRESSION THROUGH THE NIGHT. BEST CHANCES (IN THE LIKELY CATEGORY) FOR SCT SHOWERS AND ISOLATED THUNDERSTORM OVER THE WESTERN HALF OF THE AREA WILL GENERALLY OCCUR BEFORE 2 AM. THE CHANCE FOR THUNDER EAST OF THE APALACHICOLA RIVER DOES APPEAR RATHER SMALL AT THIS TIME AS THE LARGE SCALE FORCING ASSOCIATED WITH THE SHORTWAVE IS PROGGED TO WEAKEN AND SHEAR OFF TO THE NORTHEAST AS IT ENTERS THE REGION. ONE POSITIVE FACTOR INITIALLY IS A DECENT AREA OF UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE RRQ OF A 120KT 250-300MB JET ROUNDING THE BASE OF THE UPPER TROUGH. THIS DIVERGENCE IS RATHER CONCENTRATED OVER OUR WESTERN ZONES THIS EVENING AND SHOULD HELP THE LINE OF SHOWERS AND STORMS TO OUR WEST HOLD TOGETHER DURING THE FIRST HALF OF THE NIGHT. INSTABILITY ON THE OTHER HAND IS LIMITED AT BEST. IN FACT LATEST SREF PROBABILITIES FOR 500 J/KG (EVEN OVER THE WESTERN ZONES) ARE LESS THAN 10% OVER INLAND AREAS AND ONLY 20 TO 30% ALONG THE PANHANDLE COAST DURING THE FIRST HALF OF TONIGHT. LI`S ASSOCIATED WITH THE PRE-FRONTAL ENVIRONMENT ARE INITIALLY DECENT IN THE -1 TO -2 RANGE ACROSS SOUTHERN AL TO OUR WEST BUT RISE ABOVE ZERO INTO THE LATER EVENING HOURS AS THE BEST LIFT ARRIVES OVERHEAD. LATEST GFS STILL ADVERTISING LI`S AROUND 0 OVER THE WESTERN COASTAL WATERS THIS EVENING. SO AS IS OFTEN THE CASE DURING THE COOL SEASON...THE BEST INSTABILITY WILL BE LIMITED TO THE COASTAL WATERS. WILL KEEP AN ISOLATED STORM MENTION IN THE FORECAST THROUGH MIDNIGHT GENERALLY ALONG AND WEST OF THE APALACHICOLA RIVER FOR OUR LAND ZONES AND A CHANCE MENTION OF THUNDER OFFSHORE. WILL THEN RESTRICT WEATHER TYPE WORDING TO ONLY SHOWERS ACROSS THE EASTERN LAND ZONES AS THE COLD FRONT CONTINUES TO PROGRESS AND THE THERMODYNAMICS COLLAPSE. EITHER WAY THE BAND OF SHOWERS AHEAD OF THE FRONT SHOULD BE RELATIVELY THIN...ESPECIALLY OVER THE EAST...WITH ANY RAINFALL BEING BRIEF IN NATURE. AREA-WIDE QPF AMOUNTS WILL GENERALLY FALL BETWEEN ONE TENTH AND ONE QUARTER INCH OVER THE WEST (ISOLATED HIGHER AMOUNTS POSSIBLE ASSOCIATED WITH ANY THUNDERSTORMS) AND ONLY AROUND ONE TENTH OF AN INCH AT BEST ACROSS THE EAST. THEREFORE ALTHOUGH MOST LOCATIONS WILL SEE A BRIEF SHOWER AND HENCE POPS ARE ON THE HIGH SIDE IN PLACES...THE OVERALL IMPACT SHOULD BE LOW. COLD FRONT PROGGED BY ALL GUIDANCE TO EXIT THE EASTERN PART OF THE CWA IN THE FIRST FEW DAYLIGHT HOURS SATURDAY MORNING WITH RAPID CLEARING ARRIVING FROM THE WEST AS HIGH PRESSURE BUILDS ALONG THE NORTHERN GULF COAST. CAN NOT RULE OUT A BRIEF SHOWER OR SPRINKLE ACROSS THE SOUTHEAST FL BIG BEND DURING THE FIRST HALF OF THE MORNING. HOWEVER...GUIDANCE IS IN GOOD AGREEMENT SHOWING THE OVERALL DYNAMICS COLLAPSING ENOUGH TO END ALL SHOWERS AFTER SUNRISE...EXCEPT PERHAPS OVER THE EASTERN COASTAL WATERS. MUCH DRIER LOW LEVEL AIR WILL ARRIVE DURING THE DAY ON SATURDAY. THE AIRMASS IMMEDIATELY BEHIND THE FRONT IS NOT ALL THAT MUCH COLDER AND SHOULD STILL ALLOW AFTERNOON HIGH TEMPERATURES TO REACH THE LOWER AND MIDDLE 70S. ANY LINGERING MORNING CLOUDS ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA SHOULD BE EXITING BY EARLY AFTERNOON WITH PARTLY TO MOSTLY SUNNY SKIES AREA-WIDE. LARGE UPPER LEVEL TROUGH OVER THE EAST SLOWLY DE-AMPLIFIES THROUGH THE REMAINDER OF THE SHORT TERM ALLOWING A MORE ZONAL FLOW TO RETURN OVERHEAD ALONG THE NORTHERN GULF COAST. AREA WILL BE UNDER CONTROL OF SURFACE RIDGING THROUGH THE PERIOD AS HIGH PRESSURE PASSES SLOWLY OFF TO NORTHWEST AND EVENTUALLY NORTH SUNDAY NIGHT. THE RESULT IS FAIR AND SEASONABLE WEATHER SATURDAY NIGHT INTO EARLY MONDAY MORNING WITH COOL NIGHTS (A BIT BELOW CLIMO) AND A NEAR CLIMO DAY IN TERMS OF TEMPERATURE ON SUNDAY. LOW TEMPS SAT NIGHT GENERALLY THE LOWER AND MIDDLE 40S INLAND AND THE MIDDLE 40S TO NEAR 50 AT THE COAST. LOWS SUNDAY NIGHT PERHAPS A FEW DEGREES COOLER AS THE HIGH MAKES ITS CLOSEST APPROACH ALLOWING A BETTER RADIATIONAL COOLING SETUP. AT THIS TIME...FROST DOES NOT APPEAR LIKELY...BUT WILL KEEP AN EYE ON THE SITUATION FOR SOME OF THE NORMALLY COOLER INLAND SPOTS. && .LONG TERM...(MONDAY THROUGH FRIDAY). THE PERIOD STARTS OUT DRY WITH CHILLY MORNINGS AS HIGH PRESSURE BUILDS EWD OVER THE SERN STATES. THE LENGTH OF THIS DRY PERIOD IS IN DOUBT. IT NOW APPEARS THAT THE LONG WAVE TROUGH DEVELOPING OVER THE CENTRAL CONUS EARLY IN THE WORK WEEK WILL BE SLOWER TO MOVE E AND WE SHOULD BE ABLE TO KEEP POPS OUT OF THE FORECAST UNTIL WED. AFTER THAT TIME...CONFIDENCE IN THE FORECAST DIMINISHES. THE 00Z RUN OF THE GFS OFFERS A RATHER DIFFERENT SOLUTION TO THE PREVIOUS RUN, WHICH MATCHED UP WELL WITH THE 06/12Z EURO IN SHOWING A CUT OFF UPPER LOW OVER AR AT 12Z FRI. THE 18Z GFS LIFTED THIS FEATURE NEWD WHILE THE EURO MOVED IT BODILY EWD. THE LATEST GFS BRINGS A WEAKER UPPER FEATURE EWD MORE QUICKLY. FEEL THE BEST APPROACH AT THIS TIME IS TO INTRO SLIGHT CHANCE POPS ON WED AND THEN GRADUALLY INCREASE THEM THROUGH THU AND FRI. THIS IS ESSENTIALLY WHAT THE 00Z MEX SHOWS. HOWEVER...WE PLAN TO GO ABOVE THE MOS FOR NEXT FRI. && .MARINE...VERY LIGHT WINDS AND SEAS CONTINUE THIS AFTERNOON. STILL EXPECTING A SLOW INCREASE OUT OF THE SOUTH INTO THE EVENING HOURS... ESPECIALLY ACROSS THE WESTERN LEGS AS THE COLD FRONT APPROACHES. HOWEVER...WINDS WILL NOT INCREASE ABOVE 15 KNOTS UNTIL THE OVERNIGHT HOURS WHEN THE COLD FRONT PASSES AND WINDS TURN TO THE NORTHWEST. EXPECTING A PERIOD OF CAUTIONARY CONDITIONS BEHIND THE FRONTAL PASSAGE WITH THE POTENTIAL FOR A BRIEF PERIOD OF NEAR ADVISORY WINDS OVER THE WESTERN LEGS. EXPECT CAUTIONARY LEVELS TO CONTINUE INTO THE MORNING HOURS OF SATURDAY BEFORE FALLING BELOW CAUTIONARY LEVELS DURING THE AFTERNOON. WINDS AND SEAS SHOULD REMAIN BELOW HEADLINE CRITERIA THROUGH THE REMAINDER OF THE WEEKEND AS HIGH PRESSURE BUILDS ALONG THE NORTHERN GULF COAST. ANOTHER INCREASE IN WINDS WILL BE LIKELY BY TUESDAY AS HIGH PRESSURE BUILDS OFF THE MID ATLANTIC COAST AND CREATES A TIGHT PRESSURE GRADIENT ACROSS OUR WATERS BETWEEN THIS RIDGE TO THE NORTHEAST AND PALOMA (IN EITHER TROPICAL OR SUBTROPICAL FORM) TO OUR EAST. && .AVIATION... VFR CONDITIONS ARE PREVAILING ACROSS THE TAF SITES THIS AFTERNOON WITH A SHALLOW SCT CU FIELD DEVELOPING OUT AHEAD OF A WEAK SEA BREEZE IN THE FLORIDA BIG BEND...WHILE INCREASING CU AND BKN AC ARE MOVING INTO SE AL AND THE FL PANHANDLE OUT AHEAD OF THE COLD FRONT TO OUR WEST. EXPECT THESE CLOUDS TO CONTINUE TO INCREASE FROM THE WEST FOR THE REMAINDER OF THE AFTERNOON AND EVENING HOURS...WITH SCT SHOWERS DEVELOPING FROM NW TO SE ACROSS THE TAF SITES TONIGHT. CANNOT COMPLETELY RULE OUT AN ISOLATED TSTM AT DHN AND PFN BEFORE THE SFC BASED INSTABILITY DIMINISHES...SO LEFT THE TEMPO WX AS SHOWERS WITH A SCT CB CLOUD GROUP FOR THIS PACKAGE. DURING THE SCT SHOWERS...EXPECT NO WORSE THAN A PERIOD OF MVFR VIS RESTRICTIONS... BUT SINCE THE COLD FRONT WILL TAKE THE LONGEST TO REACH VLD...THERE MAY BE A SMALL WINDOW FOR POTENTIAL IFR VIS AND CIGS TO DEVELOP AT VLD BETWEEN MIDNIGHT AND 3 AM. ON SATURDAY...THE COLD FRONT SHOULD SWEEP QUICKLY EAST OF THE REGION WITH RAPIDLY CLEARING SKIES AND LIGHT TO MODERATE N-NW WINDS. && .FIRE WEATHER... A WEAKENING COLD FRONT WILL PUSH QUICKLY THROUGH THE REGION TONIGHT WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ...AND THEN MUCH DRIER AIR BUILDING INTO THE AREA FOR THE UPCOMING WEEKEND. THIS DRY AIR WILL COMBINE WITH STRONG TRANSPORT WIND SPEEDS TO ALLOW DISPERSIONS TO EXCEED 75 ACROSS THE FLORIDA BIG BEND AND PANHANDLE EACH AFTERNOON. THESE HIGH DISPERSIONS ALONG WITH RELATIVE HUMIDITIES LESS THAN 35 PERCENT WILL CREATE IDEAL RED FLAG CONDITIONS ACROSS FOR MUCH OF NORTH FLORIDA. OVER SOUTHEAST ALABAMA AND SOUTHWEST AND SOUTH CENTRAL GEORGIA...ONLY BRIEF DURATIONS OF 25 PERCENT RELATIVE HUMIDITY OR BELOW ARE EXPECTED AT THIS TIME. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 54 74 41 72 38 / 40 10 0 0 0 PANAMA CITY 54 74 48 72 45 / 60 0 0 0 0 DOTHAN 49 73 41 69 39 / 60 0 0 0 0 ALBANY 52 73 41 69 38 / 50 0 0 0 0 VALDOSTA 55 74 41 72 40 / 30 10 0 0 0 CROSS CITY 55 76 45 75 40 / 10 10 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...RED FLAG WARNING FROM 12 PM EST /11 AM CST/ TO 6 PM EST /5 PM CST/ SATURDAY FOR THE FOLLOWING ZONES: BAY...CALHOUN... DIXIE...FRANKLIN...GADSDEN...GULF...HOLMES...INLAND WALTON...JACKSON...JEFFERSON...LAFAYETTE...LEON...LIBERTY... MADISON...TAYLOR...WAKULLA...WASHINGTON. FIRE WEATHER WATCH SUNDAY AFTERNOON FOR THE FOLLOWING ZONES: BAY...CALHOUN...DIXIE...FRANKLIN...GADSDEN...GULF... HOLMES...INLAND WALTON...JACKSON...JEFFERSON...LAFAYETTE... LEON...LIBERTY...MADISON...TAYLOR...WAKULLA...WASHINGTON. GM...NONE. && $$ AVIATION/FIRE WEATHER...GOULD SYNOPSIS/SHORT TERM/MARINE...MROCZKA LONG TERM...WOOL fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 220 PM MST FRI NOV 7 2008 .DISCUSSION... 219 PM MST FRI NOV 7 2008 17Z WATER VAPOR IMAGERY/RUC ANALYSIS CONTINUED TO INDICATE A DEEP H5 LOW SLOWLY MOVING SOUTHEAST ACROSS IOWA...WITH LARGE RIDGE ACROSS THE WESTERN CONUS. AT THE SFC...A 999 MB LOW WAS LOCATED NEAR KMCW. VERY DRY AIR HAD ALSO MOVED INTO THE CWA OVERNIGHT...WITH SINGLE DIGIT DEWPOINTS ACROSS THE WESTERN PORTION OF THE AREA. TONIGHT..H3 JET STREAK WILL MOVE ACROSS THE AREA OVERNIGHT BRINGING A PERIOD OF MID AND HIGH CLOUDS...OTHERWISE WEATHER WILL BE QUIET ACROSS THE AREA OVERNIGHT. WINDS WILL RELAX LATE IN THE AFTERNOON AND INTO THE EVENING...AND ADVISORY WILL BE ALLOWED TO EXPIRE. ALTHOUGH JET STREAK WILL PROVIDE SOME LIFT OVERNIGHT...THETA E LAPSE RATES APPEAR STABLE AND WITH DRY NEAR SFC AIR DO NOT THINK ANYTHING WOULD REACH THE GROUND. TOMORROW-TOMORROW NIGHT...SHORT WAVE RIDGING WILL BE PRIMARY FORCING ACROSS THE AREA. DESPITE RIDGING ALOFT...FRONTAL ZONE IS EXPECTED TO BACK INTO THE REGION DURING THE LATE AFTERNOON. OVERNIGHT...FAIRLY STRONG WAA DEVELOPS AT H85 AND H7. DIV Q FIELDS INDICATE THAT TEMP ADVECTION SUFFICIENT FORCING FOR ASCENT DESPITE APPROACHING RIDGE AXIS...AND POINT SOUNDINGS INDICATE ASCENT INCREASING IN THE H85 TO H75 LAYER. THE OVERALL PATTERN WOULD FIT FOR -FZDZ IN SOME AREAS....BUT QUESTIONS STILL REMAIN ON THE QUALITY OF MOISTURE RETURN BEHIND THE FRONT. NAM SUGGEST TD`S IN THE LOWER 30S WILL DEVELOP BEHIND THE FRONT...WHILE THAT SEEMS A BIT ON THE HIGH SIDE THERE ARE TD VALUES THIS HIGH UPSTREAM IN MONTANA. EVEN IF THE MOISTURE RETURN IS AS STRONG ASS ADVERTISED...POINT SOUNDINGS STILL INDICATE BOUNDARY LAYER NEVER SATURATES WHICH WOULD TEND TO FAVOR STRATUS OVER ANY KIND OF -FZDZ. EITHER WAY...CURRENT SLIGHT CHANCE POPS LOOK REASONABLE AT THIS TIME. SUNDAY-SUNDAY NIGHT...POTENTIAL FOR PATCHY FZDZ WILL CONTINUE IN THE MORNING...BUT SHORT WAVE RIDGE AXIS WILL BECOME CENTERED OVER THE AREA DURING THE EARLY AFTERNOON BRINING AN END TO PRECIP CHANCES. FROM THIS POINT IN THE FORECAST MODELS DIVERGE INTO TWO SEPARATE CAMPS THAT ARE MENTIONED IN A BIT MORE DETAIL IN THE EXTENDED SECTION. WITH SUCH LARGE DIFFERENCES HARD TO PIN DOWN SPECIFICS ON AREAS WHERE BEST FORCING WILL LINE UP AND TRIED TO KEEP FORECAST GENERAL WITH RESPECT TO POPS AND PRECIP AMOUNTS. EXPECT STRONG TROUGH TO BEGIN TO OVERSPREAD THE AREA OVERNIGHT. LAPSE RATES AHEAD OF THIS SYSTEM ARE FAIRLY STEEP FOR THIS TIME OF YEAR WITH H7-H5 LAPSE RATES 7-8C/KM OVERNIGHT SUNDAY. WITH STRONG FORCING AND WEAK STABILITY WOULD EXPECT A STRONG RESPONSE TO THE APPROACHING TROUGH. ORIGINALLY PLANNED TO KEEP FORECAST ALL SNOW...BUT NAM AND 12Z ECMWF INDICATE POTENTIAL FOR A PERIOD OF MIXED PRECIPITATION WITH WARM LAYER ALOFT. ALTHOUGH THE PLACEMENT OF THE FREEZING/FROZEN/LIQUID LINE VARIES SIGNIFICANTLY FROM MODEL TO MODEL...WILL LEAN TO A MORE MIXED PCP EVENT EARLY ACROSS THE AREA AS A KIND OF WORST CASE SCENARIO. IN THE EXTENDED...MAIN CONCERN FOR THE PERIOD WILL CENTER AROUND POTENTIAL SNOW STORM ACROSS THE AREA MONDAY AND TUESDAY. OPERATIONAL MODELS STILL IN TWO DISTINCT CAMPS. GFS...84 HR NAM AND LATEST SREF SUGGEST A MORE OPEN PROGRESSIVE SYSTEM...WHILE THE CANADIAN/ECMWF/UKMET SUPPORT A STRONG NEGATIVELY TILTED TROUGH TO IMPACT THE AREA MONDAY AND TUESDAY. SOME 00Z GFS ENS SOLUTIONS SUPPORT THE STRONGER SOLUTION...WHILE 00Z CANADIAN ENSEMBLES STRONGLY SUPPORT THE NEGATIVELY TILTED TROUGH. ALTHOUGH THERE REMAINS A LARGE AMOUNT OF UNCERTAINTY WITH RESPECT TO STRENGTH OF THE SYSTEM AND LIKELY AMOUNTS...INDICATIONS INDICATE THAT HIGHER POPS ARE WARRANTED. ALTHOUGH THERE MAY BE SOME MIXED PRECIPITATION EARLY ON MONDAY...WITH THE EXPECTED STRONG LIFT AND COOLER WET BULB TEMPS...WILL KEEP FCST SIMPLE AND CALL PRECIP ALL SNOW FROM MONDAY MORNING ON. LOWERED TEMPERATURES SEVERAL DEGREES TO START THE WEEK DUE TO THE PREVIOUSLY MENTIONED STORM. OTHERWISE...UNCERTAINTY VERY HIGH FOR THE REMAINDER OF THE FCST AND WILL KEEP FORECAST CLOSE TO AVAILABLE GUIDANCE. JRM && .AVIATION... 1035 AM MST FRI NOV 7 2008 FOR THE 18Z TAF...GUSTY NORTHWESTERLY WINDS OF 20 TO 30 MPH WITH GUSTS UP TO 45 MPH WILL CONTINUE THROUGH THE AFTERNOON HOURS BEFORE SETTLING DOWN AROUND 00Z SATURDAY. SATELLITE SHOWS SCATTERED MID LEVEL CLOUDS DROPPING SOUTH CURRENTLY. TIME-HEIGHT CROSS SECTIONS AND BUFKIT POINT SOUNDINGS WOULD SUPPORT AN INCREASE IN CLOUDINESS THROUGHOUT THE AFTERNOON WITH CIGS LOWERING TO AROUND 5 KFT AGL THIS EVENING. HOWEVER VFR CONDITIONS ARE EXPECTED THROUGH THE EFFECTIVE TAF PERIOD. FOLTZ && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 448 PM EST FRI NOV 7 2008 .SYNOPSIS... WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A LARGE MID/UPPER LOW CENTERED OVER NE IA/SE MN WITH OBS INDICATING SFC LOW PRES CO-LOCATED WITH THE MID/UPPER CENTERS. SINCE SYSTEM HAS BEEN OCCLUDED FOR SOMETIME...850MB THERMAL TROF HAS WRAPPED WELL AROUND THE S SIDE OF SYSTEM WITH CAA INTO UPPER MI OCCURRING FROM THE S THIS AFTN. AS A RESULT...PCPN CHANGEOVER FROM RAIN TO SNOW HAS ALSO BEEN PROGRESSING SLOWLY N AND E ACROSS WRN WI TODAY...BUT PROGRESS HAS SLOWED CONSIDERABLY DURING THE AFTN HRS. NOT MUCH IF ANY PCPN HAS OCCURRED OVER THE FCST AREA SINCE SUNRISE AS DRY SLOT SURGED INTO UPPER MI OVERNIGHT/THIS MORNING. && .SHORT TERM (TONIGHT AND SAT)... BIG CHALLENGE IN THE SHORT TERM IS TIMING CHANGEOVER FROM RAIN TO SNOW FROM SW TO NE ACROSS FCST AREA TONIGHT/SAT. SNOW FCST IS MOST CRITICAL OVER THE W WHERE LAKE ENHANCEMENT WILL BECOME INVOLVED SAT. EXACTLY WHEN CHANGEOVER OCCURS WILL BE CRITICAL TO DETERMINING HOW MUCH SNOW MAY FALL...ESPECIALLY OVER THE FAR W AROUND KIWD. PCPN CURRENTLY WRAPPING AROUND THE MIDEVEL LOW CENTER WILL GRADUALLY SPREAD INTO THE FCST AREA TONIGHT. WILL THUS GRADUALLY INCREASE POPS FROM THE W AND S TO THE N AND E DURING THE NIGHT. BUMPED UP POPS TO LIKELY OR BETTER ALL AREAS SINCE SOME MEASURABLE PCPN SEEMS A GOOD BET. OVER THE W...ISENTROPIC ASCENT AS VIEWED ON THE 290K SFC WILL BE INCREASING OVERNIGHT. 850MB TEMPS DROPPING TO AROUND -1C OVER THE WRN LAKE WILL ALSO BE SUFFICIENT FOR LAKE ENHANCEMENT TO GET UNDERWAY LATE TONIGHT AS LOW-LEVEL WINDS BECOME NNE AND STRENGTHEN TO 25-35KT. CATEGORICAL POPS WILL BE UTILIZED THERE OVERNIGHT. WILL NEED TO WATCH FOR LAKE ENHANCEMENT OFF LAKE MICHIGAN AS WELL...WHICH MAY REQUIRE BUMPING UP POPS FURTHER IN THAT AREA. AS FOR PTYPE...WEDGE OF WARM AIR WRAPPED AROUND THE N SIDE OF MID LEVEL LOW WILL ONLY GRADUALLY COOL TONIGHT AS SYSTEM TRANSLATES E... PUSHING MAIN THRUST OF CAA ACROSS WI INTO LWR MI. AS A RESULT... NAM/GFS SHOW FREEZING LEVEL REMAINING ABOVE 1.5KFT AGL THRU 12Z SAT ACROSS THE WRN...NRN AND ERN FCST AREA. THE GFS IS SLIGHTLY WARMER THAN THE NAM AND IS PREFERRED DUE TO ITS SLIGHTLY BETTER ANALYSIS OF TEMPS AROUND THE MIDLEVEL LOW THIS MORNING PER 12Z RAOBS. AS A RESULT...PTYPE SHOULD REMAIN MOSTLY RAIN THRU THE NIGHT. A MIX OR CHANGE TO SNOW AS PTYPE SHOULD ONLY OCCUR OVER THE SCNTRL WHERE FREEZING LEVEL DROPS TO AROUND 1KFT AGL. ON SAT...DEFORMATION ZONE/ISENTROPIC ASCENT REGIME WILL SPREAD E ACROSS THE FCST AREA. WITH SUFFICIENTLY COLD AIR OVER LAKE SUPERIOR...LAKE ENHANCEMENT AS WELL AS TERRAIN ENHANCEMENT SHOULD PLAY A BIG ROLE IN PCPN COVERAGE/INTENSITY. WIND SHIFT TO THE N WILL TRANSLATE E ACROSS LAKE SUPERIOR/UPPER MI IN THE WAKE OF POSSIBLE DEVELOPING MESO LOW ON LAKE SUPERIOR...SO POPS WILL SHOW AN INCREASING TREND TO CATEGORICAL EWD INTO NCNTRL UPPER MI SAT. OTHERWISE...WITH DEFORMATION ZONE PASSING ACROSS THE AREA...LIKELY POPS ARE WARRANTED ACROSS THE ENTIRE AREA. GFS SHOWS RAPID LOWERING OF THE FREEZING LEVEL TO UNDER 1KFT AGL OVER WRN UPPER MI SAT MORNING AND INTO PORTIONS OF CNTRL UPPER MI IN THE AFTN. THUS... EXPECT A CHANGEOVER TO MAINLY SNOW AWAY FROM LAKE SUPERIOR ACROSS THE W HALF OF UPPER MI SAT. GIVEN THE UNCERTAINTY OF EXACT TIMING OF CHANGE TO SNOW...SNOW FALLING DURING THE DAYLIGHT HRS AND WARM GROUND...SNOW ACCUMULATIONS ARE VERY UNCERTAIN TO SAY THE LEAST. FOR NOW...STAYED CLOSE TO PREVIOUS FCST. SLOPPY SNOW ACCUMULATIONS ON GRASSY AREAS MAY REACH 3-4INCHES OVER THE HIGHER TERRAIN FROM AROUND KIWD TO ROCKLAND...WITH MAYBE A COUPLE OF INCHES OVER THE HIGHER TERRAIN OF THE KEWEENAW TO WRN MARQUETTE COUNTY. .LONG TERM (SAT NIGHT THROUGH NEXT FRIDAY)... PERIOD BEGINS AS UPPER/SFC LOW IS LOCATED JUST SOUTH OF HUDSON BAY AND DRIFTING FARTHER TO THE NNE. DEFORMATION/COMMA HEAD PCPN WILL BE TRANSITIONING E ACROSS THE CWA DURING THE EVENING...WHILE AN ELONGATED SFC TROUGH FROM THE MAIN LOW SLIDES E OF THE CWA. REINFORCING SHORTWAVE IS PROGGED TO DROP S AROUND THE UPPER LOW ON SAT NIGHT OVER FAR WRN UP...COINCIDING WITH SFC TROUGH DIVING S. GFS IS SLIGHTLY TO THE EAST WITH THE WAVE...WITH NAM/ECMWF/GEM DROPPING IT ACROSS NRN MN...FAR WRN LK SUPERIOR...AND INTO NW WI. ABUNDANT FORCING PRESENT WITH LEFT EXIT REGION OF WEAK JET JUST TO THE W OF THE CWA AND STRONG Q VECTOR CONVERGENCE ABOVE H500 SPREADING E ACROSS THE CWA WILL LEAD TO WIDESPREAD PCPN ACROSS THE AREA...WITH LAKE ENHANCEMENT IN LOCATIONS FAVORED BY A NNW WIND NEAR LK SUPERIOR. COLD AIR WILL DIVE S BEHIND THE SFC TROUGH AND SHORTWAVE...WITH H850 TEMPS FALLING FROM -7C AT 00Z SUN TO -10C AT 12Z SUN OVER THE WRN PART OF THE CWA. WITH LK SUPERIOR TEMPS AROUND 7/8C...THIS PRODUCES DELTA T VALUES AROUND 14-17. THE INCREASING DELTA T VALUES ALONG WITH A RISING INVERSION HEIGHT ON SAT NIGHT...TO AROUND H750 BY 12Z SUN ON NAM/GFS BUFKIT SOUNDINGS...WILL LEAD TO INTENSIFYING PCPN IN LK EFFECT AREAS. PCPN SHOULD BE ALL SNOW OVER THE WRN PART OF THE CWA FOR SAT NIGHT...AS TEMPS CONTINUE TO FALL. BUFKIT SOUNDINGS SHOW PLENTY OF MOISTURE THROUGH THE INVERSION AND TEMPS COLD ENOUGH FOR ICE CRYSTALS. THINK THE SNOW RATIO WILL BE ON THE LOWER SIDE FOR LK EFFECT DURING THE EVENING...AROUND 10 TO 1...DUE TO DEEP CLOUD DEPTH...INITIAL SYNOPTIC FORCING...AND DGZ LOCATED NEAR THE INVERSION HEIGHT. DID START TO TREND SNOW RATIOS UP OVERNIGHT...BUT ONLY TO 11/12 TO 1 RANGE...AS PCPN TRANSITIONS TO MORE TRADITIONAL LES. AS FOR THE ERN PART OF THE CWA...STARTED OFF WITH A RAIN AND SNOW MIX DURING THE EVENING...THEN QUICKLY TRANSITIONED TO ALL SNOW OVERNIGHT. BUFKIT SOUNDINGS SHOW RAPID COOLING ALOFT AFTER 03Z...WHICH ELIMINATES THE SHALLOW WARM LAYER OF 1.5KFT NEAR THE SFC. OVERALL...WILL PROBABLY SEE 2-4 INCHES OF SNOW OVER THE WEST ON SAT NIGHT...WITH SOME LOCALLY HIGHER AMOUNTS IN THE TRADITIONAL LES LOCATIONS AND HIGHER ELEVATIONS. THIS PUTS IT RIGHT ON THE EDGE OF ADVISORY CRITERIA AND THINK ISSUING ONE FOR SOME OF THE WRN COUNTIES IS LIKELY IN THE COMING SHIFTS. EXPECT THE LES TO CONTINUE ON SUN AS WINDS GRADUALLY BACK TO THE NW THROUGH THE DAY. H850 TEMPS REMAIN FAVORABLE FOR LES...WITH -9C OVER THE E AND -11C OVER THE W...WITH PLENTY OF MOISTURE THROUGH THE INVERSION. THUS HAVE BUMPED UP POPS IN THE FAVORABLE LES REGIONS FOR SUN. THINK THE SNOW/WATER RATIO WILL BE A LITTLE HIGHER ON SUN...AS DGZ STARTS TO COINCIDE WITH THE BEST OMEGA OVER THE EAST. THINK ALGER AND LUCE COUNTIES WILL SEE THE MOST SNOW ON SUN...CURRENTLY AROUND 2-3 INCHES...DUE TO THE LONGER FETCH WITH THE NW WINDS. REST OF THE FAVORABLE LES AREAS WILL SEE A COUPLE OF INCHES ON SUN. LES MAY GET SOME UPPER LEVEL SUPPORT ON SUN EVENING THROUGH MON...AS A SERIES OF SHORTWAVES MOVE AROUND THE UPPER LOW. HAVE EXTENDED THE PCPN CHANCES IN THE NW WIND AREAS DURING THIS TIME...AS PLENTY OF MOISTURE REMAINS BELOW THE INVERSION AND DELTA T VALUES ARE STILL FAVORABLE. LES WILL BEGIN TO TAPER OFF OVER THE W ON MON AFTN...AS THE INVERSION HEIGHTS FALL TOWARDS 4KFT AND DRIER AIR ALOFT MOVES IN. BROAD TROUGH OVER THE WRN CONUS ON ECMWF/GFS/GFS ENS ON TUES...WITH SFC HIGH NEAR THE REGION. THERE ARE DIFFERENCES IN THE INTENSITY AND POSITION OF THE SFC HIGH...BUT ECMWF/GFS ENS ARE BOTH INDICATING A BROAD HIGH OF 1025-1032MB STRETCHING FROM THE UPPER MIDWEST THROUGH THE GREAT LAKES AND INTO THE NE US. WITH THE HIGH MOVING IN ON TUES AND H850 TEMPS GRADUALLY WARMING...IT SHOULD BRING AN END TO THE LK EFFECT SNOW OVER THE ERN UP BY TUES NIGHT. DID HAVE THE LK EFFECT SNOW A LITTLE LONGER ON TUES...AS ECMWF/GFS ENS STILL SHOWING FAVORABLE NW WINDS AND H850 TEMPS LINGERING INTO THE AFTN AND A POSSIBLE WEAK TROUGH ROTATING AROUND THE LOW. UPPER TROUGH LOOKS TO SLOWLY TRANSITION E TUES NIGHT THROUGH FRI...AS RIDGE BUILDS OVER THE W COAST DUE TO STRONG JET COMING ONSHORE. HAVE KEPT TUES NIGHT THROUGH THURS DRY...AS HIGH TAKES HOLD OVER THE REGION. THE HIGH SHOULD KEEP THE DEVELOPING LOW OVER THE SRN PLAINS S OF THE AREA...TRACKING ALONG THE OHIO RIVER VALLEY. TEMPS WILL BE AT OR SLIGHTLY BELOW NORMAL TUES AND WED UNDER THE HIGH. SOME DIFFERENCES START TO SHOW IN DAYS 6/7 WITH THE HANDLING OF THE UPPER TROUGH...BUT IT LOOKS LIKE THE UPPER TROUGH AND ASSOCIATED CANADIAN SFC LOW WITH COLD FRONT STRETCHING S ACROSS CNTRL US WILL MOVE TOWARDS THE AREA THURS NIGHT INTO FRI. WITH LOW CONFIDENCE IN TIMING...JUST ADDED CHANCE PCPN TO THOSE TIME PERIODS. DID BUMP UP TEMPS A LITTLE ON THURS AND INTO FRI...AS ECMWF/GFS ENS START TO SHOW SW FLOW AT THE SFC AND ALOFT AHEAD OF THE COLD FRONT. STILL DIFFERENCES IN H850 TEMPS AT THIS TIME...BUT AT LEAST WANTED TO SHOW THE WARMER TREND. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... VFR CONDITIONS SHOULD PREVAIL INTO THE EVENING HRS AT KCMX/KSAW. LATER TONIGHT...MOISTURE WRAPPING AROUND A LARGE LOW PRES SYSTEM CURRENTLY OVER THE UPPER MISSISSIPPI VALLEY WILL SPREAD N AND E INTO UPPER MI. THIS WILL RESULT IN CIGS DROPPING TO MVFR WITH SCT -SHRA ALSO DEVELOPING. AS LAKE ENHANCEMENT GETS UNDERWAY...RAIN WILL BECOME STEADIER SAT MORNING...BEGINNING FIRST AT KCMX. IN ADDITION...WITH COOLING COLUMN...RAIN WILL PROBABLY MIX WITH OR EVEN CHANGE TO SNOW AS FREEZING LEVEL LOWERS BLO 1.5KFT AGL. WHETHER OR NOT SNOW MIXES WITH THE RAIN...THE ARRIVAL OF STEADIER PCPN WILL LIKELY DROP CONDITIONS INTO THE IFR RANGE. WOULD NOT BE SURPRISED TO SEE LIFR CONDITIONS AT TIMES AS WELL. && .MARINE (FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)... MAIN FCST CONCERN IS STRONG NRLY WINDS DEVELOPING FROM W TO E LATE TONIGHT THRU SAT. AS BROAD LOW PRES MOVES INTO THE UPPER LAKES... IT APPEARS A MESO LOW MAY DEVELOP OVER ERN LAKE SUPERIOR LATE TONIGHT AND SAT. WOULD THUS EXPECT MODEL GUIDANCE TO GENERALLY UNDER FCST STRENGTH OF NRLY WINDS ON THE BACKSIDE OF LOW UNDER STRENGTHENING INFLUX OF COLDER AIR FROM THE N. HAVE THUS OPTED TO HOIST GALE WARNINGS OVER ALL BUT THE FAR W AND FAR E SAT INTO EARLY SAT EVENING. A PERIOD OF N TO NW 20-30KT WINDS WILL THEN FOLLOW SAT NIGHT INTO MON. WINDS WILL SUBSIDE LATER MON INTO WED AS HIGH PRES SETTLES OVER THE GREAT LAKES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...GALE WARNING 7AM TO 4PM EST SAT LSZ263. GALE WARNING 7AM TO 9PM EST SAT LSZ264. GALE WARNING 11AM TO 9PM EST SAT LSZ265-266. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/SHORT TERM...ROLFSON LONG TERM...SRF AVIATION...ROLFSON MARINE...ROLFSON mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MARQUETTE MI 1235 PM EST FRI NOV 7 2008 UPDATED AVIATION DISCUSSION FOR 18Z TAF ISSUANCE .SYNOPSIS... ISSUED AT 6 AM EST 09Z WV IMAGERY AND RUC ANALYSIS SHOW A LARGE UPPER LOW ROTATING OVER SW MN WITH A FAIRLY BROAD UPSTREAM RIDGE OVER THE WRN CONUS. STACKED LOW PRESSURE RESULTING IN 998 MB SFC LOW PRES OVER SW MN. TIGHTLY PACKED PRESSURE GRADIENT BEHIND THE LOW IS STILL PRODUCING VERY STRONG NW WINDS (GUSTS OVER 40 MPH AT SOME LOCATIONS) ACROSS DAKOTAS AND BLIZZARD CONDITIONS OVER CENTRAL SD. OVER OUR AREA...THE INITIAL BAND OF WAA RAIN AHEAD OF THE LOW HAS GENERALLY EXITED ALL EXCEPT FAR ERN COUNTIES OF UPR MI. DRY SLOT AS DEPICTED ON FCST SNDGS AND NOTED ON WATER VAPOR LOOP IS MOVING ACROSS MUCH OF THE U.P EARLY THIS MORNING. THE DRY SLOT HAS EITHER ENDED THE RAIN OR DIMINISHED PCPN TO -DZ. && .DISCUSSION... ISSUED AT 6 AM EST GIVEN THE DRY SLOT MOVING OVER THE AREA AND THE SLOWER ADVANCE OF THE UPR LOW TODAY TOWARD THE GREAT LAKES AS DEPICTED BY THE 00Z MODELS...HAVE DECIDED TO TRIM BACK COVERAGE OF SHRA TO ISOLD FOR ALL BUT THE FAR SW FCST AREA FOR LATE IN THE AFTERNOON. AS THE UPPER LOW SLOWLY SLIDES SOUTH OF THE FCST AREA LATE TONIGHT LOOK FOR PCPN IN DEFORMATION ZONE/COMMA HEAD OF UPR LOW TO WRAP BACK TOWARD THE WRN FCST AREA ESPECIALLY TOWARD 12Z SAT WHEN MODELS SHOW INCREASING ISENTROPIC ASCENT ON THE 290-295K SFC. THUS...HAVE KEPT LIKELY POPS OVER THE FAR WEST BUT HAVE TRIMMED BACK POPS TO AROUND 40 PCT OVER THE FAR EAST DUE TO LACK OF DEEP MOISTURE AND ABSENCE OF GOOD ISENTROPIC ASCENT. GIVEN DEGREE OF WARM AIR AT 850 MB (-1 TO -2C TEMPS) THAT`S WRAPPING BEHIND THE LOW LOOK FOR PCPN TYPE TO BE MOSTLY RAIN TONIGHT. AS DEFORMATION ZONE WITH SYSTEM AND IMPRESSIVE 290-295K ISENTROPIC ASCENT SPREADS EAST SAT AFTERNOON INTO SAT NIGHT...GRADUALLY UPPED POPS TO CATEGORICAL ACROSS THE NRN AND ERN TIER. COLDER 850 MB TEMPS OF -8 TO -11C FLOODING ACROSS THE AREA LATE SAT INTO SAT NIGHT WILL ENSURE CHANGEOVER FROM LAKE ENHANCED RAIN TO LAKE ENHANCED SNOW. GIVEN THE IMPRESSIVE DYNAMICS LATE SAT INTO SAT NIGHT...WOULD EXPECT THE POTENTIAL FOR SOME HEAVY WET SNOW OVER WRN AND NCNTRL PORTIONS OF THE CWA IN NNW FLOW. ONLY LIMITATION FOR SNOW AMOUNTS IS EXPECTED LOW 10/1 SNOW/WATER RATIO AS MODEL SNDGS INDICATE BETTER MODEL OMEGA OCCURRING BELOW FAVORABLE DENDRITIC SNOW GROWTH REGION. THUS...AT THIS POINT...WOULD NOT ANTIPICATE WARNING SNOW AMOUNTS TO JUSTIFY A WATCH BUT I`M PRETTY CONFIDENT THAT ADVISORIES WILL BE NEEDED FOR SOME WRN AND PERHAPS NCNTRL COUNTIES. WILL ISSUE A SPS TO HIGHLIGHT POTENTIAL FOR SOME HEAVIER WET SNOW LATE SATURDAY INTO SUNDAY. ALTHOUGH PLAINS UPR LOW WILL BE PULLING EAST BY SUN...ANOTHER SHORTWAVE DIVING SOUTH THROUGH THE NRN PLAINS COULD PROVIDE ADDITIONAL ENHANCEMENT FOR LES AND THIS WILL NEED TO BE WATCHED ON LATER MODEL RUNS. LINGERING 850 MB TEMPS OF -9 TO -11C AND DEEP CYCLONIC NWRLY FLOW WILL STILL WARRANT LIKELY POPS FOR THE NW SNOWBELTS DOWNWIND OF LAKE SUPERIOR WITH CHC POPS OVER SRN COUNTIES. && .AVIATION (FOR THE 18Z TAF ISSUANCE)... VFR CONDITIONS SHOULD PREVAIL INTO THE EVENING HRS AT KCMX/KSAW. LATER TONIGHT...MOISTURE WRAPPING AROUND A LARGE LOW PRES SYSTEM CURRENTLY OVER THE UPPER MISSISSIPPI VALLEY WILL SPREAD N AND E INTO UPPER MI. THIS WILL RESULT IN CIGS DROPPING TO MVFR WITH SCT -SHRA ALSO DEVELOPING. AS LAKE ENHANCEMENT GETS UNDERWAY...RAIN WILL BECOME STEADIER SAT MORNING...BEGINNING FIRST AT KCMX. IN ADDITION...WITH COOLING COLUMN...RAIN WILL PROBABLY MIX WITH OR EVEN CHANGE TO SNOW AS FREEZING LEVEL LOWERS BLO 1.5KFT AGL. WHETHER OR NOT SNOW MIXES WITH THE RAIN...THE ARRIVAL OF STEADIER PCPN WILL LIKELY DROP CONDITIONS INTO THE IFR RANGE. WOULD NOT BE SURPRISED TO SEE LIFR CONDITIONS AT TIMES AS WELL. && .MARINE (FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)... SFC LOW OVER SOUTHERN MN DRIFTS NORTHEAST ACROSS THE UPPER GREAT LAKES THROUGH SATURDAY AFTN. LIGHT PRESSURE GRADIENT WITH THE LOW CENTER LEADS TO WINDS STAYING BLO 25 KNOTS INTO THIS EVENING. THEN...AS THE LOW BEGINS TO SHIFT EAST OF LAKE SUPERIOR ON SATURDAY...WINDS INCREASE FROM WEST TO EAST ACROSS LAKE SUPERIOR. COLD AIR FLOWING OVR THE WARMER LAKE LEADS TO UNSTABLE LOW LEVELS AND GOOD MIXING. THE BETTER MIXING AND TIGHT PRESSURE GRADIENT SHOULD RESULT IN 30 KNOT WINDS WITH POTENTIAL FOR A FEW GALE FORCE GUSTS TO 35 KNOTS SATURDAY AFTERNOON/EVENING BEHIND THE COLD FRONT. HIGH PRESSURE SLIDING ACROSS THE UPR GREAT LAKES LATER MONDAY THROUGH THURSDAY WILL KEEP WINDS LESS THAN 25 KNOTS. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN...NONE. LAKE SUPERIOR...NONE. LAKE MICHIGAN...NONE. && $$ SYNOPSIS/DISCUSSION...VOSS AVIATION...ROLFSON MARINE...JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 326 PM CST FRI NOV 7 2008 .DISCUSSION... WATER VAPOR IMAGERY AND RADAR TRENDS STARTING TO A NEW DEFORMATION ZONE STARTING TO TAKE SHAPE FROM NE MN INTO SOUTH CENTRAL MN. LATEST RUC SHOWING AN AXIS OF MID LEVEL THETA E ADVECTION OVER SE MN AND WEST CENTRAL WI THROUGH THE EVENING HOURS BUT BETTER QG CONV OVER WEST CENTRAL WI. 18Z NAM SHOWING THIS TREND AS WELL BUT HOLDING ON A LITTLE LONGER. THIS COMBO OF FORCING WEAKENS CONSIDERABLY ON BY SATURDAY AFTERNOON. HAVE LOWERED POPS BUT WONDER IF THEY MAY BE TOO HIGH. LOW LEVEL THICKNESS VALUES STAY UP OVER PARTS OF EAST CENTRAL MN AND WEST CENTRAL WI THIS EVENING SO WILL KEEP THE LIQUID PRECIP TYPE GOING FOR A FEW HOURS. OTHERWISE SNOW ELSEWHERE AND COULD SEE AN INCH OR TWO ADDITIONAL IN PARTS OF THE SOUTH CENTRAL TONIGHT...AND SOME LIGHT ACCUMULATIONS IN WEST CENTRAL WI ON SATURDAY. WINDS TO INCREASE MUCH OF MN CWA TONIGHT...ESPECIALLY WEST. CLOSE TO WIND ADVSY FOR A TIME. MAV MOS INFLATED WINDS SPEEDS INCREASE A BIT WEST FOR A TIME THIS EVENING AND THEN RELAX. RUC 925 WIND SPEEDS RELAX AS WELL. SHOULD STILL BE WINDY THOUGH. CLEARING INTO THE WEEKEND WILL BE SLOW...ESPECIALLY EAST WITH BOTH GFS AND NAM SHOWING A SIG PV ANOMALY DROPPING SE OUT OF CANADA. MUCH OF THE EFFECTS OF THIS FARTHER NE THOUGH. ONCE CLEARING MOVES IN TEMPS SHOULD DROP TO CLOSE TO MOS VALUES...WITH MAV BETTER AND MAYBE A LITTLE COOLER. LONG TERM TRENDS INTO MID WEEK STILL SHOWING A SPLIT FLOW...ESPECIALLY ECMWF. GFS DOES SHOW NORTHERN BRANCH WITH AN EMBEDDED WAVE ALONG ABOUT THU. GFS ENSEMBLE POPS SHOW A POSSIBILITY AT THAT TIME AS WELL. PACIFIC TYPE FLOW SUGGESTS AT LEAST A RAIN/SNOW MIX. && .AVIATION.../18Z TAF ISSUANCE/ STACKED LOW PRESSURE SYSTEM PINWHEELING GRADUALLY EAST ACROSS THE AREA. SYSTEM OVERALL WILL GO THROUGH A WEAKENING TREND THROUGH THE NEXT 24 HOURS...HOWEVER SPOKES OF FORCING FOR SNOW WITH BRIEF IFR VISBYS WILL CONTINUE THROUGH THE DURATION OF THE TAF...PRIMARILY THROUGH TONIGHT. IFR CIGS MORE COMMON DUE TO THE ABUNDANT LOW LEVEL MOISTURE. SO HAVE MENTIONED TEMPORARY CONDITIONS FOR THESE AS WELL THROUGH TONIGHT. AT THE SURFACE...NORTHWEST WINDS BEGINNING TO INCREASE ACROSS WRN MN AND THESE WILL WORK EASTWARD INTO AXN AND RWF THIS AFTN. GUSTS LIKELY GIVEN OBS OVER THE DAKOTAS AND THE STRONG UNIDIRECTIONAL FLOW PREDICTED. THESE WINDS WILL OVERSPREAD THE OTHER TAF SITES THROUGH TONIGHT AND THEN PERSIST THROUGH THE DURATION OF THE TAF. AT AXN AND RWF...BLOWING OF FALLING SNOW AND SOME OF THE SNOW COVER MAY FURTHER REDUCE VISBYS. DURING THE DAY SAT...AS ATMOSPHERIC MOISTURE WANES...THE SNOW MODE WILL MAINLY BE SHOWERS AS OPPOSED TO BANDS. AREAL COVERAGE SHOULD STILL BE GREAT THOUGH OVER ERN MN AND WRN WI. WITH THE WINDS...ITS POSSIBLE FOR IFR VISBYS IN PLACES. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JPR/MTF mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREEN BAY WI 321 PM CST FRI NOV 7 2008 .SHORT TERM (TONIGHT AND SATURDAY)...LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW AN OCCLUDED LOW DRIFTING EAST ALONG THE MN/IA BORDER...WITH AN SECONDARY COLD FRONT PINWHEELING AROUND INTO SE WISCONSIN. BAND OF PRECIP AHEAD OF THIS COLD FRONT IS SHIFTING INTO THE SW FORECAST AREA WHILE AREAS FARTHER NE HAVE SEEN CLOUDS INCREASE THROUGH THE AFTERNOON. PRECIP TYPE HAS BEEN ALL OF THE LIQUID VARIETY SO FAR...BUT MIXED AND FROZEN PRECIP LURK JUST UPSTREAM BACK TOWARDS LACROSSE. AS THE UPPER LOW PIVOTS SLIGHTLY NORTH OF DUE EAST...PRECIP TIMING/TYPE AND ACCUMULATIONS REMAIN THE PRIMARY FORECAST CONCERNS THROUGH TOMORROW. TONIGHT...THE SECONDARY COLD FRONT ALONG WITH ITS ASSOCIATED RAIN BAND WILL ROTATE NE LATE THIS AFTERNOON AND EVENING ACROSS THE FORECAST AREA. SOME OF THE RAIN ON ITS BACK EDGE WILL BEGIN TO MIX WITH SNOW OVER THE SW FORECAST AREA AS SLIGHTLY COLDER AIR WORKS NE. BETTER CHANCES OF SNOW WILL ARRIVE LATER THIS EVENING INTO THE OVERNIGHT...WHEN A POCKET OF DEEP MOISTURE WITHIN THE UPPER LOW ITSELF INTERACTS WITH COOLING BOUNDARY LAYER TEMPS AS IT PASSES ACROSS NE WISCONSIN. AREAS ADJACENT TO GREEN BAY AND LAKE MICHIGAN WILL REMAIN LIQUID THE LONGEST AS A RESULT OF LOWER ELEVATIONS AND LAKE MODIFICATION...AND MAY NOT CHANGE OVER TO COMPLETELY ALL SNOW AT ALL. HIGHEST ACCUMULATIONS SHOULD REMAIN AT OR AROUND AN INCH OVER TOWARDS THE WAUSAU/MARSHFIELD/WISCONSIN RAPIDS CORRIDOR WHERE DEEP MOISTURE AND THE COLDEST TEMPS HOLD ON THE LONGEST WITH ALL OTHER LOCATIONS UNDER A HALF INCH AWAY FROM LAKE MICHIGAN AND GREEN BAY. LOWS IN THE LOWER TO MIDDLE 30S. TOMORROW...LOW PRESSURE MOVES ACROSS NE WISCONSIN DURING THE MORNING BEFORE EXITING EAST INTO MICHIGAN DURING THE PM HOURS. SHOWERY PRECIP WILL CONTINUE FOR MUCH OF THE MORNING...AS A RESULT OF CONVERGENCE ALONG A LOW LEVEL TROUGH AND DEFORMATION FLOW ALOFT. PRECIP TYPE SHOULD BE SNOW TO START OUT WITH EXCEPT NEAR GREEN BAY AND LAKE MICHIGAN WHERE A MIX WILL BE PRESENT. MORE RAIN WILL MIX IN BY LATE MORNING INTO THE AFTERNOON DUE TO DAYTIME HEATING OVER THE LOWER TERRAIN AREAS AWAY FROM THE NORTHERN WISCONSIN PLATEAU. SLUSHY SNOW ACCUMULATIONS COULD REACH UP TO A HALF INCH OVER THE WESTERN FORECAST AREA DURING THE MORNING BEFORE SURFACE TEMPS WARM SUBSTANTIALLY ABOVE FREEZING...MELTING ANY SNOW THAT REACHES THE GROUND. BY MID TO LATE AFTERNOON...COLD ADVECTION ENSUES TOWARDS THE NORTHWEST FORECAST AREA AND TEMPS WILL BEGIN FALLING. LAKE EFFECT BANDS MAY START TO IMPACT VILAS COUNTY BUT BELIEVE THIS IS MORE OF A PROBLEM FOR LATER PERIODS. EARLY AFTERNOON HIGHS WILL RANGE FROM THE MIDDLE 30S NW TO THE LOWER 40S. MPC .LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...MAIN FCST CONCERNS INCLUDE LAKE-EFFECT (AND ENHANCED) SNOWFALL OVER NC WI SAT NGT INTO SUNDAY...AND TEMPERATURES THROUGHOUT THE PERIOD. COLD NNW FLOW ON THE BACK SIDE OF THE DEPARTING DEEP LOW PRESSURE SYSTEM WILL RESULT IN SOME LK-EFFECT SNOW SATURDAY NIGHT. LK-H8 DELTA-T`S ARE FCST TO INCREASE TO NEARLY 20 C BY SUNDAY MORNING...SO INSTABILITY WILL BE FAIRLY STG. EXPECT 1-3 INCHES OF SNOW TO FALL IN VILAS COUNTY...WITH LESS THAN AN INCH FARTHER SOUTH. ALTHOUGH THE LLVL WIND TRAJECTORIES BECOME A LITTLE TOO WESTERLY TO BE IDEAL FOR PURE LK-EFFECT SNOW ON SUNDAY...SOME LK- ENHANCED SNOW IS LIKELY AS A STG S/W TROF MOVES THROUGH N WI. HAVE INCREASED POPS ABOVE GUIDANCE ACROSS N WI ON SUNDAY...IN AXIS OF DEFORMATION TO THE LEFT OF THE VORT TRACK. ANOTHER INCH OR TWO IS PSBL ACROSS THE FAR NORTH...WITH LOCALLY HIGHER AMTS IN NW VILAS COUNTY. HAVE KEPT LOW POPS OVER NC WI ON SUNDAY NIGHT AND MONDAY...DUE TO CONTINUED COLD NW FLOW. MUCH DRIER AIR IS EXPECTED TO ARRIVE LATER ON MONDAY...WHICH SHOULD SHUT DOWN ANY LINGERING LK-EFFECT. HIGH PRESSURE IS FCST TO SETTLE ACROSS THE GREAT LKS RGN FROM MONDAY NGT THROUGH THURSDAY...WITH THE NEXT LOW PRESSURE SYSTEM TRACKING WELL TO OUR SOUTH. DEPENDING THE THE POSN OF THE SFC HIGH AND ASSOCIATED LLVL WINDS...THERE COULD BE SOME POTENTIAL FOR LK- EFFECT SNOW SHOWERS IN EASTERN WI ON TUES/WED...BUT DETAILS ARE TOO SKETCHY TO ADD A MENTION OF PCPN ATTM. HAVE ADDED SOME SMALL POPS LATE IN THE WEEK...WITH STG WAA EXPECTED ON THU NGT...AND A COLD FRONTAL PASSAGE ON FRIDAY. MOISTURE SHOULD BE LIMITED...WITH ZONAL FLOW OFF THE PACIFIC. 12Z ECMWF HAS TRENDED WETTER WITH THIS SYSTEM THOUGH...SO WILL NEED TO MONITOR TRENDS OVER THE UPCOMING DAYS. ALTHOUGH TEMPERATURES WILL BE MUCH COLDER THAN THEY HAVE BEEN OVER THE PAST SEVERAL WEEKS...THEY WILL ACTUALLY BE FAIRLY CLOSE TO NORMAL FOR MUCH OF THE PERIOD...WITH MIN TEMPS IN THE 20S AND LOWER 30S... AND MAX TEMPS IN THE UPPER 30S AND 40S. && .AVIATION (FOR THE 18Z TAFS)...LOW PRESSURE OVER THE MINNESOTA/IOWA BORDER WILL SLOWLY LIFT NORTHEAST OVER THE TAF PERIOD. PRECIPITATION WITHIN MVFR CIGS WILL START OUT AS ALL RAIN INITIALLY...AS IT MOVES INTO AUW/CWA AND RHI BY MID-AFTERNOON BEFORE MIXING WITH SNOW LATE IN THE AFTERNOON. CHANGE-OVER TO ALL SNOW WILL ARRIVE AT THESE LOCATIONS MID TO LATE EVENING...AND OCCASIONAL SNOW SHOWERS WILL THEN CONTINUE THROUGH THE REMAINDER OF THE TAF PERIOD. SOME IFR CIGS/VSBYS ARE POSSIBLE IN THE HEAVIER SNOW SHOWERS. GRB WILL HAVE THE CHANGE-OVER ARRIVE LATER MORE TOWARDS AFTER MIDNIGHT. MPC && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MPC/KIECKBUSCH wi