AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 348 AM MST THU NOV 11 2004 .SHORT TERM... (TODAY AND TONIGHT) ...RELATIVELY QUIET BUT COLD WEATHER FOR THE NEXT 24 HOURS... CURRENTLY...WATER VAPOR IMAGERY AND RUC MODEL UPPER AIR ANALYSES SHOWED A RELATIVELY WEAK H5-H3 CYCLONIC SHEAR AXIS MOVING THROUGH THE GREAT BASIN AND DESERT SW. THIS ELONGATED SHORTWAVE TROUGH WAS MOVING INTO SWRN CO EARLY THIS AM. AHEAD OF THIS FEATURE...MID LEVEL CLOUDS WERE EXPANDING PER THE IR SATELLITE IMAGERY ANIMATION IMPLYING VERTICAL MOTION. LOWER CLOUDS STILL REMAINED ACROSS S CNTRL/SERN CO...BUT A MID/HIGH LEVEL DECK WAS RESPONDING TO THE SHORTWAVE TROUGH. THIS IMPLIED AREA OF ASCENT SHOWS UP IN H7-H5 AND H5-H3 LAYER Q(S) DIV ANALYSES. REGIONAL RADAR DATA REVEALED SNOW SHOWERS DEVELOPING AHEAD OF THE SHORTWAVE TROUGH AND IN THE AREA OF IMPLIED H7-H5 LAYER Q(S) DIV ASCENT. TEMPS HAVE NOT COOLED AS MUCH AS WE ANTICIPATED THANKS TO THE EXTENSIVE BKN-OVC LOW/MID DECK KEEPING THINGS INSULATED....SO CURRENT AND AROUND SUNRISE TEMPS WILL NOT BE TOO FAR OFF FROM PROJECTED MAX TEMPS TODAY. NEXT ULJ AND ASSOCIATED LOW PRESSURE SYSTEM WAS OVER NRN CA TO JUST OF THE PACIFIC COAST. TDA...AFOREMENTIONED ELONGATED CYCLONIC SHEAR AXIS IS FORECAST TO CONTINUE MOVING THROUGH CO THIS AM/EARLY AFTN. THERE IS SOME MID LEVEL DRYING BEHIND THE TROUGH AXIS BY THIS AFTN ALONG WITH IMPLIED SUBSIDENCE PER Q DIV ANALYSES. THE COMBINATION OF THESE TWO FEATURES SHOULD LIMIT THE POTENTIAL FOR PRECIPITATION LATER THIS AFTN...SO WILL GO WITH SCATTERED POPS IN THE MTS AND HIGH VALLEYS THIS AM AND DIMINISH POPS FOR THIS AFTN. SFC RIDGE TO REMAIN FROM THE NRN PLAINS INTO SERN CO...SO THIS SHOULD CONTINUE TO "LOCK-IN" THE LOWER TROP COLD AIR MASS. MAY ACTUALLY SEE A FEW BREAKS IN THE CLOUDS THIS AFTN WITH RELATIVELY DRIER MID LEVEL AIR MOVING INTO CO...BUT WITH A RELATIVELY COLD AIR MASS AND PLENTY OF LOW/MID LEVEL MOISTURE...WE SHOULD SEE AT LEAST BKN CLOUD COVER THIS AFTN. ETA MOS MIGHT BE A LITTLE TOO WARM(IF THE CLOUDS STAY IN)...SO WILL PRETTY MUCH MAINTAIN CURRENT FORECAST HIGH TEMPERATURES. TNGT...IT SHOULD BE A RELATIVELY QUIET NGT WHILE WE WAIT FOR THE NEXT WEATHER SYSTEM TO APPROACH CO. BIG CHALLENGES WITH TEMPS TONIGHT. IF THE BKN-OVC CLOUD COVER CONTINUES...THEN TEMPS WILL NOT FALL THAT MUCH...OR AT LEAST AS MUCH AS MOS IS PROJECTING. NEXT ULJ AND ASSOCIATED CLOSED LOW IS FORECAST TO MOVE INTO THE GREAT BASIN AND EXTREME WRN CO TOWARDS EARLY FRI AM. AIR MASS ALONG THE CONTDVD PROGGED TO MOISTEN UP THROUGH THE NIGHT. TOWARDS EARLY FRI AM...SLY OROGRAPHIC INFLOW TO THE SAN JUAN MTS DEVELOPS STARTING THE UPSLOPE SNOWFALL. WILL GO WITH 'SLIGHT CHANCE' POPS FOR THE CONTDVD IN THE EVENING AND THEN INCREASE TO 'CHANCE' FOR THE ERN SAN JUAN MTS AFTER MIDNIGHT. [METZE] .LONG TERM... (FRIDAY THROUGH WEDNESDAY) MAIN CONCERN IS WEATHER SYSTEM AND SNOW AMOUNTS FOR FRIDAY AND SATURDAY. MODELS HAVE COME INTO PRETTY GOOD AGREEMENT WITH TIMING OF SYSTEM ON FRIDAY AND SATURDAY. UPPER LOW DROPS INTO AZ AND LEAVES COLORADO IN SOUTHWEST TO SOUTHERLY FLOW AHEAD OF SYSTEM. EXPECT PRECIP TO BEGIN IN WESTERN MTNS FRIDAY MORNING...THEN SPREAD EASTWARD. UPPED POPS WEST AND IN SAN LUIS VALLEY EARLY FRIDAY...ADDED SOME TO CO/NM BORDER AS WELL. WITH MID LEVEL SOUTHERLY FLOW...WOULD EXPECT SOUTHWEST MTNS AND SOUTHERN SANGRES TO HAVE BEST SNOW POTENTIAL... WITH SOME ACCUMULATIONS IN THE SAN LUIS VALLEY INTO SATURDAY...WITH SOME EMPHASIS ON THE WESTERN SIDE AS FLOW BECOMES SOUTHEAST. TROF THEN SWINGS A SERIES OF VORTICITY MAXIMA OVER THE STATE ON SATURDAY. MID LEVEL TEMPS DROP FROM ABOUT -4C ON FRIDAY TO -8C ON SATURDAY... AND WHEN COUPLED WITH DIABATIC COOLING WILL LEAD TO SOME CHILLY HIGHS FOR FRI/SAT. WILD CARD FOR SNOW WILL BE AVAILABLE MOISTURE...AND MODELS VARY ON AMOUNTS ALTHOUGH LOCATIONS SEEM TO BE IN GENERAL AGREEMENT. AM MORE CONFIDENT WITH TEMPS AND POPS THAN SNOW AMOUNTS... BUT WILL PUT IN A FIRST GUESS. APPEARS THAT SYSTEM WILL HAVE TO BRING MOISTURE WITH IT INITIALLY...THEN WILL BECOME COLD ENOUGH TO WORK OVER WHAT MOISTURE REMAINS FROM MID AND LOW LEVEL SOURCES...WITH COLDER AIR ALSO INCREASING RATIOS AS SATURDAY PROGRESSES. FOR NOW... WILL ERR ON SIDE OF CAUTION...WITH SNOW MODEL NUMBERS AND MODEL GUIDANCE SUGGESTING WARNING NUMBERS FOR THE HIGHER ELEVATIONS OF THE SOUTHWEST MOUNTAINS FRIDAY INTO SATURDAY. BEST CHANCE ON PLAINS WILL BE SATURDAY AS UPGLIDE COUPLED WITH SYNOPTIC LIFT MAY GENERATE SOME LIGHT ACCUMULATIONS. ISENTROPIC LIFT ON THE PLAINS AND OROGRAPHIC COMPONENT IN MOUNTAINS SHOULD HELP ENHANCE SNOW AMOUNTS. NO CHANGES TO SUN-WED. SYSTEM DROPS SOUTH INTO BAHA SUNDAY...AND MAKES ONLY SLIGHT PROGRESS EASTWARD INTO MONDAY. BY WEDNESDAY... SYSTEM HAS MADE IT INTO TEXAS. RESULT IS SOUTHERLY FLOW SUN/MON AS ENERGY AND MOISTURE MAY STILL ADVECT INTO COLORADO. MAY START TO CATCH A BREAK TUES/WED AS SYSTEM MOVES SOUTH AND EAST OF THE AREA. KC && .PUB WATCHES/WARNINGS/ADVISORIES...NONE. $$ co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 944 AM EST THU NOV 11 2004 .DISCUSSION... THE 12 UTC SURFACE ANALYSIS SHOWS A WARM FRONT EXTENDING FROM JUST OFF THE FLORIDA PANHANDLE COAST INTO A LOW PRESSURE CENTER OVER NORTHERN ARKANSAS. A COLD FRONT TRAILED DOWN FROM THIS LOW INTO SOUTHEAST TEXAS...AND WAS MOVING EAST SOUTHEAST AT 35 MPH BASED ON THE TIMING OF ITS ASSOCIATED ROPE CLOUD ON SATELLITE IMAGERY. A LARGE AREA OF RAIN AND ISOLATED THUNDERSTORMS BLANKETED THE WESTERN HALF OF OUR FORECAST AREA IN ASSOCIATION WITH PLENTIFUL DEEP LAYER MOISTURE...Q-G FORCING...AND ISENTROPIC LIFT. THIS RAIN HAS BEEN SPREADING EAST AT 10 MPH ACROSS OUR ALABAMA AND GEORGIA ZONES...BUT HAS MADE LITTLE PROGRESS EASTWARD IN OUR FLORIDA ZONES. THE EVOLUTION OF THIS RAIN SYSTEM POSES THE BIGGEST FORECAST CHALLENGE IN THE SHORT TERM. A LINE OF DEEP MOIST CONVECTION IS BACK-BUILDING ALONG THE WARM FRONT OFF THE WESTERN PANHANDLE AND ALABAMA COASTS. THE LATEST RUC (AND GFS AND ETA) INDICATE THE BEST SYNOPTIC SCALE LIFT MAY NOT REACH OUR EASTERN ZONES UNTIL LATER TONIGHT WHEN THE COLD FRONT APPROACHES. I INTEND TO LOWER THE POPS IN OUR EASTERNMOST ZONES A LITTLE TO REFLECT THIS TREND. AS FOR A SEVERE WEATHER THREAT TODAY...THERE HAS BEEN ONE STORM TO THE WEST OF OUR COUNTY WARNING AREA THAT HAS HAD AN IMPRESSIVE RADAR SIGNATURE...BUT IT THINK THE THREAT HERE WILL BE MINIMAL GIVEN THE LACK OF A GOOD LOW LEVEL OR UPPER JET AND STRONG...STRONG INSTABILITY...AND DEEP LAYER VERTICAL SHEAR. THE WINDS AND SEAS OVER THE COASTAL WATERS ARE STILL AT ADVISORY LEVELS SO I WILL LEAVE THEM UP. HOWEVER...THE MODELS ARE UNANIMOUS IN WEAKENING THE WINDS THIS AFTERNOON. && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...SMALL CRAFT ADVISORY GMZ770-775. && $$ FOURNIER fl AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE DES MOINES IA 906 PM CST THU NOV 11 2004 MAIN FOCUS FOR NEAR TERM IS OVERNIGHT TEMPS. AM GOING TO UNDERCUT GUIDANCE CERTAINLY IN THE NORTH TONIGHT AND LIKELY IN OTHER LOCATIONS AS WELL BUT TO A LESSER EXTENT. VERY DRY AIR AT SFC NOW LOCATED UNDER SFC RIDGE AXIS FROM SW MN THROUGH CNTRL NE WITH DEW POINTS IN THE SINGLE DIGITS AND TEMPS HAVE FALLEN ALREADY INTO THE 20S. RUC FORECASTS THE 850-SFC HIGH PRESSURE OVER NRN PORTIONS OF THE FORECAST AREA BY 9-12Z TIMEFRAME AS WELL AS NEG NEAR SFC THETA-E ADVECTION AND COULD POTENTIALLY SEE SOME VERY COLD TEMPS EVEN INTO THE SINGLE DIGITS IF LOW TDS...CALM WINDS LAST LONG ENOUGH AND SKIES REMAIN CLOUD FREE AS MODELS SUGGEST. ONLY QUESTION THAT THROWS A WRENCH IN EQUATION ARE CI CLOUDS STREAMING SOUTH FROM NRN PLAINS AND PROGGED TO REACH FA AFTER 12Z WHILE BEING SHEARED OUT CONSIDERABLY. OTHERWISE MOST FORECAST ELEMENTS LOOK GOOD AND WON'T BE ADJUSTING. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ RUSSELL ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1102 AM EST THU NOV 11 2004 .DISCUSSION... THE MAIN CONCERN WITH THIS UPDATE IS THE LAKE EFFECT SNOW POTENTIAL THIS AFTERNOON. WATER VAPOR IMAGERY AND RUC/ETA SHOWING A LONGWAVE TROUGH OVER EASTERN HUDSON BAY. A SHORTWAVE WRAPPING THROUGH THE BASE OF THIS TROUGH IS UNDER AN 850MB THERMAL TROUGH OVER EASTERN ONTARIO. SURFACE ANALYSIS SHOWING A BROAD RIDGE OVER THE DAKOTAS AND MINNESOTA. THIS IS SPREADING INTO THE WISCONSIN AND UPPER MICHIGAN. LAKE-850MB DELTA-T'S ARE AROUND 14C OVER EASTERN LAKE SUPERIOR. GREEN BAY RAOB THIS MORNING SHOWED A VERY DRY SOUNDING. LAKE EFFECT SNOW BANDS ARE SHOWING UP OVER EASTERN U.P. ON VISIBLE SATELLITE. THUS WITH DRY CONDITIONS EXPECT ONLY A FEW FLURRIES. A FEW LAKE EFFECT CLOUDS ARE SHOWING UP OVER WESTERN LAKE SUPERIOR AND ALONG THE LAKE SHORE FROM MARQUETTE TO WHITE FISH POINT. PLAN TO KEEP A MENTION OF FLURRIES IN THE FORECAST FOR THE KEWEENAW PENINSULA AND THE LAKES SHORE AREA EAST OF MARQUETTE. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 658 AM EST THU NOV 11 2004 .UPDATE... SOUTHWARD SINKING RAIN BAND HAS WEAKENED CONSIDERABLY PAST COUPLE OF HOURS...AND MOST AREAS SHOULD STRUGGLE TO RECEIVE MEASURABLE RAINFALL. PROXIMITY TO RIGHT ENTRANCE REGION OF UPPER JET SHOULD CONTINUE TO SUPPORT SOME CHANCE THIS MORNING...THOUGH. WILL UPDATE FOR SCATTERED LIGHT RAIN SHOWERS THIS MORNING WITH EXCEPTION OF DRY NORTHERN TIER OF COUNTIES. LATEST ETA AND RUC SOUNDINGS INDICATE THAT ONCE FREEZING LEVEL DROPS ENOUGH TO SUPPORT POSSIBLE SNOW MIX...MOISTURE WILL BE TOO LEAN TO TAP ANY ICE NUCLEI. && DWD .PREV DISCUSSION...ISSUED 200 AM EST THU NOV 11 YESTERDAY'S MAXES IN THE LOWER 60S WILL BE A DISTANT MEMORY AS WE HEAD INTO THE WEEKEND...AS IT TURNS MUCH COLDER. 00Z DTX SOUNDING DID IN FACT REVEAL AN 925 MB OF 10 C...WHICH YESTERDAY'S 00Z ETA MODEL FORECASTED. BASED ON THE BETTER HANDLING OF THE LOW LEVELS (RESOLUTION)...WILL RELY MOSTLY ON THE MESOETA FOR ADDRESSING ANY POTENTIAL OF LAKE EFFECT DURING THE NEXT COUPLE OF DAYS. SURFACE COLD FRONT NOW PUSHING INTO SOUTHEAST MICHIGAN EARLY THIS MORNING. POST FRONTAL PRECIPITATION ASSOCIATED WITH 850 TO 700 MB FGEN FORCING SHOWING SIGNS OF DECREASING. WILL CONTINUE TO MONITOR RADAR TRENDS TO DECIDE ON THE APPROPRIATE WORDING FOR THE ZONES. EITHER WAY...NOT A BIG DEAL...AS PRECIP WILL BE LIGHT AND OUT OF HERE BY MID MORNING NORTH OF M-59 AND BY LATE MORNING ACROSS THE SOUTHERN MICHIGAN BORDER. GOOD SUBSIDENCE/CLEARING QUICKLY ADVANCING INTO THE WESTERN GREAT LAKES. BASED ON 850 MB DEW POINT DEPRESSIONS OF 30 TO 40 C THIS AFTERNOON...THINK WE CAN GET AWAY WITH MOSTLY SUNNY SKIES ACROSS THE NORTHERN HALF OF THE CWA. HIGH CLOUDS WILL LINGER LONGER NEAR THE SOUTHERN MICHIGAN BORDER...AS THE UPPER LEVEL FLOW WILL BE MORE WEST TO EAST. UPPER LOW OVER EASTERN OKLAHOMA CONTINUES TO REMAIN WELL ORGANIZED...AND SEPARATE FROM THE NORTHERN STREAM FLOW...THUS ALLOWING FOR THE FASTER PROGRESSION OF THIS MORNING'S COLD FRONT. TOO MUCH DRY AIR AROUND TO WORRY ABOUT LAKE EFFECT THIS AFTERNOON...OR TONIGHT FOR THAT MATTER...AS INVERSION HEIGHTS WILL BE LOW (3000 TO 3500 FEET). ALSO...925 MB WINDS OVER LAKE HURON WILL BE LIGHT AND VARIABLE...THUS NOT ALLOWING FOR ANY POTENTIAL ORGANIZED DEVELOPMENT. WITH NEXT SHORTWAVE TROUGH DROPPING SOUTHEAST THROUGH THE CENTRAL GREAT LAKES TOMORROW...A BETTER CHANCE OF SOME FLURRIES ACROSS THE THUMB...AS 1000 TO 500 MB MOISTURE INCREASES TO 50 PERCENT OR BETTER....WITH INVERSION HEIGHTS CLIMBING TO AT LEAST 5500 FEET. LONG NORTHERLY FETCH SETTING UP FRIDAY NIGHT. HOWEVER...INSTABILITY AND MOISTURE IS NOT THAT GREAT BASED ON THE MESOETA/UKMET FORECASTED 850 MB TEMPS OF -8 TO -10 C. ALLOWING FOR THE POSSIBILITY THE COLDER GFS SOLUTION MAY VERIFY...HAVE GONE WITH A CHANCE OF SNOW SHOWERS ACROSS THE THUMB REGION...MAINLY FOR THE EVENING HOURS. STUCK CLOSE TO THE COLDER GFS MOS TEMPS DURING THE NEXT COUPLE OF DAYS. RIDGING AT ALL LEVELS TO BUILD INTO THE CENTRAL GREAT LAKES LATE IN THE WEEKEND...INTO EARLY NEXT WEEK. WITH A 1042 MB SURFACE HIGH SITTING OVER SOUTHERN LOWER MICHIGAN SUNDAY MORNING...HAVE LOWERED TEMPS FURTHER INTO THE UPPER TEENS TO LOWER 20S (OUTSIDE OF THE CITY). WITH THE COLD START...WILL CALL FOR MAXES IN THE MID 40S ON SUNDAY...DESPITE PLENTY OF SUNSHINE. THAT IS A GOOD 25 DEGREE DIURNAL TEMPERATURE SWING. WITH HEIGHTS CONTINUING TO BUILD FOR MONDAY...HAVE ALLOW FOR A MODERATION TO THE AIRMASS...ADDING 4 TO 8 DEGREES. RIDGE TO HOLD ON INTO TUESDAY...AS WEAKENING SHORTWAVE (EJECTED FROM UPPER LOW OVER THE SOUTHWEST CONUS) TRIES TO MOVE INTO THE GREAT LAKES REGION. && .DTX WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY FOR ALL NEARSHORE WATERS TODAY. && $$ SF EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 145 PM EST THU NOV 11 2004 .AVIATION (18Z-18Z)... AS RAIN DEVELOPS INTO THE AREA THE PRECIPITATION HAS BEEN BRINGING OCCASIONAL MVFR VISIBILITIES AND CEILINGS. EXPECT CEILINGS TO BECOME IFR LATE THIS AFTERNOON AND EVENING AS RAIN CONTINUES AND COLDER AIR FILTERS IN. IF OBSERVATIONS UPSTREAM ARE ANY INDICATION THE IFR DECK COULD MOVE IN FAIRLY QUICKLY. THERE IS THE POSSIBILITY OF CLOUDS BRIEFLY DROPPING INTO THE LIFR CATEGORY LATE TONIGHT BUT NOT ENOUGH CONFIDENCE IN THIS AT THE MOMENT TO INCLUDE IN TAFS. LATEST INDICATIONS ARE THAT RAIN WILL TAPER OFF BETWEEN 06Z AND 10Z. EXPECT SOME MIXING TO HELP CEILING LIFT BACK INTO THE MVFR RANGE BY LATE MORNING. THIS WILL ALSO RESULT IN SOME GUSTY WINDS. && .PREVIOUS DISCUSSION... THE FOLLOWING WAS ORIGINALLY ISSUED AT 1035 AM EST THU NOV 11 2004 SHORT TERM (TODAY AND TONIGHT)... MAIN CONCERN IS THAT SYSTEM IS SLOWER MOVING INTO THE REGION. THIS IS REFLECTED NOT ONLY IN LATEST TRENDS BUT ALSO IN 12Z RUC AND ETA SOLUTIONS. SO HAVE BACKED OFF SLIGHTLY ON TIMING RAIN INTO THE AREA TODAY AND ALSO EXTENDED PRECIPITATION A LITTLE LONGER THROUGH THE NIGHT. MEANWHILE A COLD FRONT IS CURRENTLY IN THE NORTHWEST PART OF THE FORECAST AREA AND HEADED SOUTHWARD. TEMPERATURES WILL BE FALLING AFTER THE FRONT PASSES. ALSO PRECIPITATION MOVING IN FROM THE SOUTHWEST WILL LIMIT THE DIURNAL RISE IN TEMPERATURES AHEAD OF THE FRONT. SO HAVE INDICATED STEADY OR FALLING READINGS FOR ALL BUT THE SOUTHEAST ZONES. THE FOLLOWING WAS ORIGINALLY ISSUED AT 333 AM EST THU NOV 11 2004 SHORT TERM (TODAY THROUGH SATURDAY NIGHT)... CURRENT SAT IMAGES INDCG AS/CS CONTINUING TO STREAM INTO FCST AREA AHEAD OF DVLPG SYSTEM. COLD FRONT EXTNDG ACRS LWR MICHIGAN SW THRU MISSOURI INTO A SFC LO CENTERED OVER EASTERN OKLAHOMA. LOWER CIGS IN FORM OF SC/AC RAPIDLY ADVANCING NORTH AND EAST UP THE OHIO RIVER VLY THRU WESTERN KY AND SW INDIANA ATTM. RAIN WITH EMBEDDED TSTMS PUSHING ACRS MISSISSIPPI RIVER INTO WESTERN KY AND SRN ILLINOIS. BIG FCST CHALLENGE CENTERS ON UNSETTLED WX OVER NEXT 24 TO 30 HOURS AS FRNTL BNDRY DROPS ACRS REGION AND SFC LO TRACKS THRU TN VLY. 00Z MODEL SOLNS HAVE SLOWED SFC LO DOWN CONSIDERABLY...AND THIS IS GOING TO CAUSE SOME CHANGES TO PREV FCST. ALL MODELS SEEM TO HAVE PICKED UP ON COLD AIR WEDGE DVLPG ON LEE SIDE OF APPALACHIAN MTNS LATE THIS AFTN AND THRU THE OVERNIGHT THAT 10/00Z ETA SOLN ORIGINALLY PICKED UP ON. THIS COMBINED WITH THE FRONT BECMG PARALLEL TO UPR FLO PATTERN CONTRIBUTING TO A SLOWER TRACK OF SFC LO THRU TN VLY. WHILE ETA REMAINS SLOWEST MODEL IN TERMS OF HANGING ON TO CLOUDS/PCPN LONGEST...GFS WITH SUPPORT OF ECMWF REMAINS A BIT FASTER AND WILL TREND TOWARDS ITS SPEED. 00Z RUNS SUGGESTING SLOWER ONSET TO PCPN THIS MRNG AS ISENT LIFT TAKING A LITTLE LONGER TO GET ESTABLISHED...AND AFOREMENTIONED SLOWER SPEED OF SFC LO TRACKING ACRS OKLAHOMA/ARKANSAS. THIS CURRENTLY BEING VERIFIED AS CLOSEST OBS INDCG PCPN ACRS SRN ILLINOIS. AS ISENT LIFT INCREASES IN WAA OVER NEXT SVRL HOURS...WILL SEE INCREASE IN PCPN ACRS KENTUCKY AND SRN INDIANA WITH SCT SHRA MOVNG INTO WESTERN FCST AREA BTWN 11-14Z. PCPN WILL QUICKLY OVERSPREAD FCST AREA THRU MID/LATE MRNG. 35KT 850 LLJ DVLPG AHEAD OF MID LVL TROF ACRS KENTUCKY THIS AFTN...WITH STRONG LO LVL CONV AT NOSE OF LLJ SWEEPING ACRS SRN FCST AREA DURING AFTN/EVNG HOURS. HEAVIEST AND MOST CONCENTRATED RAIN EXPECTED DURING THIS TIMEFRAME AS DEEP CONVERGENCE THRU 700 MB AND HIGHEST PEFF VALUES CORRELATE. HAVE MAINTAINED CAT POPS ACRS SRN 2/3 FCST AREA FOR AFTN HOURS AND EXTENDED IT INTO THE EVNG AS DEEP CONVERGENCE SWINGS EAST. NORTH OF I-70...LO LVL FORCING A BIT WEAKER AS BNDRY DROPS INTO REGION BY MID AFTN. PCPN SHOULD BE LIGHTER AND HAVE GONE WITH HIGH LKLY (70) POPS FOR TODAY. PCPN WILL TAPER ACRS WEST CNTRL OH BY LATE EVNG...AND ACRS AREAS NORTH AND WEST OF I-71 AFT MIDNITE. FURTHER SOUTH AND EAST WILL SEE RAIN THROUGHOUT THE NIGHT...BUT SHOULD SEE A GRADUAL DIMINISHING TREND TOWARDS DAWN FRI AS DEEP LO LVL CONVERGENCE MOVES EAST OF REGION AND ISENTROPIC DOWNGLIDE DVLPS. ETA INDCG SOME ELEVATED INSTABILITY AT 800 MB GRAZING AREAS ALONG AND SOUTH OF OHIO RIVER THIS EVNG...BUT WITH LO CONFIDENCE ON THUNDER WILL LEAVE IT OUT OF FCST ATTM. LO LVL MOISTURE HANGS ALL NIGHT WITH SKIES REMAINING CLOUDY ACRS ENTIRE FCST AREA. WILL LEAVE LO CHC POPS ACRS SE FCST AREA THRU MRNG HOURS ON FRI...WITH ENTIRE REGION DRY BY 15-16Z. BACK EDGE OF SC DECK WILL MAKE GRADUAL PROGRESS SOUTH AND EAST DURING THE DAY AS BROAD SFC HI BEGINS TO BUILD INTO REGION. SHOULD BE GOOD DEAL OF SUNSHINE IN WEST CNTRL OH AND EVEN DOWN INTO THE DAYTON AREA DURING AFTN HOURS. CLOUDS WILL SCATTER BY LATE AFTN IN EASTERN FCST AREA...WITH RAPID CLEARING DURING EVNG HOURS. CENTER OF SFC HI THEN DROPS DOWN INTO REGION FOR SAT AND SUN...BEGINNING ANOTHER EXTENDED PERIOD OF DRY WEATHER. TEMPS...TEMPS ARE TRICKY TODAY BASED ON CURRENT READINGS. WHILE IT HAS COOLED DOWN INTO L40S ACRS EASTERN COUNTIES...LO LVL WARM POOLING AHEAD OF FRNTL BNDRY KEEPING TEMPS UP AROUND 50 IN WESTERN COUNTIES. THIS IS NEAR OR EVEN SLIGHTLY ABV MAV GUID FOR HIGHS TODAY. FEEL A GOOD 3-5 DEGREE JUMP IN TEMPS POSSIBLE ACRS WEST...AND AS A RESULT HAVE RAISED TEMPS SIGNIFICANTLY OVER PREV FCST. ADJUSTED NORMAL DIURNAL TREND TO HRLY TEMPS WITH WARMEST TEMPS IN WEST BY 18Z...THEN STEADY OR SLOWLY FALLING BEYOND AS FRONT WORKS THRU AREA. WARMED TEMPS UP TONIGHT AS MORE CLOUDS/PCPN EXPECTED AND CAA SLOWED A BIT. WITH SC DECK AFFECTING MUCH OF FCST AREA FRI...SHOULD SEE NO MORE THAN 5 DEGREE RISE FROM LOWS TONIGHT. RYAN LONG TERM (SUNDAY THROUGH WEDNESDAY)... NO SIGNIFICANT CHANGES BEYOND SATURDAY NIGHT TO PREV FCST...SEE PREV DISCUSSION BELOW. RYAN THE FOLLOWING WAS ORIGINALLY ISSUED AT 322 PM EST WED NOV 10 2004 LONG TERM (SATURDAY THROUGH WEDNESDAY)... HIGH PRESSURE IS LOCATED OVER GREAT LAKES AT 12Z SAT. HIGH DROPS VERY SLOWLY SOUTH INTO THE OHIO VALLEY BY 12Z MONDAY. EXCEPT FOR SOME LAKE EFFECT MOISTURE AT H8 ACROSS CENTRAL OHIO FOR SATURDAY PERIOD WILL BE RELATIVELY CLOUD FREE. BY MONDAY NIGHT WAA BEGINS AND MID TO HIGH CLOUDS WORKING BACK INTO THE REGION. 00Z GFS WAS DIVING A SHORTWAVE FROM THE UPPER PLAINS INTO THE MIDWEST AND SPREADING RAIN INTO THE REGION FOR TUESDAY. 06Z GFS WAS NOT AS STRONG WITH THE FEATURE...AND NOW THE 12Z GFS NO LONGER HAS THIS SCENARIO. WENT WITH A ECMWF/DGEX BLEND ON TUE...WHICH IS CONSISTENT WITH 12Z GFS...WHICH KEPT FCST DRY. AS UPPER LOW SWINGS THROUGH THE SOUTHWEST TUE-WED...FA IS STILL UNDER INFLUENCE OF SFC HIGH. OPERATIONAL 00Z GFS WAS COLDEST OF THE MODELS. STAYED A FEW DEGREES WARMER THAN FOR HIGHS AND LOWS THROUGH THE WEEKEND. NICE WARMUP IN STORE BY TUE-WED AS WAA ON BACKSIDE OF SFC HIGH PUMPS WARMER AIR BACK INTO FA. SITES && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. IN...NONE. KY...NONE. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 1035 AM EST THU NOV 11 2004 .SHORT TERM (TODAY AND TONIGHT)... MAIN CONCERN IS THAT SYSTEM IS SLOWER MOVING INTO THE REGION. THIS IS REFLECTED NOT ONLY IN LATEST TRENDS BUT ALSO IN 12Z RUC AND ETA SOLUTIONS. SO HAVE BACKED OFF SLIGHTLY ON TIMING RAIN INTO THE AREA TODAY AND ALSO EXTENDED PRECIPITATION A LITTLE LONGER THROUGH THE NIGHT. MEANWHILE A COLD FRONT IS CURRENTLY IN THE NORTHWEST PART OF THE FORECAST AREA AND HEADED SOUTHWARD. TEMPERATURES WILL BE FALLING AFTER THE FRONT PASSES. ALSO PRECIPITATION MOVING IN FROM THE SOUTHWEST WILL LIMIT THE DIURNAL RISE IN TEMPERATURES AHEAD OF THE FRONT. SO HAVE INDICATED STEADY OR FALLING READINGS FOR ALL BUT THE SOUTHEAST ZONES. && .PREVIOUS DISCUSSION. THE FOLLOWING WAS ORIGINALLY ISSUED AT 524 AM EST THU NOV 11 2004 AVIATION (12Z-12Z)... SURFACE ANALYSIS SHOWS COLD FRONT FROM LAKE ERIE TO KSTL. SATELLITE IMAGERY AND SURFACE OBS SHOWS MAINLY CIRRUS/AC OVER FORECAST AREA. WILL SPREAD STRATA CU DECK ACROSS TAF SITE EARLY ALONG WITH THREAT OF PRECIP. WILL MAKE -SHRA IN THE PREDOMINATE PART OF THE TAF BETWEEN 17Z AT KCVG AND 20Z AT KCMH. WILL KEEP PRECIP IN THE MAIN PART OF FORECAST UNTIL AFT 00Z. FRONT BEGINS TO DRIFT SOUTH AND PRECIP WILL SLOWLY COME TO AN END FROM NORTHWEST TO SOUTHEAST OVERNIGHT. CIGS AND VSBYS WILL SLOWLY COME DOWN DURING THE DAY. IFR CONDITIONS ARE EXPECTED AFT 00Z FOR KLUK...KCVG... KILN...KDAY. CEILINGS ARE EXPECTED TO BE A BIT BETTER AT KCMH... KLCK. THE FOLLOWING WAS ORIGINALLY ISSUED AT 333 AM EST THU NOV 11 2004 SHORT TERM (TODAY THROUGH SATURDAY NIGHT)... CURRENT SAT IMAGES INDCG AS/CS CONTINUING TO STREAM INTO FCST AREA AHEAD OF DVLPG SYSTEM. COLD FRONT EXTNDG ACRS LWR MICHIGAN SW THRU MISSOURI INTO A SFC LO CENTERED OVER EASTERN OKLAHOMA. LOWER CIGS IN FORM OF SC/AC RAPIDLY ADVANCING NORTH AND EAST UP THE OHIO RIVER VLY THRU WESTERN KY AND SW INDIANA ATTM. RAIN WITH EMBEDDED TSTMS PUSHING ACRS MISSISSIPPI RIVER INTO WESTERN KY AND SRN ILLINOIS. BIG FCST CHALLENGE CENTERS ON UNSETTLED WX OVER NEXT 24 TO 30 HOURS AS FRNTL BNDRY DROPS ACRS REGION AND SFC LO TRACKS THRU TN VLY. 00Z MODEL SOLNS HAVE SLOWED SFC LO DOWN CONSIDERABLY...AND THIS IS GOING TO CAUSE SOME CHANGES TO PREV FCST. ALL MODELS SEEM TO HAVE PICKED UP ON COLD AIR WEDGE DVLPG ON LEE SIDE OF APPALACHIAN MTNS LATE THIS AFTN AND THRU THE OVERNIGHT THAT 10/00Z ETA SOLN ORIGINALLY PICKED UP ON. THIS COMBINED WITH THE FRONT BECMG PARALLEL TO UPR FLO PATTERN CONTRIBUTING TO A SLOWER TRACK OF SFC LO THRU TN VLY. WHILE ETA REMAINS SLOWEST MODEL IN TERMS OF HANGING ON TO CLOUDS/PCPN LONGEST...GFS WITH SUPPORT OF ECMWF REMAINS A BIT FASTER AND WILL TREND TOWARDS ITS SPEED. 00Z RUNS SUGGESTING SLOWER ONSET TO PCPN THIS MRNG AS ISENT LIFT TAKING A LITTLE LONGER TO GET ESTABLISHED...AND AFOREMENTIONED SLOWER SPEED OF SFC LO TRACKING ACRS OKLAHOMA/ARKANSAS. THIS CURRENTLY BEING VERIFIED AS CLOSEST OBS INDCG PCPN ACRS SRN ILLINOIS. AS ISENT LIFT INCREASES IN WAA OVER NEXT SVRL HOURS...WILL SEE INCREASE IN PCPN ACRS KENTUCKY AND SRN INDIANA WITH SCT SHRA MOVNG INTO WESTERN FCST AREA BTWN 11-14Z. PCPN WILL QUICKLY OVERSPREAD FCST AREA THRU MID/LATE MRNG. 35KT 850 LLJ DVLPG AHEAD OF MID LVL TROF ACRS KENTUCKY THIS AFTN...WITH STRONG LO LVL CONV AT NOSE OF LLJ SWEEPING ACRS SRN FCST AREA DURING AFTN/EVNG HOURS. HEAVIEST AND MOST CONCENTRATED RAIN EXPECTED DURING THIS TIMEFRAME AS DEEP CONVERGENCE THRU 700 MB AND HIGHEST PEFF VALUES CORRELATE. HAVE MAINTAINED CAT POPS ACRS SRN 2/3 FCST AREA FOR AFTN HOURS AND EXTENDED IT INTO THE EVNG AS DEEP CONVERGENCE SWINGS EAST. NORTH OF I-70...LO LVL FORCING A BIT WEAKER AS BNDRY DROPS INTO REGION BY MID AFTN. PCPN SHOULD BE LIGHTER AND HAVE GONE WITH HIGH LKLY (70) POPS FOR TODAY. PCPN WILL TAPER ACRS WEST CNTRL OH BY LATE EVNG...AND ACRS AREAS NORTH AND WEST OF I-71 AFT MIDNITE. FURTHER SOUTH AND EAST WILL SEE RAIN THROUGHOUT THE NIGHT...BUT SHOULD SEE A GRADUAL DIMINISHING TREND TOWARDS DAWN FRI AS DEEP LO LVL CONVERGENCE MOVES EAST OF REGION AND ISENTROPIC DOWNGLIDE DVLPS. ETA INDCG SOME ELEVATED INSTABILITY AT 800 MB GRAZING AREAS ALONG AND SOUTH OF OHIO RIVER THIS EVNG...BUT WITH LO CONFIDENCE ON THUNDER WILL LEAVE IT OUT OF FCST ATTM. LO LVL MOISTURE HANGS ALL NIGHT WITH SKIES REMAINING CLOUDY ACRS ENTIRE FCST AREA. WILL LEAVE LO CHC POPS ACRS SE FCST AREA THRU MRNG HOURS ON FRI...WITH ENTIRE REGION DRY BY 15-16Z. BACK EDGE OF SC DECK WILL MAKE GRADUAL PROGRESS SOUTH AND EAST DURING THE DAY AS BROAD SFC HI BEGINS TO BUILD INTO REGION. SHOULD BE GOOD DEAL OF SUNSHINE IN WEST CNTRL OH AND EVEN DOWN INTO THE DAYTON AREA DURING AFTN HOURS. CLOUDS WILL SCATTER BY LATE AFTN IN EASTERN FCST AREA...WITH RAPID CLEARING DURING EVNG HOURS. CENTER OF SFC HI THEN DROPS DOWN INTO REGION FOR SAT AND SUN...BEGINNING ANOTHER EXTENDED PERIOD OF DRY WEATHER. TEMPS...TEMPS ARE TRICKY TODAY BASED ON CURRENT READINGS. WHILE IT HAS COOLED DOWN INTO L40S ACRS EASTERN COUNTIES...LO LVL WARM POOLING AHEAD OF FRNTL BNDRY KEEPING TEMPS UP AROUND 50 IN WESTERN COUNTIES. THIS IS NEAR OR EVEN SLIGHTLY ABV MAV GUID FOR HIGHS TODAY. FEEL A GOOD 3-5 DEGREE JUMP IN TEMPS POSSIBLE ACRS WEST...AND AS A RESULT HAVE RAISED TEMPS SIGNIFICANTLY OVER PREV FCST. ADJUSTED NORMAL DIURNAL TREND TO HRLY TEMPS WITH WARMEST TEMPS IN WEST BY 18Z...THEN STEADY OR SLOWLY FALLING BEYOND AS FRONT WORKS THRU AREA. WARMED TEMPS UP TONIGHT AS MORE CLOUDS/PCPN EXPECTED AND CAA SLOWED A BIT. WITH SC DECK AFFECTING MUCH OF FCST AREA FRI...SHOULD SEE NO MORE THAN 5 DEGREE RISE FROM LOWS TONIGHT. RYAN LONG TERM (SUNDAY THROUGH WEDNESDAY)... NO SIGNIFICANT CHANGES BEYOND SATURDAY NIGHT TO PREV FCST...SEE PREV DISCUSSION BELOW. RYAN THE FOLLOWING WAS ORIGINALLY ISSUED AT 322 PM EST WED NOV 10 2004 LONG TERM (SATURDAY THROUGH WEDNESDAY)... HIGH PRESSURE IS LOCATED OVER GREAT LAKES AT 12Z SAT. HIGH DROPS VERY SLOWLY SOUTH INTO THE OHIO VALLEY BY 12Z MONDAY. EXCEPT FOR SOME LAKE EFFECT MOISTURE AT H8 ACROSS CENTRAL OHIO FOR SATURDAY PERIOD WILL BE RELATIVELY CLOUD FREE. BY MONDAY NIGHT WAA BEGINS AND MID TO HIGH CLOUDS WORKING BACK INTO THE REGION. 00Z GFS WAS DIVING A SHORTWAVE FROM THE UPPER PLAINS INTO THE MIDWEST AND SPREADING RAIN INTO THE REGION FOR TUESDAY. 06Z GFS WAS NOT AS STRONG WITH THE FEATURE...AND NOW THE 12Z GFS NO LONGER HAS THIS SCENARIO. WENT WITH A ECMWF/DGEX BLEND ON TUE...WHICH IS CONSISTENT WITH 12Z GFS...WHICH KEPT FCST DRY. AS UPPER LOW SWINGS THROUGH THE SOUTHWEST TUE-WED...FA IS STILL UNDER INFLUENCE OF SFC HIGH. OPERATIONAL 00Z GFS WAS COLDEST OF THE MODELS. STAYED A FEW DEGREES WARMER THAN FOR HIGHS AND LOWS THROUGH THE WEEKEND. NICE WARMUP IN STORE BY TUE-WED AS WAA ON BACKSIDE OF SFC HIGH PUMPS WARMER AIR BACK INTO FA. SITES && .ILN WATCHES/WARNINGS/ADVISORIES... OH...NONE. IN...NONE. KY...NONE. && $$ oh AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE SAN ANGELO TX 912 AM CST THU NOV 11 2004 .UPDATE... RECENTLY UPDATED FORECAST TO LOWER TEMPS THIS AFTERNOON. IT APPEARS THAT COMBINATION OF CLOUD COVER AND MODERATE COLD ADVECTION WILL KEEP TEMPS AT LEAST NO WARMER THAN GUIDANCE. ALSO LOWERED WINDS A NOTCH...ESPECIALLY SOUTH OF INTERSTATE 20. KDYX VAD WIND PROFILER SHOWING 15 KTS IN THE LOWER GATES. UPSTREAM 3 HOUR SURFACE BASED PRESSURE RISES INTO THE PANHANDLE ONLY RUNNING 1 TO 2 MB. SOME BREAKS IN THE CLOUDS LIKELY INTO THE AFTERNOON. WITH 850 MB THERMAL TROF ANCHORED OVER WEST CENTRAL TX...EXPECT MOSTLY CLOUDY SKIES TO PREVAIL OVER WEST CENTRAL TX. 14 && .PREV DISCUSSION... LATEST METAR DATA INDICATING SURFACE WINDS ARE STRONGER THAN PREVIOUS THINKING. LATEST RUC STILL SUGGESTS LOWER WIND SPEEDS. SO... SENT A QUICK UPDATE TO INCREASE WIND SPEEDS TO THE BREEZY RANGE ACROSS MUCH OF WEST CENTRAL TEXAS. OTHERWISE...NO OTHER CHANGES. LATEST SATELLITE IMAGERY INDICATING LOW CLOUDS CONTINUING TO SPREAD ACROSS THE BIG COUNTRY. AT THE SURFACE ACROSS WEST CENTRAL TEXAS... NORTH WINDS IN THE 10 TO 15 MPH RANGE DOMINATE...TEMPERATURES RANGE FROM AROUND 50 NORTH AND CENTRAL TO THEN MID 50S SOUTH...AND DEWPOINTS ARE AROUND 40. BIG CHALLENGE TODAY WILL BE CLOUD COVER AND AFTERNOON HIGHS. THE 09 Z RUC INDICATES 925 MB RELATIVE HUMIDITIES ABOVE 85 PERCENT WILL REMAIN MAINLY OVER THE NORTHEASTERN BIG COUNTRY THIS MORNING. HOWEVER...BASED ON LATEST LOW-LEVEL IR IMAGERY...BELIEVE RUC DID NOT INITIALIZE THIS LOW-LEVEL MOISTURE VERY WELL. WILL GO WITH MOSTLY CLOUDY SKIES DOMINATING WEST CENTRAL TEXAS TODAY WITH CLOUDY SKIES BEGINNING TODAY ACROSS THE BIG COUNTRY. MODEL MOS GUIDANCE IN VERY GOOD AGREEMENT FOR THE BIG COUNTRY...AFTERNOON HIGHS CLOSE TO THEIR NUMBERS LOOK GOOD. HOWEVER AND ELSEWHERE...MOS GUIDANCE DIVERGES. THUS...A BLEND OF MOS GUIDANCE LOOKS BEST FOR AFTERNOON HIGHS ACROSS OUR OTHER ZONES. OVERNIGHT LOWS TONIGHT ALSO A CHALLENGE. HERE MOS GUIDANCE DIVERGES AGAIN. THE ETA MOS IS MUCH WARMER...SUGGESTING LOWS IN THE UPPER 30S TO NEAR 40. THE MAV MOS CONTINUES A MORE CONSISTENT LINE WITH NUMBERS AT OR ONE DEGREE ABOVE THE FREEZING MARK. GIVEN THE POTENTIAL FOR COLD AIR ADVECTION CONTINUING TONIGHT...WILL GO WITH NUMBERS EQUAL TO OR VERY CLOSE TO MAV MOS FOR OVERNIGHT LOWS TONIGHT ACROSS WEST CENTRAL TEXAS. MOSTLY CLOUDY SKIES WILL DOMINATE WEST CENTRAL TEXAS THROUGH THE START OF THE WEEKEND. MODELS CONTINUE TO DEVELOP A STRONG CLOSED UPPER-LEVEL LOW OVER THE SOUTHERN ROCKIES DURING THE NEXT 24 TO 48 HOURS. BEST CHANCES FOR RAIN ASSOCIATED WITH THIS UPPER-LEVEL LOW WILL BEGIN SATURDAY AND CONTINUE INTO SATURDAY NIGHT. NO CHANGES HERE. && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ tx AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE SAN ANGELO TX 805 AM CST THU NOV 11 2004 .UPDATE... LATEST METAR DATA INDICATING SURFACE WINDS ARE STRONGER THAN PREVIOUS THINKING. LATEST RUC STILL SUGGESTS LOWER WIND SPEEDS. SO... SENT A QUICK UPDATE TO INCREASE WIND SPEEDS TO THE BREEZY RANGE ACROSS MUCH OF WEST CENTRAL TEXAS. OTHERWISE...NO OTHER CHANGES. && .PREV DISCUSSION... LATEST SATELLITE IMAGERY INDICATING LOW CLOUDS CONTINUING TO SPREAD ACROSS THE BIG COUNTRY. AT THE SURFACE ACROSS WEST CENTRAL TEXAS... NORTH WINDS IN THE 10 TO 15 MPH RANGE DOMINATE...TEMPERATURES RANGE FROM AROUND 50 NORTH AND CENTRAL TO THEN MID 50S SOUTH...AND DEWPOINTS ARE AROUND 40. BIG CHALLENGE TODAY WILL BE CLOUD COVER AND AFTERNOON HIGHS. THE 09 Z RUC INDICATES 925 MB RELATIVE HUMIDITIES ABOVE 85 PERCENT WILL REMAIN MAINLY OVER THE NORTHEASTERN BIG COUNTRY THIS MORNING. HOWEVER...BASED ON LATEST LOW-LEVEL IR IMAGERY...BELIEVE RUC DID NOT INITIALIZE THIS LOW-LEVEL MOISTURE VERY WELL. WILL GO WITH MOSTLY CLOUDY SKIES DOMINATING WEST CENTRAL TEXAS TODAY WITH CLOUDY SKIES BEGINNING TODAY ACROSS THE BIG COUNTRY. MODEL MOS GUIDANCE IN VERY GOOD AGREEMENT FOR THE BIG COUNTRY...AFTERNOON HIGHS CLOSE TO THEIR NUMBERS LOOK GOOD. HOWEVER AND ELSEWHERE...MOS GUIDANCE DIVERGES. THUS...A BLEND OF MOS GUIDANCE LOOKS BEST FOR AFTERNOON HIGHS ACROSS OUR OTHER ZONES. OVERNIGHT LOWS TONIGHT ALSO A CHALLENGE. HERE MOS GUIDANCE DIVERGES AGAIN. THE ETA MOS IS MUCH WARMER...SUGGESTING LOWS IN THE UPPER 30S TO NEAR 40. THE MAV MOS CONTINUES A MORE CONSISTENT LINE WITH NUMBERS AT OR ONE DEGREE ABOVE THE FREEZING MARK. GIVEN THE POTENTIAL FOR COLD AIR ADVECTION CONTINUING TONIGHT...WILL GO WITH NUMBERS EQUAL TO OR VERY CLOSE TO MAV MOS FOR OVERNIGHT LOWS TONIGHT ACROSS WEST CENTRAL TEXAS. MOSTLY CLOUDY SKIES WILL DOMINATE WEST CENTRAL TEXAS THROUGH THE START OF THE WEEKEND. MODELS CONTINUE TO DEVELOP A STRONG CLOSED UPPER-LEVEL LOW OVER THE SOUTHERN ROCKIES DURING THE NEXT 24 TO 48 HOURS. BEST CHANCES FOR RAIN ASSOCIATED WITH THIS UPPER-LEVEL LOW WILL BEGIN SATURDAY AND CONTINUE INTO SATURDAY NIGHT. NO CHANGES HERE. && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23/HUBER tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 415 AM CST THU NOV 11 2004 .SHORT TERM... LATEST SATELLITE IMAGERY INDICATING LOW CLOUDS CONTINUING TO SPREAD ACROSS THE BIG COUNTRY. AT THE SURFACE ACROSS WEST CENTRAL TEXAS... NORTH WINDS IN THE 10 TO 15 MPH RANGE DOMINATE...TEMPERATURES RANGE FROM AROUND 50 NORTH AND CENTRAL TO THEN MID 50S SOUTH...AND DEWPOINTS ARE AROUND 40. BIG CHALLENGE TODAY WILL BE CLOUD COVER AND AFTERNOON HIGHS. THE 09 Z RUC INDICATES 925 MB RELATIVE HUMIDITIES ABOVE 85 PERCENT WILL REMAIN MAINLY OVER THE NORTHEASTERN BIG COUNTRY THIS MORNING. HOWEVER...BASED ON LATEST LOW-LEVEL IR IMAGERY...BELIEVE RUC DID NOT INITIALIZE THIS LOW-LEVEL MOISTURE VERY WELL. WILL GO WITH MOSTLY CLOUDY SKIES DOMINATING WEST CENTRAL TEXAS TODAY WITH CLOUDY SKIES BEGINNING TODAY ACROSS THE BIG COUNTRY. MODEL MOS GUIDANCE IN VERY GOOD AGREEMENT FOR THE BIG COUNTRY...AFTERNOON HIGHS CLOSE TO THEIR NUMBERS LOOK GOOD. HOWEVER AND ELSEWHERE...MOS GUIDANCE DIVERGES. THUS...A BLEND OF MOS GUIDANCE LOOKS BEST FOR AFTERNOON HIGHS ACROSS OUR OTHER ZONES. OVERNIGHT LOWS TONIGHT ALSO A CHALLENGE. HERE MOS GUIDANCE DIVERGES AGAIN. THE ETA MOS IS MUCH WARMER...SUGGESTING LOWS IN THE UPPER 30S TO NEAR 40. THE MAV MOS CONTINUES A MORE CONSISTENT LINE WITH NUMBERS AT OR ONE DEGREE ABOVE THE FREEZING MARK. GIVEN THE POTENTIAL FOR COLD AIR ADVECTION CONTINUING TONIGHT...WILL GO WITH NUMBERS EQUAL TO OR VERY CLOSE TO MAV MOS FOR OVERNIGHT LOWS TONIGHT ACROSS WEST CENTRAL TEXAS. MOSTLY CLOUDY SKIES WILL DOMINATE WEST CENTRAL TEXAS THROUGH THE START OF THE WEEKEND. MODELS CONTINUE TO DEVELOP A STRONG CLOSED UPPER-LEVEL LOW OVER THE SOUTHERN ROCKIES DURING THE NEXT 24 TO 48 HOURS. BEST CHANCES FOR RAIN ASSOCIATED WITH THIS UPPER-LEVEL LOW WILL BEGIN SATURDAY AND CONTINUE INTO SATURDAY NIGHT. && .LONG TERM... NO CHANGES HERE. && .PRELIMINARY POINT TEMPS/POPS... ABILENE 53 33 49 34 / 10 10 10 20 SAN ANGELO 59 33 50 36 / 10 10 10 10 JUNCTION 61 36 52 37 / 10 10 10 10 && .SJT WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 23/HUBER tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 330 AM EST FRI NOV 12 2004 .DISCUSSION... OTHER THAN SOME -SHSN/FLURRIES TODAY OVER THE ERN FCST AREA NEAR LAKE SUPERIOR...A SOMEWHAT UNUSUAL EXTENDED STRETCH OF QUIET NOVEMBER WEATHER IS ON THE WAY FOR UPPER MI. MAIN FCST ISSUES WILL BECOME TEMPS AFTER THE FLURRIES/-SHSN TODAY. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF OVER ERN CANADA EXTENDING S INTO THE GREAT LAKES/NEW ENGLAND. TO THE W...A CLOSED HIGH WAS CENTERED OVER THE PACIFIC NW WITH ACTIVE SRN STREAM FEATURING A BROAD CLOSED LOW OVER THE SWRN STATES. ERN TROF WILL LIFT OUT OVER THE NEXT COUPLE OF DAYS WITH MAIN BAND OF WESTERLIES SHIFTING INTO CANADA TO PROVIDE A QUIET WEATHER REGIME OVER THE UPPER LAKES. SHORTWAVE EJECTING FROM SW LOW WILL PROVIDE NEXT MINIMAL CHC OF PCPN SEVERAL DAYS DOWN THE ROAD. IN THE NWRLY FLOW INTO THE GREAT LAKES...A SHORTWAVE HAS TRACKED JUST NE OF LAKE SUPERIOR OVERNIGHT WITH LITTLE IMPACT ON THE WEATHER HERE. ANOTHER SUBTLE SHORTWAVE WAS DROPPING SE TOWARD WRN LAKE SUPERIOR. A BAND OF FLURRIES/-SHSN DEVELOPED OVER THE ERN LAKE ALONG SLIGHT WIND SHIFT ASSOCIATED WITH SHORTWAVE EARLIER IN THE NIGHT...BUT PCPN DISSIPATED RAPIDLY AS IT REACHED SHORE. KMQT RADAR IS ONLY SHOWING HINTS OF SOME FLURRIES AT TIMES OVER ERN LAKE SUPERIOR IN NW FLOW NOW WHILE SATELLITE IMAGERY SHOWS ONLY SOME WEAK BANDING OVER NCNTRL/NE LAKE. IN THE WAKE OF SHORTWAVE THAT PASSED E OF LAKE SUPERIOR OVERNIGHT... SFC HIGH PRES WILL BUILD ACROSS THE WRN GREAT LAKES THIS AFTN WITH WINDS BECOMING GENERALLY LIGHT/VRBL. 850MB TEMPS HOVERING AROUND -10/-11C WILL PROVIDE ADEQUATE OVERWATER INSTABILITY FOR LES...BUT DRY AIRMASS (FCST SOUNDINGS SHOW AN INVERTED-V LOOK WHICH HAS BEEN A COMMON FEATURE OF COLD AIRMASSES SO FAR THIS SEASON) WILL CERTAINLY LIMIT INTENSITY. PLUS ORGANIZATION WILL BE HINDERED BY DECREASING WINDS...AND DAYTIME HEATING WILL BE A BIT OF INHIBITING FACTOR AS WELL. WILL FOLLOW ALONG LINES OF EVENING SHIFT UPDATE AND DOWNPLAY LES TO JUST SCT -SHSN/FLURRIES OVER THE E. OVER THE WRN LAKE...850MB TEMPS ARE A FEW DEGREES WARMER WHICH WILL BE SUFFICIENT TO SUPPRESS ANY LES FROM DEVELOPING. OTHERWISE...EXPECT QUITE A BIT OF SUNSHINE TODAY AFTER PATCH OF MID/HIGH CLOUDS PASSES DURING THE MORNING. AIRMASS TODAY LOOKS SIMILAR TO YESTERDAY...AND SO EXPECT HIGH TEMPS TO BE SIMILAR AS WELL WHICH IS WHAT MOS GUIDANCE SHOWS. EXPECT VERY GOOD RADIATIONAL COOLING TONIGHT WITH CLEAR SKIES...BUT IT WON'T BE PERFECT AS SFC RIDGE AXIS SLIPS JUST S OF UPPER MI DURING THE NIGHT...ALLOWING VERY LIGHT SWRLY FLOW TO HAVE A SLIGHT IMPACT...MAINLY OVER WRN/NCNTRL FCST AREA. SCNTRL/SE FCST AREA LIKELY TO SEE THE LOWEST TEMPS...BEING CLOSER TO SFC RIDGE AXIS. THERE WILL BE A LARGE RANGE OF MINS AS IS USUALLY THE CASE UNDER GOOD RADIATIONAL COOLING. ETA AND GFS COOP MOS NUMBERS DOWN AROUND 10F IN THE TYPICAL COLD SPOTS LOOKS PRETTY REASONABLE WITH LOWS RANGING UP TO THE MID 20S NEAR LAKE SUPERIOR. WITH MID/UPPER RIDGE BUILDING ACROSS THE MISSISSIPPI VALLEY INTO THE WRN GREAT LAKES OVER THE WEEKEND...SUPPORTING A BUILDING SFC HIGH OVER THE SRN GREAT LAKES...SAT/SUN ARE SHAPING UP TO BE FINE MID NOVEMBER DAYS WITH PLENTY OF SUNSHINE. IN FACT...MODEL RH TIME SECTIONS ARE VERY DRY AND ONLY HINT AT SOME HIGH CLOUDS. WITH HIGH CENTERED TO THE S...THERE WILL BE A SW BREEZE BOTH DAYS...AND LOWS SAT NIGHT WILL CERTAINLY NOT BE AS COLD AS TONIGHT. SUN WILL BE WARMER THAN SAT AS AIRMASS MODIFIES (850MB TEMPS RISE FROM ABOUT 0C W TO -4C E AT 12Z SAT TO AROUND 4C BY 12Z SUN)...BUT WON'T BE ABLE TO MIX THAT HIGH WITH LOW SUN ANGLE. MIXING TO ABOUT 925/900MB YIELDS HIGHS CLOSE TO THAT OF MOS GUIDANCE BOTH DAYS...ROUGHLY MID 40S SAT AND UPPER 40S/LOW 50S SUN. WARMEST READINGS BOTH DAYS WILL BE IN THE SW/W WIND DOWNSLOPE AREAS. BY MON...ETA/GFS SHOW A SHORTWAVE EJECTING FROM SWRN STATES TOWARD WRN LAKES. GFS GENERATES SOME LIGHT PCPN POSSIBLY AS EARLY AS MON EVENING OVER SCNTRL UPPER MI...BUT MORE SO ON TUE. HAVE DOUBTS ABOUT SUBSTANTIAL MOISTURE RETURN AS EARLY AS MON AND PREFER DRIER ECMWF SOLUTION. IT THEN SEEMS QUITE UNLIKELY THAT ANY PCPN WILL OCCUR AS SHORTWAVE DRIVES INTO RIDGE POSITION MON NIGHT/TUE...BUT WILL MAINTAIN GOING CHC POPS FOR MON NIGHT/TUE IN LIGHT OF GFS/CANADIAN MODEL INDICATIONS OF SOME VERY LIGHT PCPN. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 307 AM EST FRI NOV 12 2004 .DISCUSSION... OVERALL, LITTLE CHANGE TO OUR GOING FORECAST/GRIDS. SPLIT FLOW ACROSS NORTH AMERICA PER THE H2O VAPOR LOOP ANALYSIS WITH TROF AXIS PROGRESSING ACROSS THE GREAT LAKES INTO NEW ENGLAND...MEANWHILE A SHORT WAVE ENERGY WAS TRACKING EAST ACROSS THE LOWER OHIO VALLEY. LOOKING UPSTREAM, ANOTHER SHORT WAVE IS SEEN DIVING SOUTHEAST FROM LAKE WINNIPEG INTO THE NORTHERN MISSISSIPPI RIVER VALLEY WITH AN ENHANCED REGION OF COLD CLOUD TOPS (MOSTLY CIRRUS CLOUDS). THERE SEEMS TO BE ANOTHER WEAKER JET STREAK ACROSS LAKE SUPERIOR WITH ENTRANCE REGION DYNAMICS RESULTING IN THIS CLOUD COVERAGE THIS MORNING (LATEST RUC HAS AN EXCELLENT HANDLE ON THIS FEATURE). FURTHER UPSTREAM WE HAVE A CUT OFF LOW ACROSS THE FOUR CORNERS REGION WHICH IS JUST NORTH OF THE SOUTHERN BRANCH OF THE JET. THEN A POTENT SYSTEM OUT IN THE PACIFIC WHICH WILL BE DAYS AWAY... FOR TODAY... UPSTREAM CONDITIONS ON THURSDAY WITH NEARLY FULL SUNSHINE, THEY WERE ONLY ABLE TO CLIMB INTO THE LOWER 40S AND REALLY DO NOT SEE MUCH REASON TO GO HIGHER HERE. EXCEPTION WOULD BE SOUTHEAST COUNTIES AS WE CONTINUE TO BE AFFECTED WITH OUR FIRST CIRRUS CLOUD DECK WITH LEAD 120KT JET EXTENDING INTO THE ST LAWRENCE VALLEY...THEREFORE A SLIGHTLY WARMER START. THIS FEATURE WILL BECOME FURTHER REMOVED TOWARD SUNRISE THEN THE APPROACH OF THE WEAKER SYSTEM AND ASSOCIATED SHORT WAVE FOR THIS AFTERNOON. THIS NEXT WAVE IS YET ANOTHER SHOT OF COLD ADVECTION WITH SURFACE COLD FRONT ANALYZED JUST NORTH OF THE GREAT LAKES. WHILE THE SURFACE FEATURE WILL BECOME WASHED OUT TO SOME EXTENT THIS AFTERNOON AS LARGE SURFACE HIGH BECOMES DOMINANT (NEAR 1040MB), 850MB FRONT WILL BE MORE APPARENT WITH TEMPS OVER LAKE HURON DROPPING TOWARD -10C BY EVENING. MOISTURE REMAINS LEAN BUT WITH INCREASED DELTA T/S AND SOME ASSISTANCE WITH WEAK WAVE ALOFT, ENOUGH TO KEEP THE SLIGHT MENTION OF SOME FLURRIES ACROSS THE THUMB LATER THIS AFTERNOON. TONIGHT... AS PREVIOUS DISCUSSIONS HAVE POINTED OUT, LAKE EFFECT ACTIVITY BECOMES A LITTLE CONCERN. THE GFS SOUNDINGS REMAINS QUITE DRY TO INHIBIT ANY LAKE EFFECT ACTIVITY WITH LARGE SCALE SUBSIDENCE THROUGH THE COLUMN. THE ETA ON THE OTHER HAND WITH BETTER HORIZONTAL AND VERTICAL RESOLUTION SHOWS A LITTLE DIFFERENT STORY. THE 850MB FRONTAL BOUNDARY SLIDES SOUTH INTO THE CENTER OF THE CWA WITH TEMPS OVER LAKE HURON DROPPING BELOW -10C...WHICH RESULTS IN CONDITIONAL LAKE INSTABILITY. MODIFYING THE PARCELS WITH LAKE TEMPS INTO THE UPPER 40S, LAKE INDUCED CAPES CLIMB TO BETWEEN 200-300 J/KG. 1000-850MB FLOW IS NORTHEAST AND SOUNDINGS REVEAL LITTLE DEVIATION FROM THIS TRAJECTORY OVERNIGHT UP TO THE INVERSION. HOWEVER, INVERSION HEIGHTS BARELY TAP INTO FAVORABLE ICE NUCLEATION WITH -10C SEEN IN THE BUFKIT PROFILES TOP OF THE MOISTURE COLUMN. IN ADDITION, 925/950MB CONVERGENCE FIELDS ARE QUITE WEAK OVERNIGHT BUT OMEGA VALUES IN THIS LAYER DO HINT TOWARD SOME SMALL SCALE LIFT. THEREFORE, WE WILL HOLD ONTO THE CHANCE OF SNOW SHOWERS AND EXTEND THE CHANCE INTO BAY COUNTY WITH A STRAIGHT LINE NORTHEAST TRAJECTORY ACROSS SAGINAW BAY. FURTHER INLAND, WITH SOME LAKE CLOUD BOUNCING AROUND... TEMPS SHOULD NOT HAVE ANY PROBLEMS DROPPING BACK INTO THE 20S WHICH WILL BE BELOW GUIDANCE VALUES. THEREAFTER...HIGH PRESSURE AT ALL LEVELS SETTLES SLOWLY THROUGH THE AREA OVER THE WEEKEND ON INTO EARLY NEXT WEEK. NOT MUCH TO BE SAID HERE...AS IT WILL BRING TRANQUIL WEATHER FOR SEVERAL DAYS INTO EARLY NEXT WEEK. && .DTX WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY TODAY AND TONIGHT NEARSHORE WATERS OF LAKE ERIE. && $$ BGM EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 308 AM EST FRI NOV 12 2004 .DISCUSSION...SYNOPSIS...SPLIT FLOW PATTERN REMAINS IN PLACE ACROSS NORTH AMERICA...ANCHORED BY A REX BLOCK ACROSS THE WEST. NORTHERN STREAM TROUGH BOTTOMING OUT ACROSS THE GREAT LAKES...WITH WV IMAGERY SHOWING A COUPLE OF SHORT WAVES IN THE VICINITY WITHIN THIS FLOW. RECENT PATTERN ACROSS THE WEST HAS FEATURED SEVERAL INSTANCES OF TROUGH SPLITTING AS ENERGY PUSHES INLAND FROM THE PACIFIC. LOOKS LIKE ANOTHER ROUND OF THIS IN STORE AS UPPER LOWER NEAR 48N/150W SPLITS AS IT ENCOUNTERS WESTERN CANADIAN RIDGE. PIECE OF THIS TROUGH WILL KICK OUT CURRENT UPPER VORTEX SPINNING OVER THE SOUTHWEST U.S...FORMING A NEW LOW OVER THE BAJA BY SUNDAY IN A DISCONTINUOUS RETROGRESSION SORT OF FASHION. THIS WHOLE PROCESS WILL HELP BUILD HEIGHTS ACROSS THE CENTRAL U.S. AND EVENTUALLY INTO MI BY SUNDAY. NOT A LOT TO CONTEND WITH THIS FORECAST CYCLE...SHORT WAVE TROUGH AND A WEAK REINFORCING PUSH OF COLDER AIR INTO THE STATE LATER TODAY WILL THE BE THE MAIN PROBLEM...WITH DEEP LAYER RIDGING BUILDING IN FOR THE WEEKEND. TODAY/TONIGHT...GUIDANCE STILL INDICATING A SECONDARY SHORT WAVE TROUGH WILL ROTATE ACROSS THE FORECAST AREA THIS AFTERNOON/EARLY EVENING...THOUGH WV IMAGERY ALSO SHOWING A LEAD WAVE DROPPING SOUTHEAST INTO THE MN ARROWHEAD...THOUGH ATMOSPHERE AHEAD OF IT IS PRETTY DRY PER 00Z RAOBS WITH JUST A CI SHIELD ASSOCIATED WITH THIS FEATURE. EVEN MAIN FEATURE PROGGED BY MODELS NOT EXPECTED TO HAVE MUCH MOISTURE WITH IT...SO WILL SEE AT LEAST IN AN INCREASE IN HIGH CLOUDS ACROSS NORTHERN MI THIS MORNING. ANOTHER ISSUE DEALS WITH LAKE EFFECT WITH 850MB THERMAL TROUGH REINFORCED A BIT WITH TEMPERATURES COOLING BACK DOWN TO -10C OR SO. SOME ENHANCED BANDS OCCURRING EARLY THIS MORNING ON EASTERN LAKE SUPERIOR PER MONTREAL RIVER RADAR...WITH A FEW RETURNS BRUSHING WHITEFISH POINT. SOME INCREASE IN LOW LEVEL RH AND CONVERGENCE ALONG A SURFACE TROUGH LIKELY RESPONSIBLE FOR THIS...THE QUESTION IS WILL IT PERSIST? LOW LEVEL WINDS FORECAST TO SHIFT NORTH THIS MORNING AS SURFACE TROUGH MOVES THROUGH AND WEAKENS...SO CURRENT ACTIVITY OVER THE LAKE WILL GET PULLED INTO EASTERN UPPER. THOUGH THERE HAVE BEEN SOME SPOTTY 28+ DBZ RETURNS JUST NORTH OF WHITEFISH BAY...RECENT RADAR TRENDS HAVE BEEN ON A DOWNWARD SLIDE SO MAY NOT AMOUNT TO MUCH MORE THAN FLURRIES. BY THIS AFTERNOON...GFS/RUC SUGGEST SURFACE WINDS WILL BECOME MORE NORTHEAST WHICH WOULD PRETTY MUCH SHUT EVERYTHING OFF FOR EASTERN UPPER. ETA KEEPS WINDS NORTH-NORTHWEST WHICH COULD STILL KEEP SOME FLURRIES GOING AROUND WHITEFISH BAY DURING THE AFTERNOON. AS FOR NORTHERN LOWER...WINDS ALSO TURN DUE NORTH THIS MORNING...WHICH WILL BRING SOME LAKE CLOUDS (WHICH ARE ALREADY DEVELOPING NORTH OF GRAND TRAVERSE BAY) INTO AREAS ALONG/WEST OF US-131. WOULDN'T BE SURPRISED TO SEE SOME FLURRIES ESPECIALLY DURING THE FIRST HALF OF THE DAY GIVEN LONGER EFFECTIVE FETCH. DEEP LAYER SUBSIDENCE SPREADS ACROSS THE FORECAST AREA TONIGHT IN WAKE OF SHORT WAVE TROUGH PASSAGE. MAY BE SOME LINGERING LAKE CLOUDS OVERNIGHT ON THE LAKE HURON SIDE...BUT OVERALL LIGHT WINDS SHOULD ALLOW FOR LAND BREEZES TO DOMINATE AND LIKELY PUSH ANY RESIDUAL CLOUD COVER FARTHER OUT INTO THE LAKE OVERNIGHT. SOME WAA CLOUDS/ PRECIP WILL SLIDE NORTH OF THE U.P. TONIGHT...AS A RESULT MAY SEE SOME HIGH CLOUD SOUTHEAST INTO PARTS OF THE FORECAST AREA. MARINE...NO HEADLINES ANTICIPATED WITH SURFACE HIGH RIDGING IN FROM THE NORTHEAST. SATURDAY...QUIET DAY SATURDAY WITH SURFACE HIGH/DRY AIR IN PLACE AND RISING HEIGHTS ALOFT. JUST SOME NUISANCE CLOUD COVER ISSUES TO DEAL WITH...DISPOSITION OF POTENTIAL MID-LAKE MICHIGAN CONVERGENCE BAND AS WINDS SWING AROUND TO WEST/SOUTHWEST DURING THE MORNING FOR ONE...PERHAPS SOME SOUTHWEST FLOW SC INTO THE STRAITS AREA LATER IN THE DAY. MARINE...WINDS EXPECTED TO PICK UP A BIT FROM THE SOUTHWEST AROUND WHITEFISH BAY/ST MARY'S RIVER SATURDAY AFTERNOON... AND ACROSS NORTHERN LAKES MICHIGAN/HURON SATURDAY NIGHT. WINDS WITHIN MIXED LAYER MAY BE ENOUGH (20-25KT) TO BRING ABOUT SCA CONDITIONS BY SATURDAY NIGHT IN SOME NEARSHORE ZONES...ESPECIALLY WHERE LOCAL EFFECTS CAN PROVIDE A BOOST. SUNDAY AND EXTENDED PERIODS...STILL LOOKING DRY AT LEAST THROUGH MONDAY AT THIS POINT...THINGS BEGIN TO CHANGE TUESDAY AS REMNANTS OF INITIAL SOUTHWESTERN U.S. LOW LIFT INTO THE NORTHERN PLAINS. WAA/ RETURN FLOW PATTERN SETS UP IN WAKE OF DEPARTING DEEP LAYER RIDGING...AND COMBINED WITH SHORT WAVE ENERGY MAY BRING IN SOME SHOWERS AS EARLY AS TUESDAY AFTERNOON THOUGH CURRENT GFS IS STILL PRETTY DRY DOWNSTAIRS. WILL ADD IN CHANCE POPS FOR TUESDAY NIGHT AND CONTINUE WEDNESDAY AHEAD OF ANOTHER NORTHERN STREAM SHORT WAVE AND ASSOCIATED COLD FRONT. && .APX...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JPB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 310 AM CST FRI NOV 12 2004 .DISCUSSION...FORECAST FOCUS ON OVERALL QUIET WX REGIME. LARGE CANADIAN HIGH PRESSURE SETTLING IN OVER REGION FOR TODAY AND THE WEEKEND. WEAK WAA WILL ALLOW TEMPS TO WARM JUST A FEW DEGREES EACH DAY. HIGH CLOUDS ASSOC WITH CANADIAN VORT MAY BRUSH CWA TODAY. ALSO BUFKIT AND CROSS SECTIONS INDICATE VRY SHALLOW LOW LEVEL MOIST WHICH SUPPORTS CU DVLPMT. ALSO INTERESTING NARROW...THO WELL DEFINED...NE/SW ORIENTED BAND OF LAKE EFFECT CLOUDINESS SHOWING UP ON IR IMAGERY. DELTA T ARND 13/14C AND INVERSION HEIGHTS PER BUFFY AN UNIMPRESSIVE 2.5-3K. SW EDGE LOOKS LESS DEFINED THAN NE PTN LINE CLOSER TO LWR MI. WILL NOT GET TOO WORRIED ABOUT THIS FEATURE ATTM... THO DULY NOTED. LATEST 9Z 11/3 IMAGE SHOWS SW EDGE OF CLOUDS JUST OFFSHORE FROM MKE DRIFTING SOUTH. RUC CU RULE SUPPORTS ETA BUFKIT WITH FEW-SCT CU IN THE FAR EAST WHILE ETA CU RULE A PLUS 2 CWA WIDE AND NOT LATCHING ONTO ANY THIN LYR OF MOIST. OVERALL APPEARS WE CAN STAY THE COURSE FOR NOW WITH EITHER SUNNY OR M SUNNY FCST. THE HIGH REMAINS DOMINANT THRU SUNDAY WITH ASSOC DRY COLUMN AND SUBSIDENCE. UPPER LEVELS NOT SUPPORTIVE OF ANY LIFT WITH RIDGING DOMINATING. THE TREND OF SLIGHTLY WARMER TEMPS EACH DAY INTO WEEKEND LOOKS GOOD GIVEN MODIFICATION OF H8 TEMPS WITH TIME AND ALSO THE TREND OF SFC FLOW GOING FROM NE TO SE WITH PASSAGE OF SURFACE ANTICYCLONE. && .MKX WATCHES/WARNING/ADVISORIES...NONE. $$ wi AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE MELBOURNE FL 1010 AM EST FRI NOV 12 2004 .DISCUSSION... MORNING SOUNDINGS FROM KXMR AND KTBW REVEAL A FAIRLY STRONG CAP IN THE H80-H70 LYR...WITH A RESPECTABLE AMOUNT OF MOISTURE TRAPPED BLO. COLD FRONT APPROACHING FROM THE NW HAS PUSHED INTO THE FAR WRN PANHANDLE...WITH AN H50 VORT MAX AND H25 DIVERGENCE MAX SKIRTING THE NRN PENINSULA. LATEST RUC80 ANALYSIS SHOWS DECENT H100-H70 MOISTURE OVER THE REGION...WITH DRIER AIR ALOFT. WEAK COLD AIR ADVECTION IS OCCURRING AT H70...BUT TEMP ADVECTION IS NEUTRAL AT H85. AS SUCH...DO NOT ANTICIPATE THE CAP IS GOING TO BREAK TODAY...SO THE DRY AIR ALOFT WILL NOT MIX DOWN. ISOLD SHRAS HAVE DEVELOPED RECENTLY OVER THE SRN CWA...AND WITH DIURNAL HEATING AND LOW LVL MOISTURE ADVECTION...EXPECT TO SEE ISOLD WEAK LOW TOPPED SHRAS DEVELOP AHEAD OF THE APPROACHING FRONT. WILL UPDATE ZONES SHORTLY TO ADD SMALL POPS TO THE FCST. MINOR ADJUSTMENTS TO THE WINDS MAY BE NECESSARY AS WELL...MAINLY ALONG THE COAST. && .MARINE... WHILE SRLY WINDS HAVE DECREASED TO ~10KT...SWELLS ARE STILL HOVERING AROUND 4-5FT. RESULTING IN COMBINED SEAS JUST BELOW 7FT. AS SUCH... PLAN TO TRIM COMBINED SEAS BY A FOOT AND PARE BACK THE SCA TO A CAUTIONARY STMT FOR THIS AFTN. && .MLB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...BRAGAW LONG TERM....CRISTALDI fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1100 AM EST FRI NOV 12 2004 .DISCUSSION... THE MAIN CONCERN WITH THIS UPDATE FORECAST PACKAGE IS THE CLOUD COVER AND FLURRIES POTENTIAL OVER EASTERN U.P. WATER VAPOR AND RUC/ETA SHOW A LONGWAVE TROUGH OVER EASTERN CANADA...A RIDGE OVER THE ROCKY MOUNTAINS AND A CLOSED LOW OVER THE GULF OF ALASKA. A WEAK SHORTWAVE IS MOVING THROUGH THE U.P. THIS MORNING. SURFACE ANALYSIS SHOWS A BROAD RIDGE ACROSS THE UPPER MISSISSIPPI RIVER VALLEY AND ONTARIO. THE RIDGE IS SPLIT BY A WEAK FRONT WHICH RUNS FROM WESTERN ONTARIO ACROSS LAKE SUPERIOR AND EASTERN U.P. TO SOUTHEAST ONTARIO. THE SHORTWAVE ENERGY WILL SHIFT ACROSS THE FORECAST AREA THIS AFTERNOON. THE FRONTAL SYSTEM ACROSS THE FORECAST AREA WILL WEAKEN AND DIE OUT. THUS THE RIDGE WILL BECOME THE DOMINATE CONDITIONS ACROSS THE AREA. WINDS WILL REMAIN LIGHT. THE AIR TEMPERATURE OVER LAKE SUPERIOR IS AROUND 34F/2C MAKING FOR THE LAKE-850MB DELTA-T'S AROUND 12C OVER THE EASTERN LAKE SUPERIOR. THE FORECAST SOUNDING FOR EASTERN U.P. SHOW A CLOUD DECK AROUND 3K TO 5K FEET...WHICH IS CONFIRMED BY THE ERY AND ISQ OBSERVATIONS. THE ETA FORECAST SOUNDINGS STILL SHOW A SURFACE BASE INVERTED V OVER EASTERN U.P. THIS AFTERNOON. THIS SHOULD PRODUCE SOME SNOW BUT WITH THE DRY CONDITION AT THE SURFACE...MOST OF THE SNOW SHOULD EVAPORATE BEFORE REACHING GROUND. A FEW FLURRIES WILL STILL BE POSSIBLE OVER THE EAST CWA THIS AFTERNOON. LOWER DELTA-T'S AND WARMER TEMPERATURES WILL PREVAIL THROUGH THE AFTERNOON OVER THE WEST SO PRECIPITATION IS UNLIKELY. TEMPERATURES ARE RUNNING A FEW DEGREES WARMER THAN GUIDANCE...SO MAY BRING UP THE TEMPERATURES A LITTLE THIS AFTERNOON IN THE FORECAST. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DLG mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1058 AM EST FRI NOV 12 2004 .UPDATE... UPDATE FOCUS IS WITH LAKE EFFECT POTENTIAL. NORTHERN STREAM WAVE JUST DIGGING INTO NORTHERN LOWER/NORTHERN LAKE HURON...WITH A WEAKENING COLD FRONT AT THE SURFACE. VERY DRY AIRMASS AHEAD OF THIS FEATURE /0.13" PRECIPITABLE WATER PER 12Z DTX SOUNDING/...WITH CLEAR SKIES ACROSS SOUTHEAST MICHIGAN. ONLY A NARROW BAND OF CU ACROSS SOUTHERN HURON AS WELL...EXTENDING BACK TO THE BRUCE PENINSULA IN WEAK NORTH/NORTHEASTERLY FLOW. BETTER LOW-LEVEL CONVERGENCE ACROSS NORTHERN HURON...IN ADDITION TO WEAK SYNOPTIC LIFT/MOISTURE AND COLDER AIR/STEEPER LOW-LEVEL LAPSE RATES. EVEN SEEING SOME WEAK ECHOES UP TO 10KFT ON APX RADAR. EXPECT THESE SNOW SHOWERS WILL CONTINUE TO DRIFT/DEVELOP SOUTHWARD THROUGH THE DAY AHEAD OF THE UPPER WAVE. 12Z RUC/ETA ARE PRETTY SIMILAR INDICATING BETTER LOW-LEVEL MOISTURE AND CONVERGENCE WILL WORK INTO THE THUMB AROUND 00Z THIS EVENING. IN THE MEANTIME THROUGH THE AFTERNOON...EXPECT SKIES TO REMAIN MOSTLY SUNNY /SOME CIRRUS BUT EVEN THAT HAS THINNED A BIT SINCE OVERNIGHT/ EVEN IN THE NORTH THROUGH THE DAY. ADDITIONAL CLOUDS AND A CHANCE OF SNOW STILL LOOKS GOOD FOR TONIGHT THOUGH...AS MORE ORGANIZED NORTHEAST FLOW SETS UP ACROSS LAKE HURON...IN ADDITION TO HIGH 1000-850MB RH AND WEAK 950MB CONVERGENCE. TEMPERATURES THIS MORNING HAVE RESPONDED VERY QUICKLY...ONCE WE MIXED OUT THE SHALLOW SURFACE INVERSION. MOST STATIONS ALREADY INTO THE UPPER 30S AS OF 15Z...AFTER STARTING THE MORNING IN THE 20S OR EVEN UPPER 10S. WITH FEW CLOUDS TO LIMIT INSOLATION...SHOULD BE ABLE TO MAKE IT INTO THE LOW/MID 40S. && BRAVENDER .PREV DISCUSSION...307 AM EST FRI NOV 12 2004 OVERALL, LITTLE CHANGE TO OUR GOING FORECAST/GRIDS. SPLIT FLOW ACROSS NORTH AMERICA PER THE H2O VAPOR LOOP ANALYSIS WITH TROF AXIS PROGRESSING ACROSS THE GREAT LAKES INTO NEW ENGLAND...MEANWHILE A SHORT WAVE ENERGY WAS TRACKING EAST ACROSS THE LOWER OHIO VALLEY. LOOKING UPSTREAM, ANOTHER SHORT WAVE IS SEEN DIVING SOUTHEAST FROM LAKE WINNIPEG INTO THE NORTHERN MISSISSIPPI RIVER VALLEY WITH AN ENHANCED REGION OF COLD CLOUD TOPS (MOSTLY CIRRUS CLOUDS). THERE SEEMS TO BE ANOTHER WEAKER JET STREAK ACROSS LAKE SUPERIOR WITH ENTRANCE REGION DYNAMICS RESULTING IN THIS CLOUD COVERAGE THIS MORNING (LATEST RUC HAS AN EXCELLENT HANDLE ON THIS FEATURE). FURTHER UPSTREAM WE HAVE A CUT OFF LOW ACROSS THE FOUR CORNERS REGION WHICH IS JUST NORTH OF THE SOUTHERN BRANCH OF THE JET. THEN A POTENT SYSTEM OUT IN THE PACIFIC WHICH WILL BE DAYS AWAY... FOR TODAY... UPSTREAM CONDITIONS ON THURSDAY WITH NEARLY FULL SUNSHINE, THEY WERE ONLY ABLE TO CLIMB INTO THE LOWER 40S AND REALLY DO NOT SEE MUCH REASON TO GO HIGHER HERE. EXCEPTION WOULD BE SOUTHEAST COUNTIES AS WE CONTINUE TO BE AFFECTED WITH OUR FIRST CIRRUS CLOUD DECK WITH LEAD 120KT JET EXTENDING INTO THE ST LAWRENCE VALLEY...THEREFORE A SLIGHTLY WARMER START. THIS FEATURE WILL BECOME FURTHER REMOVED TOWARD SUNRISE THEN THE APPROACH OF THE WEAKER SYSTEM AND ASSOCIATED SHORT WAVE FOR THIS AFTERNOON. THIS NEXT WAVE IS YET ANOTHER SHOT OF COLD ADVECTION WITH SURFACE COLD FRONT ANALYZED JUST NORTH OF THE GREAT LAKES. WHILE THE SURFACE FEATURE WILL BECOME WASHED OUT TO SOME EXTENT THIS AFTERNOON AS LARGE SURFACE HIGH BECOMES DOMINANT (NEAR 1040MB), 850MB FRONT WILL BE MORE APPARENT WITH TEMPS OVER LAKE HURON DROPPING TOWARD -10C BY EVENING. MOISTURE REMAINS LEAN BUT WITH INCREASED DELTA T/S AND SOME ASSISTANCE WITH WEAK WAVE ALOFT, ENOUGH TO KEEP THE SLIGHT MENTION OF SOME FLURRIES ACROSS THE THUMB LATER THIS AFTERNOON. TONIGHT... AS PREVIOUS DISCUSSIONS HAVE POINTED OUT, LAKE EFFECT ACTIVITY BECOMES A LITTLE CONCERN. THE GFS SOUNDINGS REMAINS QUITE DRY TO INHIBIT ANY LAKE EFFECT ACTIVITY WITH LARGE SCALE SUBSIDENCE THROUGH THE COLUMN. THE ETA ON THE OTHER HAND WITH BETTER HORIZONTAL AND VERTICAL RESOLUTION SHOWS A LITTLE DIFFERENT STORY. THE 850MB FRONTAL BOUNDARY SLIDES SOUTH INTO THE CENTER OF THE CWA WITH TEMPS OVER LAKE HURON DROPPING BELOW -10C...WHICH RESULTS IN CONDITIONAL LAKE INSTABILITY. MODIFYING THE PARCELS WITH LAKE TEMPS INTO THE UPPER 40S, LAKE INDUCED CAPES CLIMB TO BETWEEN 200-300 J/KG. 1000-850MB FLOW IS NORTHEAST AND SOUNDINGS REVEAL LITTLE DEVIATION FROM THIS TRAJECTORY OVERNIGHT UP TO THE INVERSION. HOWEVER, INVERSION HEIGHTS BARELY TAP INTO FAVORABLE ICE NUCLEATION WITH -10C SEEN IN THE BUFKIT PROFILES TOP OF THE MOISTURE COLUMN. IN ADDITION, 925/950MB CONVERGENCE FIELDS ARE QUITE WEAK OVERNIGHT BUT OMEGA VALUES IN THIS LAYER DO HINT TOWARD SOME SMALL SCALE LIFT. THEREFORE, WE WILL HOLD ONTO THE CHANCE OF SNOW SHOWERS AND EXTEND THE CHANCE INTO BAY COUNTY WITH A STRAIGHT LINE NORTHEAST TRAJECTORY ACROSS SAGINAW BAY. FURTHER INLAND, WITH SOME LAKE CLOUD BOUNCING AROUND... TEMPS SHOULD NOT HAVE ANY PROBLEMS DROPPING BACK INTO THE 20S WHICH WILL BE BELOW GUIDANCE VALUES. THEREAFTER...HIGH PRESSURE AT ALL LEVELS SETTLES SLOWLY THROUGH THE AREA OVER THE WEEKEND ON INTO EARLY NEXT WEEK. NOT MUCH TO BE SAID HERE...AS IT WILL BRING TRANQUIL WEATHER FOR SEVERAL DAYS INTO EARLY NEXT WEEK. && .DTX WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY TODAY AND TONIGHT NEARSHORE WATERS OF LAKE ERIE. && $$ BGM EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 710 AM EST FRI NOV 12 2004 .UPDATE... CIRRUS FINALLY HAS MADE ITS MOVE OUT OF SOUTHEAST MI...WITH HELP OF WEAKENING UPPER LEVEL DIVERGENCE AS PER LATEST RUC. WILL SHORTLY UPDATE TO REFLECT THESE CLOUD TRENDS FOR THIS MORNING. && DWD .PREV DISCUSSION...ISSUED 307 AM EST FRI NOV 12 OVERALL, LITTLE CHANGE TO OUR GOING FORECAST/GRIDS. SPLIT FLOW ACROSS NORTH AMERICA PER THE H2O VAPOR LOOP ANALYSIS WITH TROF AXIS PROGRESSING ACROSS THE GREAT LAKES INTO NEW ENGLAND...MEANWHILE A SHORT WAVE ENERGY WAS TRACKING EAST ACROSS THE LOWER OHIO VALLEY. LOOKING UPSTREAM, ANOTHER SHORT WAVE IS SEEN DIVING SOUTHEAST FROM LAKE WINNIPEG INTO THE NORTHERN MISSISSIPPI RIVER VALLEY WITH AN ENHANCED REGION OF COLD CLOUD TOPS (MOSTLY CIRRUS CLOUDS). THERE SEEMS TO BE ANOTHER WEAKER JET STREAK ACROSS LAKE SUPERIOR WITH ENTRANCE REGION DYNAMICS RESULTING IN THIS CLOUD COVERAGE THIS MORNING (LATEST RUC HAS AN EXCELLENT HANDLE ON THIS FEATURE). FURTHER UPSTREAM WE HAVE A CUT OFF LOW ACROSS THE FOUR CORNERS REGION WHICH IS JUST NORTH OF THE SOUTHERN BRANCH OF THE JET. THEN A POTENT SYSTEM OUT IN THE PACIFIC WHICH WILL BE DAYS AWAY... FOR TODAY... UPSTREAM CONDITIONS ON THURSDAY WITH NEARLY FULL SUNSHINE, THEY WERE ONLY ABLE TO CLIMB INTO THE LOWER 40S AND REALLY DO NOT SEE MUCH REASON TO GO HIGHER HERE. EXCEPTION WOULD BE SOUTHEAST COUNTIES AS WE CONTINUE TO BE AFFECTED WITH OUR FIRST CIRRUS CLOUD DECK WITH LEAD 120KT JET EXTENDING INTO THE ST LAWRENCE VALLEY...THEREFORE A SLIGHTLY WARMER START. THIS FEATURE WILL BECOME FURTHER REMOVED TOWARD SUNRISE THEN THE APPROACH OF THE WEAKER SYSTEM AND ASSOCIATED SHORT WAVE FOR THIS AFTERNOON. THIS NEXT WAVE IS YET ANOTHER SHOT OF COLD ADVECTION WITH SURFACE COLD FRONT ANALYZED JUST NORTH OF THE GREAT LAKES. WHILE THE SURFACE FEATURE WILL BECOME WASHED OUT TO SOME EXTENT THIS AFTERNOON AS LARGE SURFACE HIGH BECOMES DOMINANT (NEAR 1040MB), 850MB FRONT WILL BE MORE APPARENT WITH TEMPS OVER LAKE HURON DROPPING TOWARD -10C BY EVENING. MOISTURE REMAINS LEAN BUT WITH INCREASED DELTA T/S AND SOME ASSISTANCE WITH WEAK WAVE ALOFT, ENOUGH TO KEEP THE SLIGHT MENTION OF SOME FLURRIES ACROSS THE THUMB LATER THIS AFTERNOON. TONIGHT... AS PREVIOUS DISCUSSIONS HAVE POINTED OUT, LAKE EFFECT ACTIVITY BECOMES A LITTLE CONCERN. THE GFS SOUNDINGS REMAINS QUITE DRY TO INHIBIT ANY LAKE EFFECT ACTIVITY WITH LARGE SCALE SUBSIDENCE THROUGH THE COLUMN. THE ETA ON THE OTHER HAND WITH BETTER HORIZONTAL AND VERTICAL RESOLUTION SHOWS A LITTLE DIFFERENT STORY. THE 850MB FRONTAL BOUNDARY SLIDES SOUTH INTO THE CENTER OF THE CWA WITH TEMPS OVER LAKE HURON DROPPING BELOW -10C...WHICH RESULTS IN CONDITIONAL LAKE INSTABILITY. MODIFYING THE PARCELS WITH LAKE TEMPS INTO THE UPPER 40S, LAKE INDUCED CAPES CLIMB TO BETWEEN 200-300 J/KG. 1000-850MB FLOW IS NORTHEAST AND SOUNDINGS REVEAL LITTLE DEVIATION FROM THIS TRAJECTORY OVERNIGHT UP TO THE INVERSION. HOWEVER, INVERSION HEIGHTS BARELY TAP INTO FAVORABLE ICE NUCLEATION WITH -10C SEEN IN THE BUFKIT PROFILES TOP OF THE MOISTURE COLUMN. IN ADDITION, 925/950MB CONVERGENCE FIELDS ARE QUITE WEAK OVERNIGHT BUT OMEGA VALUES IN THIS LAYER DO HINT TOWARD SOME SMALL SCALE LIFT. THEREFORE, WE WILL HOLD ONTO THE CHANCE OF SNOW SHOWERS AND EXTEND THE CHANCE INTO BAY COUNTY WITH A STRAIGHT LINE NORTHEAST TRAJECTORY ACROSS SAGINAW BAY. FURTHER INLAND, WITH SOME LAKE CLOUD BOUNCING AROUND... TEMPS SHOULD NOT HAVE ANY PROBLEMS DROPPING BACK INTO THE 20S WHICH WILL BE BELOW GUIDANCE VALUES. THEREAFTER...HIGH PRESSURE AT ALL LEVELS SETTLES SLOWLY THROUGH THE AREA OVER THE WEEKEND ON INTO EARLY NEXT WEEK. NOT MUCH TO BE SAID HERE...AS IT WILL BRING TRANQUIL WEATHER FOR SEVERAL DAYS INTO EARLY NEXT WEEK. && .DTX WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY TODAY AND TONIGHT NEARSHORE WATERS OF LAKE ERIE. && $$ BGM EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 230 PM EST FRI NOV 12 2004 .DISCUSSION... IMMEDIATE CONCERN WILL BE TO JUDGE THE POTENTIAL FOR LAKE EFFECT PRECIPITATION TONIGHT INTO SATURDAY MORNING. THEREAFTER...A BULK OF THE FORECAST REMAINS QUIET AS SPRAWLING HIGH PRESSURE SLOWLY SINKS SOUTHEAST ACROSS THE GREAT LAKES OVER THE WEEKEND AND ON THROUGH THE FIRST HALF OF NEXT WEEK. FOLLOWING ETA/RUC LOW LEVEL WIND/TEMPERATURE/MOISTURE FIELDS...THE CONDITIONS STILL APPEAR TO BE MARGINAL FOR WIDESPREAD LAKE EFFECT ACTIVITY. INVERSION HEIGHTS ARE FORECAST TO RISE TO AROUND 5KFT BY LATE THIS EVENING...WITH TEMPERATURES AT THE BASE OF THE INVERSION PUSHING -10C. RUC13 IS THE MOST INTERESTING OF THE TWO AS IT DOES PRODUCE A NICE CONVERGENCE LINE FROM JUST SOUTH OF THE BRUCE PENINSULA ON TO THE MICHIGAN SHORELINE...CENTERED ON SANILAC COUNTY. QPF SOLUTIONS W/ THIS IDEA ARE RATHER ROBUST AS WELL...PUSHING A QUARTER OF AN INCH LOCALLY OVERNIGHT. THIS AREA OF CONVERGENCE EDGED SLOWLY TO THE WEST OVERNIGHT INTO SATURDAY MORNING AS THE DOMINANT SYNOPTIC FLOW SWINGS FROM NORTH TO NORTHEAST TO EAST AS HIGH PRESSURE SETTLES INTO AREA. ETA HINTS AT THE ABOVE SCENARIO BUT REMAINS VERY WEAK IN ITS DEPICTION OF THE LOW LEVEL CONVERGENT AREA...AND ALSO QPF. GIVEN THE MARGINAL NATURE OF THE EVENT...WILL LEAN TOWARD THE ETA SOLUTION AND KEEP THE GOING FORECAST PRETTY MUCH INTACT. EVEN IF A DECENT BAND CAN ORGANIZE...WATER TEMPERATURES IN THE MID/UPPER 40S WILL MINIMIZE ANY SIGNIFICANT ACCUMULATION ANYWAY. WITH WORD THE FORECAST AS CHANCE OR SCATTERED. AND KEEP IT FROM THE THUMB ON INTO PARTS OF THE SAGINAW VALLEY AS WINDS TREND FROM NORTH TO NORTHEAST OVERNIGHT. VERY LITTLE NEEDS TO BE DONE WITH FORECAST FROM SUNDAY INTO ABOUT WEDNESDAY AS A 1040 MB HIGH IS STILL FORECAST TO DRIFT THROUGH THE AREA. THE NEXT PROBLEM IN THE FORECAST EVOLVES AROUND THE RETURN FLOW AROUND THIS HIGH PRESSURE AS IT CONTINUES ON TO THE EAST COAST. AT THE SAME TIME...THE UPPER LEVEL RIDGE THAT BUILDS INTO THE AREA THIS WEEKEND INTO EARLY NEXT WEEK SHIFTS TO THE SOUTHEAST...AND ALLOWS SHORTWAVES RIDING ALONG THE STRONG ZONAL FLOW OF NORTHERN STREAM ACROSS SOUTHERN CANADA TO PENETRATE CLOSER AND CLOSER TO THE GREAT LAKES. THE ACTUAL PROGS FROM THE MODELS ARE STILL VERY UNCERTAIN WITH HOW TO HANDLE THIS TRANSITION...SO CONFIDENCE IS PRETTY LOW ON THE DETAILS...BUT...IN GENERAL...WOULD EXPECT AN INCREASING LIKELIHOOD OF SHOWERS FROM LATE WEDNESDAY ON INTO THE WEEKEND. AS RIDGE SHIFTS SLOWLY SOUTHEAST OF AREA...SURFACE FRONT DEFINING THE SOUTHERN EDGE OF COOLER POLAR AIR WILL SLOWLY SINK SOUTH INTO THE AREA...DUE TO THE INCREASED INFLUENCE OF NORTHERN STREAM SHORTWAVES. BY THE WEEKEND...MODELS ALSO SUGGEST THAT MORE TROFFING WILL OCCUR ACROSS THE WESTERN CONUS...EVENTUALLY LEADING TO A MORE SUSTAINED SOUTHWESTERLY UPPER LEVEL FLOW INTO THE GREAT LAKES. THIS WILL MAKE MORE AND MORE MOISTURE AVAILABLE ACROSS THE REGION. && .DTX WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY TONIGHT FOR THE NEARSHORE WATERS OF LAKE ERIE. && $$ GURNEY EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi