AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 1145 AM CST FRI DEC 1 2006 .DISCUSSION FOR MORNING GRIDS/ZONES... 245 AM CST OBVIOUS FOCUS ON SHORT TERM OF FORECAST...WITH MAJOR WINTER STORM IN PROGRESS ACROSS THE FORECAST AREA THIS MORNING. VIGOROUS UPPER LOW LIFTING ACROSS SOUTHEAST MISSOURI PER VAPOR LOOPS AT 0830Z...WITH ASSOCIATED 997 MB SFC LOW ANALYZED ALONG THE IL/IND BORDER JUST SOUTH OF KLWV. IMPRESSIVE AREA OF SFC PRESSURE FALLS OF BETTER THAN 8 MB/3HRS OCCURRING ACROSS CENTRAL IL...NORTHWEST OF THE ACTUAL SFC LOW TRACK...LIKELY AN INDICATION OF VERTICAL MOTION FROM STRONG FRONTOGENETIC FORCING ALONG SHARP BAROCLINIC ZONE...AND STRONG UPPER DIVERGENCE ASSOCIATED WITH TEXT BOOK COUPLED UPPER JET STRUCTURE. TOUGH FORECAST FOR SNOW AMOUNTS WITH THIS SYSTEM...GIVEN VERY POTENT DYNAMICS...THOUGH THERMAL PROFILE HAS MAINTAINED MIX OF SN/PL/RA OVER SOUTHEASTERN COUNTIES OF FCST AREA WHERE WARMER LOW LEVELS HAVE NOT BEEN OVERCOME. FAIRLY DECENT AGREEMENT IN 0-12 HR FCSTS OF RUC/NAM/GFS THAT AREA GENERALLY EAST OF INTERSTATE 57 WILL REMAIN GENERALLY A MIX OF PCPN TYPES EARLY THIS MORNING...BEFORE COLUMN COOLS ENOUGH FOR CHANGE OVER TO ALL FROZEN PCPN. ANOTHER COMPLICATING FACTOR IN THE SOUTHEASTERN PARTS OF THE CWA IS THE APPROACH OF THE DRY SLOT...NOTED IN SAT AND RADAR NOW PUNCHING INTO EAST CENTRAL IL. THIS EXPECTED TO FURTHER LIMIT SNOW ACCUMULATION POTENTIAL EAST OF INTERSTATE 55...SO HAVE CHOSEN TO DOWNGRADE WINTER STORM WARNING TO WINTER WX ADVISORY FOR THESE COUNTIES FOR CONTINUED MIX THIS MORNING. HAVE DECREASED TOTAL SNOW IN THOSE AREAS FROM AROUND 6-7 INCHES I-55 CORRIDOR...TO 1-3 INCHES IN MUCH OF NORTHWEST INDIANA. FARTHER WEST...AGAIN MODEL FORECASTS IN PRETTY GOOD AGREEMENT WITH DEFORMATION ZONE SETTING UP FROM NERN MISSOURI THROUGH NORTH CENTRAL/NORTHEAST IL. THIS ROUGHLY ALONG KUIN...KRPJ/KDKB...TO KMKE LINE...WHERE THERMAL PROFILES ARE COLD ENOUGH FOR PRECIP TO FALL ENTIRELY AS SNOW. BASED ON THIS HAVE SHIFTED AXIS OF HEAVIEST SNOWFALL SLIGHTLY NORTHWEST FROM PREVIOUS FORECAST. STILL APPEARS THAT 8-12 INCHES LIKELY ACROSS THE REMAINING WARNING AREA THIS MORNING...AGAIN WITH AXIS OF HEAVIEST SNOW FROM EASTERN LEE/LASALLE CO NORTHEAST THROUGH LAKE/MCHENRY COUNTIES. GIVEN STRONG FRONTOGENETIC FORCING AND BANDING IN DEFORMATION ZONE...COULD SEE SOME LOCALLY SLIGHTLY HIGHER AMOUNTS. VERY SHARP EDGE TO DEFORMATION PRECIP FIELD TO THE NORTHWEST WHICH WILL RESULT IN SNOW AMOUNTS TAPERING OFF QUICKLY INTO NW IL/EASTERN IA. FORECAST REPRESENTS BEST SHOT AT SLICING THINGS BASED ON CURRENT RADAR/SATELLITE AND MODEL TRENDS. HAVE ALSO MENTIONED POTENTIAL FOR BLOWING SNOW NORTH AND WEST WHERE SNOW TO LIQUID RATIOS A LITTLE HIGHER...AS NNW WINDS EXPECTED TO GUST 25 TO 35 MPH LATER THIS MORNING INTO EARLY AFTN AS LOW LIFTS NORTHEAST ACROSS LOWER MICHIGAN AND INTO ONTARIO. HELD ONTO A LOW CHANCE POP FOR SOME LIGHT SNOW AS DEPARTING DEFORMATION ZONE MAY LINGER EARLY THIS AFTERNOON ESPECIALLY NORTHEAST. SYSTEM FORECAST TO LIFT OUT FAIRLY RAPIDLY THIS AFTERNOON...WITH PRECIP GENERALLY ENDING EARLY AFTERNOON. FAIRLY STRONG SUBSIDENCE DEVELOPING IN WAKE OF DEPARTING SYSTEM SHOULD HELP CLEAR SKIES INTO MISSISSIPPI VALLEY BY LATE AFTN. WENT SIGNIFICANTLY BELOW GUIDANCE TEMPS FOR TODAYS MAXES AND TONIGHTS LOWS NORTHWEST HALF OR SO CWA PER CURRENT OBS AND EXPECTED SNOW FIELD...AS MOS NUMBERS ALL APPEAR TOO WARM THERE. NO SIG CHANGES TO REMAINDER OF FCST AT THIS TIME. RATZER && .AVIATION... 1145 AM CST RE 18Z TAFORS...STORM RAPIDLY WINDING DOWN WITH UPR LO MOVG NEWRD FM NERN IND AND SFC LO IN CNTRL LWR MI. BACK EDGE OF LAST SN BAND FROM RFD TO VYS TO BMI WITH RADAR AND SATELLITE SHOWING CONTG DEC IN INTENSITY. THIS TO CLR CHI TERMINALS BTWN 19Z AND 20Z BRINGING SN TO END. MODERATELY STRONG NW WINDS CAUSING SOME BLSN BUT GUSTINESS RAPIDLY DROPS OFF ACROSS NW IL AND S CNTRL WI AS PRES RISE CENTER MOVG FM E CNTRL IL INTO NW IND. WNDS TO CONT TO BACK AND SLACKEN AS SFC LO MOVS OVR THE LWR GRTLKS BY LATER AFTERNOON. CIGS BREAKINGUP ACROSS SW WI AND NW IL AND CLRG TO CONT TO SPREAD EWRD DURG THE AFTERNOON WITH QUICK EXIT OF SYSTEM. WNDS CONT TO WEAKEN THIS EVE THEN BACK FURTHER TO SWRLY AHEAD OF APPROACHING REINFORCING CDFNT CURRENTLY MOVG THRU DKTS. TRS && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...WINTER STORM WARNING GENERALLY NORTHWEST OF INTERSTATE 57 THROUGH 18Z TODAY. .IN...WINTER WEATHER ADVISORY THROUGH 18Z TODAY. .LM...GALE WARNING THROUGH 00Z. SCA FOR NEASHRE TONIGHT. 3&& $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE INDIANAPOLIS IN 1218 PM EST FRI DEC 1 2006 .AVIATION...DISCUSSION FOR 18Z TAFS. A PUBLIC WIND ADVISORY IS IN EFFECT UNTIL 00Z. SUSTAINED WIND 20-30KTS WITH GUSTS AS HIGH AS 50KTS WILL CONTINUE UNTIL AROUND 00Z. STRONG LOW PRESSURE WAS THROUGH INDIANA AND INTO MICHIGAN. AS THIS LOW CONTINUES NE THE SURFACE PRESSURE GRADIENT WILL RELAX AND WIND WILL DIMINISH TO AROUND 10 TO 15KTS AFTER SUNSET. MVFR CIGS WILL GIVE WAY TO VFR LATER THIS EVENING. SKIES WILL CLEAR BUT WIND WILL STAY UP ENOUGH TO PREVENT FOG FORMATION. && .UPDATE... UPDATED GRIDS/TEXT TO TRY AND REFLECT TEMPERATURES AT 12Z. WARM AIR WORKED IN FARTHER N THAT ORIGINALLY THOUGHT. THUS HIGH TEMPERATURES CAME OUT HIGHER THAN ON PREV FORECAST. SOME AREAS MAY SEE AN HOUR WARMER THAN FORECAST DUE TO UNCERTAINTY OF TIMING OF ARRIVAL OF COLDER AIR ACROSS ERN AND NERN FA. PRECIP HAD DIMINISHED CONSIDERABLY BUT MORE IS DEVELOPING ACROSS SWRN IN. THUS LOWERED POPS A LITTLE...BUT DIDN/T REDUCE TOO MUCH UNTIL TRENDS CAN BE DETERMINED. && .PREV DISCUSSION... //HAVE DECIDED TO START WIND ADVISORY AT 13Z RATHER THAN 15Z. NO OTHER CHANGES// FORECAST FOCUS CENTERS ON TEMPERATURES/PRECIPITATION/WIND TODAY. AT 07Z SURFACE LOW WAS LOCATED TO THE E OF KEVV. UPPER LOW WAS BACK ACROSS MO/AR BORDER. RAIN COVERED MUCH OF THE FORECAST AREA /FA/ WITH TEMPERATURES RANGING FROM THE UPPER 30S N TO MID TO UPPER 40S SOUTH. MODELS IN FAIR AGREEMENT. AT 06Z NAM/NGM WAS CLOSER TO REALITY THAN GFS. WILL THUS LEAN TOWARD NAM/NGM SOLUTION TODAY. OTHERWISE AFTER TODAY MODELS ARE SIMILAR AND WILL USE A BLEND. PRESENT INDICATIONS ARE THAT SURFACE LOW WILL RAPIDLY MOVE NE THROUGH THE FA AND BE ACROSS EAST CENTRAL IN BY 12Z. CURRENT TIMING OF DRY SLOT PUTS IT ACROSS SWRN THIRD TO HALF OF FA BY 12Z. BASED ON THESE TRENDS...HAVE BASICALLY KEPT PREV FORECAST OF CHANCE POPS AFT 12Z ACROSS FAR SW INCREASING TO CATEGORICAL POPS ACROS FAR N. COLDER AIR SHOULD BE WORKING INTO SW FA AT 12Z SO PLAN TO START THEM WITH A MIX OF RA/SN WITH RAIN ELSEWHERE. BY MID MORNING COLDER AIR WILL HAVE SWEPT ACROSS FA CHANGING PRECIP TO SNOW. HOWEVER BY THEN BULK OF MOISTURE WILL BE NE OF THE FA. DURING THE AFTERNOON POPS WILL DECREASE AS SYSTEM EXITS. GIVEN ALL OF THIS WILL CONTINUE TREND OF SMALL SNOWFALL AMOUNTS...WITH HIGHEST OF 1 TO 2 INCHES ACROSS NW FA. OTHER FACTOR WILL BE WINDS TODAY. PROFILER NETWORK ALREADY SHOWING 50KT AT 850 APPROACHING FA WITH CURRENT KIND VAD WIND PROFILE SHOWING 40KT AT 4000 FT. THESE WINDS WILL MIX DOWN AS SYSTEM EXITS TO THE NE THIS MORNING. BUFKIT SOUNDINGS AND RUC WIND GUST FORECASTS CONFIRM THIS BY INDICATING GUSTS OVER 45 MPH POSSIBLE ACROSS THE FA. THUS WILL EXPAND WIND ADVISORY TO ENTIRE FA. TEMPERATURES WILL FALL MOST OF THE DAY TODAY. 12Z TEMPERATURES WILL BE THUS BE THE HIGH TEMPERATURE FOR MANY AREAS TODAY. BASED ON CURRENT TRENDS WILL MAKE BEST EDUCATED GUESS AS TO WHAT THIS WILL BE...AND THIS ENDS UP WARMER THAN MAV NUMBERS INDICATE PER GFS/S FASTER SYSTEM. TONIGHT WINDS WILL DIMINISH AND SKIES WILL BE PARTLY CLOUDY AS COLDER DRIER AIR WORKS IN. MOS TEMPERATURES ARE SIMILAR MOST AREAS AND LOOK OK...BUT MAV LOOKS A BIT WARM IN THE SOUTH. WILL CUT SOME THERE. WILL KEEP EXTENDED DRY FOR NOW BUT GFS CONTINUES TO INDICATE A SMALL CHANCE FOR SNOW ON TUE AND THU/FRI. NOT SURE ABOUT MOISTURE AVAILABILITY ON TUE AND WILL LET LATER SHIFTS HAVE A LOOK AT THU/FRI. && .IND WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM UNTIL 7 PM EST FOR ENTIRE FORECAST AREA. && $$ SHORT TERM/AVIATION...SALLY LONG TERM...TUCEK in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 655 AM EST FRI DEC 1 2006 .UPDATE... SOME REPORTS FROM MICHIGAN COUNTIES OF ICING ALONG WITH LIMBS AND SMALL TREES COMING DOWN. FEW PROBLEMS ON THE ROADS THOUGH. SHOULD SEE INCREASED ACCUMULATION NEXT FEW HOURS FOR DRY SLOT WORKS IN. HAVE UPGRADED THESE COUNTIES TO WINTER STORM WARNING FOR COMBINATION OF THIS ICING AND POSSIBLE SNOW WITH COMMA HEAD LATER THIS MORNING AND THIS AFTERNOON. CANCELLED THE WIND ADVISORY FOR HILLSDALE COUNTY AS IT WAS REPLACED WITH THE WARNING. && .AVIATION... FEW CHANGES TO PREVIOUS THINKING WITH TAF ISSUANCE. STILL EXPECT COMMA HEAD AND DEFORMATION AREA TO BRING BRIEF HEAVY SNOW TO KSBN. KFWA STILL LOOKS TO REMAIN EAST OF THIS AREA AND SHOULD NOT GET INTO THE HEAVY SNOW. LAKE ENHANCE BAND EXPECTED AT KSBN LATE AFTERNOON AS WELL BEFORE MOISTURE PULLS EAST AND PCPN ENDS THIS EVENING. && .SHORT TERM... TODAY AND TONIGHT OBVIOUS CHALLENGE IN THE SHORT TERM IS PRECIPITATION TYPE AND AMOUNTS TODAY WITH STRONG LOW PRESSURE MOVING ACROSS THE AREA. GENERALLY FOLLOWING BLEND OF RUC AND NAM ALONG WITH REMOTE SENSING TOOLS FOR SHORT TERM FORECAST. WATER VAPOR SHOWS POTENT UPPER LOW MOVING OUT OF ARKANSAS AND MISSOURI THIS MORNING AND HEADING NORTHEAST. THIS LOW SHOULD CROSS OUR CENTRAL FORECAST AREA THIS AFTERNOON...ALONG A LINE FROM ABOUT GUS TO LAF TO TOL. MSAS ANALYSIS PLACES SURFACE LOW JUST EAST OF EVV AT 07Z WITH STRONG 3HR PRESSURE FALLS FROM CENTRAL IL TO SOUTHWEST OHIO. RUC40 SEEMS TO HAVE BEST HANDLE ON THIS SITUATION AND MOVES UPPER LOW TO JUST SOUTH OF GUS BY 15Z WITH SURFACE LOW TO NORTHERN OHIO. GIVEN RAPID MOVEMENT OF UPPER SYSTEM SEEN ON WATER VAPOR...THIS FAST MOVEMENT NOW SEEMS REASONABLE. REGIONAL RADAR EARLY THIS MORNING SHOWS WIDESPREAD PRECIPITATION AHEAD OF MAIN LOW WITH MOSTLY RAIN AND TEMPERATURES IN THE MID TO UPPER 30S ACROSS OUR AREA. SOME EARLY REPORTS OF FREEZING RAIN IN THE WARNING AREA AND 07Z SURFACE OBSERVATIONS INDICATING SOME SNOW ALREADY MIXING WITH RAIN IN THE EAST WITH STRONGER OMEGA AND DYNAMIC COOLING. WITH APPROACH OF LOW EXPECT WARM POCKET OF TEMPS ALOFT TO MOVE OVER THE AREA EARLY THIS MORNING...KEEPING MOST OF THE PCPN IN THE FORM OF RAIN CENTRAL AND EAST WITH FREEZING RAIN NORTHWEST WHERE SURFACE TEMPS DROP TO 31 TO 32F. SOME SLEET ALSO EXPECTED WITH SHALLOW SUB FREEZING LAYER NEAR THE SURFACE. FAR NORTH AND NORTHEAST AREAS MAY EXPERIENCE BRIEF FREEZING RAIN TOWARD DAYBREAK BEFORE LOW MOVES CLOSER AND TEMPS RISE BRIEFLY. NO PLANS TO EXPAND ADVISORY EAST BUT WILL MONITOR AND HANDLE WITH SHORT TERM FORECASTS. ONCE SURFACE LOW PASSES EAST THIS MORNING COLD AIR WILL QUICKLY RACE IN AND CHANGE RAIN TO SNOW FROM WEST TO EAST. DRY SLOT SHOULD MOVE INTO CENTRAL AND EAST SHORTLY AFTER CHANGEOVER AND LIMIT ACCUMULATIONS THERE. DEFORMATION ZONE AND TROWEL NORTH AND WEST OF MID AND UPPER LEVEL CIRCULATION WILL BRING MODERATE TO HEAVY SNOW WEST OF THE UPPER LOW TRACK. HEAVIEST SNOW STILL EXPECTED WITHIN CURRENT WARNING AREA WITH LESS ACCUMULATIONS IN THE ADVISORY AREA. NO CHANGES PLANNED TO HEADLINES AT THIS TIME. AS THE DEFORMATION AREA PASSES BY...A BRIEF WINDOW OF OPPORTUNITY SETS UP FOR LAKE ENHANCEMENT THIS AFTERNOON. NAM40 SHOWS THIS NICELY WITH A CONVERGENT LOW LEVEL FLOW OVER THE LAKE AND LONG FETCH ON BACKSIDE OF LOW. LOW LEVEL OMEGA FIELDS SHOW GOOD LIFT CENTERED AROUND 21Z. MOISTURE QUICKLY MOVES OUT SHORTLY AFTER 00Z BUT NW TO W FETCH AND DELTA T VALUES IN MID TEENS SHOULD KEEP AT LEAST SCT SNOW SHOWERS AND FLURRIES GOING ACROSS MICHIGAN COUNTIES THROUGH THE EVENING HOURS. FINALLY...STRONG WINDS A CONCERN LATE THIS MORNING AND AFTERNOON AS DEEPENING LOW PASSES BY AND STRONG COLD AIR ADVECTION RUSHES IN. STRONG 3HR PRESSURE RISE AND FALL COUPLET TO MOVE NORTHEAST AND AID IN STRONGER WINDS. BEST COLD AIR ADVECTION AND STRONGER WINDS MOVE BY TO OUR SOUTHEAST BUT SOUTHEAST HALF OF FORECAST AREA STILL SHOULD SEE STRONG WINDS MIXED DOWN WITH THE COLD AIR. 850MB WINDS NEAR 50 KNOTS WITH 925MB AROUND 40KTS. IT IS RARE FOR US TO REACH HIGH WIND WARNING CRITERIA WITHOUT THE HELP OF CONVECTIVE LINE OR PRECIPITATION BRINGING THE WINDS DOWN. THERE WILL BE SOME SNOW SHOWERS IN THE EAST BUT FEEL GUSTS TO 58 MPH WILL BE ISOLATED AT BEST. HAVE THEREFORE STAYED WITH A WIND ADVISORY FOR EASTERN AREAS BUT WILL HIGHLIGHT GUSTS OF 50 TO 55 MPH FROM A LINE EAST OF MARION TO NAPOLEON. && .LONG TERM... SATURDAY THROUGH THURSDAY MAIN CONCERNS IN THE LONG TERM REVOLVE AROUND TIMING/AMPLITUDE OF SEVERAL CLIPPER SYSTEMS AND LAKE EFFECT POTENTIAL. MATURING +PNA PATTERN WILL EVOLVE THROUGH THE MEDIUM RANGE PERIOD...WITH A RIDGE DEVELOPING AT LEAST TEMPORARILY ALONG THE WEST COAST...ALLOWING FOR A MODESTLY DEEP DOWNSTREAM TROUGH TO DEVELOP OVER THE EASTERN HALF OF NOAM. FAVORABLE HIGH LATITUDE BLOCKING WILL NOT BE PRESENT WITH A +NAO CYCLE CONTINUING. THE UPCOMING 7 DAYS WILL BE VERY WINTRY WITH BELOW NORMAL TEMPERATURES AND SEVERAL CHANCES AT SNOW...HOWEVER GIVEN THE LACK OF -NAO THE COLD PATTERN IS UNLIKELY TO LOCK IN FOR MORE THAN A WEEK OR SO WITH A MODERATING TREND POSSIBLE JUST PAST THE END OF THE FORECAST PERIOD. FIRST CONCERN WILL BE LAKE EFFECT POTENTIAL SAT NGT INTO MON AS MUCH COLDER AIR ADVECTS INTO THE REGION BEHIND AN ARCTIC FROPA. INITIALLY SAT NGT INTO SUN FLOW IS WESTERLY AND SYNOPTIC SCALE MOISTURE NOT VERY DEEP. THAT SAID...00Z/01 NAM-WRF 925MB PLUME ANALYSIS SUGGESTING POTENTIAL FOR AN I-94 CONVERGENCE BAND TO DEVELOP ACROSS SW LOWER MICHIGAN LATE SAT NGT AND SUN. GIVEN WESTERLY FLOW...MAJORITY OF LAKE EFFECT ACTIVITY WILL BE HELD ALONG/NORTH OF THE MI/IN STATE LINE. SUN NGT STRONG MID LEVEL SHORTWAVE CROSSES THE GREAT LAKES...POSSIBLY STRONG ENOUGH TO GENERATE A FEW SYNOPTIC SCALE -SHSN...ALTHOUGH DEEP MOISTURE IS LACKING. BEHIND THIS SHORTWAVE CLOUD BEARING FLOW WILL SHIFT TO THE WNW OR NW...AND MORE FAVORABLE MOISTURE PROFILE WILL DEVELOP SOUTHWARD ACROSS LAKE MICHIGAN IN MOIST CYCLONIC LOW LEVEL FLOW. APPEARS BEST WINDOW FOR ACCUMULATING LAKE EFFECT SNOW FOR OUR CWA WILL BE SUN NGT INTO MON MORNING...CONCURRENT WITH BEST LAKE EFFECT PARAMETERS AND MORE FAVORABLE FETCH. HAVE CONTINUED WITH HIGH CHANCE POPS FOR NOW GIVEN INHERENT UNCERTAINTY WITH MESOSCALE EVENTS AT THIS TIME RANGE... HOWEVER LATER SHIFTS WILL PROBABLY NEED TO INCREASE POPS WITH AN ADVISORY CRITERIA EVENT WITHIN THE REALM OF POSSIBILITY. LATEST GFS FORECASTING SURFACE RIDGE TO CROSS THE CWA MIDDAY MON ALLOWING BOUNDARY LAYER FLOW TO BACK SW AND SHIFT ANY REMAINING LAKE EFFECT BACK INTO SW LOWER MICHIGAN AND MAINLY NORTH OF THE CWA. NEXT IN A SERIES OF CLIPPERS THEN FORECAST TO DROP SE THROUGH THE NORTHERN GREAT LAKES MON NGT INTO TUE. 12Z/30 GFS LOST CONTINUITY WITH THIS FEATURE...HOWEVER NEW 00Z/01 ITERATION IS BACK TO A SIMILAR LOOK OF 00Z/30 RUN. WILL MAINTAIN CONTINUITY FOR MON NGT/TUE AND KEEP LOW CHANCE POPS FOR SNOW ACROSS THE ENTIRE CWA. IF THIS SYSTEM BECOMES A LITTLE MORE AMPLIFIED...MAY SEE A GENERAL LGT SNOWFALL WITHIN WAA REGIME AHEAD OF CLIPPER...FOLLOWED BY MORE LAKE EFFECT POTENTIAL BEHIND. MUCH UNCERTAINTY IN REGARDS TO LATER PERIODS FROM TUE NGT INTO THU. GIVEN THE FAVORABLE LONGWAVE PATTERN FOR NUMEROUS CLIPPER TYPE SHORTWAVES...HAVE MAINTAINED CHANCE POPS THAT PREVIOUS SHIFT ADDED. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM EST THIS AFTERNOON FOR INZ007-INZ008-INZ009-INZ017-INZ018-INZ022-INZ023-INZ024- INZ025-INZ026-INZ027-INZ032-INZ033-INZ034. WINTER WEATHER ADVISORY UNTIL 6 PM EST /5 PM CST/ THIS AFTERNOON FOR INZ005-INZ006-INZ013-INZ014-INZ015-INZ016-INZ020. WINTER STORM WARNING UNTIL 6 PM EST /5 PM CST/ THIS AFTERNOON FOR INZ003-INZ004-INZ012. MI...WINTER STORM WARNING UNTIL 6 PM EST THIS AFTERNOON FOR MIZ077-MIZ081. OH...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM EST THIS AFTERNOON FOR OHZ001-OHZ002-OHZ004-OHZ005-OHZ015-OHZ016-OHZ024-OHZ025. LM...SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR LMZ043- LMZ046. GALE WARNING FROM 10 AM THIS MORNING TO 7 PM EST THIS EVENING FOR LMZ043-LMZ046. && $$ SHORT TERM...LASHLEY LONG TERM/AVIATION...HITCHCOCK in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE INDIANAPOLIS IN 630 AM EST FRI DEC 1 2006 .UPDATE... UPDATED GRIDS/TEXT TO TRY AND REFLECT TEMPERATURES AT 12Z. WARM AIR WORKED IN FARTHER N THAT ORIGINALLY THOUGHT. THUS HIGH TEMPERATURES CAME OUT HIGHER THAN ON PREV FORECAST. SOME AREAS MAY SEE AN HOUR WARMER THAN FORECAST DUE TO UNCERTAINTY OF TIMING OF ARRIVAL OF COLDER AIR ACROSS ERN AND NERN FA. PRECIP HAD DIMINISHED CONSIDERABLY BUT MORE IS DEVELOPING ACROSS SWRN IN. THUS LOWERED POPS A LITTLE...BUT DIDN/T REDUCE TOO MUCH UNTIL TRENDS CAN BE DETERMINED. && .AVIATION...FOR THE 12Z TAFS EXPECT LOW MVFR CIGS IN THE 010-020 RANGE TO PERSIST THIS MORNING ALONG WITH VERY STRONG SW GRADIENT WINDS AS THE POWERFUL SFC LOW TRACKS TOWARD LAKE ERIE. BEST CHANCE FOR MIXED PRECIP OR SHSN APPEARS TO BE 15-21Z AS THE SOUTHERN FLANK OF THE DEFORMATION ZONE TRANSLATES ACROSS THE AREA. BUFKIT SUGGESTS THE STRONGEST WIND GUSTS MAY BE THIS AM HOWEVER MIXING HT WINDS STILL IN THE 40KT RANGE EARLY THIS AFTERNOON. WINDS SHOULD DECREASE AND PRECIP SHOULD END TOWARD 00Z. CIGS SHOULD ALSO BECOME VFR BY 06Z. && .PREV DISCUSSION... //HAVE DECIDED TO START WIND ADVISORY AT 13Z RATHER THAN 15Z. NO OTHER CHANGES// FORECAST FOCUS CENTERS ON TEMPERATURES/PRECIPITATION/WIND TODAY. AT 07Z SURFACE LOW WAS LOCATED TO THE E OF KEVV. UPPER LOW WAS BACK ACROSS MO/AR BORDER. RAIN COVERED MUCH OF THE FORECAST AREA /FA/ WITH TEMPERATURES RANGING FROM THE UPPER 30S N TO MID TO UPPER 40S SOUTH. MODELS IN FAIR AGREEMENT. AT 06Z NAM/NGM WAS CLOSER TO REALITY THAN GFS. WILL THUS LEAN TOWARD NAM/NGM SOLUTION TODAY. OTHERWISE AFTER TODAY MODELS ARE SIMILAR AND WILL USE A BLEND. PRESENT INDICATIONS ARE THAT SURFACE LOW WILL RAPIDLY MOVE NE THROUGH THE FA AND BE ACROSS EAST CENTRAL IN BY 12Z. CURRENT TIMING OF DRY SLOT PUTS IT ACROSS SWRN THIRD TO HALF OF FA BY 12Z. BASED ON THESE TRENDS...HAVE BASICALLY KEPT PREV FORECAST OF CHANCE POPS AFT 12Z ACROSS FAR SW INCREASING TO CATEGORICAL POPS ACROS FAR N. COLDER AIR SHOULD BE WORKING INTO SW FA AT 12Z SO PLAN TO START THEM WITH A MIX OF RA/SN WITH RAIN ELSEWHERE. BY MID MORNING COLDER AIR WILL HAVE SWEPT ACROSS FA CHANGING PRECIP TO SNOW. HOWEVER BY THEN BULK OF MOISTURE WILL BE NE OF THE FA. DURING THE AFTERNOON POPS WILL DECREASE AS SYSTEM EXITS. GIVEN ALL OF THIS WILL CONTINUE TREND OF SMALL SNOWFALL AMOUNTS...WITH HIGHEST OF 1 TO 2 INCHES ACROSS NW FA. OTHER FACTOR WILL BE WINDS TODAY. PROFILER NETWORK ALREADY SHOWING 50KT AT 850 APPROACHING FA WITH CURRENT KIND VAD WIND PROFILE SHOWING 40KT AT 4000 FT. THESE WINDS WILL MIX DOWN AS SYSTEM EXITS TO THE NE THIS MORNING. BUFKIT SOUNDINGS AND RUC WIND GUST FORECASTS CONFIRM THIS BY INDICATING GUSTS OVER 45 MPH POSSIBLE ACROSS THE FA. THUS WILL EXPAND WIND ADVISORY TO ENTIRE FA. TEMPERATURES WILL FALL MOST OF THE DAY TODAY. 12Z TEMPERATURES WILL BE THUS BE THE HIGH TEMPERATURE FOR MANY AREAS TODAY. BASED ON CURRENT TRENDS WILL MAKE BEST EDUCATED GUESS AS TO WHAT THIS WILL BE...AND THIS ENDS UP WARMER THAN MAV NUMBERS INDICATE PER GFS/S FASTER SYSTEM. TONIGHT WINDS WILL DIMINISH AND SKIES WILL BE PARTLY CLOUDY AS COLDER DRIER AIR WORKS IN. MOS TEMPERATURES ARE SIMILAR MOST AREAS AND LOOK OK...BUT MAV LOOKS A BIT WARM IN THE SOUTH. WILL CUT SOME THERE. WILL KEEP EXTENDED DRY FOR NOW BUT GFS CONTINUES TO INDICATE A SMALL CHANCE FOR SNOW ON TUE AND THU/FRI. NOT SURE ABOUT MOISTURE AVAILABILITY ON TUE AND WILL LET LATER SHIFTS HAVE A LOOK AT THU/FRI. && .IND WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM UNTIL 7 PM EST FOR ENTIRE FORECAST AREA. && $$ PUBLIC...CS AVIATION...CO in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE INDIANAPOLIS IN 625 AM EST FRI DEC 1 2006 .AVIATION...FOR THE 12Z TAFS EXPECT LOW MVFR CIGS IN THE 010-020 RANGE TO PERSIST THIS MORNING ALONG WITH VERY STRONG SW GRADIENT WINDS AS THE POWERFUL SFC LOW TRACKS TOWARD LAKE ERIE. BEST CHANCE FOR MIXED PRECIP OR SHSN APPEARS TO BE 15-21Z AS THE SOUTHERN FLANK OF THE DEFORMATION ZONE TRANSLATES ACROSS THE AREA. BUFKIT SUGGESTS THE STRONGEST WIND GUSTS MAY BE THIS AM HOWEVER MIXING HT WINDS STILL IN THE 40KT RANGE EARLY THIS AFTERNOON. WINDS SHOULD DECREASE AND PRECIP SHOULD END TOWARD 00Z. CIGS SHOULD ALSO BECOME VFR BY 06Z. && .PREV DISCUSSION... //HAVE DECIDED TO START WIND ADVISORY AT 13Z RATHER THAN 15Z. NO OTHER CHANGES// FORECAST FOCUS CENTERS ON TEMPERATURES/PRECIPITATION/WIND TODAY. AT 07Z SURFACE LOW WAS LOCATED TO THE E OF KEVV. UPPER LOW WAS BACK ACROSS MO/AR BORDER. RAIN COVERED MUCH OF THE FORECAST AREA /FA/ WITH TEMPERATURES RANGING FROM THE UPPER 30S N TO MID TO UPPER 40S SOUTH. MODELS IN FAIR AGREEMENT. AT 06Z NAM/NGM WAS CLOSER TO REALITY THAN GFS. WILL THUS LEAN TOWARD NAM/NGM SOLUTION TODAY. OTHERWISE AFTER TODAY MODELS ARE SIMILAR AND WILL USE A BLEND. PRESENT INDICATIONS ARE THAT SURFACE LOW WILL RAPIDLY MOVE NE THROUGH THE FA AND BE ACROSS EAST CENTRAL IN BY 12Z. CURRENT TIMING OF DRY SLOT PUTS IT ACROSS SWRN THIRD TO HALF OF FA BY 12Z. BASED ON THESE TRENDS...HAVE BASICALLY KEPT PREV FORECAST OF CHANCE POPS AFT 12Z ACROSS FAR SW INCREASING TO CATEGORICAL POPS ACROS FAR N. COLDER AIR SHOULD BE WORKING INTO SW FA AT 12Z SO PLAN TO START THEM WITH A MIX OF RA/SN WITH RAIN ELSEWHERE. BY MID MORNING COLDER AIR WILL HAVE SWEPT ACROSS FA CHANGING PRECIP TO SNOW. HOWEVER BY THEN BULK OF MOISTURE WILL BE NE OF THE FA. DURING THE AFTERNOON POPS WILL DECREASE AS SYSTEM EXITS. GIVEN ALL OF THIS WILL CONTINUE TREND OF SMALL SNOWFALL AMOUNTS...WITH HIGHEST OF 1 TO 2 INCHES ACROSS NW FA. OTHER FACTOR WILL BE WINDS TODAY. PROFILER NETWORK ALREADY SHOWING 50KT AT 850 APPROACHING FA WITH CURRENT KIND VAD WIND PROFILE SHOWING 40KT AT 4000 FT. THESE WINDS WILL MIX DOWN AS SYSTEM EXITS TO THE NE THIS MORNING. BUFKIT SOUNDINGS AND RUC WIND GUST FORECASTS CONFIRM THIS BY INDICATING GUSTS OVER 45 MPH POSSIBLE ACROSS THE FA. THUS WILL EXPAND WIND ADVISORY TO ENTIRE FA. TEMPERATURES WILL FALL MOST OF THE DAY TODAY. 12Z TEMPERATURES WILL BE THUS BE THE HIGH TEMPERATURE FOR MANY AREAS TODAY. BASED ON CURRENT TRENDS WILL MAKE BEST EDUCATED GUESS AS TO WHAT THIS WILL BE...AND THIS ENDS UP WARMER THAN MAV NUMBERS INDICATE PER GFS/S FASTER SYSTEM. TONIGHT WINDS WILL DIMINISH AND SKIES WILL BE PARTLY CLOUDY AS COLDER DRIER AIR WORKS IN. MOS TEMPERATURES ARE SIMILAR MOST AREAS AND LOOK OK...BUT MAV LOOKS A BIT WARM IN THE SOUTH. WILL CUT SOME THERE. WILL KEEP EXTENDED DRY FOR NOW BUT GFS CONTINUES TO INDICATE A SMALL CHANCE FOR SNOW ON TUE AND THU/FRI. NOT SURE ABOUT MOISTURE AVAILABILITY ON TUE AND WILL LET LATER SHIFTS HAVE A LOOK AT THU/FRI. && .IND WATCHES/WARNINGS/ADVISORIES... WIND ADVISORY FROM 8 AM TO 7 PM EST FOR ENTIRE FORECAST AREA. && $$ PUBLIC...CS AVIATION...CO in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 221 PM MST FRI DEC 1 2006 .DISCUSSION...FORECAST PROBLEMS WILL BE LOW PRECIPITATION CHANCE TONIGHT FOLLOWED BY HIGH TEMPERATURES THROUGH MONDAY. SATELLITE SHOWING A PROGRESSIVE FLOW PATTERN FROM THE CENTRAL THROUGH NORTH AMERICA. PATTERN IS A LITTLE MORE AMPLIFIED FROM THE EASTERN PACIFIC TO OVER THE UNITED STATES AND CANADA. STRONG SYSTEM OVER SOUTHERN CANADA IS MOVING SOUTH. AT JET LEVEL...MODELS DID FINE EXCEPT IN ONE AREA. AT 12Z...THE GFS AND NAM WERE TOO STRONG/TOO FAR NORTHEAST WITH THE JET SEGMENT OVER NORTHERN UTAH AND WESTERN COLORADO. THE UKMET WAS THE BEST. BY 18Z THE MODELS WERE MATCHING UP WITH REALITY BETTER. AT MID LEVELS... SATELLITE WOULD INDICATE MODELS ARE NOT STRONG ENOUGH IN THE CENTRAL PACIFIC. ESPECIALLY BY 18Z...MODELS WERE NOT STRONG/AMPLIFIED ENOUGH WITH THE TWO STRONG PACIFIC SYSTEMS...ESPECIALLY THE THE ONE NEAR 180 WEST. THE GFS WAS DOING BETTER WITH THE EASTERN MOST SYSTEM WITH THE UKMET THE BEST NEAR 180 WEST. MODELS WERE CLOSE ON SOUTHERN CANADIAN SYSTEM. HOWEVER...GFS STARTED OUT THE BEST. GOING BY THE HEIGHT ANALYSIS...MODELS WERE NOT AMPLIFIED ENOUGH AND NOT FAR ENOUGH EAST. THE GFS DID BETTER WITH THE SOUTHERN CANADIAN SYSTEM. AT LOW LEVELS...MODELS WERE HAVE THEIR TROUBLES. THEY WERE NOT CATCHING THE LEE TROUGH CURRENTLY GOING ON WITH THE NAM...ECMWF... AND RUC13 DOING THE BEST. ON THE TEMPERATURES...THE GFS FOLLOWED CLOSELY BY THE UKMET AND ECMWF WERE DOING THE BEST. BECAUSE OF HOW IT IS DOING WITH THE JET AND OUT OVER THE CENTRAL PACIFIC LIKE THE UKMET THE BEST WITH TIME...ESPECIALLY ALOFT. THE GFS IS CLOSE IN ITS SOLUTION WITH THE UKMET ALOFT AS FAR AS THE AMPLIFICATION OF THE PATTERN AND WHAT DOES WITH THE EASTERN MOST PACIFIC SYSTEM. THE NAM IS THE MOST AMPLIFIED BUT NOT THAT MUCH WORSE. SO OVERALL WILL USE A BLEND OF THE UKMET...GFS...AND RUC13. TONIGHT/SATURDAY...FIRST WHAT TO DO WITH PRECIPITATION CHANCES TONIGHT. AREA IS IN LEFT REAR QUADRANT OF JET THROUGH THE NIGHT. DECENT FRONTOGENETIC FORCING REMAINS UNTIL BETWEEN 06Z AND 12Z. CURRENTLY HAVE FLURRIES IN THE SOUTHWEST PORTION OF THE AREA...AND THIS MESHES WELL WITH CURRENT ACTIVITY. HOWEVER...WILL EXTEND IT THROUGH THE NIGHT BASED ON THE FORCING AND SOUNDINGS IN THAT AREA. MINS WILL BE WARMER IN THE SOUTHWEST WITH THE CLOUDS. RAISE THE MINS A LITTLE HERE. IF CLOUDS GO AWAY QUICKER...THEN MINS WILL HAVE TO BE LOWERED. STRONG NORTH TO SOUTH JET PUNCHING INTO THE NORTH CENTRAL PORTION OF THE COUNTRY BEHIND THE EXITING TROUGH. VERY COLD AIR ALOFT MOVING INTO THE AREA WITH THE COLD POOL OVER OR NEAR THE NORTHWEST HALF OF THE AREA. CLOUD COVER THICKENS UP DURING THE DAY. AIR MASS IS REALLY DRY AND THE TQ INDEX DOES NOT SUPPORT ANY INSTABILITY SHOWERS BUT WILL HAVE SOME CLOUD COVER. BEFORE CLOUD COVER ARRIVED TODAY... TEMPERATURES WARMED UP NICELY...EVEN IN SNOW COVERED AREAS. SO BASED ON THAT...WILL MAKE THE ASSUMPTION THAT THE SNOW FIELD OVER US WILL NOT HAVE MUCH IMPACT...ESPECIALLY LIKE WHAT THE 2 METERS HAVE. 2 METERS ALSO LOOK TO HANG ONTO THE SNOW FIELD AND COLD TEMPERATURES TOO LONG AS WELL. DESPITE THAT THE NUMERICAL GUIDANCE IS PRETTY COLD. 850 MB TEMPERATURES SUPPORT CURRENT FORECAST OF MAXES AND WILL CHANGE LITTLE IF ANY. SATURDAY NIGHT/SUNDAY...COLD POOL ALOFT MOVES ACROSS DURING THE NIGHT. LEFT FRONT QUADRANT OF THE NORTH TO SOUTH JET MOVES INTO THE AREA DURING THE DAY. AS A RESULT HIGHER LEVEL CLOUD COVER INCREASES BY LATE MORNING OVER THE NORTH AND MOVES SOUTH THROUGH THE AFTERNOON. LOW LEVELS REMAIN DRY. THERE IS STILL A DIFFERENCE BETWEEN MODELS AS FAR AS WINDS AND TEMPERATURES. THE GFS IS THE WARMEST AND SWINGS THE WINDS ARE TO SOUTHWEST QUICKLY AND RATHER STRONGLY. THE UKMET DOES THIS BUT IS NOT AS STRONG AND IS SUPPORTED BY THE RUC13. THE NAM KEEPS WINDS OUT OF A NORTHERLY DIRECTION. CONSIDERING THE FLOW ALOFT IS NORTH TO NORTH NORTHWEST...THINK THE SOUTHWEST WINDS LOOK SUSPECT. HOWEVER...THE NAM 850 MB TEMPERATURES STILL LOOK TOO COLD. THE UKMET IS SLIGHTLY COLDER THE GFS. WILL RAISE MAXES SOME BUT WILL KEEP BELOW GUIDANCE. SUNDAY NIGHT/MONDAY...RIDGING AND DOWNSLOPE WINDS PUSH INTO THE AREA DURING THE DAY. ONCE AGAIN CLOUD COVER INCREASES THROUGH THE DAY WITH THE GFS THE MOST AGGRESSIVE. WILL GO WITH THE WARMER AND LESS CLOUD SOLUTION AND DID RAISE MAXES A FEW DEGREES. TUESDAY THROUGH FRIDAY...MODELS NOT TOO DIFFERENT. GENERAL PATTERN REMAINS THE SAME WITH SOME KIND OF NORTHERLY COMPONENT ALOFT WITH TROUGH OFF THE WEST COAST...RIDGE OVER WESTERN NORTH AMERICA...AND MEAN TROUGH OVER THE EASTERN PORTION OF THE COUNTRY. TUESDAY WILL BE THE TRICKIEST WITH MODELS SHOWING A DIFFERENCE IN WHEN THE FRONT COMES THROUGH. GFS IS A LITTLE FASTER. THE FIRST BOUNDARY MAY NOT BE THE COLDEST AIR INITIALLY BUT WITH NORTHERLY SURFACE WINDS TEMPERATURES WILL NOT WARM UP MUCH. EVEN THOUGH GFS IS STRONGER ALOFT WITH SYSTEM COMING THROUGH WEDNESDAY AND THURSDAY...ESSENTIALLY IT AND THE ECMWF SHOW A FAIRLY STRONG SYSTEM MOVING THROUGH. AS A RESULT...COLD SURFACE RIDGE WILL SAG IN OVER THE AREA THROUGH THIS TIME...AND LIKE THE HPC DEPICTION. WILL GO COOLER THAN GUIDANCE. THURSDAY NIGHT AND FRIDAY SURFACE RIDGE PULLS AWAY WITH RIDGING ALOFT. THIS WILL ALLOW A DECENT WARMUP AND WILL GO NEAR TO SLIGHTLY ABOVE GUIDANCE. MOISTURE AT LOW LEVELS LOOKS TO STAY CUTOFF. HOWEVER...WITH THE FRONTAL PASSAGES AND LIFT ALOFT COULD SEE SOME VERY SPOTTY PRECIPITATION BUT NOT WORTH MENTIONING THIS FAR OUT. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ BULLER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1023 AM MST FRI DEC 1 2006 .UPDATE... SEVERAL FORECAST CONCERNS FOR THE SHORT TERM...INCLUDING CLOUDS...TEMPS AND WX/POPS. 12Z RUC/NAM INDICATING WEAK H5 VORT MAX SLIDING SOUTH ACROSS THE CWA. FAIRLY STRONG/PERSISTENT AREA OF H650 MB FRONTOGENESIS AHEAD OF THIS FEATURE. LOW LEVELS VERY DRY...AS EVIDENCED BY KLBF/KDEN 12Z RAOBS. MODELS/RAOBS INDICATE WEAK AREA OF ELEVATED INSTABILITY BETWEEN H7 AND H6...WHICH COINCIDES WELL WITH RETURNS ON RADAR. INITIALLY THOUGHT BOUNDARY LAYER TOO DRY TO SUPPORT PRECIP REACHING THE GROUND...BUT 15Z OB AT KAKO HAD -SN (WITH AN 8C DEWPOINT DEPRESSION). DRY AIR/SHOWERY NATURE OF THE PRECIP WILL LIKELY LIMIT AMOUNTS...BUT SCATTERED FLURRIES LOOK TO BE A GOOD BET ACROSS THE WEST. SNOW ALSO APPEARS TO BE HAVING A MINIMAL IMPACT ON TEMPS...AS TEMPS HAVE QUICKLY ROSE ABOVE FREEZING ACROSS MUCH OF THE WEST. USING AN AVG MIXED DEPTH OF 500M WOULD YIELD TEMPS IN THE UPPER 30S AND LOW 40S...WHICH APPEAR REASONABLE. UPPED TEMPERATURES SEVERAL DEGREES IN THE SNOW COVERED AREAS TO COVER THIS. MAIN TEMP CONCERN IS ALSO INCREASING CLOUD COVER FROM THE NORTH. A FEW AREAS (NAMELY KITR/KGLD/KCBK) WILL LIKELY SEE THEIR MAX TEMPS BY 19Z BEFORE CLOUD COVER COMES AND LIMITS HEATING. WITH THIS IN MIND...WILL ONLY GO A FEW DEGREES HIGHER THAN CURRENT TEMPS. DESPITE WARMER TEMPS...PREVIOUSLY MENTIONED DRY LAYER WOULD ALLOW ANY PRECIP TO QUICKLY WET BULB TO FLURRIES...SO DO NOT ANTICIPATE ANY MIXED PRECIP. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ JRM ks AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TAUNTON MA ISSUED BY NATIONAL WEATHER SERVICE UPTON NY 1120 AM EST FRI DEC 1 2006 ...DAMAGING WINDS STILL EXPECTED ACROSS MUCH OF SOUTHERN NEW ENGLAND THIS EVENING AND INTO THE NIGHT... .MEDIA NOTE...START TIME OF WARNINGS/ADVISORIES HAS BEEN PUSHED TO THIS EVENING. .SYNOPSIS... UNSEASONABLY MILD THIS AFTERNOON AND EVENING...FOLLOWED BY A COLD FRONTAL PASSAGE LATE THIS EVENING ACCOMPANIED BY LOW TOPPED CONVECTION AND POTENTIALLY DAMAGING WINDS. TEMPS BACK TO NEAR NORMAL TEMPS BY SUNDAY AND THEN BELOW NORMAL EARLY NEXT WEEK. COASTAL LOW MAY CLIP SOUTHEASTERN NEW ENGLAND SUNDAY NIGHT IN EARLY MONDAY. && .SHORT TERM /THIS AFTERNOON THROUGH SUNDAY/... AS OF 10 AM...TEMPS IN THE LOWER TO MID 60S WITH BACKDOOR FRONT JUST INTO SOUTHEAST MAINE. THIS FRONT HAS ADVANCED SOUTHWEST INTO THE TROPICAL SOUTHWESTERLY FLOW. BASED ON LATEST RUC AND TRENDS IN KGYX VELOCITY FIELDS AND SURFACE OBSERVATIONS DON/T EXPECT THIS TO GET FURTHER SOUTH THAN PORTSMOUTH. LEADING EDGE OF THE FRONT EXPECTED TO MIX OUT AS IT PUSHED SOUTHWEST. THUS BASICALLY EXPECTING IT TO STAY IN KGYX/S COUNTY WARNING AREA. CLOUDS REMAIN THROUGH THE DAY...THOUGH DON/T BE SURPRISED TO SEE A BRIEF BREAK. TEMPS SHOULD SLOWLY CLIMB THROUGH THE AFTERNOON...BUT FALL JUST SHORT OF THE RECORD. PASSING SHOWERS REMAIN LIKELY...THOUGH NOTHING OF MUCH SIGNIFICANCE AS MAIN SHOWERS IS NOW PASSING ACROSS EASTERN MASS. MAIN EVENT IS THIS EVENING. INTERPRETATION OF LATEST DATA SUGGEST THAT THERE IS A NARROW OPPORTUNITY FOR 50 KT GUST JUST AHEAD OF THE FRONT. THIS PERIOD WILL ALSO BE ACCOMPANIED WITH LOW TOPPED CONVECTION. TIMING IS FROM 01Z (8 PM) FOR THE WESTERN SECTIONS UNTIL MIDNIGHT IN THE EAST AS THE MAIN LOW PRESSURE SYSTEM TRACKS INTO NORTHERN NEW ENGLAND. STRONG LOW LEVEL JET OF 70 KNOTS TRAVERSE THE REGION AND THUS PRESENTS THE DANGER. WITH SURFACE DEWPOINTS NEAR 60 SHOULD RESULT IN A COUPLE HUNDRED J/KG OF CAPE. WITH SO MUCH FORCING THIS SHOULD BE ENOUGH TO GET A NARROW COLD FRONTAL RAIN BAND WITH EMBEDDED THUNDERSTORMS TO DEVELOP JUST AHEAD OF THE FRONT. ALTHOUGH THE INVERSION WILL KEEP THE STRONGEST WINDS FROM MIXING DOWN...THE SHOWER AND THUNDERSTORM ACTIVITY IN THE WARM SECTOR SHOULD BE ABLE TO BRING DOWN 45 TO 55 MPH WIND GUSTS. THEREFORE...ALL AREAS TO THE SOUTH OF THE MASSACHUSETTS TURNPIKE REMAIN IN A HIGH WIND WARNING. THE AREAS TO THE NORTH WILL BE CHANGED FROM A WATCH TO AN ADVISORY. INTENSE LOW LEVEL SHEAR SUPPORTS ISOLATED TORNADOES...ESPECIALLY WESTERN SECTIONS. THUS...WATCHING FOR ROTATION IN ANY CELLS THAT DEVELOP. WITH CELL MOTION AT NEARLY 70 KTS...ANY POSSIBLE TOR SHOULD BE SHORT LIVED...BUT COVER A MODERATELY LONG SWATH OF AREA. SEE STORM PREDICTION CENTER PRODUCTS FOR DETAILS. THE SHOWER AND THUNDERSTORM ACTIVITY WILL QUICKLY COME TO AN END THIS EVENING. HOWEVER...COLD ADVECTION AND THE CHANGE IN PRESSURE WILL BRING THE POTENTIAL FOR 45 TO 55 MPH WESTERLY WIND GUSTS FOR A FEW HOURS AS THE COOLER AIR MOVES INTO THE REGION. IT WILL TAKE SOMETIME FOR THE REAL CHILLY AIR TO MOVE INTO OUR REGION...SO WILL FOLLOW MAV LOWS WITH READINGS EXPECTED TO FALL INTO THE LOW TO MID 40S ACROSS MOST LOCATIONS...WITH SOME 30S IN THE HIGHER TERRAIN. TIGHT GRADIENT PERSISTS SATURDAY INTO SAT NIGHT. WITH FAST WEST FLOW AND HIGH PRESSURE BUILDING...LOOKS DRY THRU WEEKEND. SUNDAY...WINDS ABATE AS THE HIGH MOVES ACROSS LOCAL AREA AND OFFSHORE. TEMPS NEAR NORMAL. && .LONG TERM /MONDAY THROUGH FRIDAY/... PROGRESSIVE SHORTWAVE MOVES ACROSS NEW ENG...AND LOW PRESSURE DEVELOPS WELL SOUTHEAST OF ACK. MOST GFS ENSEMBLE MEMBERS PROG LOW POSITION OFFSHORE WITH THIS LOW...SO COASTAL LOCALES...EXTREME SE WILL BE THE MOST SUSCEPTIBLE TO ANY RAIN/SNOW. VERY QUICK LOOK AT 12Z NAM INDICATES A POSITION MUCH CLOSER TO THE COAST. WILL HAVE TO KEEP AN EYE ON LATER RUNS...BUT FOR NOW...WILL LEAN TOWARD ENSEMBLE...HPC AND KEEP LOW FURTHER OFFSHORE. THIS STORM EXITS QUICKLY AND NEXT SHORTWAVE SWINGS ACROSS GRTLKS REGION TOWARD NEW ENGLAND LATER TUESDAY. SOME SNOW SHOWERS ACCOMPANY THIS LOW LATE TUESDAY AND TUESDAY NIGHT. THIS TROUGH AXIS MOVES EAST AS WEDNESDAY PROGRESSES AND STRONG HIGH PRESSURE BUILD ACROSS MID WEST BEHIND COLD FRONTAL PASSAGE. TEMPS MUCH MORE SEASONABLE THROUGH THE EXTENDED PERIOD. && .AVIATION... WARM SECTOR IS OVER THE REGION WITH STRONG COLD FRONTAL PASSAGE THIS EVENING. GENERALLY MVFR WITH AREAS OF IFR CONDITIONS THIS AFTERNOON. PASSING SHOWERS WILL LOWER VSBY INTO THE 3-5SM CATEGORY AT TIME. MAIN EVENT OF LOW LEVEL WIND SHEAR AND CONVECTION OCCURS FROM 00 TO 06Z. LOW LEVEL JET DOES DEVELOP BY LATE AFTERNOON RESULTING IN POSSIBLE COMPRESSION CONCERNS. FOLLOWING FRONT...EXPECT GUSTS OF 35 TO 45 KTS. THESE DO DIMINISH TO 25 TO 35 KT IN VFR CONDITIONS ON SATURDAY...BUT GENERAL AVIATION SHOULD EXPECT AT LEAST MODERATE LOW LEVEL MECHANICAL TURBULENCE ON SATURDAY. SEE AVIATION WEATHER CENTER FORECASTS FOR DETAILS. && .MARINE... NO CHANGES ON THE MARINE AT THIS TIME. GALE FORCE WIND GUSTS EXPECTED TO DEVELOP ACROSS THE WATERS LATE THIS AFTERNOON. WE ARE VERY CONFIDENT IN STRONG GALE FORCE WIND GUSTS TO 45 KNOTS ACROSS ALL WATERS...ESPECIALLY POST FRONTAL. HAVE ALSO GONE WITH STORM WARNINGS FOR OUR SOUTHERN OUTER-WATERS AND NANTUCKET SOUND TONIGHT WHERE NAM/GFS BOTH INDICATE 50 KNOT WIND GUSTS FOR NANTUCKET. SEAS WILL QUICKLY BUILD TO BETWEEN 13 AND 17 FEET ACROSS OUR SOUTHERN OPEN WATERS TONIGHT AS THE WINDS RAPIDLY INCREASE. IN LONGER TERM...GALE FORCE WINDS WILL LINGER SAT OVER MOST OF WATERS BEFORE WINDS AND SEAS FINALLY DIMINISH SAT NIGHT. NEXT SYSTEM PASSING WELL SE OF NEW ENGLAND MON WILL BRING INCREASING WINDS AND SEAS... BUT MORE LIKELY STAYING WITHIN SMALL CRAFT ADVISORY RANGE AT THIS TIME. && .HYDROLOGY... RAINFALL AMOUNTS SHOULD GENERALLY BE ON THE ORDER OF 0.25 AND 0.75 INCHES. HOWEVER...LOCALLY HIGHER AMOUNTS SHOULD OCCUR IN THE CONVECTION WITH SOME 1 TO 2 INCH AMOUNTS POSSIBLE. THE HEAVIEST RAIN MAY FALL ACROSS SOUTHERN MA AND NORTHERN MA AS THE BACKDOOR COLD FRONT PROVIDES SOME ADDITIONAL CONVERGENCE. POOR DRAINAGE STREET FLOODING WILL OCCUR WITH THE HEAVY LINE OF SHOWERS THIS EVENING...BUT NO SERIOUS FLOODING PROBLEMS ARE EXPECTED. && .CLIMATE... RECORD HIGHS FRI LOOK SAFE AS MOST OF THEM ARE AROUND 70F...EXCEPT WORCESTER WHICH IS IN MID 60S. RECORDS WARM MINS / RECORD HIGHS FOR TODAY ARE AS FOLLOWS... BDL - HARTFORD WINDSOR LOCKS.... 47 IN 1991 / 70 IN 2001 BOS - BOSTON LOGAN AIRPORT...... 51 IN 2001 / 71 IN 2001 ORH - WORCESTER AIRPORT......... 50 IN 1934 / 64 IN 2001 PVD - PROVIDENCE TF GREEN....... 49 IN 2001 / 71 IN 2001 PRELIMINARY NOVEMBER CLIMATE SUMMARIES HAVE BEEN ISSUED. IT CERTAINLY WAS A WARM MONTH AND WAS IN THE TOP 5 FOR ALL FOUR LONG TERM CLIMATE SITES. AVERAGE MONTHLY TEMPERATURES ARE AS FOLLOWS... PVD - 49.2 DEGREES. 2ND WARMEST ON RECORD...BEHIND 49.8 IN 1948. BOS - 49.1 DEGREES. 4TH WARMEST ON RECORD. BDL - 46.8 DEGREES. TIES FOR 4TH WARMEST ON RECORD. ORH - 45.9 DEGREES. WARMEST ON RECORD...AHEAD OF 45.2 IN 1975. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...HIGH WIND WARNING FROM 5 PM THIS AFTERNOON TO 5 AM EST SATURDAY FOR CTZ002>004. MA...WIND ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM EST SATURDAY FOR MAZ005>007-014-026. HIGH WIND WARNING FROM 5 PM THIS AFTERNOON TO 5 AM EST SATURDAY FOR MAZ002>004-008>013-015>024. NH...WIND ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM EST SATURDAY FOR NHZ011-012-015. RI...HIGH WIND WARNING FROM 5 PM THIS AFTERNOON TO 5 AM EST SATURDAY FOR RIZ001>008. MARINE...STORM WARNING FROM 6 PM THIS EVENING TO 11 AM EST SATURDAY FOR ANZ232-254-255. GALE WARNING FROM 6 PM THIS EVENING TO 6 PM EST SATURDAY FOR ANZ231-233>235-237-250. GALE WARNING FROM 6 PM THIS EVENING TO 1 PM EST SATURDAY FOR ANZ230-236. && $$ SHORT TERM...TONGUE/OKX LONG TERM....WICHROWSKI/OKX ma AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 948 PM EST FRI DEC 1 2006 .UPDATE... CONCERNS FOCUS ON LES HEADLINES TONIGHT. WATER VAPOR LOOP AND RUC ANALYSIS SHOWS A VIGOROUS SHORTWAVE/CLOSED MID-LVL LOW LIFTING NE INTO ERN ONTARIO WHILE ANOTHER SHORTWAVE IS ROTATING EAST INTO NRN MN. MOIST LOW-LEVEL NRLY FLOW ON BACKSIDE OF SYSTEM OVER ERN ONTARIO COMBINED WITH -16C TEMPS AT BASE OF INVERSION NEAR 800 MB RESULTING IN LES BANDS OVER NCNTRL LAKE SUPERIOR WITH LAKE DELTA-T'S IN EXCESS OF 20C. THESE BANDS HAVE BECOME MORE ROBUST THIS EVENING OVER MQT AND WRN ALGER COUNTIES WITH INCREASED LOW-LEVEL CONVERGENCE FROM WINDS BACKING MORE NW OVER LAND. NOT MUCH ORGANIZATION TO LES BANDS BUT THERE IS GENERALLY A GOOD DEAL OF 20+ DBZ RETURNS WITH A FEW SPOTS OF 30+ DBZ ON RADAR. BANDS COULD ALSO BE AIDED BY WEAK MID-LVL Q-VECT CONV FROM SHORTWAVE MOVING IN FROM THE NRN PLAINS. MESOSCALE MODELS SUGGEST BEST CONVERGENCE WILL SHIFT PARALLEL TO THE LAKE SUPERIOR SHORELINE OVERNIGHT AS WINDS WEAKEN AND BACK MORE WRLY. SO...EXPECT A MORE DOMINANT BAND TO SET UP ALONG THE LAKE SUPERIOR SHORELINE IN MQT COUNTY AND THEN SHIFT INTO THE MUNISING AREA TOWARD 12Z. WILL CONTINUE THE ADVISORIES FOR MQT AND ALGER COUNTIES FOR THE OVERNIGHT HOURS WITH 3-6 INCHES OF ADDITIONAL ACCUMULATION EXPECTED MAINLY OVER HIGHER TERRAIN FROM BIG BAY THROUGH NEGAUNEE AND FROM SKANDIA OVER TO WETMORE. CONVERGENCE BAND FROM REMNANTS OF MESOLOW OVER WRN LAKE SUPERIOR STILL AFFECTING KIWD AREA AS NOTED ON KDLH RADAR. MESOSCALE MODELS SUGGEST THIS CONVERGENCE BAND SHOULD LIFT NE TOWARD THE KEWEENAW PENINSULA TOWARD 12Z AND PERHAPS DROP ANOTHER QUICK INCH OR TWO OF SNOW OVER FAVORED LOCATIONS OF THE WEST. ELSEWHERE...EXPECT JUST SCT LIGHT SNOW SHOWERS OR FLURRIES OVERNIGHT AS WINDS WILL CONTINUE TO BACK WRLY. && .DISCUSSION... NEXT 2 DAYS OFFER SIGNIFICANT FCST CHALLENGES WHICH ALL REVOLVE AROUND LES. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VERY IMPRESSIVE SHORTWAVE/CLOSED MID LEVEL LOW MOVING ACROSS SE LWR MI. INTENSITY IS REVEALED BY THE 12Z KILX SOUNDING WHICH INDICATED A WHOPPING 12HR 500MB HEIGHT FALL OF 270M. TO THE W...A CLOSED MIDLEVEL LOW WAS ALONG THE ND/SASKATCHEWAN/MANITOBA BORDER AND A SHORTWAVE TROF EXTENDED FROM THE LOW INTO MN. SOME -SN WAS ASSOCIATED WITH SHORTWAVE. SNOW SHIELD ON NW SIDE OF SYSTEM OVER LWR MI HAS BRUSHED THE ERN FCST AREA THIS AFTN...ROUGHLY E OF A KESC TO AU TRAIN LINE. DESPITE NE WINDS...LES INTO NCNTL UPPER MI HAD BEEN ALMOST NONEXISTENT THRU EARLY AFTN...AND LATE MORNING TAMDAR SOUNDING FROM KSAW EXPLAINED WHY. TEMPS WERE JUST COLD ENOUGH FOR LES...BUT INVERSION WAS BASED AT 911MB OR 2.9KFT AGL WITH SHARP DRYING ABOVE IT. WITH INFLUX OF DEEP MOISTURE IN THE LAST COUPLE OF HRS...LES HAS DEVELOPED. TO THE W...SLIGHTLY COLDER AIRMASS AND LOW-LEVEL CONVERGENCE WITH INDICATIONS OF A MESOLOW CIRCULATION PER SFC OBS A FEW HRS AGO TOWARD APOSTLES/KDLH IS SUPPORTING BETTER LES OVER FAR WRN LAKE SUPERIOR. TOO MUCH SHEAR BTWN THE SFC AND 4KFT PER KDLH VAD WIND PROFILE PREVENTED ORGRANIZED MESOLOW STRUCTURE OF LES. SNOW THAT HAS MOVED INTO THE ERN FCST AREA WILL PULL OUT DURING THE EARLY EVENING. NOT EXPECTING MUCH MORE THAN 1 INCH OR SO OF ADDITIONAL ACCUMULATION. OTHERWISE...FIRST CONCERN IS ONGOING LES ADVY FOR MARQUETTE/ALGER TONIGHT. 12Z NAM ACTUALLY HAD A NICE HANDLE ON THE TEMP/MOISTURE PROFILE OVER NCNTRL UPPER MI THIS MORNING AS FCST SOUNDING COMPARED QUITE WELL TO LATE MORNING TAMDAR SOUNDING FROM KSAW. AS IN THE LATEST AND PREVIOUS GFS/NAM RUNS AND LATEST RUC...COLUMN WILL BE MOISTENING (AND IT HAS RECENTLY) AS WRN FRINGE OF MOISTURE SHIELD ASSOCIATED WITH LWR MI SYSTEM EXPANDS TO CNTRL UPPER MI...AND 850MB TEMPS FALL TO AROUND -12C. IN ADDITION... SHORTWAVE OVER MN WILL REACH WRN UPPER MI THIS EVENING...PROVIDING FORCING TO HELP RAISE INVERSION HEIGHTS TO AROUND 7KFT. AT THE LOW-LEVELS...NICE AREA OF LOW-LEVEL CONVERGENCE IS INDICATED BY RUC13/NAM ACROSS SCNTRL LAKE SUPERIOR TO THE SHORELINE OF NCNTRL UPPER MI (WINDS BACK NRLY OVER LAKE SUPERIOR AND MORE WRLY OVER THE LAND). SO...IT APPEARS CONDITIONS WILL BE QUITE FAVORABLE FOR LES AND WILL HOLD ONTO ADVYS FOR MARQUETTE/ALGER TONIGHT. AREAS THAT RECEIVE ADVY LEVEL SNOW AMOUNTS WILL PROBABLY BE LIMITED TO WHERE ANY DOMINANT BANDS DEVELOP...AND THERE MAY BE ONLY ONE OF THEM. TO THE W...CONVERGENCE AREA OVER FAR WRN LAKE SUPERIOR IS TO BECOME ORIENTED IN A WNW-ESE BAND AND LIFT NE THRU THE NIGHT. PROGRESSION SHOULD REMAIN FAST ENOUGH TO PRECLUDE THE NEED FOR AN ADVY FOR GOGEBIC/ONTONAGON AS CONVERGENCE SHIFTS TO THE KEWEENAW LATE. EXTREMELY CHALLENGING FCST SHAPING UP FOR SAT/SUN. IN THE BIG PICTURE...MIDLEVEL LOW/TROFFING TO W WILL ONLY DRIFT E WITH AXIS REACHING UPPER MI SUN. END RESULT WILL BE A PROLONGED PERIOD OF AT LEAST WEAK FORCING AS INDICATED BY 850-500MB QVECTOR PROGS...AND THERE WILL BE A DEEP MOISTURE PROFILE AS SHOWN BY NAM/GFS FCST SOUNDINGS. MEANWHILE...850MB TEMPS LOWER FROM AROUND -12C SAT TO -16C BY LATE SUN AFTN. SO THERE WILL BE MORE THAN ENOUGH INSTABILITY FOR LES EVEN WITHOUT SYNOPTIC FORCING. WHAT HAPPENS AT THE LOW-LEVELS IS THE BIG PROBLEM. CONVERGENCE THAT DEVELOPS TONIGHT AS DISCUSSED ABOVE (OVER SCNTRL LAKE SUPERIOR AND THE WNW/ESE BAND OVER WRN LAKE SUPERIOR) WILL SHARPEN OVER THE RELATIVELY WARM WATERS OF THE LAKE UNDER SYNOPTIC FORCING. ANY MESOLOWS THAT DEVELOP ALONG THIS CONVERGENCE ZONE WILL ALTER THE CONVERGENCE PATTERN AND THUS SHIFT LES WHICH SHOULD BECOME QUITE INTENSE DUE TO ALL OF THE FAVORABLE FACTORS THAT ARE COMING TOGETHER. ALL MODEL SOLUTIONS SUPPORT SOME TYPE OF MESOLOW FORMING ALONG CONVERGENCE ZONE OVER WRN LAKE SUPERIOR. THE MESOLOW PRODUCED BY THE LOCALLY RUN HI RESOLUTION WRF CAUSES THE ERN PART OF THE CONVERGENCE BAND TO LIFT N OF THE KEWEENAW SAT. REGIONAL CANADIAN LEANS TOWARD THIS SOLUTION. RUC13/NAM DO NOT LIFT CONVERGENCE COMPLETELY N OF THE KEWEENAW. WITH LIGHT WINDS ALL THE WAY THRU 700MB FROM SAT AFTN THRU MUCH OF SAT NIGHT...THERE WON'T BE MUCH TO FORCE MOVEMENT OF LES ONSHORE. SO IT MAY TURN OUT THAT LES EVENTUALLY JUST STAYS MOSTLY OUT OVER THE WATER IN THE BOUNDARY LAYER CONVERGENCE ZONE OR WRAPPED MOSTLY AROUND WHATEVER MESOLOW OR MESOLOWS DEVELOP. WOULD LIKE TO MAKE A DECISION NOW ON THE LES WATCH FOR THE KEWEENAW SAT/SAT NIGHT...BUT THERE IS FAR TOO MUCH UNCERTAINTY TO HAVE CONFIDENCE IN GOING WITH ANYTHING OTHER THAN A WATCH RIGHT NOW. WITH DEEP MOISTURE/SYNOPTIC FORCING/PLENTY OF INSTABILITY AND NICE INTERSECTION OF UPWARD MOTION AND FAVORABLE DENDRITIC SNOW GROWTH TEMPS...VERY HVY LES WILL NO DOUBT OCCUR...BUT FOR NOW THE WHERE AND EXACTLY WHEN IS UNCERTAIN. HEAVY LES IN THE CONVERGENCE ZONE WILL SHIFT S AND IMPACT THE REST OF WRN AND NORTHERN UPPER MI LATER SAT NIGHT INTO SUN MORNING AS WINDS SHIFT N. HEADLINES WILL CERTAINLY BE NEEDED...BUT HOW FAST THE MAIN BAND OF SNOW MOVES WILL MAKE ALL THE DIFFERENCE IN SNOW AMOUNTS. TUE THRU FRI...TYPICAL EARLY DEC WEATHER WILL DOMINATE THRU THE MUCH OF THIS TIME FRAME WITH NEARLY CONTINUOUS...BUT SHIFTING LES...AND TEMPS MOSTLY BLO NORMAL AS GENERAL MEAN TROF POSITION WILL BE OVER ERN NAMERICA. AT THE VERY END OF THIS FCST PERIOD AND FARTHER DOWN THE ROAD...LOOKS LIKE A TRANSITION WILL OCCUR TO ZONAL FLOW WITH PACIFIC AIRMASSES ONCE AGAIN BECOMING DOMINANT. EARLY IN THE PERIOD...00Z ECWMF/CANADIAN/UKMET/06Z GFS ARE IN DECENT AGREEMENT ON A SHORTWAVE MOVING E OF THE UPPER LAKES TUE. GFS IS A BIT SLOWER ALOFT AND WITH THE ASSOCIATED SFC LOW EXITING THE UPPER LAKES. THIS IS A RECENT TREND WITH THE GFS...SO IT NEEDS TO BE CONSIDERED...BUT GIVEN THE MORE PROGRESSIVE LOOK OF THE OTHER MODELS...WILL TAKE A COMPROMISE APPROACH. SO...THERE SHOULD BE A PERIOD OF DECENT LES IN THE NW (POSSIBLY BRIEF NRLY) FLOW BEHIND SYSTEM INTO AT LEAST THE FIRST PART OF TUE DURING PERIOD OF CYCLONIC FLOW WITH 850MB TEMPS DIVING TO AROUND -17C. MUCH MORE UNCERTAINTY FOLLOWS WED THRU FRI WITH CONSIDERABLE TIMING DIFFERENCES IN SHORTWAVES MAINTAINING ERN TROF. PER HPC DISCUSSSION...WILL LEAN TOWARD 00Z ECMWF WHICH KEEPS MORE NRN STREAM DOMINANCE WITH ERN TROF PERSISTENCE. EVEN SO... SHORTWAVE TIMING UNCERTAINTIES WILL KEEP CONFIDENCE IN PCPN FCST LOW...IN PARTICULAR WHERE LES WILL PREVAIL EACH DAY. OUTSIDE OF LES...ANY SNOW WILL BE LIGHT WITH LACK OF MOISTURE. NEXT SHORTWAVE IS TENTATIVELY EXPECTED TO PASS EARLY WED...BRINGING A RESURGENCE OF LES IN NW FLOW (AND AGAIN POSSIBLY BRIEF NRLY FLOW) AS ANOTHER SHOT OF COLD AIR ARRIVES...DROPPING 850MB TEMPS DOWN TOWARD -20C. HIGH PRES WILL THEN SETTLE SE INTO THE CNTRL CONUS THU AND SLIP E TOWARD THE OHIO VALLEY FRI. WOULD THUS EXPECT A LIGHTER PURE LES REGIME TO PREVAIL THU FOR NW FLOW AREAS WITH A DIMINISHING TREND INTO FRI AS WINDS BACK WRLY AND TEMPS BEGIN TO MODERATE. && .MQT WATCHES/WARNINGS/ADVISORIES... LES ADVY MIZ005-006 TONIGHT. LES WATCH MIZ001-003 SAT-SAT NIGHT. && $$ VOSS (UPDATE) ROLFSON (PREV DISCUSSION) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 453 PM EST FRI DEC 1 2006 .DISCUSSION... NEXT 2 DAYS OFFER SIGNIFICANT FCST CHALLENGES WHICH ALL REVOLVE AROUND LES. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VERY IMPRESSIVE SHORTWAVE/CLOSED MID LEVEL LOW MOVING ACROSS SE LWR MI. INTENSITY IS REVEALED BY THE 12Z KILX SOUNDING WHICH INDICATED A WHOPPING 12HR 500MB HEIGHT FALL OF 270M. TO THE W...A CLOSED MIDLEVEL LOW WAS ALONG THE ND/SASKATCHEWAN/MANITOBA BORDER AND A SHORTWAVE TROF EXTENDED FROM THE LOW INTO MN. SOME -SN WAS ASSOCIATED WITH SHORTWAVE. SNOW SHIELD ON NW SIDE OF SYSTEM OVER LWR MI HAS BRUSHED THE ERN FCST AREA THIS AFTN...ROUGHLY E OF A KESC TO AU TRAIN LINE. DESPITE NE WINDS...LES INTO NCNTL UPPER MI HAD BEEN ALMOST NONEXISTENT THRU EARLY AFTN...AND LATE MORNING TAMDAR SOUNDING FROM KSAW EXPLAINED WHY. TEMPS WERE JUST COLD ENOUGH FOR LES...BUT INVERSION WAS BASED AT 911MB OR 2.9KFT AGL WITH SHARP DRYING ABOVE IT. WITH INFLUX OF DEEP MOISTURE IN THE LAST COUPLE OF HRS...LES HAS DEVELOPED. TO THE W...SLIGHTLY COLDER AIRMASS AND LOW-LEVEL CONVERGENCE WITH INDICATIONS OF A MESOLOW CIRCULATION PER SFC OBS A FEW HRS AGO TOWARD APOSTLES/KDLH IS SUPPORTING BETTER LES OVER FAR WRN LAKE SUPERIOR. TOO MUCH SHEAR BTWN THE SFC AND 4KFT PER KDLH VAD WIND PROFILE PREVENTED ORGRANIZED MESOLOW STRUCTURE OF LES. SNOW THAT HAS MOVED INTO THE ERN FCST AREA WILL PULL OUT DURING THE EARLY EVENING. NOT EXPECTING MUCH MORE THAN 1 INCH OR SO OF ADDITIONAL ACCUMULATION. OTHERWISE...FIRST CONCERN IS ONGOING LES ADVY FOR MARQUETTE/ALGER TONIGHT. 12Z NAM ACTUALLY HAD A NICE HANDLE ON THE TEMP/MOISTURE PROFILE OVER NCNTRL UPPER MI THIS MORNING AS FCST SOUNDING COMPARED QUITE WELL TO LATE MORNING TAMDAR SOUNDING FROM KSAW. AS IN THE LATEST AND PREVIOUS GFS/NAM RUNS AND LATEST RUC...COLUMN WILL BE MOISTENING (AND IT HAS RECENTLY) AS WRN FRINGE OF MOISTURE SHIELD ASSOCIATED WITH LWR MI SYSTEM EXPANDS TO CNTRL UPPER MI...AND 850MB TEMPS FALL TO AROUND -12C. IN ADDITION... SHORTWAVE OVER MN WILL REACH WRN UPPER MI THIS EVENING...PROVIDING FORCING TO HELP RAISE INVERSION HEIGHTS TO AROUND 7KFT. AT THE LOW-LEVELS...NICE AREA OF LOW-LEVEL CONVERGENCE IS INDICATED BY RUC13/NAM ACROSS SCNTRL LAKE SUPERIOR TO THE SHORELINE OF NCNTRL UPPER MI (WINDS BACK NRLY OVER LAKE SUPERIOR AND MORE WRLY OVER THE LAND). SO...IT APPEARS CONDITIONS WILL BE QUITE FAVORABLE FOR LES AND WILL HOLD ONTO ADVYS FOR MARQUETTE/ALGER TONIGHT. AREAS THAT RECEIVE ADVY LEVEL SNOW AMOUNTS WILL PROBABLY BE LIMITED TO WHERE ANY DOMINANT BANDS DEVELOP...AND THERE MAY BE ONLY ONE OF THEM. TO THE W...CONVERGENCE AREA OVER FAR WRN LAKE SUPERIOR IS TO BECOME ORIENTED IN A WNW-ESE BAND AND LIFT NE THRU THE NIGHT. PROGRESSION SHOULD REMAIN FAST ENOUGH TO PRECLUDE THE NEED FOR AN ADVY FOR GOGEBIC/ONTONAGON AS CONVERGENCE SHIFTS TO THE KEWEENAW LATE. EXTREMELY CHALLENGING FCST SHAPING UP FOR SAT/SUN. IN THE BIG PICTURE...MIDLEVEL LOW/TROFFING TO W WILL ONLY DRIFT E WITH AXIS REACHING UPPER MI SUN. END RESULT WILL BE A PROLONGED PERIOD OF AT LEAST WEAK FORCING AS INDICATED BY 850-500MB QVECTOR PROGS...AND THERE WILL BE A DEEP MOISTURE PROFILE AS SHOWN BY NAM/GFS FCST SOUNDINGS. MEANWHILE...850MB TEMPS LOWER FROM AROUND -12C SAT TO -16C BY LATE SUN AFTN. SO THERE WILL BE MORE THAN ENOUGH INSTABILITY FOR LES EVEN WITHOUT SYNOPTIC FORCING. WHAT HAPPENS AT THE LOW-LEVELS IS THE BIG PROBLEM. CONVERGENCE THAT DEVELOPS TONIGHT AS DISCUSSED ABOVE (OVER SCNTRL LAKE SUPERIOR AND THE WNW/ESE BAND OVER WRN LAKE SUPERIOR) WILL SHARPEN OVER THE RELATIVELY WARM WATERS OF THE LAKE UNDER SYNOPTIC FORCING. ANY MESOLOWS THAT DEVELOP ALONG THIS CONVERGENCE ZONE WILL ALTER THE CONVERGENCE PATTERN AND THUS SHIFT LES WHICH SHOULD BECOME QUITE INTENSE DUE TO ALL OF THE FAVORABLE FACTORS THAT ARE COMING TOGETHER. ALL MODEL SOLUTIONS SUPPORT SOME TYPE OF MESOLOW FORMING ALONG CONVERGENCE ZONE OVER WRN LAKE SUPERIOR. THE MESOLOW PRODUCED BY THE LOCALLY RUN HI RESOLUTION WRF CAUSES THE ERN PART OF THE CONVERGENCE BAND TO LIFT N OF THE KEWEENAW SAT. REGIONAL CANADIAN LEANS TOWARD THIS SOLUTION. RUC13/NAM DO NOT LIFT CONVERGENCE COMPLETELY N OF THE KEWEENAW. WITH LIGHT WINDS ALL THE WAY THRU 700MB FROM SAT AFTN THRU MUCH OF SAT NIGHT...THERE WON'T BE MUCH TO FORCE MOVEMENT OF LES ONSHORE. SO IT MAY TURN OUT THAT LES EVENTUALLY JUST STAYS MOSTLY OUT OVER THE WATER IN THE BOUNDARY LAYER CONVERGENCE ZONE OR WRAPPED MOSTLY AROUND WHATEVER MESOLOW OR MESOLOWS DEVELOP. WOULD LIKE TO MAKE A DECISION NOW ON THE LES WATCH FOR THE KEWEENAW SAT/SAT NIGHT...BUT THERE IS FAR TOO MUCH UNCERTAINTY TO HAVE CONFIDENCE IN GOING WITH ANYTHING OTHER THAN A WATCH RIGHT NOW. WITH DEEP MOISTURE/SYNOPTIC FORCING/PLENTY OF INSTABILITY AND NICE INTERSECTION OF UPWARD MOTION AND FAVORABLE DENDRITIC SNOW GROWTH TEMPS...VERY HVY LES WILL NO DOUBT OCCUR...BUT FOR NOW THE WHERE AND EXACTLY WHEN IS UNCERTAIN. HEAVY LES IN THE CONVERGENCE ZONE WILL SHIFT S AND IMPACT THE REST OF WRN AND NORTHERN UPPER MI LATER SAT NIGHT INTO SUN MORNING AS WINDS SHIFT N. HEADLINES WILL CERTAINLY BE NEEDED...BUT HOW FAST THE MAIN BAND OF SNOW MOVES WILL MAKE ALL THE DIFFERENCE IN SNOW AMOUNTS. TUE THRU FRI...TYPICAL EARLY DEC WEATHER WILL DOMINATE THRU THE MUCH OF THIS TIME FRAME WITH NEARLY CONTINUOUS...BUT SHIFTING LES...AND TEMPS MOSTLY BLO NORMAL AS GENERAL MEAN TROF POSITION WILL BE OVER ERN NAMERICA. AT THE VERY END OF THIS FCST PERIOD AND FARTHER DOWN THE ROAD...LOOKS LIKE A TRANSITION WILL OCCUR TO ZONAL FLOW WITH PACIFIC AIRMASSES ONCE AGAIN BECOMING DOMINANT. EARLY IN THE PERIOD...00Z ECWMF/CANADIAN/UKMET/06Z GFS ARE IN DECENT AGREEMENT ON A SHORTWAVE MOVING E OF THE UPPER LAKES TUE. GFS IS A BIT SLOWER ALOFT AND WITH THE ASSOCIATED SFC LOW EXITING THE UPPER LAKES. THIS IS A RECENT TREND WITH THE GFS...SO IT NEEDS TO BE CONSIDERED...BUT GIVEN THE MORE PROGRESSIVE LOOK OF THE OTHER MODELS...WILL TAKE A COMPROMISE APPROACH. SO...THERE SHOULD BE A PERIOD OF DECENT LES IN THE NW (POSSIBLY BRIEF NRLY) FLOW BEHIND SYSTEM INTO AT LEAST THE FIRST PART OF TUE DURING PERIOD OF CYCLONIC FLOW WITH 850MB TEMPS DIVING TO AROUND -17C. MUCH MORE UNCERTAINTY FOLLOWS WED THRU FRI WITH CONSIDERABLE TIMING DIFFERENCES IN SHORTWAVES MAINTAINING ERN TROF. PER HPC DISCUSSSION...WILL LEAN TOWARD 00Z ECMWF WHICH KEEPS MORE NRN STREAM DOMINANCE WITH ERN TROF PERSISTENCE. EVEN SO... SHORTWAVE TIMING UNCERTAINTIES WILL KEEP CONFIDENCE IN PCPN FCST LOW...IN PARTICULAR WHERE LES WILL PREVAIL EACH DAY. OUTSIDE OF LES...ANY SNOW WILL BE LIGHT WITH LACK OF MOISTURE. NEXT SHORTWAVE IS TENTATIVELY EXPECTED TO PASS EARLY WED...BRINGING A RESURGENCE OF LES IN NW FLOW (AND AGAIN POSSIBLY BRIEF NRLY FLOW) AS ANOTHER SHOT OF COLD AIR ARRIVES...DROPPING 850MB TEMPS DOWN TOWARD -20C. HIGH PRES WILL THEN SETTLE SE INTO THE CNTRL CONUS THU AND SLIP E TOWARD THE OHIO VALLEY FRI. WOULD THUS EXPECT A LIGHTER PURE LES REGIME TO PREVAIL THU FOR NW FLOW AREAS WITH A DIMINISHING TREND INTO FRI AS WINDS BACK WRLY AND TEMPS BEGIN TO MODERATE. && .MQT WATCHES/WARNINGS/ADVISORIES... LES ADVY MIZ005-006 TONIGHT. LES WATCH MIZ001-003 SAT-SAT NIGHT. && $$ ROLFSON mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 340 PM EST FRI DEC 1 2006 .SHORT TERM...TONIGHT AND SATURDAY POTENT WINTER STORM IS EXITING THE REGION WITH SOME ADDITIONAL WRAP AROUND MOISTURE TO PROVIDE A LITTLE ADDITIONAL SNOWFALL...HOWEVER... ANY ACCUMULATIONS WILL BE MINOR. SUBSIDENCE WILL QUICKLY SPREAD ACROSS THE STATE IN THE WAKE OF THIS SYSTEM (850-500 MB OMEGA OF -5 TO -10 UBAR/SEC) AND THIS SHOULD PROVIDE BREAKS IN THE OVERCAST OVERNIGHT FROM SOUTH TO NORTH. THIS WILL PLAY HAVOC WITH THE LOW TEMPERATURE FORECAST AS AROUND THE TRI CITIES THEY RECEIVED SOME SNOW COVER ALONG WITH UPSTREAM SNOW COVER YET THE REMAINDER OF THE CWA LITTLE IF ANY SNOW COVER TO FIND. THOUGHTS ARE FOR MIDDLE 20S FOR AN AVERAGE YET ISOLATED LOWER NUMBERS ACROSS THE SOUTHERN COUNTIES WHERE FAVORABLE SKIES SHOULD ALLOW FOR ADDITIONAL COOLING AND WHERE SNOW COVER IS IN PLACE. A MINOR SHORT WAVE RIDGE AXIS SLIPS ACROSS THE REGION SATURDAY WITH LINGERING LOWER LEVEL MOISTURE ERODING AND ALLOWING FOR PTSUNNY CONDITIONS IN ADVANCE OF THE CLIPPER. TEMPERATURES WILL LIKELY HAVE A TOUGH TIME REACHING THE MIDDLE 30S GIVEN UPSTREAM TEMPERATURES THIS AFTERNOON WERE HAVING A TOUGH TIME CLIMBING OUT OF THE 20S...SO SOME LAKE MODIFICATION WOULD SUPPORT LOWER 30S FOR THE CWA (EXCEPTION WOULD BE NEAR DETROIT WITH MIDDLE 30S). && .LONG TERM... A WEAK COLD FRONT WILL MOVE THROUGH SE MICHIGAN SATURDAY NIGHT AS PART OF THE CENTRAL CANADIAN LOW PRESSURE SYSTEM AND BRING WITH IT A SMALL CHANCE OF SNOW SHOWERS OR FLURRIES. MOISTURE WILL BE SHALLOW WITH THIS FRONT ACCORDING TO THE 12Z MODELS BUT THE AIR WILL BE COLD ENOUGH TO GET A BOOST OF MOISTURE FROM LAKE MICHIGAN AS IT MOVES THROUGH THE REGION. LAKE EFFECT WILL THEN REMAIN SHALLOW THROUGH THE DAY ON SUNDAY UNTIL THE UPPER TROUGH ASSOCIATED WITH THE CENTRAL CANADA LOW MOVES INTO LOWER MICHIGAN. THE UPPER SUPPORT WITH THIS WAVE WILL BE LAKE ENHANCED AND WILL SPREAD NUMEROUS SNOW SHOWERS INTO THE TRI CITIES AND NORTHERN THUMB, FOCUSED BY THE LOW LEVEL WIND FIELD, BUT WITH ACCUMULATION OF AN INCH OR LESS. EXPECT SCATTERED COVERAGE OVER THE REST OF SE MICHIGAN DURING THIS TIME. CLOSE ON THE HEELS OF THIS SYSTEM IS A POSSIBLE CLIPPER FOR MONDAY. THERE IS SOME SUPPORT FOR THE GFS SOLUTION FROM THE EURO AND CANADIAN MODELS REGARDING THIS FEATURE; BUT TIMING, STRENGTH, AND MOISTURE CONTENT UNCERTAINTY ARGUE AGAINST ANYTHING MORE THAN A CHANCE OF SNOW SHOWERS IN THIS FORECAST PACKAGE. THE TROUGH-RIDGE-TROUGH LONG WAVE PATTERN FROM THE EASTERN PACIFIC INTO EASTERN NORTH AMERICA WILL PERSIST DURING THE MIDDLE AND END OF NEXT WEEK. SMALLER SCALE UPPER WAVES WILL MOVE THROUGH THE PATTERN AND HELP MAINTAIN THE LONG WAVE TROUGH OVER THE GREAT LAKES, KEEPING OUR TEMPERATURES BELOW NORMAL THROUGH THE PERIOD AND GIVING US A SHOT AT SOME SNOW FROM TIME TO TIME. THESE INDIVIDUAL SHORT WAVES WILL BE DIFFICULT TO PIN DOWN SEVERAL DAYS IN ADVANCE WHICH SUPPORTS OUR GOING FORECAST WITH SOME MENTION OF SNOW EACH DAY THROUGH THURSDAY. AT THIS POINT, THE BEST CHANCE OF A DRY DAY WILL BE ON WEDNESDAY, BUT RATHER THAN REMOVE ANY CHANCE OF SNOW WE WILL JUST TAPER BACK THE POP FOR NOW. THERE IS SOME INDICATION IN THE GLOBAL MODELS OF THE LONG WAVE UPPER RIDGE MOVING CLOSER TO US BY FRIDAY. THIS WOULD HELP MORE FIRMLY RULE OUT A CHANCE OF SNOW HEADING INTO NEXT WEEKEND BUT WITH CONTINUED COLD TEMPERATURES. && .PREV DISCUSSION...ISSUED 1224 PM EST FRI DEC 1 2006 AVIATION... THE 17Z SURFACE ANALYSIS SHOWS ALMOST A DOUBLE SURFACE LOW...WITH AN AREA OF LOW PRESSURE NEAR PTK AND ANOTHER AREA NEAR ERIE PA. THE LOW NEAR PTK IS FORECAST TO LIFT INTO THE SOUTHERN BASIN OF LAKE HURON BY 21Z. THE BULK OF THE PRECIPITATION FOR THE REMAINDER OF THE AFTERNOON WILL BE TO THE NORTH AND WEST OF THE SURFACE LOW TRACK. HOWEVER...ADDITIONAL CONVECTIVE SHOWERS HAVE BEEN OCCURRING ACROSS THE REST OF SOUTHEAST MICHIGAN AND ACROSS NORTHERN INDIANA...ASSOCIATED WITH THE UPPER LEVEL LOW. THE PRECIPITATION WILL PERSIST ACROSS THE FORECAST AREA THROUGH 21Z...THEN QUICKLY COME TO AN END AS THE LOW MOVES OFF TO THE NORTHEAST. FIRST ISSUE WITH THE FORECAST THIS AFTERNOON AND EVENING WILL BE THE WIND. THE STRONGEST WINDS WILL OCCUR TO THE SOUTH OF THE LOW TRACK THIS AFTERNOON...WHICH WILL IMPACT THE DETROIT AREA. GUSTS ARE ALREADY APPROACHING 40 KNOTS NEAR THE OHIO BORDER. AS THE LOW PULLS OFF TO THE NORTHEAST...FNT AND MBS WILL EXPERIENCE THE STRONGER WINDS AFTER 21Z. THE NEXT CONCERN WILL BE THE CHANGE OVER TO SNOW. BASED ON LOW LEVEL THICKNESSES PER BOTH RUC AND NAM12...MBS SHOULD SEE PRECIP CHANGE OVER TO ALL SNOW AROUND 19Z...WITH FNT AND DTW/DET CHANGING OVER BETWEEN 19 AND 21Z. SNOWFALL WILL BE MORE PERSISTENT AT MBS THROUGH THE AFTERNOON AND WOULD EXPECT SOME PERIODS OF IFR CONDITIONS IN THE SNOW. SNOWFALL AROUND FNT AND DETROIT LATER THIS AFTERNOON WILL BE MORE CONVECTIVE IN NATURE AND MAY JUST BRIEFLY REDUCE VISIBILITIES TO THE IFR CATEGORY. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LAKE HURON...GALE WARNING...ALL OPEN WATERS...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON INCLUDING SAGINAW UNTIL 4 AM SATURDAY. LAKE ST CLAIR...GALE WARNING...UNTIL 4 AM SATURDAY. MI WATERS OF LAKE ERIE...GALE WARNING...UNTIL 4 AM SATURDAY. LOW WATER ADVISORY...UNTIL 10 AM SATURDAY. && $$ SHORT TERM...BGM LONG TERM....BT AVIATION...CONSIDINE YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1224 PM EST FRI DEC 1 2006 .AVIATION... THE 17Z SURFACE ANALYSIS SHOWS ALMOST A DOUBLE SURFACE LOW...WITH AN AREA OF LOW PRESSURE NEAR PTK AND ANOTHER AREA NEAR ERIE PA. THE LOW NEAR PTK IS FORECAST TO LIFT INTO THE SOUTHERN BASIN OF LAKE HURON BY 21Z. THE BULK OF THE PRECIPITATION FOR THE REMAINDER OF THE AFTERNOON WILL BE TO THE NORTH AND WEST OF THE SURFACE LOW TRACK. HOWEVER...ADDITIONAL CONVECTIVE SHOWERS HAVE BEEN OCCURRING ACROSS THE REST OF SOUTHEAST MICHIGAN AND ACROSS NORTHERN INDIANA...ASSOCIATED WITH THE UPPER LEVEL LOW. THE PRECIPITATION WILL PERSIST ACROSS THE FORECAST AREA THROUGH 21Z...THEN QUICKLY COME TO AN END AS THE LOW MOVES OFF TO THE NORTHEAST. FIRST ISSUE WITH THE FORECAST THIS AFTERNOON AND EVENING WILL BE THE WIND. THE STRONGEST WINDS WILL OCCUR TO THE SOUTH OF THE LOW TRACK THIS AFTERNOON...WHICH WILL IMPACT THE DETROIT AREA. GUSTS ARE ALREADY APPROACHING 40 KNOTS NEAR THE OHIO BORDER. AS THE LOW PULLS OFF TO THE NORTHEAST...FNT AND MBS WILL EXPERIENCE THE STRONGER WINDS AFTER 21Z. THE NEXT CONCERN WILL BE THE CHANGE OVER TO SNOW. BASED ON LOW LEVEL THICKNESSES PER BOTH RUC AND NAM12...MBS SHOULD SEE PRECIP CHANGE OVER TO ALL SNOW AROUND 19Z...WITH FNT AND DTW/DET CHANGING OVER BETWEEN 19 AND 21Z. SNOWFALL WILL BE MORE PERSISTENT AT MBS THROUGH THE AFTERNOON AND WOULD EXPECT SOME PERIODS OF IFR CONDITIONS IN THE SNOW. SNOWFALL AROUND FNT AND DETROIT LATER THIS AFTERNOON WILL BE MORE CONVECTIVE IN NATURE AND MAY JUST BRIEFLY REDUCE VISIBILITIES TO THE IFR CATEGORY. && .PREV DISCUSSION...ISSUED 1055 AM EST FRI DEC 1 2006 UPDATE... WINTER HEADLINES HAVE BEEN DROPPED AS WARMER AIR CONTINUES TO ADVANCE NORTH. SURFACE LOW AT 15Z WAS OVER KPTK AND UPPER LOW WAS NOT THAT FAR BEHIND. THE UPPER LOW WILL MOVE ACROSS THE STATE TODAY WITH A GOOD COVERAGE OF SHOWERS. LATEST RUC/NAM ARE IN GOOD AGREEMENT WITH KEEPING THE BOUNDARY LAYER ABOVE FREEZING FOR MOST OF THE CWA. THE EXCEPTION WILL BE ACROSS MIDLAND COUNTY AS THEY REMAIN ON THE EDGE OF FREEZING TEMPERATURES. HOWEVER...WITH LATENT HEAT RELEASE FROM THE FREEZING RAIN AND THE INFLUX OF WARMER AIR FROM THE WARM WATERS OF LAKE HURON/SAGINAW BAY WILL KEEP THE BOUNDARY LAYER ABOVE FREEZING INTO EARLY AFTERNOON. AS UPPER LOW PASSES BY TO OUR NORTH...WEAKENING DEFORMATION WILL PROVIDE SNOW SHOWERS AND PERHAPS A PERIOD OF SNOW NORTH OF M59 BEFORE ENDING NEAR 00Z. HOWEVER...ADDITIONAL ACCUMULATIONS WILL LIKELY BE LOW ENOUGH TO NOT WARRANT ADDITIONAL HEADLINES. THE MAIN SHORT TERM ISSUE IS THE WINDS AS MIXING LAYER HEIGHTS HAS THE POTENTIAL TO TAP INTO THE MID 40KT RANGE. ACROSS INDIANA WIND GUSTS WERE APPROACHING 50 KNOTS AND FORECAST SOUNDINGS AND MIXING LAYER HEIGHTS SUGGEST THIS POTENTIAL...HENCE THE WIND ADVISORY HOISTED FOR THE SOUTHERN CWA. WILL CONTINUE TO MONITOR TRENDS IF ADJUSTMENTS ARE NEEDED IN THE WIND HEADLINES. PREV DISCUSSION...ISSUED AT 354 AM SHORT TERM...TODAY AND TONIGHT WINTER STORM IS BASICALLY ON TRACK AS PRECIPITATION CONTINUES TO SPREAD NORTH INTO THE AREA. PRECIPITATION TYPE WILL BE THE BIGGEST CHALLENGE...AND ALREADY SEE THE NEED TO LOWER SNOW AMOUNTS SOME ON ALONG INTERSTATE 69 AND UP INTO PARTS OF THE THUMB AS MUCH OF THE PRECIPITATION WILL BE A MIXTURE OF FREEZING RAIN/RAIN EARLY THIS MORNING. THE WARNING STILL LOOKS OK AS ANY REDUCTION IN SNOW TOTALS WILL BE MADE UP FOR IN ICING POTENTIAL. AREAS NEAR/WEST OF SAGINAW STILL APPEAR IN A GOOD SPOT TO RECEIVE HEAVY SNOWFALL...ALTHOUGH STILL EXPECT A MIXTURE OF SLEET/SNOW AT TIMES. WILL BE WATCHING PART OF THE ADVISORY AREA...LIVINGSTON AND OAKLAND COUNTIES...AS TEMPERATURES AROUND 30 ARE LEADING TO GLAZING ALREADY. TO THIS POINT...THE ROADS ARE FINE...BUT OTHER SURFACES AREA ICING OVER PRETTY QUICKLY. IF TEMPERATURES DO NOT COME UP IN THE NEXT FEW HOURS...MAY HAVE TO UPGRADE TO A WARNING...AT LEAST UNTIL SURFACE TEMPERATURES CLIMB ABOVE FREEZING LATER THIS MORNING. MODELS ARE SIMILAR IN THE OVERALL EVOLUTION OF THIS SYSTEM AS THE SURFACE LOW NOW HEADING THROUGH SOUTHERN ILLINOIS/INDIANA DEEPENS AS IT TRACKS OVER SOUTHEAST LOWER MICHIGAN TODAY. THIS WILL ENSURE RAIN FROM THE CITY OF DETROIT SOUTH...WITH A MIXTURE OF PRECIPITATION THROUGH THE REST OF THE AREA...INCLUDING FREEZING RAIN/RAIN BETWEEN M 59 AND I 69...AND SNOW/SLEET AND SOME FREEZING RAIN NORTH OF THAT. THIS ALL CHANGES TO SNOW THIS AFTERNOON AS COLDER AIR WRAPS IN BEHIND THE STORM SYSTEM. BY THAT TIME...THE OVERALL INTENSITY OF PRECIPITATION WILL BE WANING. LONG TERM... THE ARCTIC AIR LOOKS TO BE STAYING A WHILE AS THE POLAR JET IS FORECASTED TO BE OVER OR JUST SOUTH OF THE GREAT LAKES REGION THROUGH THE PERIOD. BETWEEN LAKE EFFECT ACTIVITY...DIURNAL EFFECTS...AND THE TIMING OF SHORTWAVES...IT WILL BE DIFFICULT NOT TO INCLUDE A CHANCE OF SNOW SHOWERS OR FLURRIES THROUGH THE ENTIRE PERIOD. THE BEST CHANCE FOR SNOW SHOWERS APPEARS TO BE LATE SUNDAY/SUNDAY NIGHT AS AN UPPER LEVEL WAVE MOVES THROUGH. VERY COLD AIR ASSOCIATED WITH THIS UPPER LEVEL TROUGH/WAVE...-39 C AT 500 MB/-16 C AT 850 MB. BOTH THE 00Z NAM/GFS INDICATING MEASURABLE QPF EXTENDING INTO SOUTHEAST MICHIGAN AS WELL AS A FAIRLY WELL DEFINED SURFACE TROUGH WORKING THROUGH WITH HIGH 850-700 MB RH INDICATED. BUMPED POPS UP 10 PERCENT SUNDAY/SUNDAY NIGHT AND THERE IS A PRETTY GOOD CHANCE THEY NEED TO BE ADJUSTED UP FURTHER AS WE PIN DOWN THE TIMING. THE 00Z UKMET IS THE FASTEST WITH THE NAM BEING THE SLOWEST. FOR THE REMAINDER OF THE FORECAST...WILL PUT THE MOST STOCK IN THE 00Z EUROPEAN...WHICH IS IN GENERAL AGREEMENT WITH THE 00Z GFS ENSEMBLE MEAN. THE 00Z OPERATIONAL GFS RUN REALLY BEGINS TO DIVERGE BY TUESDAY. ALTHOUGH THE 00Z EUROPEAN IS INDICATING WEAK SHORTWAVE RIDGING ON TUESDAY...WILL MAINTAIN CHANCE POPS FOR CONTINUITY. TEMPERATURES WILL BE A GOOD 10+ DEGREES BELOW NORMAL THROUGH THE PERIOD. MIN TEMPERATURES WILL HAVE THE BIGGEST BUST POTENTIAL...WITH ANY GIVEN NIGHT BEING CONSIDERABLY COLDER DEPENDENT ON LACK OF SKY COVER AND POSSIBLE SNOW ON THE GROUND. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY...MIZ063-MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-MIZ082- MIZ083 UNTIL 4 PM FRIDAY. LAKE HURON...GALE WARNING...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON INCL SOUTH HALF UNTIL 4 AM SATURDAY. LAKE ST CLAIR...GALE WARNING...LCZ460 UNTIL 4 AM SATURDAY. MI WATERS OF LAKE ERIE...GALE WARNING...LEZ444 UNTIL 4 AM SATURDAY. && $$ SHORT TERM...DG LONG TERM....SF AVIATION...CONSIDINE YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1055 AM EST FRI DEC 1 2006 .UPDATE... WINTER HEADLINES HAVE BEEN DROPPED AS WARMER AIR CONTINUES TO ADVANCE NORTH. SURFACE LOW AT 15Z WAS OVER KPTK AND UPPER LOW WAS NOT THAT FAR BEHIND. THE UPPER LOW WILL MOVE ACROSS THE STATE TODAY WITH A GOOD COVERAGE OF SHOWERS. LATEST RUC/NAM ARE IN GOOD AGREEMENT WITH KEEPING THE BOUNDARY LAYER ABOVE FREEZING FOR MOST OF THE CWA. THE EXCEPTION WILL BE ACROSS MIDLAND COUNTY AS THEY REMAIN ON THE EDGE OF FREEZING TEMPERATURES. HOWEVER...WITH LATENT HEAT RELEASE FROM THE FREEZING RAIN AND THE INFLUX OF WARMER AIR FROM THE WARM WATERS OF LAKE HURON/SAGINAW BAY WILL KEEP THE BOUNDARY LAYER ABOVE FREEZING INTO EARLY AFTERNOON. AS UPPER LOW PASSES BY TO OUR NORTH...WEAKENING DEFORMATION WILL PROVIDE SNOW SHOWERS AND PERHAPS A PERIOD OF SNOW NORTH OF M59 BEFORE ENDING NEAR 00Z. HOWEVER...ADDITIONAL ACCUMULATIONS WILL LIKELY BE LOW ENOUGH TO NOT WARRANT ADDITIONAL HEADLINES. THE MAIN SHORT TERM ISSUE IS THE WINDS AS MIXING LAYER HEIGHTS HAS THE POTENTIAL TO TAP INTO THE MID 40KT RANGE. ACROSS INDIANA WIND GUSTS WERE APPROACHING 50 KNOTS AND FORECAST SOUNDINGS AND MIXING LAYER HEIGHTS SUGGEST THIS POTENTIAL...HENCE THE WIND ADVISORY HOISTED FOR THE SOUTHERN CWA. WILL CONTINUE TO MONITOR TRENDS IF ADJUSTMENTS ARE NEEDED IN THE WIND HEADLINES. && .PREV DISCUSSION...ISSUED 620 AM EST FRI DEC 1 2006 AVIATION... WIDE SWATH OF PRECIPITATION WILL SPREAD UP THROUGH THE AREA THIS MORNING AND CONTINUE TO SOME DEGREE THIS AFTERNOON AS STORM SYSTEM OVER ILLINOIS TRACKS NORTHEAST RIGHT OVER THE TOP OF THE AREA. KDTW AND KDET WILL REMAIN MAINLY RAIN...WITH -SN MIXING IN LATE IN THE AFTERNOON ON THE BACKSIDE OF THIS SYSTEM. KFNT/KMBS WILL SEE A MIX OF -SN/PL/FZRA THIS MORNING...GOING TO ALL SNOW THIS AFTERNOON. OF THE TWO...KFNT WILL SEE MORE FZRA/RA...KMBS MORE SNOW/PL THIS AM. CEILINGS WILL BOB BETWEEN IFR/MVFR...BUT TREND HIGHER DURING THE DAY AS DRY SLOT RACES NORTH INTO THE AREA. WRAPAROUND AROUND MOISTURE BY LATE TODAY INTO TONIGHT WILL MAINLY BE MVFR WITH LITTLE MORE THAN FLURRIES BY 00Z AND BEYOND. PREV DISCUSSION...ISSUED AT 354 AM SHORT TERM...TODAY AND TONIGHT WINTER STORM IS BASICALLY ON TRACK AS PRECIPITATION CONTINUES TO SPREAD NORTH INTO THE AREA. PRECIPITATION TYPE WILL BE THE BIGGEST CHALLENGE...AND ALREADY SEE THE NEED TO LOWER SNOW AMOUNTS SOME ON ALONG INTERSTATE 69 AND UP INTO PARTS OF THE THUMB AS MUCH OF THE PRECIPITATION WILL BE A MIXTURE OF FREEZING RAIN/RAIN EARLY THIS MORNING. THE WARNING STILL LOOKS OK AS ANY REDUCTION IN SNOW TOTALS WILL BE MADE UP FOR IN ICING POTENTIAL. AREAS NEAR/WEST OF SAGINAW STILL APPEAR IN A GOOD SPOT TO RECEIVE HEAVY SNOWFALL...ALTHOUGH STILL EXPECT A MIXTURE OF SLEET/SNOW AT TIMES. WILL BE WATCHING PART OF THE ADVISORY AREA...LIVINGSTON AND OAKLAND COUNTIES...AS TEMPERATURES AROUND 30 ARE LEADING TO GLAZING ALREADY. TO THIS POINT...THE ROADS ARE FINE...BUT OTHER SURFACES AREA ICING OVER PRETTY QUICKLY. IF TEMPERATURES DO NOT COME UP IN THE NEXT FEW HOURS...MAY HAVE TO UPGRADE TO A WARNING...AT LEAST UNTIL SURFACE TEMPERATURES CLIMB ABOVE FREEZING LATER THIS MORNING. MODELS ARE SIMILAR IN THE OVERALL EVOLUTION OF THIS SYSTEM AS THE SURFACE LOW NOW HEADING THROUGH SOUTHERN ILLINOIS/INDIANA DEEPENS AS IT TRACKS OVER SOUTHEAST LOWER MICHIGAN TODAY. THIS WILL ENSURE RAIN FROM THE CITY OF DETROIT SOUTH...WITH A MIXTURE OF PRECIPITATION THROUGH THE REST OF THE AREA...INCLUDING FREEZING RAIN/RAIN BETWEEN M 59 AND I 69...AND SNOW/SLEET AND SOME FREEZING RAIN NORTH OF THAT. THIS ALL CHANGES TO SNOW THIS AFTERNOON AS COLDER AIR WRAPS IN BEHIND THE STORM SYSTEM. BY THAT TIME...THE OVERALL INTENSITY OF PRECIPITATION WILL BE WANING. LONG TERM... THE ARCTIC AIR LOOKS TO BE STAYING A WHILE AS THE POLAR JET IS FORECASTED TO BE OVER OR JUST SOUTH OF THE GREAT LAKES REGION THROUGH THE PERIOD. BETWEEN LAKE EFFECT ACTIVITY...DIURNAL EFFECTS...AND THE TIMING OF SHORTWAVES...IT WILL BE DIFFICULT NOT TO INCLUDE A CHANCE OF SNOW SHOWERS OR FLURRIES THROUGH THE ENTIRE PERIOD. THE BEST CHANCE FOR SNOW SHOWERS APPEARS TO BE LATE SUNDAY/SUNDAY NIGHT AS AN UPPER LEVEL WAVE MOVES THROUGH. VERY COLD AIR ASSOCIATED WITH THIS UPPER LEVEL TROUGH/WAVE...-39 C AT 500 MB/-16 C AT 850 MB. BOTH THE 00Z NAM/GFS INDICATING MEASURABLE QPF EXTENDING INTO SOUTHEAST MICHIGAN AS WELL AS A FAIRLY WELL DEFINED SURFACE TROUGH WORKING THROUGH WITH HIGH 850-700 MB RH INDICATED. BUMPED POPS UP 10 PERCENT SUNDAY/SUNDAY NIGHT AND THERE IS A PRETTY GOOD CHANCE THEY NEED TO BE ADJUSTED UP FURTHER AS WE PIN DOWN THE TIMING. THE 00Z UKMET IS THE FASTEST WITH THE NAM BEING THE SLOWEST. FOR THE REMAINDER OF THE FORECAST...WILL PUT THE MOST STOCK IN THE 00Z EUROPEAN...WHICH IS IN GENERAL AGREEMENT WITH THE 00Z GFS ENSEMBLE MEAN. THE 00Z OPERATIONAL GFS RUN REALLY BEGINS TO DIVERGE BY TUESDAY. ALTHOUGH THE 00Z EUROPEAN IS INDICATING WEAK SHORTWAVE RIDGING ON TUESDAY...WILL MAINTAIN CHANCE POPS FOR CONTINUITY. TEMPERATURES WILL BE A GOOD 10+ DEGREES BELOW NORMAL THROUGH THE PERIOD. MIN TEMPERATURES WILL HAVE THE BIGGEST BUST POTENTIAL...WITH ANY GIVEN NIGHT BEING CONSIDERABLY COLDER DEPENDENT ON LACK OF SKY COVER AND POSSIBLE SNOW ON THE GROUND. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...WIND ADVISORY...MIZ063-MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-MIZ082- MIZ083 UNTIL 4 PM FRIDAY. LAKE HURON...GALE WARNING...NORTH HALF GALE WARNING...NEARSHORE WATERS FROM PORT AUSTIN TO PORT HURON INCLUDING SAGINAW BAY-SOUTH HALF- SOUTH HALF UNTIL 4 AM SATURDAY. LAKE ST CLAIR...GALE WARNING...LCZ460 UNTIL 4 AM SATURDAY. MI WATERS OF LAKE ERIE...GALE WARNING...LEZ444 UNTIL 4 AM SATURDAY. && $$ SHORT TERM...BGM LONG TERM....SF YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE). mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 955 PM CST FRI DEC 1 2006 .DISCUSSION... MONITORING THE PATCHY FOG FORMING OVER THE DEEP SNOWPACK OVER SOUTHEAST KS AND SOUTHWEST MO. SO FAR THE FOG IS RATHER PATCHY AND SHALLOW. SATELLITE IMAGERY SHOWING MID LEVEL CLOUD DECK HAS THICKENED CONSIDERABLY ACROSS THE NORTHERN HALF OF KS SINCE 23Z AND IT HAS EXPANDED EASTWARD INTO WEST CENTRAL MO...RIGHT ON TOP OF THE DEEPER SNOW PACK. THIS SHOULD SLOW DOWN THE COOLING OVER THE SNOW PACK AND THUS REDUCE THE THREAT OF WIDESPREAD DENSE FOG OVER THE AREA. CURRENT FORECAST ALREADY HAS FREEZING FOG MENTIONED IN THE COUNTIES WITH THE DEEP SNOW SO WILL NOT ISSUE ANY ADVISORY AT THIS TIME. WILL CONTINUE TO MONITOR THE SITUATION AND IT IS POSSIBLE AN ADVISORY WILL BE NEEDED LATER TONIGHT SHOULD CONDITIONS DETERIORATE RAPIDLY. MJ && .PREV DISCUSSION... 339 PM... VISIBLE SATELLITE IMAGERY SNOWS A THICK BAND OF SNOW FROM THE TEXAS PANHANDLE NORTHEAST THROUGH CENTRAL MISSOURI INTO THE LOWER GREAT LAKES. WEST WINDS AT THE SURFACE HAVE HELPED TEMPERATURES JUMP INTO THE 30S THIS AFTERNOON IN THE AREAS FREE OF SNOW. SNOW COVERED AREAS WERE NOT QUIT THAT LUCKY...RANGING THROUGH THE 20S. SNOW PACK IS AT ITS THICKEST ACROSS OUR SOUTHEAST TIER OF COUNTIES WITH TOTALS IN EXCESS OF 14 INCHES WITH ISOLATED REPORTS UP TO 18 INCHES. A BIT MORE NATIONALLY...A BROAD TROUGH PREVAILS ACROSS THE CONUS. THE SHORTWAVE THAT BOUGHT OUR WINTER WEATHER LAST NIGHT IS CURRENTLY LIFTING THROUGH THE GREAT LAKES. FARTHER NORTHWEST ANOTHER SHORTWAVE CAN BE SEEN MOVING EAST SOUTHEAST THROUGH SOUTHERN MANITOBA. MEANWHILE...STILL FARTHER WEST...A SIGNIFICANT RIDGE IS RESIDING JUST OFF THE WEST COAST...READYING ITSELF FOR LANDFALL THIS WEEKEND. THE SHORTWAVE IN SOUTHERN MANITOBA WILL SWING INTO THE UPPER GREAT LAKES THIS WEEKEND...BUT A GENERAL LACK OF MOISTURE IN THE WAKE OF THURSDAY NIGHTS SNOW STORM WILL PREVENT ANY ACTIVITY ALONG THE FRONT IN THE CENTRAL PLAINS. IT WILL HOWEVER PUSH ANOTHER SHOT OF COLD AIR SOUTH INTO THE CENTRAL PLAINS LATE SATURDAY...THUS DROPPING AFTERNOON HIGHS BETWEEN SATURDAY AND SUNDAY AND TURNING WINDS BACK TO THE NORTH. FOCUS THROUGH THE WEEKEND WILL BE TEMPERATURES...ESPECIALLY THE OVERNIGHT LOWS. NEAR CLOUDLESS SKIES WILL PREVAIL ACROSS THE LOWER MISSOURI RIVER VALLEY TONIGHT. WITH A SIGNIFICANT SNOW PACK ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA I WILL BE UNDERCUTTING EVEN THE COLDEST GUIDANCE NUMBERS IN THE SNOW COVERED AREAS. PREVIOUS SHIFTS FORECAST OF LOW SINGLE DIGITS LOOK VERY REASONABLE ACROSS THE SOUTHEAST TIER OF COUNTIES...SO HAVE MADE LITTLE CHANGE TO TONIGHTS FORECAST. LIKEWISE FOR THE LOW SUNDAY AND MONDAY MORNING...GUIDANCE NUMBERS COME DOWN SOME FOR SUNDAY MORNING AS THE COLD AIR SURGES SOUTH. STILL...CONTINUED UNDERCUTTING GUIDANCE IN SNOW COVERED AREAS. SNOW FREE AREAS HOWEVER SHOULD FALL NEAR GUIDANCE NUMBERS. THE OTHER CONCERN FOR THE NEXT FEW NIGHTS WITH BE FREEZING FOG. TEMPERATURES WILL BE IN FREE FALL TONIGHT WITH THE CLEAR SKIES...SLOWING DOWN ONLY AS THEY HIT THE DEWPOINT VALUE. WITH SUCH A THICK AND EXPANSIVE SNOW PACK PROVIDING MOISTURE WE COULD EASILY SATURATE. THE QUESTION IS WHETHER OR NOT WE FREEZE THE MOISTURE OUT AS FROST BEFORE WE GET THE FOG. HAVE OPTED TO ADD PATCHY FREEZING FOG AS A HEDGE. REGARDLESS OF WHETHER WE GET FOG OR NOT...SURFACES WILL BE SLICK TONIGHT AS ANY MELTED SNOW ON THE ROADS WILL REFREEZE. WILL ADJUST THE HAZARDOUS WEATHER OUTLOOK TO REFLECT THIS THINKING. A STOUT NORTH SURFACE WIND SATURDAY NIGHT BEHIND THE FRONT SHOULD MITIGATE THIS PROBLEM SUNDAY MORNING. THE COLD PUSH FROM THE SHORTWAVE OVER THE WEEKEND SHOULD NOT LAST LONG. THE EAST PACIFIC RIDGE WILL HAVE MOVED INTO THE WESTER REGION BY MONDAY...AND WILL QUICKLY GET HIT ON THE CHIN WITH A FAST MOVING SHORTWAVE. THE NET RESULT FOR THE PLAINS IS A RETURN OF SOUTHERLY WINDS BY MONDAY AFTERNOON MODERATING TEMPERATURES. HAVE CONTINUED THE TREND OF MODERATING TEMPERATURES UP FOR MONDAY AND TUESDAY...BUT NOT AS MUCH AS GUIDANCE NUMBERS AS SOUTH WINDS WILL ADVECT OVER WHAT IS LEFT OF THE SNOW PACK ACROSS THE SOUTHERN HALF OF THE CWA. THESE TEMPERATURES WILL NEED TO BE AGGRESSIVELY ADJUSTED BASED ON WIND DIRECTION AND SNOW PACK CONDITIONS. FOR THE LAST HALF OF NEXT WEEK MID RANGE MODELS ARE IN GENERAL AGREEMENT THAT SHORTWAVE THAT CRESTED RIDGE WILL DIP INTO THE PLAINS. SOME DISCREPANCY STILL EXIST IN HOW FAR INTO THE PLAINS IT WILL DIG. ECMWF LOOKS BETTER AS IT KEEPS THE WAVE MORE PROGRESSIVE AND SHEARS IT APART LESS THAN THE GFS. EITHER WAY ANOTHER SHOT OF COLD AIR SHOULD MAKE ITS WAY SOUTH. HOWEVER...LOOKING AT THE FORECAST SOURCE REGION...NORTHEAST PACIFIC OCEAN...OF THE AIRMASS ARRIVING WITH THE SHORTWAVE...TEMPERATURES SHOULD NOT TUMBLE FAR. ADDITIONALLY...HAVE KEPT THE GOING FORECAST DRY AS THE WAVE PASSES BY AS THE SURFACE HIGH AHEAD OF IT SHOULD KEEP MUCH OF THE MOISTURE RETURN FROM THE GULF CUTOFF UNTIL VERY LATE IN THE WEEK. CUTTER $$ .PREVIOUS DISCUSSION... /350 AM CST FRI DEC 1 2006/ WINTER STORM IS GRADUALLY BEGINNING TO TAPER OFF FROM WEST TO EAST ACROSS THE FORECAST AREA THIS MORNING. THE BACK EDGE OF THE DEFORMATION ZONE HEAVY SNOW BAND MATCHES UP WELL WITH THE 700 MB TROWAL AXIS AS DEPICTED IN THE RUC MODEL. AS OF 930Z...THE BACK EDGE OF SIGNIFICANT SNOWFALL STRETCHED FROM NEAR KIRKSVILLE...TO WARRENSBURG...TO NEVADA. THE RUC 700MB THETA-E FIELDS INDICATE THE TROWAL AXIS WILL BE EXITING THE FORECAST AREA ALMOST RIGHT AT 12Z. THEREFORE...WILL KEEP THE CURRENT HEAVY SNOW WARNING GOING FOR OUR FAR EASTERN COUNTIES THROUGH 12Z...BUT WILL NOT EXTEND ANY HEADLINES LATER INTO THE MORNING. AREAS WITHIN THE WARNING AREA MAY PICK UP ANOTHER COUPLE OF INCHES WITHIN THE NEXT 2 TO 3 HOURS. CONSIDERED HOISTING A BLOWING SNOW ADVISORY DURING THE MORNING HOURS ACROSS THE SOUTHEAST PORTION OF THE CWA AFTER THE SNOW ENDS .HOWEVER...GUSTY WINDS LOOK TO SUBSIDE RATHER QUICKLY AS THE STRONGER SURFACE PRESSURE GRADIENT SHIFTS OFF TO THE EAST. INTO EARLY NEXT WEEK...THE PRIMARY FORECAST CONCERN LOOKS TO BE TEMPERATURES...AS PRECIPITATION CHANCES LOOK TO BE MINIMAL. IN THE TEMPERATURE GRIDS...AN ATTEMPT WAS MADE TO COOL DOWN AREAS OVER THE SNOW PACK LEFT BEHIND BY THE FIRST WINTER STORM OF THE SEASON. THIS AFTERNOON...AREAS WHICH RECEIVED 10+ INCHES OF SNOW ALONG OUR SOUTHERN BORDER WILL BE HARD PRESSED TO RISE OUT OF THE MIDDLE 20S...WHILE PARTS OF NORTHWEST MISSOURI WHICH MISSED THE STORM SHOULD WARM TO AROUND 36 OR 37 DEGREES. FOR TONIGHT...I UNDERCUT MOS GUIDANCE IN EXCESS OF 10 DEGREES ALONG THE DEEPER SNOWPACK. SINGLE DIGITS ARE LIKELY EVERYWHERE THAT RECEIVED SIGNIFICANT SNOW FROM THE STORM...WITH THE COLDEST READINGS LIKELY FROM MOUND CITY...TO BUTLER...TO SEDALIA. LOWS ACROSS THESE LOCATIONS MAY FLIRT WITH 1 OR 2 DEGREES ABOVE ZERO. ON SATURDAY...ANOTHER FRONT WILL BRING A REINFORCING SHOT OF COLD AIR TO THE REGION...BUT THERE DOESN'T LOOK TO BE ANY PRECIPITATION AS MOISTURE WILL BE QUITE LIMITED. SUNDAY LOOKS TO BE QUITE COLD AS 850MB TEMPERATURES RANGING FROM -10 TO -16 DEG C OVERSPREAD THE REGION. THIS COLD AIRMASS...AND THE LINGERING SNOW PACK WILL KEEP AFTERNOON HIGHS IN THE 20S AREAWIDE. SAW && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ WFO EAX mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 339 PM CST FRI DEC 1 2006 .DISCUSSION... VISIBLE SATELLITE IMAGERY SNOWS A THICK BAND OF SNOW FROM THE TEXAS PANHANDLE NORTHEAST THROUGH CENTRAL MISSOURI INTO THE LOWER GREAT LAKES. WEST WINDS AT THE SURFACE HAVE HELPED TEMPERATURES JUMP INTO THE 30S THIS AFTERNOON IN THE AREAS FREE OF SNOW. SNOW COVERED AREAS WERE NOT QUIT THAT LUCKY...RANGING THROUGH THE 20S. SNOW PACK IS AT ITS THICKEST ACROSS OUR SOUTHEAST TIER OF COUNTIES WITH TOTALS IN EXCESS OF 14 INCHES WITH ISOLATED REPORTS UP TO 18 INCHES. A BIT MORE NATIONALLY...A BROAD TROUGH PREVAILS ACROSS THE CONUS. THE SHORTWAVE THAT BOUGHT OUR WINTER WEATHER LAST NIGHT IS CURRENTLY LIFTING THROUGH THE GREAT LAKES. FARTHER NORTHWEST ANOTHER SHORTWAVE CAN BE SEEN MOVING EAST SOUTHEAST THROUGH SOUTHERN MANITOBA. MEANWHILE...STILL FARTHER WEST...A SIGNIFICANT RIDGE IS RESIDING JUST OFF THE WEST COAST...READYING ITSELF FOR LANDFALL THIS WEEKEND. THE SHORTWAVE IN SOUTHERN MANITOBA WILL SWING INTO THE UPPER GREAT LAKES THIS WEEKEND...BUT A GENERAL LACK OF MOISTURE IN THE WAKE OF THURSDAY NIGHTS SNOW STORM WILL PREVENT ANY ACTIVITY ALONG THE FRONT IN THE CENTRAL PLAINS. IT WILL HOWEVER PUSH ANOTHER SHOT OF COLD AIR SOUTH INTO THE CENTRAL PLAINS LATE SATURDAY...THUS DROPPING AFTERNOON HIGHS BETWEEN SATURDAY AND SUNDAY AND TURNING WINDS BACK TO THE NORTH. FOCUS THROUGH THE WEEKEND WILL BE TEMPERATURES...ESPECIALLY THE OVERNIGHT LOWS. NEAR CLOUDLESS SKIES WILL PREVAIL ACROSS THE LOWER MISSOURI RIVER VALLEY TONIGHT. WITH A SIGNIFICANT SNOW PACK ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA I WILL BE UNDERCUTTING EVEN THE COLDEST GUIDANCE NUMBERS IN THE SNOW COVERED AREAS. PREVIOUS SHIFTS FORECAST OF LOW SINGLE DIGITS LOOK VERY REASONABLE ACROSS THE SOUTHEAST TIER OF COUNTIES...SO HAVE MADE LITTLE CHANGE TO TONIGHTS FORECAST. LIKEWISE FOR THE LOW SUNDAY AND MONDAY MORNING...GUIDANCE NUMBERS COME DOWN SOME FOR SUNDAY MORNING AS THE COLD AIR SURGES SOUTH. STILL...CONTINUED UNDERCUTTING GUIDANCE IN SNOW COVERED AREAS. SNOW FREE AREAS HOWEVER SHOULD FALL NEAR GUIDANCE NUMBERS. THE OTHER CONCERN FOR THE NEXT FEW NIGHTS WITH BE FREEZING FOG. TEMPERATURES WILL BE IN FREE FALL TONIGHT WITH THE CLEAR SKIES...SLOWING DOWN ONLY AS THEY HIT THE DEWPOINT VALUE. WITH SUCH A THICK AND EXPANSIVE SNOW PACK PROVIDING MOISTURE WE COULD EASILY SATURATE. THE QUESTION IS WHETHER OR NOT WE FREEZE THE MOISTURE OUT AS FROST BEFORE WE GET THE FOG. HAVE OPTED TO ADD PATCHY FREEZING FOG AS A HEDGE. REGARDLESS OF WHETHER WE GET FOG OR NOT...SURFACES WILL BE SLICK TONIGHT AS ANY MELTED SNOW ON THE ROADS WILL REFREEZE. WILL ADJUST THE HAZARDOUS WEATHER OUTLOOK TO REFLECT THIS THINKING. A STOUT NORTH SURFACE WIND SATURDAY NIGHT BEHIND THE FRONT SHOULD MITIGATE THIS PROBLEM SUNDAY MORNING. THE COLD PUSH FROM THE SHORTWAVE OVER THE WEEKEND SHOULD NOT LAST LONG. THE EAST PACIFIC RIDGE WILL HAVE MOVED INTO THE WESTER REGION BY MONDAY...AND WILL QUICKLY GET HIT ON THE CHIN WITH A FAST MOVING SHORTWAVE. THE NET RESULT FOR THE PLAINS IS A RETURN OF SOUTHERLY WINDS BY MONDAY AFTERNOON MODERATING TEMPERATURES. HAVE CONTINUED THE TREND OF MODERATING TEMPERATURES UP FOR MONDAY AND TUESDAY...BUT NOT AS MUCH AS GUIDANCE NUMBERS AS SOUTH WINDS WILL ADVECT OVER WHAT IS LEFT OF THE SNOW PACK ACROSS THE SOUTHERN HALF OF THE CWA. THESE TEMPERATURES WILL NEED TO BE AGGRESSIVELY ADJUSTED BASED ON WIND DIRECTION AND SNOW PACK CONDITIONS. FOR THE LAST HALF OF NEXT WEEK MID RANGE MODELS ARE IN GENERAL AGREEMENT THAT SHORTWAVE THAT CRESTED RIDGE WILL DIP INTO THE PLAINS. SOME DISCREPANCY STILL EXIST IN HOW FAR INTO THE PLAINS IT WILL DIG. ECMWF LOOKS BETTER AS IT KEEPS THE WAVE MORE PROGRESSIVE AND SHEARS IT APART LESS THAN THE GFS. EITHER WAY ANOTHER SHOT OF COLD AIR SHOULD MAKE ITS WAY SOUTH. HOWEVER...LOOKING AT THE FORECAST SOURCE REGION...NORTHEAST PACIFIC OCEAN...OF THE AIRMASS ARRIVING WITH THE SHORTWAVE...TEMPERATURES SHOULD NOT TUMBLE FAR. ADDITIONALLY...HAVE KEPT THE GOING FORECAST DRY AS THE WAVE PASSES BY AS THE SURFACE HIGH AHEAD OF IT SHOULD KEEP MUCH OF THE MOISTURE RETURN FROM THE GULF CUTOFF UNTIL VERY LATE IN THE WEEK. CUTTER $$ .PREVIOUS DISCUSSION... /350 AM CST FRI DEC 1 2006/ WINTER STORM IS GRADUALLY BEGINNING TO TAPER OFF FROM WEST TO EAST ACROSS THE FORECAST AREA THIS MORNING. THE BACK EDGE OF THE DEFORMATION ZONE HEAVY SNOW BAND MATCHES UP WELL WITH THE 700 MB TROWAL AXIS AS DEPICTED IN THE RUC MODEL. AS OF 930Z...THE BACK EDGE OF SIGNIFICANT SNOWFALL STRETCHED FROM NEAR KIRKSVILLE...TO WARRENSBURG...TO NEVADA. THE RUC 700MB THETA-E FIELDS INDICATE THE TROWAL AXIS WILL BE EXITING THE FORECAST AREA ALMOST RIGHT AT 12Z. THEREFORE...WILL KEEP THE CURRENT HEAVY SNOW WARNING GOING FOR OUR FAR EASTERN COUNTIES THROUGH 12Z...BUT WILL NOT EXTEND ANY HEADLINES LATER INTO THE MORNING. AREAS WITHIN THE WARNING AREA MAY PICK UP ANOTHER COUPLE OF INCHES WITHIN THE NEXT 2 TO 3 HOURS. CONSIDERED HOISTING A BLOWING SNOW ADVISORY DURING THE MORNING HOURS ACROSS THE SOUTHEAST PORTION OF THE CWA AFTER THE SNOW ENDS .HOWEVER...GUSTY WINDS LOOK TO SUBSIDE RATHER QUICKLY AS THE STRONGER SURFACE PRESSURE GRADIENT SHIFTS OFF TO THE EAST. INTO EARLY NEXT WEEK...THE PRIMARY FORECAST CONCERN LOOKS TO BE TEMPERATURES...AS PRECIPITATION CHANCES LOOK TO BE MINIMAL. IN THE TEMPERATURE GRIDS...AN ATTEMPT WAS MADE TO COOL DOWN AREAS OVER THE SNOW PACK LEFT BEHIND BY THE FIRST WINTER STORM OF THE SEASON. THIS AFTERNOON...AREAS WHICH RECEIVED 10+ INCHES OF SNOW ALONG OUR SOUTHERN BORDER WILL BE HARD PRESSED TO RISE OUT OF THE MIDDLE 20S...WHILE PARTS OF NORTHWEST MISSOURI WHICH MISSED THE STORM SHOULD WARM TO AROUND 36 OR 37 DEGREES. FOR TONIGHT...I UNDERCUT MOS GUIDANCE IN EXCESS OF 10 DEGREES ALONG THE DEEPER SNOWPACK. SINGLE DIGITS ARE LIKELY EVERYWHERE THAT RECEIVED SIGNIFICANT SNOW FROM THE STORM...WITH THE COLDEST READINGS LIKELY FROM MOUND CITY...TO BUTLER...TO SEDALIA. LOWS ACROSS THESE LOCATIONS MAY FLIRT WITH 1 OR 2 DEGREES ABOVE ZERO. ON SATURDAY...ANOTHER FRONT WILL BRING A REINFORCING SHOT OF COLD AIR TO THE REGION...BUT THERE DOESN'T LOOK TO BE ANY PRECIPITATION AS MOISTURE WILL BE QUITE LIMITED. SUNDAY LOOKS TO BE QUITE COLD AS 850MB TEMPERATURES RANGING FROM -10 TO -16 DEG C OVERSPREAD THE REGION. THIS COLD AIRMASS...AND THE LINGERING SNOW PACK WILL KEEP AFTERNOON HIGHS IN THE 20S AREAWIDE. SAW && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ WFO EAX mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 849 PM EST FRI DEC 1 2006 .SHORT TERM /REST OF TONIGHT/... NW WIND SHIFT DEFINING THE SFC COLD FRONT HAS JUST MADE ITS WAY INTO THE TRIAD. THIS WIND SHIFT LAGS THE DEWPOINT DISCONTINUITY BOUNDARY COURTESY OF STRONG DOWNWARD MIXING OF DRIER ALOFT...WHICH HAS ALLOWED DEWPOINTS TO DROP WELL INTO THE 30S AND UPPER 20S IN THE WESTERN PIEDMONT. SKIES ARE SKC ACROSS THE ENTIRE CWA WITH WIND GUSTS FADING FROM WEST TO EAST AS MIXING LESSENS WITH LOSS OF DAYTIME HEATING AND AS SFC ANTICYCLONE BUILDS IN FROM THE MISSISSIPPI VALLEY. LATEST RUC HAS A GOOD HANDLE ON THE FROPA...CLEARING THE EASTERN MOST CWA SHORTLY AFTER 06Z. MAIN FORECAST CHALLENGE IS TONIGHT'S FORECAST LOWS. WINDS WILL NO DOUBT WILL BE KEY. THE RUC HAS WINDS DROPPING OFF TO LESS THAN 5KTS BY 09Z WHICH COULD PROVIDE JUST ENOUGH TIME FOR TEMPERATURES TO DROP BELOW FORECAST LOWS...ESPECIALLY FROM RDU WEST. WILL OPEN UP THE TEMPERATURE TOWARD THE COLDER SIDE. OTHERWISE...WILL FRESHEN UP HOURLY T/TD GRIDS WITH PASSING FROPA. && .PREV DISCUSSION... (ISSUED 545 PM EST FRI DEC 1 2006) SHORT TERM /REST OF TONIGHT/... QUICK UPDATE TO ACCOUNT FOR DRIER AIR SURGING INTO THE WESTERN CWA FASTER THAN CURRENT FORECAST INDICATES. UPDATE TO INCLUDE AMENDMENTS TO DIGITAL FORECAST PRODUCTS ONLY. ZONE PACKAGE UPDATE WILL BE ADJUSTED LATER IN THE EVENING. PREV DISCUSSION... (ISSUED 220 PM EST FRI DEC 1 2006) SYNOPSIS... SFC ANALYSIS THIS AFTERNOON SHOWS DEEP 990 MB SFC LOW IN VICINITY OF LAKE ERIE/HURON. STRONG COLD FRONT EXTENDS FROM WESTERN PA SOUTH ALONG THE APPALACHIANS THROUGH PORTIONS OF WV/VA/TN/GA. ACROSS CENTRAL NC...TEMPS RANGED FROM THE LOWER 70S (NW) TO UPPER 70S (SE) AND DEWPOINTS WERE IN THE MID 60S. WINDS WERE GUSTING FROM THE SOUTH AT 30 TO 40 MPH. SHORT TERM /TONIGHT THROUGH SATURDAY/... BACK EDGE OF PRE-FRONTAL CLOUD BAND IS APPROACHING THE CWA FROM THE WEST EARLY THIS AFTERNOON. THE ACTUAL SFC FRONT IS LOCATED ALONG AND JUST WEST OF THE MOUNTAINS AS OF 18Z. EXPECT THE AREA OF SHOWERS CURRENTLY OVER CENTRAL NC TO CONTINUE MOVING EAST...ADVECTING OUT OF THE CWA BY 21Z-00Z. CEILINGS WILL BEGIN TO SCATTER OUT FROM WEST TO EAST LATER THIS AFTERNOON AND EVENING...BECOMING MOSTLY CLEAR TONIGHT AS DRY AIR FILTERS IN BEHIND FROPA. WINDS WILL GRADUALLY DECREASE TONIGHT AS THE PRESSURE GRADIENT WEAKENS BEHIND THE FRONT. RUC SFC THETA-E FORECAST DEPICTS THE COLDER...DRIER POST-FRONTAL AIRMASS CROSSING WEST-EAST THROUGH THE CWA BETWEEN 21Z-06Z TONIGHT. BLEND OF GUIDANCE GIVES LOW TEMPS TONIGHT IN THE UPPER 30S (NW) TO MID 40S (SE). SATURDAY...CLEAR OR MOSTLY CLEAR SKIES AT THE BEGINNING OF THE DAY WILL GIVE WAY TO PARTLY CLOUDY SKIES IN THE AFTERNOON AS GFS/NAM TIME/HEIGHT CROSS SECTIONS INDICATE INCREASING MID/UPPER LEVEL MOISTURE (ABOVE 700 MB) AS THE DAY PROGRESSES. BLEND OF GUIDANCE AND LOW-LEVEL THICKNESSES SUGGEST HIGH TEMPS IN THE UPPER 50S (NW) TO LOWER 60S (SE). -VINCENT LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... SATURDAY NIGHT THROUGH SUNDAY NIGHT... MID LEVEL VORT DIVES SOUTHEAST SAT NIGHT...SHARPENING TROUGH THAT WILL MOVE INTO OHIO VALLEY LATE SUNDAY INTO MONDAY. TAIL END OF LONG WAVE TROUGH WILL SWING ACROSS MID ATLC REGION LATE SUNDAY INTO MONDAY. BOTH NAM/GFS SHOWING WEAK WAVE DEVELOPING OFF THE CAROLINAS COAST ON OLD FRONTAL BOUNDARY SUNDAY AFTERNOON. ADDITIONALLY BOTH (GFS/NAM) MODELS PUSHING DEEPER MOISTURE/QPF FURTHER WESTWARD INTO CWA SUNDAY AFTERNOON THROUGH FIRST HALF OF SUNDAY NIGHT. HOWEVER BEST SUPPORT FOR PRECIP REMAIN MAINLY OVER SOUTHERN AND EASTERN SECTIONS AS ATLC INFLOW FAIRLY WEAK AND BRIEF. AT THIS POINT DONT EXPECT PRECIP TO REACH NORTHWEST PIEDMONT. SO WILL CONTINUE CURRENT TREND OF CONFINING LOW POPS MAINLY TO SOUTH AND EAST SECTIONS...HIGHEST EASTERN THIRD. MONDAY THROUGH FRIDAY... CHILLY HIGH PRESSURE WILL DOMINATE THROUGH THE WEEK. COLD WITH TEMPERATURES BELOW SEASONAL NORMS THROUGH THE WEEK. AVIATION... COLD FRONT TO MOVE THROUGH LATER HIS EVENING. INT-GSO...TIL 21Z BKN LAYERS 4-6 KFT VSBYS UNRESTRICTED. AFTER 21Z THRU 23Z SCATTERED CLOUDS 5KFT. RDU-FAY-RWI...BKN LAYERS 3-5KFT VSBYS UNRESTRICTED. TIL 21Z CIGS 2-3KFT VSBYS 3-5 MILES IN BRIEFLY LOWERING IN SCATTERED SHOWERS. AFTER 21Z THROUGH 23Z SCT TO BKN LAYERS 4-6KFT VSBYS UNRESTRICTED. VFR CONDITIONS AT ALL TAF SITES AFTER 23Z. GUSTY SURFACE WINDS 15 TO 25 MPH WITH OCNL GUSTS TO 40 MPH TIL 21Z. WINDS DIMINISHING AFTER 21Z TO 10 TO 15 MPH...BRIEF GUSTS TO 25 MPH TIL 00Z. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...LOCKLEAR nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 545 PM EST FRI DEC 1 2006 .SHORT TERM /REST OF TONIGHT/... QUICK UPDATE TO ACCOUNT FOR DRIER AIR SURGING INTO THE WESTERN CWA FASTER THAN CURRENT FORECAST INDICATES. UPDATE TO INCLUDE AMENDMENTS TO DIGITAL FORECAST PRODUCTS ONLY. ZONE PACKAGE UPDATE WILL BE ADJUSTED LATER IN THE EVENING. && .PREV DISCUSSION... (ISSUED 220 PM EST FRI DEC 1 2006) SYNOPSIS... SFC ANALYSIS THIS AFTERNOON SHOWS DEEP 990 MB SFC LOW IN VICINITY OF LAKE ERIE/HURON. STRONG COLD FRONT EXTENDS FROM WESTERN PA SOUTH ALONG THE APPALACHIANS THROUGH PORTIONS OF WV/VA/TN/GA. ACROSS CENTRAL NC...TEMPS RANGED FROM THE LOWER 70S (NW) TO UPPER 70S (SE) AND DEWPOINTS WERE IN THE MID 60S. WINDS WERE GUSTING FROM THE SOUTH AT 30 TO 40 MPH. SHORT TERM /TONIGHT THROUGH SATURDAY/... BACK EDGE OF PRE-FRONTAL CLOUD BAND IS APPROACHING THE CWA FROM THE WEST EARLY THIS AFTERNOON. THE ACTUAL SFC FRONT IS LOCATED ALONG AND JUST WEST OF THE MOUNTAINS AS OF 18Z. EXPECT THE AREA OF SHOWERS CURRENTLY OVER CENTRAL NC TO CONTINUE MOVING EAST...ADVECTING OUT OF THE CWA BY 21Z-00Z. CEILINGS WILL BEGIN TO SCATTER OUT FROM WEST TO EAST LATER THIS AFTERNOON AND EVENING...BECOMING MOSTLY CLEAR TONIGHT AS DRY AIR FILTERS IN BEHIND FROPA. WINDS WILL GRADUALLY DECREASE TONIGHT AS THE PRESSURE GRADIENT WEAKENS BEHIND THE FRONT. RUC SFC THETA-E FORECAST DEPICTS THE COLDER...DRIER POST-FRONTAL AIRMASS CROSSING WEST-EAST THROUGH THE CWA BETWEEN 21Z-06Z TONIGHT. BLEND OF GUIDANCE GIVES LOW TEMPS TONIGHT IN THE UPPER 30S (NW) TO MID 40S (SE). SATURDAY...CLEAR OR MOSTLY CLEAR SKIES AT THE BEGINNING OF THE DAY WILL GIVE WAY TO PARTLY CLOUDY SKIES IN THE AFTERNOON AS GFS/NAM TIME/HEIGHT CROSS SECTIONS INDICATE INCREASING MID/UPPER LEVEL MOISTURE (ABOVE 700 MB) AS THE DAY PROGRESSES. BLEND OF GUIDANCE AND LOW-LEVEL THICKNESSES SUGGEST HIGH TEMPS IN THE UPPER 50S (NW) TO LOWER 60S (SE). -VINCENT LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... SATURDAY NIGHT THROUGH SUNDAY NIGHT... MID LEVEL VORT DIVES SOUTHEAST SAT NIGHT...SHARPENING TROUGH THAT WILL MOVE INTO OHIO VALLEY LATE SUNDAY INTO MONDAY. TAIL END OF LONG WAVE TROUGH WILL SWING ACROSS MID ATLC REGION LATE SUNDAY INTO MONDAY. BOTH NAM/GFS SHOWING WEAK WAVE DEVELOPING OFF THE CAROLINAS COAST ON OLD FRONTAL BOUNDARY SUNDAY AFTERNOON. ADDITIONALLY BOTH (GFS/NAM) MODELS PUSHING DEEPER MOISTURE/QPF FURTHER WESTWARD INTO CWA SUNDAY AFTERNOON THROUGH FIRST HALF OF SUNDAY NIGHT. HOWEVER BEST SUPPORT FOR PRECIP REMAIN MAINLY OVER SOUTHERN AND EASTERN SECTIONS AS ATLC INFLOW FAIRLY WEAK AND BRIEF. AT THIS POINT DONT EXPECT PRECIP TO REACH NORTHWEST PIEDMONT. SO WILL CONTINUE CURRENT TREND OF CONFINING LOW POPS MAINLY TO SOUTH AND EAST SECTIONS...HIGHEST EASTERN THIRD. MONDAY THROUGH FRIDAY... CHILLY HIGH PRESSURE WILL DOMINATE THROUGH THE WEEK. COLD WITH TEMPERATURES BELOW SEASONAL NORMS THROUGH THE WEEK. AVIATION... COLD FRONT TO MOVE THROUGH LATER HIS EVENING. INT-GSO...TIL 21Z BKN LAYERS 4-6 KFT VSBYS UNRESTRICTED. AFTER 21Z THRU 23Z SCATTERED CLOUDS 5KFT. RDU-FAY-RWI...BKN LAYERS 3-5KFT VSBYS UNRESTRICTED. TIL 21Z CIGS 2-3KFT VSBYS 3-5 MILES IN BRIEFLY LOWERING IN SCATTERED SHOWERS. AFTER 21Z THROUGH 23Z SCT TO BKN LAYERS 4-6KFT VSBYS UNRESTRICTED. VFR CONDITIONS AT ALL TAF SITES AFTER 23Z. GUSTY SURFACE WINDS 15 TO 25 MPH WITH OCNL GUSTS TO 40 MPH TIL 21Z. WINDS DIMINISHING AFTER 21Z TO 10 TO 15 MPH...BRIEF GUSTS TO 25 MPH TIL 00Z. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...LOCKLEAR nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 220 PM EST FRI DEC 1 2006 .SYNOPSIS... SFC ANALYSIS THIS AFTERNOON SHOWS DEEP 990 MB SFC LOW IN VICINITY OF LAKE ERIE/HURON. STRONG COLD FRONT EXTENDS FROM WESTERN PA SOUTH ALONG THE APPALACHIANS THROUGH PORTIONS OF WV/VA/TN/GA. ACROSS CENTRAL NC...TEMPS RANGED FROM THE LOWER 70S (NW) TO UPPER 70S (SE) AND DEWPOINTS WERE IN THE MID 60S. WINDS WERE GUSTING FROM THE SOUTH AT 30 TO 40 MPH. && .SHORT TERM /TONIGHT THROUGH SATURDAY/... BACK EDGE OF PRE-FRONTAL CLOUD BAND IS APPROACHING THE CWA FROM THE WEST EARLY THIS AFTERNOON. THE ACTUAL SFC FRONT IS LOCATED ALONG AND JUST WEST OF THE MOUNTAINS AS OF 18Z. EXPECT THE AREA OF SHOWERS CURRENTLY OVER CENTRAL NC TO CONTINUE MOVING EAST...ADVECTING OUT OF THE CWA BY 21Z-00Z. CEILINGS WILL BEGIN TO SCATTER OUT FROM WEST TO EAST LATER THIS AFTERNOON AND EVENING...BECOMING MOSTLY CLEAR TONIGHT AS DRY AIR FILTERS IN BEHIND FROPA. WINDS WILL GRADUALLY DECREASE TONIGHT AS THE PRESSURE GRADIENT WEAKENS BEHIND THE FRONT. RUC SFC THETA-E FORECAST DEPICTS THE COLDER...DRIER POST-FRONTAL AIRMASS CROSSING WEST-EAST THROUGH THE CWA BETWEEN 21Z-06Z TONIGHT. BLEND OF GUIDANCE GIVES LOW TEMPS TONIGHT IN THE UPPER 30S (NW) TO MID 40S (SE). SATURDAY...CLEAR OR MOSTLY CLEAR SKIES AT THE BEGINNING OF THE DAY WILL GIVE WAY TO PARTLY CLOUDY SKIES IN THE AFTERNOON AS GFS/NAM TIME/HEIGHT CROSS SECTIONS INDICATE INCREASING MID/UPPER LEVEL MOISTURE (ABOVE 700 MB) AS THE DAY PROGRESSES. BLEND OF GUIDANCE AND LOW-LEVEL THICKNESSES SUGGEST HIGH TEMPS IN THE UPPER 50S (NW) TO LOWER 60S (SE). -VINCENT && .LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/... SATURDAY NIGHT THROUGH SUNDAY NIGHT... MID LEVEL VORT DIVES SOUTHEAST SAT NIGHT...SHARPENING TROUGH THAT WILL MOVE INTO OHIO VALLEY LATE SUNDAY INTO MONDAY. TAIL END OF LONG WAVE TROUGH WILL SWING ACROSS MID ATLC REGION LATE SUNDAY INTO MONDAY. BOTH NAM/GFS SHOWING WEAK WAVE DEVELOPING OFF THE CAROLINAS COAST ON OLD FRONTAL BOUNDARY SUNDAY AFTERNOON. ADDITIONALLY BOTH (GFS/NAM) MODELS PUSHING DEEPER MOISTURE/QPF FURTHER WESTWARD INTO CWA SUNDAY AFTERNOON THROUGH FIRST HALF OF SUNDAY NIGHT. HOWEVER BEST SUPPORT FOR PRECIP REMAIN MAINLY OVER SOUTHERN AND EASTERN SECTIONS AS ATLC INFLOW FAIRLY WEAK AND BRIEF. AT THIS POINT DONT EXPECT PRECIP TO REACH NORTHWEST PIEDMONT. SO WILL CONTINUE CURRENT TREND OF CONFINING LOW POPS MAINLY TO SOUTH AND EAST SECTIONS...HIGHEST EASTERN THIRD. MONDAY THROUGH FRIDAY... CHILLY HIGH PRESSURE WILL DOMINATE THROUGH THE WEEK. COLD WITH TEMPERATURES BELOW SEASONAL NORMS THROUGH THE WEEK. && .AVIATION... COLD FRONT TO MOVE THROUGH TLATER HIS EVENING. INT-GSO...TIL 21Z BKN LAYERS 4-6 KFT VSBYS UNRESTRICTED. AFTER 21Z THRU 23Z SCATTERED CLOUDS 5KFT. RDU-FAY-RWI...BKN LAYERS 3-5KFT VSBYS UNRESTRICTED. TIL 21Z CIGS 2-3KFT VSBYS 3-5 MILES IN BRIEFLY LOWERING IN SCATTERED SHOWERS. AFTER 21Z THROUGH 23Z SCT TO BKN LAYERS 4-6KFT VSBYS UNRESTRICTED. VFR CONDITIONS AT ALL TAF SITES AFTER 23Z. GUSTY SURFACE WINDS 15 TO 25 MPH WITH OCNL GUSTS TO 40 MPH TIL 21Z. WINDS DIMINISHING AFTER 21Z TO 10 TO 15 MPH...BRIEF GUSTS TO 25 MPH TIL 00Z. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT SHORT TERM...VINCENT LONG TERM...RA AVIATION...RA nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 1228 PM EST FRI DEC 1 2006 .AVIATION /18Z-18Z/... SURFACE ANALYSIS DEEP LOW OVER THE SOUTHERN GREAT LAKES WITH STRONG PRESSURE GRADIENT ACROSS TAF SITES. SURFACE OBS ARE GENERALLY SHOWING SOUTHWEST WINDS SUSTAINED AROUND 30 KTS WITH GUSTS IN GENERAL ABOVE 40 KTS. KILN RADAR SHOWS SCATTERED RAIN SHOWERS AROUND KCMH AND KLCK AND SCATTERED SNOW SHOWERS ACROSS THE OTHER TAF SITES. WILL KEEP THE TRENDS OF PRECIOUS FORECAST. WINDS WILL DIE OFF QUICKLY AFTER SUNSET AS THE GRADIENT LOOSENS UP AND DEEP MIXING IS CUT OFF. WILL CLEAR OUT CLOUDS AFTER 06Z WITH STRONG SUBSIDENCE. TIPTON && .PREV DISCUSSION... /ISSUED 1134 AM EST FRI DEC 1 2006/ SHORT TERM /REST OF TODAY/... SURFACE ANALYSIS SHOWS ELONGATED DEEP LOW FROM SOUTH BEND TO CLEVELAND WITH STRONG PRESSURE GRADIENT OVER REGION. OBS HAVE SHOWN NUMEROUS OBS WITH GUSTS OVER 40 KTS AND A FEW NEAR 50 KTS...SUCH AS KDAY FROM 1445Z. SATELLITE IMAGERY SHOWS NUMEROUS BREAKS IN THE DRY SLOT. KILN RADAR SHOWING NUMEROUS SMALL SHOWERS. WE HAVE HAD A FEW REPORTS IN OUR FAR WEST OF A MIX. HAVE UPDATED ZONES TO GET RIDE OF HIGH POPS AND TO ADJUST TEMP WORDING. THIS AFT EXPECTING SCATTERED RAIN SHOWERS TO TURN TO SNOW SHOWERS. WIND GUSTS SHOULD BE THE WORST THROUGH 20Z TO 21Z WHEN MIXING BEGINS TO END. LATEST NAM/RUC SHOWING 50 KTS THROUGH 18Z ACROSS THE SOUTH AND 21Z ACROSS THE NORTH. TIPTON PREV DISCUSSION... /ISSUED 837 AM EST FRI DEC 1 2006/ SHORT TERM /REST OF TODAY/... LATEST SFC MAP SHOWS COLD FRONT PUSHING EAST THRU CENTRAL OHIO ATTM. CONVECTIVE LINE ASSOCIATED WITH THIS FRONT HAS SHIFTED EAST OF FA WITH DRY SLOT WORKING INTO SE IN AND SW OHIO. THEREFORE HAVE DROPPED ALL SEVERE/TORNADO WATCHES IN ILN/S FA. GRADIENT INCREASES THIS AFTERNOON WITH 45 TO 50 KNOT WINDS INDICATED AT 925MB. WITH MIXING EXPECT TO SEE WIND GUSTS IN EXCESS OF 50 MPH. HAVE CONTD HIGH WIND WARNING ACRS THE ENTIRE AREA THRU THE AFTN. REMAINDER OF THE FCST LOOKS GOOD WITH FALLING TEMPS AND SCTD RAIN SHOWERS CHANGING TO SNOW SHOWS WITH UPPER LOW EJECTING NE ACRS IN INTO SE LOWER MI THIS AFTN. PREV DISCUSSION... /ISSUED 656 AM EST FRI DEC 1 2006/ AVIATION /12Z-12Z/... THE SFC LOW WAS LOCATED OVER INDIANA THIS MORNING WITH NUMEROUS SHOWERS ACROSS AREAS EAST OF I-75. AS THE LOW PROGRESSES NE...PCPN WILL SCATTERED. SW WINDS WILL GUST WILL BE NEAR/ABOVE 40 KTS AT TIMES 16Z-23Z...DROPPING NEAR 20 KTS IN THE EVENING AS THE LOW MOVES NORTH OF THE REGION. GENERALLY...VFR CIGS WILL DROP TO MVFR OVER THE NEXT FEW HOURS AND REMAIN MVFR THROUGH 06Z...THEN SCATTERING OUT SW TO NE. MVFR VISIBILITIES WITH -SHSN ARE POSSIBLE AFTER 18Z AND THROUGH THE EARLY EVENING. PREV DISCUSSION... /ISSUED 532 AM EST FRI DEC 1 2006/ SHORT TERM /TODAY THROUGH SUNDAY/... PRIMARY LOW PRESSURE SYSTEM IS CURRENTLY OVER SOUTHERN ILLINOIS WITH A SECONDARY LOW STARTING TO DEVELOP IN SOUTHERN INDIANA. THE ENTIRE SYSTEM IS QUICKLY MOVING NORTH NORTHEAST. WARM SECTOR IS SPREADING NORTH EARLY THIS MORNING. THEN STRONG COLD AIR ADVECTION WILL OCCUR ON THE BACK SIDE OF THE LOW WHICH SHOULD RESULT IN EXCELLENT MIXING WITH SOME WIND GUSTS UP TO 60 MPH PARTICULARLY FROM MID MORNING THROUGH MID AFTERNOON. WIDESPREAD PRECIPITATION WILL COME TO AN END THIS MORNING AS DRY SLOT MOVES IN. BUT SHOULD STILL SEE SCATTERED RAIN AND SNOW SHOWERS DURING THE AFTERNOON AND THEN DIMINISH BY EVENING. HIGH PRESSURE THEN BUILDS INTO THE REGION WITH A REINFORCING PUSH OF COLD AIR ON SUNDAY. PREV DISCUSSION... /ISSUED 342 PM EST THU NOV 30 2006/ LONG TERM /SUNDAY THROUGH THURSDAY/... LONG WAVE TROUGH OVER EASTERN CONUS WILL PERSIST THROUGH THE PERIOD. THIS WILL RESULT IN COOL AND MAINLY DRY WEATHER FOR ILN AREA. SUNDAY WILL BE DRY WITH HIGH PRESSURE BUILDING IN FROM THE WEST. A SHORT WAVE TROUGH WILL BRING THE CHANCE FOR SNOW SHOWERS TO OUR NORTHERN COUNTIES SUNDAY NIGHT THROUGH TUESDAY. LAKE ENHANCEMENT MAY COME INTO PLAY DURING THAT PERIOD. AFTER HIGH PRESSURE AND DRY AIR OVERSPREADS THE AREA ON WEDNESDAY...A TROUGH OF LOW PRESSURE TRAVELING NEAR THE GULF COAST MAY THROW SOME MOISTURE INTO THE OHIO VALLEY IN THE FORM OF SNOW. TEMPERATURES ARE FORECAST TO BE BELOW NORMAL. UNDERCUT HPC GUIDANCE SUNDAY NIGHT WHEN AIRMASS IS PROGGED TO BE COLDEST...WITH 1000-850MB THICKNESS OF 1236M INDICATED AT CVG. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR OHZ026-034-035- 042>046-051>056-060>065-074. HIGH WIND WARNING UNTIL 6 PM EST THIS AFTERNOON FOR OHZ070>073- 077>082-088. KY...HIGH WIND WARNING UNTIL 6 PM EST THIS AFTERNOON FOR KYZ089>100. IN...HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR INZ050-058-059. HIGH WIND WARNING UNTIL 6 PM EST THIS AFTERNOON FOR INZ066-073>075- 080. && $$ oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 1134 AM EST FRI DEC 1 2006 .SHORT TERM /REST OF TODAY/... SURFACE ANALYSIS SHOWS ELONGATED DEEP LOW FROM SOUTH BEND TO CLEVELAND WITH STRONG PRESSURE GRADIENT OVER REGION. OBS HAVE SHOWN NUMEROUS OBS WITH GUSTS OVER 40 KTS AND A FEW NEAR 50 KTS...SUCH AS KDAY FROM 1445Z. SATELLITE IMAGERY SHOWS NUMEROUS BREAKS IN THE DRY SLOT. KILN RADAR SHOWING NUMEROUS SMALL SHOWERS. WE HAVE HAD A FEW REPORTS IN OUR FAR WEST OF A MIX. HAVE UPDATED ZONES TO GET RIDE OF HIGH POPS AND TO ADJUST TEMP WORDING. THIS AFT EXPECTING SCATTERED RAIN SHOWERS TO TURN TO SNOW SHOWERS. WIND GUSTS SHOULD BE THE WORST THROUGH 20Z TO 21Z WHEN MIXING BEGINS TO END. LATEST NAM/RUC SHOWING 50 KTS THROUGH 18Z ACROSS THE SOUTH AND 21Z ACROSS THE NORTH. TIPTON && .PREV DISCUSSION... /ISSUED 837 AM EST FRI DEC 1 2006/ SHORT TERM /REST OF TODAY/... LATEST SFC MAP SHOWS COLD FRONT PUSHING EAST THRU CENTRAL OHIO ATTM. CONVECTIVE LINE ASSOCIATED WITH THIS FRONT HAS SHIFTED EAST OF FA WITH DRY SLOT WORKING INTO SE IN AND SW OHIO. THEREFORE HAVE DROPPED ALL SEVERE/TORNADO WATCHES IN ILN/S FA. GRADIENT INCREASES THIS AFTERNOON WITH 45 TO 50 KNOT WINDS INDICATED AT 925MB. WITH MIXING EXPECT TO SEE WIND GUSTS IN EXCESS OF 50 MPH. HAVE CONTD HIGH WIND WARNING ACRS THE ENTIRE AREA THRU THE AFTN. REMAINDER OF THE FCST LOOKS GOOD WITH FALLING TEMPS AND SCTD RAIN SHOWERS CHANGING TO SNOW SHOWS WITH UPPER LOW EJECTING NE ACRS IN INTO SE LOWER MI THIS AFTN. PREV DISCUSSION... /ISSUED 656 AM EST FRI DEC 1 2006/ AVIATION /12Z-12Z/... THE SFC LOW WAS LOCATED OVER INDIANA THIS MORNING WITH NUMEROUS SHOWERS ACROSS AREAS EAST OF I-75. AS THE LOW PROGRESSES NE...PCPN WILL SCATTERED. SW WINDS WILL GUST WILL BE NEAR/ABOVE 40 KTS AT TIMES 16Z-23Z...DROPPING NEAR 20 KTS IN THE EVENING AS THE LOW MOVES NORTH OF THE REGION. GENERALLY...VFR CIGS WILL DROP TO MVFR OVER THE NEXT FEW HOURS AND REMAIN MVFR THROUGH 06Z...THEN SCATTERING OUT SW TO NE. MVFR VISIBILITIES WITH -SHSN ARE POSSIBLE AFTER 18Z AND THROUGH THE EARLY EVENING. PREV DISCUSSION... /ISSUED 532 AM EST FRI DEC 1 2006/ SHORT TERM /TODAY THROUGH SUNDAY/... PRIMARY LOW PRESSURE SYSTEM IS CURRENTLY OVER SOUTHERN ILLINOIS WITH A SECONDARY LOW STARTING TO DEVELOP IN SOUTHERN INDIANA. THE ENTIRE SYSTEM IS QUICKLY MOVING NORTH NORTHEAST. WARM SECTOR IS SPREADING NORTH EARLY THIS MORNING. THEN STRONG COLD AIR ADVECTION WILL OCCUR ON THE BACK SIDE OF THE LOW WHICH SHOULD RESULT IN EXCELLENT MIXING WITH SOME WIND GUSTS UP TO 60 MPH PARTICULARLY FROM MID MORNING THROUGH MID AFTERNOON. WIDESPREAD PRECIPITATION WILL COME TO AN END THIS MORNING AS DRY SLOT MOVES IN. BUT SHOULD STILL SEE SCATTERED RAIN AND SNOW SHOWERS DURING THE AFTERNOON AND THEN DIMINISH BY EVENING. HIGH PRESSURE THEN BUILDS INTO THE REGION WITH A REINFORCING PUSH OF COLD AIR ON SUNDAY. PREV DISCUSSION... /ISSUED 342 PM EST THU NOV 30 2006/ LONG TERM /SUNDAY THROUGH THURSDAY/... LONG WAVE TROUGH OVER EASTERN CONUS WILL PERSIST THROUGH THE PERIOD. THIS WILL RESULT IN COOL AND MAINLY DRY WEATHER FOR ILN AREA. SUNDAY WILL BE DRY WITH HIGH PRESSURE BUILDING IN FROM THE WEST. A SHORT WAVE TROUGH WILL BRING THE CHANCE FOR SNOW SHOWERS TO OUR NORTHERN COUNTIES SUNDAY NIGHT THROUGH TUESDAY. LAKE ENHANCEMENT MAY COME INTO PLAY DURING THAT PERIOD. AFTER HIGH PRESSURE AND DRY AIR OVERSPREADS THE AREA ON WEDNESDAY...A TROUGH OF LOW PRESSURE TRAVELING NEAR THE GULF COAST MAY THROW SOME MOISTURE INTO THE OHIO VALLEY IN THE FORM OF SNOW. TEMPERATURES ARE FORECAST TO BE BELOW NORMAL. UNDERCUT HPC GUIDANCE SUNDAY NIGHT WHEN AIRMASS IS PROGGED TO BE COLDEST...WITH 1000-850MB THICKNESS OF 1236M INDICATED AT CVG. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR OHZ026-034- 035-042>046-051>056-060>065-074. HIGH WIND WARNING UNTIL 6 PM EST THIS AFTERNOON FOR OHZ070>073- 077>082-088. KY...HIGH WIND WARNING UNTIL 6 PM EST THIS AFTERNOON FOR KYZ089>100. IN...HIGH WIND WARNING UNTIL 7 PM EST THIS EVENING FOR INZ050-058- 059. HIGH WIND WARNING UNTIL 6 PM EST THIS AFTERNOON FOR INZ066- 073>075-080. && $$ SHORT TERM... oh AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CHARLESTON SC 644 PM EST DEC 1 2006 .AVIATION UPDATE /00Z-00Z/...RECENTLY AMENDED THE KCHS TAF TO INCLUDE A MENTION OF LOW-LVL WIND SHEAR THROUGH 03Z. SFC WINDS HAVE DROPPED OFF CONSIDERABLY OVER THE PAST FEW HOURS BUT WINDS JUST OFF THE SFC ARE STILL HOWLING WITH 1000 FT WINDS OF 30-35 KT MEASURED ON THE DURING THE FIRST FEW MINUTES OF THE EVENING CHS SOUNDING. IN FACT A REPORT OF LOW-LVL WIND SHEAR FROM THE SFC TO 1500 FT WAS RECENTLY RECEIVED VIA A PIREP FROM THE JAMES ISLAND EXECUTIVE AIRPORT /KJZI/. THE RISK FOR WIND SHEAR WILL QUICKLY DIMINISH BY 03Z AS A CDFNT MOVES THROUGH THE TERMINAL AND THE WESTERN FRINGE OF THE LLJ SHIFTS OFF THE COAST. THE LOW-LVL JET APPEARS TO HAVE CLEARED THE KSAV TERMINAL BASED ON THE KCLX VWP AND 21Z RUC OUTPUT SO THE RISK FOR LOW-LVL WIND SHEAR THERE IS LOW. && .MARINE UPDATE...WE HAVE RECEIVED SEVERAL REPORTS OF DENSE SEA FOG OFF THE BEAUFORT COUNTY COAST OVER THE PAST HOUR OR SO...THE LAST OF WHICH WAS IN CALIBOGUE SOUND OFF THE SOUTHERN END OF HILTON HEAD ISLAND. CONDITIONS REMAIN VERY FAVORABLE FOR PATCHES OF DENSE SEA FOG TO DEVELOP WITH VSBYS DROPPING TO THAN LESS THAN 1/2 NM. THE COLD FRONT MOVING THROUGH THE SC MIDLANDS AND EAST-CENTRAL GA SHOULD BE OFF THE COAST BY 9 OR 10 PM...SO ANY RESIDUAL SEA FOG WILL BE PUSHED OUT TO SEA AS OFFSHORE WINDS DEVELOP. THE COASTAL WATERS FORECAST HAS BEEN UPDATED TO REFLECT PATCHY DENSE SEA FOG AND A MARINE WEATHER STATEMENT HAS BEEN ISSUED THROUGH 9 PM. AT THIS POINT...I DO NOT SEE THE NEED TO ISSUE A DENSE FOG ADVISORY FOR ANY OF THE NEARSHORE MARINE ZONES OR THE ADJACENT PUBLIC ZONES GIVEN THE SHORT DURATION AND OVERALL LIMITED SPATIAL EXTENT OF THE FOG. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...LAKE WIND ADVISORY FOR LAKE MOULTRIE SCZ045 UNTIL 11 PM. MARINE...SMALL CRAFT ADVISORY AMZ330-350-352-354-374. && $$ ST sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 204 PM EST FRI DEC 1 2006 .SHORT TERM (TONIGHT THROUGH MONDAY)... LATEST OBS SHOW THAT SUSTAINED WINDS HAVE DECREASED TO BETWEEN 15 AND 25 KTS WITH THE HIGHEST GUSTS TO 35 KTS. VWP SHOWS WINDS TO 5000 FT ARE DOWN TO 30 KTS...AND RUC SHOWS WINDS CONTINUING TO DECREASE INTO THE EVENING. THUS WILL ALLOW ALL HIGH WIND WARNINGS/ADVISORIES TO EXPIRE WITH THE AFTERNOON PACKAGE ISSUANCE. ADVECTION OF COLD DRY AIR INTO THE AREA WILL CONTINUE OVERNIGHT...AND WITH CLEAR SKIES TEMPS WILL DROP INTO THE 20S. THE SURFACE HIGH THAT BUILDS OVER THE AREA ORIGINATES FROM THE TEXAS AREA...SO TEMPS WILL RECOVER INTO THE 50S ON SATURDAY. A PLUME OF UPPER LEVEL MOISTURE SEEN OVER NORTHERN MEXICO IN WV IMAGERY WILL BRING SOME CIRRUS TO THE AREA BEGINNING SATURDAY AFTERNOON AND SATURDAY NIGHT. THE MODELS HAVE SOME DIFFERENCES WITH THE TIMING AND STRENGTH OF AN UPPER TROUGH THAT BRINGS A SURGE OF COLD AIR ON SUNDAY NIGHT/MONDAY. THE GFS HAS A LESS AMPLIFIED TROUGH...AND THUS IS FASTER TO BRING THE COLD AIR IN. THE GFS HAS A WEAKER SURFACE HIGH AND THE EXTENT OF THE COLD SURGE IS NOT AS FAR SOUTH AS THE NAM. AT THIS TIME A COMPROMISE SOLUTION SEEMS BEST...AND WILL HAVE HIGHS ON MONDAY IN THE 35 TO 45 RANGE...A BIT BELOW GFS MOS. MOISTURE WILL BE TOO LIMITED FOR ANY PRECIP WITH THE TROUGH PASSAGE ON MONDAY. .LONG TERM (MONDAY NIGHT THROUGH FRIDAY)... NO SIGNIFICANT CHANGES WERE MADE TO THE FORECAST THIS PERIOD. DRY WEATHER WITH BELOW NORMAL TEMPERATURES ARE EXPECTED. A WEAK LOW PRESSURE TROUGH CROSSES THE AREA ON WEDNESDAY WITH LITTLE IMPACT ON THE SENSIBLE WEATHER. A HIGH PRESSURE AREA FROM CANADA WILL BRING ANOTHER SURGE OF COLD AIR ON THURSDAY. && .PRELIMINARY POINT TEMPS/POPS... CHATTANOOGA AIRPORT, TN 35 55 32 56 / 0 0 0 0 KNOXVILLE MCGHEE TYSON AIRPORT, TN 30 52 33 53 / 0 0 0 0 OAK RIDGE, TN 31 51 32 53 / 0 0 0 0 TRI CITIES AIRPORT, TN 27 52 28 51 / 0 0 0 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ DGS tn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MORRISTOWN TN 1047 AM EST FRI DEC 1 2006 .DISCUSSION... UPDATE WILL DECREASE WIND SPEEDS AND LOWER THE HIGH WIND WARNING TO A WIND ADVISORY IN THE CENTRAL VALLEY/NORTHERN PLATEAU AREAS. THE HIGHEST WINDS CAME AS THE SHOWERS PAST THROUGH EARLIER THIS MORNING...WITH MEASURED GUSTS OF 60-75 MPH IN SOME SPOTS AND NUMEROUS TREES DOWN ACROSS THE ENTIRE AREA. AN LSR WILL BE SENT SHORTLY WITH MORE DETAILS ON THESE REPORTS. THE FRONT IS LOCATED FROM LEE CO. VA TO AROUND CHEROKEE CO. NC AT THIS TIME. TEMPS WILL CONTINUE TO FALL THROUGH THE DAY AS THE FRONT MOVES ACROSS THE AREA. HIGHER ELEVATIONS WILL CONTINUE TO SEE WINDS SUSTAINED BETWEEN 30 AND 40 MPH WITH GUSTS TO 60 MPH. VALLEY LOCATIONS WILL BE MAINLY BETWEEN 25 AND 35 MPH WITH GUSTS TO 50 MPH. WINDS ALOFT DECREASE THROUGH THE AFTERNOON PER THE RUC MODEL...SO GUSTS SHOULD WEAKEN TO UNDER 40 MPH BY 4 PM. THUS THE EXPIRATION TIME OF THE WARNING/ADVISORY WAS CHANGED TO 4 PM. && .MRX WATCHES/WARNINGS/ADVISORIES... NC...WIND ADVISORY UNTIL 4 PM FRIDAY FOR THE FOLLOWING ZONES: CHEROKEE...AND CLAY. TN...WIND ADVISORY UNTIL 4 PM FRIDAY FOR THE FOLLOWING ZONES: ANDERSON...BLEDSOE...BRADLEY...CAMPBELL...CLAIBORNE...EAST POLK...GRAINGER...HAMBLEN...HAMILTON...JEFFERSON...KNOX... LOUDON...MARION...MCMINN...MEIGS...MORGAN...NW BLOUNT... NORTH SEVIER...NORTHWEST COCKE...NORTHWEST MONROE...RHEA... ROANE...SCOTT TN...SEQUATCHIE...UNION...AND WEST POLK. HIGH WIND WARNING UNTIL 4 PM FRIDAY FOR THE FOLLOWING ZONES: BLOUNT SMOKY MOUNTAINS...COCKE SMOKY MOUNTAINS...HANCOCK... HAWKINS...JOHNSON...NORTHWEST CARTER...NORTHWEST GREENE... SEVIER SMOKY MOUNTAINS...SOUTHEAST CARTER...SOUTHEAST GREENE...SOUTHEAST MONROE...SULLIVAN...UNICOI...AND WASHINGTON TN. VA...HIGH WIND WARNING UNTIL 4 PM FRIDAY FOR THE FOLLOWING ZONES: LEE...RUSSELL...SCOTT...WASHINGTON...AND WISE. && $$ DGS/TD tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WA 506 PM PST FRI DEC 1 2006 .SYNOPSIS...BELOW NORMAL TEMPERATURES WILL ACCOMPANY A DRYING TREND THROUGH THE WEEKEND. FOLLOWING THE THREAT OF ISOLATED SNOWS TODAY OVER MAINLY THE IDAHO PANHANDLE...THE MAIN WEATHER THREAT WILL TURN TO FOG AND LOW CLOUDS THE NEXT FEW DAYS. && .DISCUSSION... TONIGHT...NORTHWEST FLOW WILL BE GIVING WAY TO A BUILDING UPPER LEVEL RIDGE OVERNIGHT. RUC ANALYSIS OF 21Z 250MB WINDS DEPICT A 120KT JET STREAK DIVING THROUGH CENTRAL WASHINGTON. SOME WIDELY SCATTERED MOUNTAIN SNOW SHOWERS ARE BEING DETECTED EAST OF THE JET CORE IN THE CYCLONIC FLOW. THE INSTABILITY DRIVING THESE SNOW SHOWERS ARE IN THE LAYER BELOW 700MB...AND AS TEMPERATURES AT THIS LEVEL WARM OVERNIGHT...THE SHALLOW CONVECTIVE ACTIVITY WILL WANE. UP TO AN INCH OF SNOW IS POSSIBLE FOR THE CAMAS PRAIRIE AND THE CENTRAL PANHANDLE MOUNTAINS...BUT ELSEWHERE PRECIPITATION CHANCES WILL BE VERY LOW. AS UPPER LEVEL RIDGING BUILDS INTO THE REGION FOR THE WEEKEND... THE CONCERN FOR FOG AND AIR STAGNATION ARISES. WFOS SPOKANE AND PENDLETON ALONG WITH STATE AND LOCAL AGENCIES AGREED TO HOLD OFF ON THE ISSUANCE OF AN AIR STAGNATION ADVISORY FOR THE WEEKEND. PARTICULATE LEVELS THIS MORNING WERE BELOW ADVISORY CRITERIA...BUT LEVELS ARE EXPECTED TO RISE THROUGH THE WEEKEND TO MODERATE LEVELS. THE POTENTIAL FOR AN AIR STAGNATION ADVISORY WILL LIKELY BE GIVEN STRONG CONSIDERATION EARLY NEXT WEEK...DEPENDING ON THE STRENGTH OF THE MONDAY NIGHT/TUESDAY SYSTEM. /GKOCH SATURDAY THROUGH MONDAY...UPPER LEVEL RIDGE WILL MOVE INLAND SATURDAY NIGHT AND SUNDAY. DRY FORECAST EXCEPT FOR PERHAPS A LIGHT FLURRY FALLING OUT OF THE STRATUS. MAIN FORECAST CONCERN IS FOG AND STRATUS POTENTIAL. WITH SNOW ON THE GROUND...AND MODELS INDICATING LOW LEVEL MOISTURE STICKING AROUND...PLUS VERY LITTLE MIXING...THINK THE VALLEY STRATUS AND FOG WILL REMAIN IN PLACE THROUGH MOST OF THE WEEKEND. THERE MAY BE BRIEF PERIODS IN THE MID TO LATE AFTERNOON WHERE THE CLOUDS WILL LIFT AND THE SUN MAY PEAK OUT...BUT IT WILL BE SHORT-LIVED. TEMPERATURES WILL REMAIN BELOW AVERAGE FOR THIS TIME OF THE YEAR...AND WITH THE LOW CLOUDS AND FOG...NOT A LOT OF VARIATION BETWEEN THE HIGH AND LOW TEMPERATURES. MONDAY IS WHERE MODELS START TO DIVERGE. MODELS HAVE DIFFERING TIMING OF THE NEXT TROUGH TO MOVE INTO THE AREA WITH THE ECMWF AND CANADIAN FASTER THAN THE GFS/UKMET. GIVEN THERE IS A STRONG RIDGE THAT THE TROUGH MUST ENCOUNTER...WOULD TEND TO THINK THE SLOWER OF THE MODELS IS CORRECT. HOWEVER AT THIS TIME ONLY LOWERED VALLEY CHANCE OF PRECIPITATION TO SLIGHT CHANCE...OTHERWISE NO BIG CHANGES MADE. /KOCH MONDAY NIGHT THROUGH FRIDAY NIGHT...MODEL INITIALIZATIONS LOOKED PRETTY REASONABLE AGAIN TODAY. TWO MAIN AREAS OF DISTURBED WEATHER OVER THE PACIFIC CAN BE RELATIVELY WELL RECOGNIZED FROM THE WATER VAPOR IMAGERY...A WEAKENING NEGATIVELY-TILTED SHORT WAVE BETWEEN 140W AND 150W OFF THE CALIFORNIA COAST...AND ANOTHER CLOSED 500 MB LOW NEAR 45N/160W. MODELS HAVE BEEN RELATIVELY CONSISTENT OVER THE PAST COUPLE OF DAYS WITH QUICKLY LIFTING THE SOUTHERN WAVE NORTH AHEAD OF THE CLOSED LOW...GRADUALLY BROADENING THE WAVE AND WEAKENING ITS AMPLITUDE WITH TIME. THE ONLY REAL ISSUES OF NOTE WITH THIS SEEM TO BE ITS TIMING AND HOW MUCH WAVE DEAMPLIFICATION OCCURS AS THIS WAVE REACHES THE TOP OF THE LONGWAVE RIDGE CURRENTLY PARKED NEAR THE WEST COAST. THE CURRENT GFS IS MUCH MORE AGGRESSIVE WITH WEAKENING THE SHORT WAVE AND ALSO 500 MB LOW OVER THE NEXT COUPLE OF DAYS THAN YESTERDAY'S RUN. IT IS ALSO SIGNIFICANTLY SLOWER WITH THE MOVEMENT OF BOTH FEATURES THAN THE 12Z ECMWF OR 12Z CANADIAN NOT TO MENTION ITS OWN ENSEMBLE MEAN. HOWEVER...THIS IS NOT THE ONLY THING THE MODELS DIVERGE ON TODAY. WITH REALLY NO INDICATION ON ANY MODEL EXCEPT THE CANADIAN THAT THE FIRST WAVE WILL BE ABLE TO SUCCESSFULLY CREST THE RIDGE IN AN COHERE FASHION...BELIEVE LITTLE WILL RESULT OVER THE CWA FROM THIS WAVE. MORE DISCREPANCIES OCCUR WITH THE CLOSED LOW AS WELL. WHILE THERE IS A RELATIVE AMOUNT OF CERTAINTY THAT THE MAIN IMPETUS OF LIFT FROM THE CLOSED LOW WILL STAY OFF SHORE...MODELS FOR THE PAST SEVERAL DAYS HAVE INDICATED A GOOD CHUNK OF MID-LEVEL ENERGY SHOULD COME ON SHORE LATE MONDAY. THE GFS AND CANADIAN CONTINUE TO DO THIS...ALBEIT IN A VERY WEAKENED FASHION. THE NEW ECMWF HAS COMPLETELY BACKED OFF FROM THIS SOLUTION. THE 500 MB WAVE THAT PIVOTS SOUTH OF THE PARENT LOW OFF THE BRITISH COLUMBIA COAST HARDLY MAKES IT INTO THE AREA...AND GIVEN THE ORIENTATION OF THE HEIGHT LINES...WOULD BE SURPRISED IF THERE WAS ANY SIGNIFICANT LIFT PRESENT ANYWHERE IN THE CWA IF THIS SOLUTION PANS OUT. FOR THESE REASONS AND BECAUSE IT FLOWS MORE FROM CONTINUITY FROM PREVIOUS FORECASTS...HAVE FOLLOWED SOMEWHAT OF A COMPROMISE BETWEEN THE 00Z ECMWF AND 12Z CANADIAN BUT MAINLY IGNORING WHAT THE CANADIAN DOES WITH THE FIRST WAVE. BELIEVE MORE RUNS FROM THE GFS AND ECMWF WILL NEED TO BE SEEN BEFORE ANY CONFIDENCE IN WEAKENING OF THE SYSTEM FOR MONDAY NIGHT CAN TRULY BE FORECAST...ESPECIALLY CONSIDERING THAT A SLOWER MOVING SOLUTION WITH THE FIRST WAVE MAY LEAD TO PHASING WITH THE SECOND AND STRONGER WAVE. AFTER THESE SYSTEMS CLEAR THE AREA AROUND TUESDAY...GOOD ENSEMBLE AND OPERATIONAL MODEL AGREEMENT ON THE RIDGE BUILDING BACK INTO THE AREA. WITH RH VALUES IN THE BOUNDARY LAYER NEVER DROPPING BELOW 90 PERCENT BELOW 925 MB PER THE GFS AND RELATIVELY STRONG LOW-LEVEL INVERSIONS BUILDING IN...BELIEVE LOW STRATUS AND FREEZING FOG MAY BE ISSUES GOING INTO NEXT WEEK. MOS TEMPERATURES WOULD SUGGEST THAT TEMPERATURES ACROSS THE CWA SHOULD TOP FREEZING IN THE AFTERNOONS...HOWEVER GIVEN LOW CLOUDS AND COLD AIR IN PLACE UNDER THE STRONG INVERSIONS...FIND THIS HIGHLY UNLIKELY. HAVE THEREFORE UNDERCUT MOS HIGHS THROUGH THE PERIOD AND STUCK WITHIN REACH OF THE MEX LOWS FOR THE MOST PART. /FRIES && .AVIATION... IFR/MVFR CEILINGS AND VISIBILITY DUE TO STRATUS AND FOG WILL CONTINUE AS THE LOW LEVEL INVERSION STRENGTHENS BELOW 4K FT THROUGH THE PERIOD. INSTABILITY SNOW SHOWERS WITHIN THE N-NW FLOW WILL BE FOUND ACROSS THE BLUE MTS AND THE CENTRAL AND SRN ID PANHANDLE. IMPROVING CONDS IS POSSIBLE BETWEEN 18Z-00Z ESPECIALLY IN THE BASIN...KGEG/COE AREA AND KPUW AREA. RFOX. && .PRELIMINARY POINT TEMPS/POPS... SPOKANE 17 21 15 24 19 28 / 0 0 0 0 0 20 COEUR D'ALENE 15 23 16 26 18 28 / 10 0 0 0 0 20 PULLMAN 20 26 20 28 23 31 / 10 0 0 0 0 20 LEWISTON 23 30 25 31 25 34 / 10 0 0 0 0 20 COLVILLE 8 20 9 24 15 27 / 0 0 0 0 0 20 SANDPOINT 14 23 12 25 15 27 / 10 0 0 0 0 20 KELLOGG 19 22 18 26 19 27 / 10 0 0 0 0 20 MOSES LAKE 16 24 15 26 18 29 / 0 0 0 0 0 20 WENATCHEE 18 24 16 26 20 28 / 0 0 0 0 0 20 OMAK 13 22 11 24 19 28 / 0 0 0 0 0 20 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...NONE. WA...NONE. && $$ wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 330 AM EST SAT DEC 2 2006 .SYNOPSIS... 07Z WATER VAPOR AND H4 RUC ANALYSIS NOW SHOW MUCH OF THE NATION UNDER THE INFLUENCE OF A LONE WAVE TROUGH WITH ITS AXIS EXTENDING SOUTHWEST FROM A CLOSED UPPER LOW OVER THE UPPER MISSISSIPPI VALLEY AND SOUTHWEST ONTARIO TO THE FOUR CORNERS REGION OF THE SOUTHWEST. POTENT UPPER LOW THAT WAS ASSOCIATED WITH ALL THE WINTRY PRECIPITATION ACROSS THE MID-SECTION OF THE COUNTRY THE PAST 48 HOURS IS NOW WEAKENING AS IT LIFTS NORTH ALONG THE EASTERN EDGE OF THE TROUGH INTO QUEBEC. UPPER LEVEL RIDGING CENTERED OVER THE BAHAMAS HAS BEEN PUSHED OFF THE EAST COAST INTO THE ATLANTIC BY THE CONTINENTAL TROUGH. AT THE SURFACE...THE COLD FRONT THAT BROUGHT THE SHOWERS TO THE REGION YESTERDAY IS NOW STALLING OUT JUST TO THE SOUTHEAST AND SOUTH OF OUR FORECAST AREA. SKIES HAVE GENERALLY BECOME MOSTLY CLEAR WITH THE EXCEPTION OF THE EASTERN BIG BEND WHERE SOME MID/HIGH CLOUDS LINGER CLOSER TO THE FRONTAL BOUNDARY. COLD ADVECTION IS OCCURRING FROM THE NORTHWEST THIS OVERNIGHT WITH TEMPERATURES FALLING INTO THE UPPER 30S AND LOWER 40S IN MOST OF OUR WESTERN AND NORTHERN AREAS AND INTO THE UPPER 40S AND 50S ACROSS OUR SOUTHEASTERN AREAS. THIS REPRESENTS UP TO A 30F 24 HR TEMP CHANGE FROM THE PRE-FRONTAL AIR EXPERIENCED AT THIS TIME LAST NIGHT WHEN SOME STATIONS FAILED TO FALL BELOW 70 DEGREES. && .SHORT TERM (SATURDAY THROUGH MONDAY)... COLD FRONT HAS STALLED TO THE SOUTH OF THE AREA ACROSS THE CENTRAL FLORIDA PENINSULA...TAKING THE BULK OF THE CLOUDCOVER WITH IT. HOWEVER...SOME HIGHER LEVEL CIRRUS IS EXPECTED AT TIMES THROUGH THE DAY ACROSS THE REGION TO FILTER THE SUN. AS WE HEAD INTO THE AFTERNOON HOURS...A WAVE DEVELOPING ALONG THE FRONT TO OUR SOUTH WILL ALLOW THE BOUNDARY TO BEGIN TO PUSH BACK NORTH. THIS WILL HAVE MOST INFLUENCE OVER THE SOUTHEASTERN BIG BEND ZONES WHERE SKIES SHOULD BECOME MOSTLY CLOUDY WITH EVEN THE VERY SLIGHT CHANCE OF A SHOWER OR TWO LATE IN THE DAY. TONIGHT THIS BOUNDARY AND THE ASSOCIATED MOISTURE MAKE EVEN MORE PROGRESS NORTH. THE CHANCE FOR SHOWERS WILL ALSO SPREAD NORTH AND WEST. HAVE ONLY LEFT AREAS WEST OF PANAMA CITY UP INTO SOUTHEASTERN ALABAMA WITH SILENT TEN POPS OVERNIGHT. THE REST OF THE AREAS RANGES FROM SLIGHT CHANCE TO HIGH END CHANCE POPS DOWN TOWARD TAYLOR...DIXIE AND LAFAYETTE COUNTIES. NOT EXPECTING ANY HEAVY RAIN...BUT STILL UP TO A QUARTER INCH IS NOT OUT OF THE QUESTION WITH DECENT SHOWER COVERAGE EXPECTED IN PLACES. COLDEST TEMPERATURES TONIGHT WILL BE AWAY FROM THE CLOUDS AND RAIN UP INTO SOUTHEAST ALABAMA WHERE UPPER 30 TO LOWER 40S SHOULD BE COMMON. WITH THE WARMEST TEMPERATURES DOWN TOWARD CROSS CITY WITH MIDDLE AND UPPER 50S COMMON. THE PATTERN CONTINUES INTO THE DAY ON SUNDAY WITH THE SHOWER COVERAGE LIKELY AT ITS PEAK DURING THE MORNING HOURS. AT THIS TIME EVEN OUR FAR WESTERN AND NORTHERN ZONES MAY SEE A QUICK SPRINKLE OR SHOWER. A POTENT SHORTWAVE WILL BE DIGGING THROUGH THE CENTER OF THE NATION ON SUNDAY PASSING NORTH OF OUR REGION LATE SUNDAY AND SUNDAY NIGHT. COLD AND STRONG SURFACE HIGH PRESSURE WILL FOLLOW THIS UPPER LEVEL FEATURE. AS THE WAVE ALONG THE FRONT INTENSIFIES INTO A CLOSED LOW OFF THE SOUTHEAST COAST SUNDAY NIGHT IT SHOULD HELP TO START THE BOUNDARY MOVING SOUTHEAST AGAIN WITH THE MOISTURE AND SHOWERS COLLAPSING SOUTHEAST AS WELL. THE HIGH TO OUR NORTHWEST WILL FINISH THE JOB AND PUSH THE OLD BOUNDARY AND ANY MOISTURE/CLOUDS ASSOCIATED WITH IT WELL SOUTH AND EAST OF OUR AREA BY EARLY MONDAY MORNING. STRONG COLD AIR ADVECTION WILL COMMENCE FROM THE NORTH AND NORTHWEST AS THIS HIGH BUILDS IN. SUNDAY NIGHT LOWS ARE LIKELY TO FALL INTO THE 30S NORTHWEST AND NORTH TO 40S SOUTH AND EAST AND THEN REBOUND ONLY INTO THE 50S TO NEAR 60 ON MONDAY (DESPITE PLENTY OF SUNSHINE). QUICK NOTE...LATE MONDAY NIGHT INTO THE EARLY MORNING HOURS OF TUESDAY CONTINUES TO LOOK LIKE OUR FIRST WIDESPREAD FREEZE EVENT. AS HIGH PRESSURE CONTINUES TO BUILD FROM THE WEST WITH VERY DRY AIR...CLEAR SKIES AND DIMINISHING WINDS...THE BOUNDARY LAYER SHOULD BE ABLE TO DECOUPLE AND ALLOW FOR VERY GOOD RADIATIONAL COOLING CONDITIONS. IF GUIDANCE DOES NOT CHANGE SIGNIFICANTLY THEN MANY LOCATIONS TOWARD SUNRISE ON TUESDAY MAY SEE TEMPERATURES IN THE UPPER 20S...WITH NORMALLY COLDER LOCATIONS INTO THE MIDDLE 20S. EVEN AREAS VERY NEAR THE COAST COULD SEE TEMPERATURES FLIRTING WITH THE FREEZING MARK FOR A FEW HOURS. && .LONG TERM (TUESDAY THROUGH FRIDAY)... AFTER A COLD START TUESDAY MORNING...TEMPERATURES SHOULD BE ABLE TO REBOUND QUICKLY UNDER PLENTY OF SUNSHINE INTO THE UPPER 50S AND LOWER 60S. HIGH PRESSURE REMAINS IN CONTROL OF THE REGION THROUGH THE DAY ON WEDNESDAY BEFORE EXITING OFF THE EASTERN SEABOARD. FOR THE SECOND HALF OF NEXT WEEK...GUIDANCE CONTINUES TO INDICATE A WEAK WAVE DEVELOPING IN THE WESTERN GULF OF MEXICO AND THEN SLOWLY PROGRESSING EAST TOWARD THE NORTHEASTERN GULF. THE LATEST RUN OF THE GFS IS A BIT SLOWER WITH THIS FEATURE. THIS VERY WEAK LOW NOW LOOKS TO INFLUENCE OUR REGION MOSTLY FROM LATER FRIDAY INTO THE FIRST PART OF NEXT SATURDAY. HOWEVER...THIS IS A LONG WAY OUT AND DETAILS ARE HIGHLY UNCERTAIN. DECIDED TO LEAVE THE SLIGHT CHANCE POPS FOR THURSDAY IN THE GRIDS AS SHOWERS ASSOCIATED WITH ISENTROPIC LIFT ARE LIKELY TO DEVELOP WELL OUT AHEAD OF THE MAIN FEATURE. IF THIS GULF WAVE DOES SLIDE JUST SOUTH OF THE AREA THEN THE COMBINATION OF SHOWERS AND ADVECTION OF DRIER LOW LEVEL AIR FROM THE NORTH MAY RESULT IN MUCH COOLER DAYTIME TEMPERATURES THAN IS CURRENTLY ADVERTISED IN THE GRIDS FROM FRIDAY INTO SATURDAY. UNTIL THE DETAILS OF THIS SYSTEM ARE MORE CERTAIN...THERE IS LITTLE REASON TO DIVERGE SIGNIFICANTLY FROM GUIDANCE. && .AVIATION... AFTER SEVERAL DAYS OF COMPLEX AND VARIABLE TAFS OVER THE REGION...THE NEXT 24-36 HRS WILL SEE QUITE A BREAK AT ALL OF THE SITES...WITH NOTHING WORSE THAN VFR CONDITIONS EXPECTED. AS THE STALLED OUT COLD FRONT BEGINS TO RETURN BACK TO THE NORTH...HIGH CLOUDS WILL BE ON THE INCREASE BY SATURDAY NIGHT...WITH LOWER CLOUDS AND SHOWERS EXPECTED TO RETURN BY SUNDAY. && .MARINE... GRADIENT BETWEEN THE FRONTAL BOUNDARY TO OUR SOUTH AND HIGH PRESSURE TO OUR NORTHWEST HAS KEPT THE WINDS UP A BIT OVERNIGHT ACROSS THE COASTAL WATERS WITH GENERALLY 10 TO 15 KNOTS WINDS. SEAS HAVE BEEN SURPRISINGLY HIGH AT THE OFFSHORE BUOYS BUT HAVE BEEN TRENDING DOWN IN THE PAST FEW HOURS. SHOULD SEE THE WINDS DROP OFF A BIT THIS AFTERNOON BUT WILL LEAVE THE SMALL CRAFT EXERCISE CAUTION WORDING IN THE OFFSHORE ZONES THIS MORNING. WINDS AND SEAS FALL BELOW CAUTION LEVELS TONIGHT INTO MUCH OF SUNDAY AS THE BOUNDARY TO OUR SOUTH COME BACK NORTH AND WEAKENS THE GRADIENT. STRONG HIGH PRESSURE THEN PUSHES THE BOUNDARY SOUTH SUNDAY NIGHT AND MONDAY WITH GUSTY NORTH TO NORTHEAST WINDS DEVELOPING. SMALL CRAFT ADVISORY CONDITIONS APPEAR LIKELY...ESPECIALLY ACROSS THE OFFSHORE WATERS BY LATE SUNDAY NIGHT AND CONTINUING THROUGH THE DAY ON MONDAY. && .FIRE WEATHER... RED FLAG WARNING CRITERIA IS EXPECTED TO BE REACHED FOR SEVERAL HOURS THIS AFTERNOON ACROSS INLAND PORTIONS OF THE EASTERN FLORIDA PANHANDLE. STRONG HIGH PRESSURE IS THEN EXPECTED TO ACROSS THE REGION FOR FOR THE MONDAY THROUGH WEDNESDAY TIME FRAME. THIS HIGH IS EXPECTED TO BRING WITH IT SOME VERY DRY LOW LEVEL AIR AND RED FLAG CRITERIA IS LIKELY TO BE MET BOTH MONDAY AND TUESDAY AFTERNOON ACROSS ALMOST THE ENTIRE COUNTY WARNING AREA. && .PRELIMINARY POINT TEMPS/POPS... TALLAHASSEE 66 47 66 43 59 / 05 20 30 10 05 PANAMA CITY 64 48 65 43 58 / 05 20 20 10 05 DOTHAN 63 40 65 36 56 / 05 10 20 05 05 ALBANY 65 42 64 37 57 / 05 10 20 05 05 VALDOSTA 66 51 65 43 58 / 10 30 30 10 05 CROSS CITY 71 56 69 49 63 / 20 40 40 20 10 && .TAE WATCHES/WARNINGS/ADVISORIES... AL...NONE. GA...NONE. FL...RED FLAG WARNING IN EFFECT FROM 11 AM CST TO 5 PM CST FOR PORTIONS OF THE EASTERN FLORIDA PANHANDLE INCLUDING THE COUNTIES OF CALHOUN...JACKSON...WALTON...WASHINGTON AND HOLMES. GM...NONE. && $$ AVIATION/FIRE WX...GOULD PUBLIC/MARINE...MROCZKA fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 350 AM EST SAT DEC 2 2006 .DISCUSSION... 00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW POTENT SHRTWV THAT BROUGHT A COUPLE OF INCHES OF SN TO THE ERN ZNS YDAY HEADING QUICKLY ENE. CYC NLY FLOW IN THE WAKE OF ASSOCIATED SFC LO DELIVERING SOME LES TO THE AREA EARLY THIS MRNG. DPVA/H85-5 QVECTOR CNVGC ASSOCIATED WITH SHRTWV MOVING THRU WI LAST EVNG ENHANCED THE LES A BIT...BUT RADAR TRENDS SUG ACTIVITIY ON THE WANE FOR NOW WITH ARRIVAL OF DNVA/ H85-5 QVECTOR DVGC/WEAK SFC RDGING FM MN. PRESENT LES APPEARS TO BE MOST PRONOUNCED OVER THE W IN THE LLVL CNVGC ZN BTWN NE WINDS OVER THE KEWEENAW AND LAND BREEZE WSW FLOW NOTED AT IWD AS WELL AS IN ALGER COUNTY WHERE NNE FLOW OVER LK SUP CONVERGING WITH WNW LAND BREEZE FLOW OBSVD FM MQT-ESC. 01Z TAMDAR SDNG FM SAW SHOWED INVRN BASE ARND H8 WITH BASE TEMP NR -17C ABV MOIST SUB INVRN LYR. FARTHER W...FAIRLY IMPRESSIVE SHRTWV NOTED ON IR STLT IMAGERY MOVING INTO NW MN. ASSOCIATED SFC LO JUST S OF LK WINNIPEG AT 04Z WITH ATTENDANT FAIRLY SHARP COLD FNT EXTENDING S ACRS WRN MN. NW WIND GUSTS AOA 30 MPH BEHIND THIS BNDRY. ALTHOUGH PWAT FAIRLY LO AT 0.18 INCH...00Z BIS SDNG IS RELATIVELY MOIST THRU THE ENTIRE TROP TO H3 AND SHOWS INVRN BASE ARND H75 WITH TEMP THERE -17C INDICATING A DEEP LYR WITH FVRBL SN GROWTH TEMPS. MAIN FCST CONCERNS THIS PACKAGE ARE LES TRENDS/AMTS/HEADLINES. FOR TDAY...LARGER SCALE MODELS IN GOOD AGREEMENT SHOWING SHRTWV TO THE W MOVING E INTO THE UPR GRT LKS WITH BAND OF ASSOCIATED DPVA/ H85-5 QVECTOR CNVGC IMPACTING THE FA. GUIDANCE INDICATES LLVL FLOW WL BACK INTO EARLY SAT WITH THE APRCH OF THIS SYS. SO ONGOING LES OVER THE W AND NCNTRL SHOULD BEGIN TO SHIFT TO THE NE AS WINDS OVER LAND TURN SW. WL CANX MQT ADVY AS LES OUT OF THE COUNTY AS OF 08Z BUT PERSIST THE ALGER HEADLINE THRU THE MRNG. THE BIG QUESTION IS WHERE POTENTIALLY HVY LES IN AREA OF ENHANCED LLVL CNVGC WL SETUP LATER THIS MRNG INTO TNGT. CERTAINLY THE UPSTREAM 00Z BIS SNDG HINTS THAT SGNFT LES COULD FALL GIVEN FVRBL THERMODYNAMIC PROFILE FOR DEEP INSTABILITY/SN GROWTH. GFS/NAM/ UKMET ALL IN GOOD AGREEMENT DEPICTING SHARP LLVL CNVGC SETTING UP ACRS THE KEWEENAW PENINSULA WITH LK ENHANCED SFC TROF HELPING TO FOCUS THE LLVL CNVGC. THE CNDN MODEL IS SOMEWHAT SIMILAR BUT SHOWS THE FOCUSED H95 CNVGC SETTING UP OVER JUST KEWEENAW COUNTY. THE 00Z RUC13 AND 12Z HI RES LOCAL MODEL ON THE OTHER HAND HINTS AT DVLPMNT OF MESOLO OVER WRN LK SUP THAT ENHANCES THE LLVL SW FLOW ACRS THE WRN ZNS SO THAT FOCUSED CNVGC IS FARTHER N OUT OVER THE OPEN LAKE. SINCE THE LLVL FLOW ATTM AT PILM4/ROAM4/P59 IS A STEADY NNE WITH RUC13 SHOWING PRES RISES UP TO 2MB/3HRS OVER ONTARIO ALL DAY... PREFER TO FOLLOW THE LARGER SCALE MODELS WITH FOCUSED LLVL CNVGC FARTHER S ACRS THE KEWEENAW. GIVEN POTENTIAL FOR IMPRESSIVE DEEP INSTABILITY/FVRBL SN GROWTH...HAVE OPTED TO UPGRADE WATCH TO WRNG FOR NRN HOUGHTON AND KEWEENAW COUNTIES. LES CHART SUGS 6"/ 12HRS... WHICH MAY BE CONSERVATIVE WITH SUCH FOCUSED LLVL CNVGC. WL INCRS POPS A BIT ACRS SRN SCHOOLCRAFT COUNTY DOWNSTREAM OF LK MI WITH EXPECTATION FOR SOME LES OFF LK MI FOR A TIME THIS WHILE THE FLOW OFF THE WATER IS UNIDIRECTIONAL SW. HOWEVER INITIALLY DRY LLVLS AND STEADILY SHIFTING WINDS WL LIMIT PSBL ACCUMULATION THERE. ALTHOUGH THERE WL BE SOME SCT -SHSN OVER THE REST OF THE FA WITH PASSAGE OF HEALTHY DYNAMICS...SW FLOW NOT FVRBL FOR ANY ADVY SN ELSEWHERE. ONCE SHRTWV TRACKS TO THE E TNGT...LLVL FLOW FCST TO TURN TO THE N AND SHIFT AXIS OF SHARPER LLVL CNVGC TO THE S. SAME DISAGREEMENT ON THE TIMING/LOCATION OF THE WSHFT/TROF...BUT MOST GUIDANCE EXCEPT RUC13 SHOWS FLOW TURNING TO AN UNFVRBL N OVER THE KEWEENAW BY 06Z. BUT KEPT WRNG GOING THRU 09Z TO TAKE INTO ACCOUNT SLOWER RUC13 SCENARIO AND TO GIVE MAX TIME TO VERIFY WRNG IN CASE LLVL CNVGC FOCUSED FARTHER N INITIALLY. ALSO OPTED TO ISSUE LES WATCH FOR GOGEBIC/ONTONAGON AND BARAGA/MQT COUNTIES AFT 03Z TNGT TO ACCOUNT FOR SAME FVRBL SN GROWTH/INSTABILITY AS WELL AS SHARP CYC NNE FLOW DOWN THE LENGTH OF WRN LK SUP/INTO THE NCNTRL U.P. AND BEEFY LLVL CNVGC FCST BTWN THE STRENGTHENING NLY FLOW AND ANTICIPATED WLY LAND BREEZE FLOW AHEAD OF WSHFT. ALTHOUGH TROF PROGGED TO PUSH TO THE S AND CYC FLOW FCST TO WEAKEN A BIT AND DEEPER MSTR PROGGED TO EXIT ON SUN ESPECIALLY IN THE AFTN AS LLVL FLOW BACKS SLOWLY AND SHRTWV EXITS TO THE E...MAINTAINED WATCH THRU THE DAY WITH PERSISTENT COLD NLY FLOW AND ALL MODELS SHOWING LINGERING H95 CNVGC (SHIFTING A BIT WITH THE WINDS). EXTENDED WATCH FOR BARAGA ONLY UNTIL 18Z AS FLOW PROGGED TO BCM A MORE UNFVRBL NNW IN THE AFTN. ALSO TOYED WITH POSTING WATCH FOR ALGER COUNTY ESPECIALLY FOR SUN...BUT WITH FLOW INITIALLY MORE NNE AT TIME OF SHARPEST LLVL CNVGC/DEEPER LLVL MSTR. THINK ALGER WL END UP WITH ADVY SN FALL ONCE WINDS SHIFT MORE NNW IN THE AFTN AND LLVL CNVGC WANES A BIT/DEEPER MSTR DEPARTS. AS NEXT SHRTWV APRCHS SUN NGT AND LLVL FLOW BACKS TO THE SW...LES WL DIMINISH. ALTHOUGH GFS/UKMET SHOW FAIRLY IMPRESSIVE DPVA/MODEST ISENTROPIC LIFT/H85-5 QVECTOR CNVGC IN ADVANCE OF NEXT SHRTWV IN NW FLOW ALF...INITIAL DRYNESS OF AIRMASS WL LIMIT SN CHCS. SO MAINTAINED ONLY SCHC POPS AWAY FM LK MOISTENING. COORDINATED WITH APX/DLH/GRB. && .MQT WATCHES/WARNINGS/ADVISORIES... LES ADVY MIZ006 UNTIL 17Z TDAY. LES WRNG MIZ001-003 14Z TDAY-06Z SUN. LES WATCH MIZ002-005-009 03Z-24Z SUN. LES WATCH MIZ004 03Z-18Z SUN. && $$ KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 343 AM CST SAT DEC 2 2006 .DISCUSSION SOME PATCHY DENSE FOG DEVELOPED ACROSS PARTS OF SOUTHEAST KANSAS DURING THE EARLY MORNING HOURS OVER THE SNOW PACK FROM YESTERDAY'S WINTER STORM. OUR CURRENT GRIDS CONTAIN PATCHY FREEZING FOG ACROSS ROUGHLY THE SOUTHEAST HALF OF THE FORECAST AREA THROUGH 15Z. A DECENT SWATH OF MID LEVEL CLOUD COVER IS STREAMING IN FROM THE WEST. WITH THIS IN MIND I MAY SCALE BACK THE FOG IN THE GRIDS BUT KEEP SOME IN ACROSS OUR FAR SOUTHERN AREAS. THIS REGION IS CLOSE TO THE EDGE OF THE CLOUD COVER AND MAY EXPERIENCE CLEARING FOR A TIME. THE PRIMARY FORECAST ISSUE THROUGH AT LEAST THE FIRST HALF OF NEXT WEEK WILL BE TEMPERATURES...AS A LACK OF MOISTURE WILL KEEP PRECIPITATION CHANCES MINIMAL AT BEST. TEMPERATURES WILL BE A CHALLENGE THE NEXT FEW DAYS...AS THE EFFECTS OF A REINFORCING SHOT OF COLD AIR AND THE LINGERING SNOW PACK WILL NEED TO BE ASSESSED. ONCE THING THAT IS FOR CERTAIN...BELOW NORMAL TEMPERATURES WILL CONTINUE ACROSS THE REGION. A QUICK MOVING FRONTAL BOUNDARY WILL PUSH INTO THE FORECAST AREA FROM THE NORTHWEST THIS MORNING...AND PASS THROUGH THE REMAINDER OF THE CWA BY 00Z SUNDAY. GENERALLY TRENDED TOWARD THE COOLER MET GUIDANCE FOR AREAS WITHOUT SNOW COVER...AND UNDERCUT GUIDANCE BY SEVERAL DEGREES OVER THE SNOW PACK AREAS. GENERALLY KEPT HIGHS IN THE UPPER 20S SOUTH/SOUTHEAST OF AN OLATHE TO KIRKSVILLE LINE. WENT WITH UPPER 30S ACROSS NORTHWEST MISSOURI...WITH TEMPERATURES LIKELY BECOMING STEADY OR SLIGHTLY DROPPING DURING THE AFTERNOON AS COLD AIR ADVECTION KICKS IN BEHIND THE FRONT. AS MENTIONED BEFORE...MOISTURE AVAILABILITY IS LIMITED...SO THE DRY GRIDS LOOK GOOD WITH THIS FRONTAL PASSAGE. THERE SHOULD BE SINGLE DIGITS LOWS ACROSS THE SNOW PACK TONIGHT AS LESS CLOUD COVER IS EXPECTED...AND ONCE AGAIN CUT GUIDANCE VALUES BY SEVERAL DEGREES IN THESE AREAS. IN ADDITION...A COLD AIRMASS BEHIND THE FRONT WILL LIKELY ALLOW THE REMAINDER OF THE FORECAST AREA TO DIP INTO THE LOWER TEENS. SUNDAY WILL BE LIKELY BE THE COOLEST DAY IN THE 7 DAY PERIOD AS -12 TO -14 DEG C 850 MB AIR OVERSPREADS THE AREA. DAYTIME TEMPERATURES WILL STRUGGLE TO REACH THE 30 DEGREE MARK...AND MUCH OF THE AREA WILL ONLY HIT THE MIDDLE 20S. BY MONDAY...WESTERLY DOWNSLOPE FLOW DEVELOPS...BRINGING A WARMER AIRMASS WHICH MAY ALLOW THE NON-SNOW COVER AREAS TO WARM INTO THE MIDDLE 30S TO NEAR 40 DEGREES. STILL EXPECTING SIGNIFICANT COVERAGE OF LINGERING SNOW COVER ACROSS SOUTHEAST SECTIONS OF THE FORECAST AREA. THEREFORE...I TEMPERED THE WARM UP SOMEWHAT...AND KEPT HIGHS ONLY IN THE LOWER 30S. SAW .PREV DISCUSSION / 955 PM CST FRI DEC 1/... MONITORING THE PATCHY FOG FORMING OVER THE DEEP SNOWPACK OVER SOUTHEAST KS AND SOUTHWEST MO. SO FAR THE FOG IS RATHER PATCHY AND SHALLOW. SATELLITE IMAGERY SHOWING MID LEVEL CLOUD DECK HAS THICKENED CONSIDERABLY ACROSS THE NORTHERN HALF OF KS SINCE 23Z AND IT HAS EXPANDED EASTWARD INTO WEST CENTRAL MO...RIGHT ON TOP OF THE DEEPER SNOW PACK. THIS SHOULD SLOW DOWN THE COOLING OVER THE SNOW PACK AND THUS REDUCE THE THREAT OF WIDESPREAD DENSE FOG OVER THE AREA. CURRENT FORECAST ALREADY HAS FREEZING FOG MENTIONED IN THE COUNTIES WITH THE DEEP SNOW SO WILL NOT ISSUE ANY ADVISORY AT THIS TIME. WILL CONTINUE TO MONITOR THE SITUATION AND IT IS POSSIBLE AN ADVISORY WILL BE NEEDED LATER TONIGHT SHOULD CONDITIONS DETERIORATE RAPIDLY. MJ && .PREV DISCUSSION... 339 PM... VISIBLE SATELLITE IMAGERY SNOWS A THICK BAND OF SNOW FROM THE TEXAS PANHANDLE NORTHEAST THROUGH CENTRAL MISSOURI INTO THE LOWER GREAT LAKES. WEST WINDS AT THE SURFACE HAVE HELPED TEMPERATURES JUMP INTO THE 30S THIS AFTERNOON IN THE AREAS FREE OF SNOW. SNOW COVERED AREAS WERE NOT QUIT THAT LUCKY...RANGING THROUGH THE 20S. SNOW PACK IS AT ITS THICKEST ACROSS OUR SOUTHEAST TIER OF COUNTIES WITH TOTALS IN EXCESS OF 14 INCHES WITH ISOLATED REPORTS UP TO 18 INCHES. A BIT MORE NATIONALLY...A BROAD TROUGH PREVAILS ACROSS THE CONUS. THE SHORTWAVE THAT BOUGHT OUR WINTER WEATHER LAST NIGHT IS CURRENTLY LIFTING THROUGH THE GREAT LAKES. FARTHER NORTHWEST ANOTHER SHORTWAVE CAN BE SEEN MOVING EAST SOUTHEAST THROUGH SOUTHERN MANITOBA. MEANWHILE...STILL FARTHER WEST...A SIGNIFICANT RIDGE IS RESIDING JUST OFF THE WEST COAST...READYING ITSELF FOR LANDFALL THIS WEEKEND. THE SHORTWAVE IN SOUTHERN MANITOBA WILL SWING INTO THE UPPER GREAT LAKES THIS WEEKEND...BUT A GENERAL LACK OF MOISTURE IN THE WAKE OF THURSDAY NIGHTS SNOW STORM WILL PREVENT ANY ACTIVITY ALONG THE FRONT IN THE CENTRAL PLAINS. IT WILL HOWEVER PUSH ANOTHER SHOT OF COLD AIR SOUTH INTO THE CENTRAL PLAINS LATE SATURDAY...THUS DROPPING AFTERNOON HIGHS BETWEEN SATURDAY AND SUNDAY AND TURNING WINDS BACK TO THE NORTH. FOCUS THROUGH THE WEEKEND WILL BE TEMPERATURES...ESPECIALLY THE OVERNIGHT LOWS. NEAR CLOUDLESS SKIES WILL PREVAIL ACROSS THE LOWER MISSOURI RIVER VALLEY TONIGHT. WITH A SIGNIFICANT SNOW PACK ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA I WILL BE UNDERCUTTING EVEN THE COLDEST GUIDANCE NUMBERS IN THE SNOW COVERED AREAS. PREVIOUS SHIFTS FORECAST OF LOW SINGLE DIGITS LOOK VERY REASONABLE ACROSS THE SOUTHEAST TIER OF COUNTIES...SO HAVE MADE LITTLE CHANGE TO TONIGHTS FORECAST. LIKEWISE FOR THE LOW SUNDAY AND MONDAY MORNING...GUIDANCE NUMBERS COME DOWN SOME FOR SUNDAY MORNING AS THE COLD AIR SURGES SOUTH. STILL...CONTINUED UNDERCUTTING GUIDANCE IN SNOW COVERED AREAS. SNOW FREE AREAS HOWEVER SHOULD FALL NEAR GUIDANCE NUMBERS. THE OTHER CONCERN FOR THE NEXT FEW NIGHTS WITH BE FREEZING FOG. TEMPERATURES WILL BE IN FREE FALL TONIGHT WITH THE CLEAR SKIES...SLOWING DOWN ONLY AS THEY HIT THE DEWPOINT VALUE. WITH SUCH A THICK AND EXPANSIVE SNOW PACK PROVIDING MOISTURE WE COULD EASILY SATURATE. THE QUESTION IS WHETHER OR NOT WE FREEZE THE MOISTURE OUT AS FROST BEFORE WE GET THE FOG. HAVE OPTED TO ADD PATCHY FREEZING FOG AS A HEDGE. REGARDLESS OF WHETHER WE GET FOG OR NOT...SURFACES WILL BE SLICK TONIGHT AS ANY MELTED SNOW ON THE ROADS WILL REFREEZE. WILL ADJUST THE HAZARDOUS WEATHER OUTLOOK TO REFLECT THIS THINKING. A STOUT NORTH SURFACE WIND SATURDAY NIGHT BEHIND THE FRONT SHOULD MITIGATE THIS PROBLEM SUNDAY MORNING. THE COLD PUSH FROM THE SHORTWAVE OVER THE WEEKEND SHOULD NOT LAST LONG. THE EAST PACIFIC RIDGE WILL HAVE MOVED INTO THE WESTER REGION BY MONDAY...AND WILL QUICKLY GET HIT ON THE CHIN WITH A FAST MOVING SHORTWAVE. THE NET RESULT FOR THE PLAINS IS A RETURN OF SOUTHERLY WINDS BY MONDAY AFTERNOON MODERATING TEMPERATURES. HAVE CONTINUED THE TREND OF MODERATING TEMPERATURES UP FOR MONDAY AND TUESDAY...BUT NOT AS MUCH AS GUIDANCE NUMBERS AS SOUTH WINDS WILL ADVECT OVER WHAT IS LEFT OF THE SNOW PACK ACROSS THE SOUTHERN HALF OF THE CWA. THESE TEMPERATURES WILL NEED TO BE AGGRESSIVELY ADJUSTED BASED ON WIND DIRECTION AND SNOW PACK CONDITIONS. FOR THE LAST HALF OF NEXT WEEK MID RANGE MODELS ARE IN GENERAL AGREEMENT THAT SHORTWAVE THAT CRESTED RIDGE WILL DIP INTO THE PLAINS. SOME DISCREPANCY STILL EXIST IN HOW FAR INTO THE PLAINS IT WILL DIG. ECMWF LOOKS BETTER AS IT KEEPS THE WAVE MORE PROGRESSIVE AND SHEARS IT APART LESS THAN THE GFS. EITHER WAY ANOTHER SHOT OF COLD AIR SHOULD MAKE ITS WAY SOUTH. HOWEVER...LOOKING AT THE FORECAST SOURCE REGION...NORTHEAST PACIFIC OCEAN...OF THE AIRMASS ARRIVING WITH THE SHORTWAVE...TEMPERATURES SHOULD NOT TUMBLE FAR. ADDITIONALLY...HAVE KEPT THE GOING FORECAST DRY AS THE WAVE PASSES BY AS THE SURFACE HIGH AHEAD OF IT SHOULD KEEP MUCH OF THE MOISTURE RETURN FROM THE GULF CUTOFF UNTIL VERY LATE IN THE WEEK. CUTTER $$ .PREVIOUS DISCUSSION... /350 AM CST FRI DEC 1 2006/ WINTER STORM IS GRADUALLY BEGINNING TO TAPER OFF FROM WEST TO EAST ACROSS THE FORECAST AREA THIS MORNING. THE BACK EDGE OF THE DEFORMATION ZONE HEAVY SNOW BAND MATCHES UP WELL WITH THE 700 MB TROWAL AXIS AS DEPICTED IN THE RUC MODEL. AS OF 930Z...THE BACK EDGE OF SIGNIFICANT SNOWFALL STRETCHED FROM NEAR KIRKSVILLE...TO WARRENSBURG...TO NEVADA. THE RUC 700MB THETA-E FIELDS INDICATE THE TROWAL AXIS WILL BE EXITING THE FORECAST AREA ALMOST RIGHT AT 12Z. THEREFORE...WILL KEEP THE CURRENT HEAVY SNOW WARNING GOING FOR OUR FAR EASTERN COUNTIES THROUGH 12Z...BUT WILL NOT EXTEND ANY HEADLINES LATER INTO THE MORNING. AREAS WITHIN THE WARNING AREA MAY PICK UP ANOTHER COUPLE OF INCHES WITHIN THE NEXT 2 TO 3 HOURS. CONSIDERED HOISTING A BLOWING SNOW ADVISORY DURING THE MORNING HOURS ACROSS THE SOUTHEAST PORTION OF THE CWA AFTER THE SNOW ENDS .HOWEVER...GUSTY WINDS LOOK TO SUBSIDE RATHER QUICKLY AS THE STRONGER SURFACE PRESSURE GRADIENT SHIFTS OFF TO THE EAST. INTO EARLY NEXT WEEK...THE PRIMARY FORECAST CONCERN LOOKS TO BE TEMPERATURES...AS PRECIPITATION CHANCES LOOK TO BE MINIMAL. IN THE TEMPERATURE GRIDS...AN ATTEMPT WAS MADE TO COOL DOWN AREAS OVER THE SNOW PACK LEFT BEHIND BY THE FIRST WINTER STORM OF THE SEASON. THIS AFTERNOON...AREAS WHICH RECEIVED 10+ INCHES OF SNOW ALONG OUR SOUTHERN BORDER WILL BE HARD PRESSED TO RISE OUT OF THE MIDDLE 20S...WHILE PARTS OF NORTHWEST MISSOURI WHICH MISSED THE STORM SHOULD WARM TO AROUND 36 OR 37 DEGREES. FOR TONIGHT...I UNDERCUT MOS GUIDANCE IN EXCESS OF 10 DEGREES ALONG THE DEEPER SNOWPACK. SINGLE DIGITS ARE LIKELY EVERYWHERE THAT RECEIVED SIGNIFICANT SNOW FROM THE STORM...WITH THE COLDEST READINGS LIKELY FROM MOUND CITY...TO BUTLER...TO SEDALIA. LOWS ACROSS THESE LOCATIONS MAY FLIRT WITH 1 OR 2 DEGREES ABOVE ZERO. ON SATURDAY...ANOTHER FRONT WILL BRING A REINFORCING SHOT OF COLD AIR TO THE REGION...BUT THERE DOESN'T LOOK TO BE ANY PRECIPITATION AS MOISTURE WILL BE QUITE LIMITED. SUNDAY LOOKS TO BE QUITE COLD AS 850MB TEMPERATURES RANGING FROM -10 TO -16 DEG C OVERSPREAD THE REGION. THIS COLD AIRMASS...AND THE LINGERING SNOW PACK WILL KEEP AFTERNOON HIGHS IN THE 20S AREAWIDE. SAW && .EAX WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. $$ WFO EAX mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 930 PM MST FRI DEC 1 2006 .SYNOPSIS...ONE MORE WEAK SYSTEM TO CLIP NORTHERN AND EASTERN AREAS LATE TONIGHT THROUGH SATURDAY. IN THE WAKE OF THIS SYSTEM A STRONG RIDGE OF HIGH PRESSURE WILL PREVAIL THROUGH MOST OF NEXT WEEK. && .DISCUSSION...MEAN LONGWAVE TROUGH ENCOMPASSES MUCH OF THE CONUS THIS EVENING PER WATER VAPOR IMAGERY. WEAK SHORTWAVE TROUGH DIGGING ALONG BACKSIDE OF THIS LONGWAVE THROUGH CENTRAL ID WILL PUSH SOUTH THROUGH UT LATE TONIGHT THROUGH SATURDAY MORNING. HAVE SEEN AN INCREASE IN RETURNS ACROSS THE GSL THIS EVENING AS WAVE APPROACHES. LAKE-700MB TEMP DIFFERENTIAL IS SUFFICIENT TO SUPPORT WEAK INSTABILITY /-14C OBSERVED THIS EVENING AT KSLC AND LAKE TEMP NEAR 4C/...HOWEVER 00Z KSLC SOUNDING INDICATES LAYER OF INSTABILITY LIKELY QUITE SHALLOW DUE TO INVERSION ABOVE 600MB. 00Z RUC ANALYSIS INDICATES 500MB BAROCLINIC ZONE STRETCHING ACROSS FAR NORTHEAST UT...WHICH IS FORECAST TO SAG SOUTHWARD LATE TONIGHT THROUGH EARLY SATURDAY. THIS WOULD INCREASE DEPTH OF INSTABILITY ACROSS GSL...AND PERHAPS SUPPORT LAKE ENHANCED SHOW SHOWERS PRIMARILY ACROSS TOOELE COUNTY. ADDITIONALLY...AS SHORTWAVE APPROACHES MAY SEE AN INCREASE IN COVERAGE OF LIGHT PRECIPITATION ACROSS HIGHER TERRAIN OF NORTHERN UT. HAVE UPDATED FORECAST THIS EVENING TO ADD MENTION OF FLURRIES OR LIGHT SNOW ACROSS WASATCH FRONT...AS WELL AS RAISED POPS ACROSS HIGHER TERRAIN OF NORTHERN UT. ADDITIONALLY...CLOUD COVER OVERNIGHT WILL LIKELY KEEP TEMPS IN THE 20S FOR MOST LOCATIONS ALONG THE WASATCH FRONT. 700MB TEMPS PROGGED TO FALL NEAR -17C SATURDAY AFTERNOON BEFORE SHORTWAVE TROUGH TRANSLATES SOUTH AND MID-LEVEL WARM ADVECTION SPREADS ACROSS REGION SATURDAY NIGHT. THIS WILL RESULT IN STRONG VALLEY INVERSIONS...WITH MODELS KEEPING SURFACE RIDGE IN PLACE ACROSS THE REGION THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. AS A RESULT EXPECT TO SEE INCREASING AIR STAGNATION ACROSS WASATCH FRONT EARLY NEXT WEEK. && .AVIATION...CIGS AT KSLC ARE EXPECTED TO REMAIN BELOW 7000 FT THROUGH ABOUT 08Z...BUT THERE IS A 30 PERCENT CHANCE THAT THEY WILL REMAIN THAT LOW INTO THE MORNING. ADDITIONALLY...THERE IS A 20 PERCENT CHANCE OF SNOW FLURRIES DEVELOPING OVERNIGHT...BUT IF THIS OCCURS CONDITIONS SHOULD REMAIN VFR. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...NONE. WY...NONE. && $$ SEAMAN/TRAPHAGAN FOR MORE INFORMATION FROM NOAA/S NATIONAL WEATHER SERVICE VISIT... HTTP://WEATHER.GOV/SALTLAKECITY (ALL LOWER CASE) ut AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 600 AM CST SAT DEC 2 2006 .DISCUSSION FOR MORNING GRIDS/ZONES... 335 AM CST WITH FIRST MAJOR WINTER STORM OF THE SEASON NOW WELL OUT OF THE PICTURE STAGE RIGHT...FOCUS SHIFTS TO BROAD UPPER TROUGHING OVER MAJORITY OF CONUS NEXT SEVERAL DAYS...AND MAINLY TEMP TRENDS AS SERIES OF SHORT WAVE TROUGHS OF VARYING AMPLITUDE ROTATE THOUGH UPPER MIDWEST AND GREAT LAKES REGION THROUGH FORECAST PERIOD. EFFECTS OF A FOOT OR SO OF NEW SNOW COVER OVER WESTERN HALF OF FORECAST AREA ALSO A SIGNIFICANT CONSIDERATION FOR TEMP FORECAST. VAPOR LOOPS INDICATE FAIRLY STRONG SHORT WAVE TROUGH ROTATING FROM WESTERN CANADIAN PRAIRIES INTO THE NORTHERN PLAINS EARLY THIS MORNING. THIS WAVE EXPECTED TO PROGRESS TO THE UPPER MISSISSIPPI RIVER VALLEY LATER TODAY...WITH MAIN EFFECT BEING SOME MID/HIGH CLOUDINESS MAINLY NORTH OF THE FORECAST AREA. 285 K ISENTROPIC SFC FORECASTS FROM GFS INDICATE SOME MODEST UPGLIDE ACROSS THE AREA ASSOCIATED WITH LOW/MID LEVEL WAA IN ADVANCE OF THIS FEATURE THIS AFTERNOON...THOUGH STRONGEST NET ISENTROPIC OMEGA AND LOWEST CONDENSATION PRESSURE DEFICITS REMAIN NORTH OF THE WI BORDER. RELATIVELY DRY MID LEVELS DENOTED IN MODEL TIME/HEIGHT SECTIONS THUS MAINLY ONLY SOME PATCHY MID/HIGH CLOUDS EXPECTED LATER TODAY AFTER SUNNY START. SHORT PERIOD OF LOW LEVEL WARM ADVECTION TODAY AHEAD OF SFC COLD FRONT ASSOCIATED WITH AFOREMENTIONED SHORT WAVE...THOUGH SNOW COVER OVER MUCH OF WESTERN CWA EXPECTED TO NEGATIVELY AFFECT TEMPS. READINGS IN SINGLE DIGITS OVER WESTERN COUNTIES OVER DEEPEST SNOW COVER THIS MORNING WILL RESULT IN STRONG LOW LEVEL INVERSION TO OVERCOME...ALONG WITH REDUCTION IN ALBEDO AND LONG FETCH OF SNOW COVER TO LIMIT TEMP CLIMB. MODEL 950 HPA TEMPS -2C TO -4C WOULD SUGGEST TEMPS 36 TO 39 DEG F OR SO...WHICH AGREE NICELY WITH SFC PARCEL TRAJECTORIES FROM KFSD AREA WHICH WAS AROUND 37 FRI...HOWEVER BASED ON OUR DEEP SNOW COVER HAVE CUT FORECAST MAXES BACK ABOUT 10 DEGREES TO MID/UPR 20S WEST...WHILE KEEPING CLOSER TO MID 30S SOUTHEAST WHERE LITTLE OR NO SNOW COVER EXISTS. SHORT WAVE PASSES NORTH OF THE FORECAST AREA THIS EVENING...WITH SURFACE COLD FRONT MOVING THROUGH EARLY EVENING. THIS FRONT VERY EVIDENT IN CURRENT SFC ANALYSIS...WITH SFC DEW POINT TEMPS CURRENTLY IN THE NEGATIVE SINGLE DIGITS ALONG/BEHIND BOUNDARY ACROSS DAKOTAS/WESTERN MN AT 08 UTC. SUBSIDENCE IN LOW LEVEL CAA BEHIND FRONT TO RESULT IN SFC RIDGE BUILDING INTO IL OVERNIGHT...WITH 950 HPA TEMPS FALLING TO -11C OR SO OVER NCNTRL IL BY 12Z SUNDAY. COLD/DRY AIR...CLR/PTLY CLOUDY SKIES AND DECREASING WINDS SHOULD RESULT IF STRONG RADIATIONAL COOLING ACROSS SNOW COVER...AND AGAIN CALLS FOR SIGNIFICANTLY UNDERCUTTING GUIDANCE TEMPS INTO SINGLE DIGITS AGAIN ESPECIALLY WESTERN 1/2 OF CWA. THIS ASSUMING AT LEAST SOME PATCHY CLOUDS AND 5 MPH WIND...BUT IF SKIES CLEAR AND WIND GOES CALM THIS MAY NOT BE COLD ENOUGH. 950 HPA TEMPS -8/-10C SUNDAY AS LONG WAVE TROUGH AXIS MOVES THROUGH ALOFT SUGGEST CONTINUED COLD CONDITIONS...TEMPS IN LOW-MID 20S...THOUGH WITH A LITTLE MORE CLOUD COVER. SOME WEAK MID LEVEL OMEGA NOTED IN MODEL TSECTS...THOUGH GIVEN SUCH DRY LOW LEVELS EXPECT NO SIGNIFICANT POTENTIAL FOR PRECIP. SOME SIGNIFICANT TIMING/PLACEMENT ISSUES AMONG MODELS BY 48 HRS/00Z MON WITH UPPER TROUGH POSITION WITH GFS/GEM AND UKMET OVER IL...WHILE NAM LAGS BY NEARLY 300 MI. FOR NOW HAVE FAVORED GFS DEPICTION GIVEN SUPPORT OF OTHER GLOBAL MODELS. ANOTHER SHEARED WAVE...WEAK SFC TROUGH AND REINFORCEMENT OF COLD AIR ARRIVES MONDAY...MAINTAINING SIMILAR TEMPS TO SUNDAY. THIS PATTERN CONTINUES BEYOND DAY 3...WITH SERIES OF RELATIVELY WEAK SHORT WAVES AFFECTING MAINLY UPPER GREAT LAKES REGION. UPPER TROUGH GRADUALLY SHIFTS A BIT TO THE EAST THOUGH...WITH SOUTHERN PERIPHERY OF ARCTIC AIR/LOW LEVEL BAROCLINIC ZONE STRETCHING FROM NORTHERN PLAINS TO LOWER GREAT LAKES BY MID WEEK. PERHAPS BEST CHANCE FOR SOME LIGHT PRECIP APPEARS LATE TUES AS GFS/CANADIAN GEM ARE SIMILAR IN TAKING FAST MOVING PACIFIC WAVE ACROSS NRN PLAINS WITH WEAK SFC WAVE DEVELOPING ALONG BAROCLINIC ZONE AND SQUEEZING OUT SOME LIGHT WAA QPF BY EARLY WED MORNING. CONFIDENCE NOT REAL HIGH WITH TIMING OF THESE FEATURES OUT AT DAYS 4/5...BUT HAVE ADDED CHANCE OF FLURRIES TUES NIGHT. LITTLE CHANGE TO REMAINDER OF FORECAST OTHER THAN FOR SOME TWEAKS IN THE INTEREST OF COLLABORATIVE IMPROVEMENT TO GRIDS. RATZER && .AVIATION DISCUSSION FOR 12Z TAFS... 600 AM CST VFR CONDITIONS ARE EXPECTED TO PERSIST ACROSS TERMINALS DURING THIS FORECAST PERIOD WITH THE MAIN FORECAST CONCERN ON WINDS TODAY AS FRONTAL BOUNDARY APPROACHES. LATEST MSAS DATA FROM 11Z INDICATES FRONTAL BOUNDARY EXTENDING FROM EXTREME SERN MINNESOTA INTO SOUTH CENTRAL IOWA. MAIN SYNOPTIC FEATURE THIS MORNING IS BROAD UPPER LOW ACROSS THE NORTHERN PLAINS INTO THE UPPER MIDWEST. A SHORT WAVE TROUGH ROTATING AROUND THIS FEATURE WILL CONTINUE TO TAKE THIS FRONTAL BOUNDARY EASTWARD THROUGH THE DAY. LATEST PROFILER DATA FROM WOOD LAKE MINNESOTA SUGGESTS THIS SHORT WAVE TROUGH AXIS CURRENTLY PROGRESSING THROUGH SOUTH CENTRAL MINNESOTA. THIS VORT MAX SHOULD SWING NORTHEAST INTO NORTHWEST WISCONSIN THIS MORNING WHICH MAY ACTUALLY SLOW DOWN THE FRONT AS IT CONTINUES TO TRACK THROUGH EASTERN IOWA THIS MORNING. NOT MANY CHANGES WERE MADE TO THE 12Z TAFS IN COMPARISON TO THE 06Z ISSUANCE IN TERMS OF WIND DIRECTION TRENDS...EXCEPT TO SLIGHTLY MOVE UP TIMING ON WIND TRANSITION WITH THE APPROACHING FRONT. CURRENTLY HAVE RFD TO A 280-300 DIRECTION BY 22Z...AND AT REMAINDER OF TERMINALS IN THE 00Z-01Z TIME FRAME. WITH MAIN UPPER FORCING LIFTING NORTHEAST WITH THIS SHORT WAVE TROUGH TODAY...MVFR CIGS CURRENTLY BEING REPORTED ACROSS SOUTHERN MINNESOTA WILL REMAIN TO THE NORTH OF THE TERMINALS. MAY SEE LOW COVERAGE DIURNAL CU FORM...BUT NOTHING OF OPERATIONAL SIGNIFICANCE. OTHER QUESTION TODAY WILL BE CONCERNING WIND SPEEDS. GIVEN RECENT SNOWFALL ACROSS THE AREA...HAVE FAVORED RUC IDEA IN TERMS OF LOW LEVEL THERMODYNAMIC PROFILES WITH A MORE SHALLOW PRE-FRONTAL MIXED LAYER. WRF/NAM BUFKIT SOUNDINGS FROM 00Z RUNS INDICATED POTENTIAL FOR GUSTS UP AROUND 20 KTS OR SO BUT WILL HOLD OFF ON THIS FOR NOW WITH CONCERN THAT MIXING HEIGHTS ARE TOO HIGH. WINDS SHOULD DROP BACK TO AROUND 5 KNOTS LATE THIS EVENING BEHIND THE FRONT. MARSILI && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LM...SMALL CRAFT ADVSRY INDIANA NEARSHORE THIS MORNING. && $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LUBBOCK TX 523 AM CST SAT DEC 2 2006 .UPDATE... HAVE SENT OUT AN UPDATED ZFP TO INCLUDE MENTION OF FREEZING FOG THIS MORNING ACRS MUCH OF THE NORTHERN/CENTRAL COUNTIES. AREA SFC OBS ARE NOW SHOWING 1/2 MILE VSBY AT PLAINVIEW AND LUBBOCK. FOG SHOULD BEGIN TO DISSIPATE BY 16Z OR SO AS NORTHERLY WINDS INCREASE. HOWEVER...LATEST WRF AND RUC MODELS DO SUGGEST THAT LOW CLOUDS WILL LIKELY PERSIST THROUGHOUT MOST OF THE DAY...RESULTING IN A CHILLY DECEMBER DAY. SGE && .PREV DISCUSSION... /ISSUED 245 AM CST SAT DEC 2 2006/ SHORT TERM... THIS PORTION OF THE FORECAST WILL BECOME INCREASINGLY INTERESTING LATER TODAY AND TONIGHT AS A RATHER STRONG VORT MAX CURRENTLY DIVING SOUTH THROUGH THE WASATCH MOUNTAIN RANGE MOVES INTO NEW MEXICO TONIGHT. FIRST HOWEVER...PORTIONS OF THE NORTHERN/CENTRAL CWFA WILL LIKELY HAVE TO DEAL WITH SOME PATCHY FOG AND LOW CLOUDS THIS MORNING AS RH VALUES ARE NEAR SATURATION. RECENT LOOPS OF THE 11-3.9 MICRON SATELLITE IMAGERY ARE ALREADY DEPICTING EITHER FOG AND/OR LOW CLOUDS BEGINNING TO FORM FROM NEAR TULIA TO FLOYDADA. THE WRF MODEL CONTINUES TO BE MORE AGGRESSIVE ON LOW CLOUDS EXPANDING OVER MUCH OF THE NORTHERN/CENTRAL COUNTIES AROUND SUNRISE. COUPLED WITH THE NEXT COLD FRONT PUSHING SOUTH THROUGH WEST TEXAS...HIGHS TODAY WILL REMAIN IN THE 30S ACRS MUCH OF THE NORTHERN HALF OF THE CWFA WITH LWR-MID 40S SOUTH. NORTH WINDS WILL INCREASE TO AROUND 15 MPH BY EARLY AFTN AS HIGH PRESSURE BUILDS SOUTH THROUGH THE PLAINS. FOR TONIGHT...ATTENTION WILL TURN TO THE MID LEVEL DISTURBANCE DIGGING INTO NEW MEXICO ON THE HEELS OF A STRONG 100 KT JET MAX. AS THIS VORT MAX NEARS...ENOUGH LIFT AND UPSLOPE FLOW WILL AID IN GENERATING LIGHT SNOW ACRS THE SANGRE DE CRISTOS AND ADJACENT PLAINS. FOR THE LUBBOCK CWA...THIS EVENT STILL APPEARS TO BE MORE OF A FREEZING DRIZZLE SCENARIO AS PRIMARILY THE LOWER LEVELS WILL BE SATURATED. HOWEVER...WILL LEAVE THE MENTION OF LIGHT SNOW AS TEMPS NEAR THE CLOUD TOPS WILL BE NEAR -12 TO -14 C. ANY AMOUNTS ARE EXPECTED TO BE VERY LIGHT WITH NO ADVISORIES ANTICIPATED. LONG TERM... STILL THE POSSIBILITY OF SOME ONGOING VERY LIGHT PRECIPITATION SUNDAY...ALTHOUGH FORCING WILL BE WEAK AS POSITIVELY TILTED SHORTWAVE TROUGH SWINGS SOUTHEAST ACROSS WEST TEXAS. WRF/NAM INDICATING A SATURATED LAYER FROM NEAR THE SURFACE TO ABOVE 700 MB WITH NORTHEAST UPSLOPE WINDS. VERY LITTLE LIFT IN SATURATED LAYER HOWEVER. WILL HOLD ON TO SLIGHT CHANCE POPS THROUGH NOON SUNDAY. SHOULD SEE RAPID CLEARING WEST OF TROUGH AXIS SUNDAY AFTERNOON. WITH CLOUD COVER HOLDING ON INTO THE AFTERNOON...AND VERY COLD LOWER TO MID LEVEL TEMPERATURES...SHOULD SEE HIGHS SUNDAY REMAINING IN THE 30S FOR MOST AREAS...WITH PERHAPS A FEW 40S ACROSS THE EXTREME SOUTHWEST. BACK TO FLAT NW FLOW FOR MOST OF THE UPCOMING WEEK WITH MODERATING TEMPERATURES. LOOKS A LITTLE MORE INTERESTING LATE IN THE WEEK AS MODELS ARE STILL BRINGING A SHORTWAVE SOUTHEAST ACROSS THE ROCKIES AND INTO THE CENTRAL PLAINS LATE THURSDAY INTO FRIDAY. ALSO... SUBTROPICAL MOISTURE WILL CONTINUE TO INCREASE IN SOUTHERN STREAM FROM BAJA E/NE INTO SOUTHWEST TEXAS. AS CENTRAL PLAINS SHORTWAVE PUSHES A FRONT SOUTH INTO THE REGION...WE MAY SEE ENOUGH MOISTURE TO GENERATE SOME RAIN SHOWERS. KEPT IN SLIGHT CHANCE OF RAIN LATE WEDNESDAY AND THURSDAY...WITH SLIGHT CHANCE OF SNOW SHOWERS THURSDAY NIGHT AS COLDER AIR DEEPENS BEHIND FRONT. && .PRELIMINARY POINT TEMPS/POPS... FRIONA 34 17 34 16 46 / 10 20 20 0 0 TULIA 36 18 33 18 47 / 10 20 10 0 0 PLAINVIEW 36 20 33 20 47 / 10 20 20 0 0 LEVELLAND 39 20 36 24 49 / 10 20 20 0 0 LUBBOCK 38 21 35 24 48 / 10 20 20 0 0 BROWNFIELD 42 23 39 23 51 / 10 20 20 0 0 CHILDRESS 39 22 37 23 48 / 0 20 10 10 10 SPUR 40 24 36 24 51 / 0 10 20 0 0 ASPERMONT 45 26 38 26 52 / 0 10 20 0 0 && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 21/06 tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 226 PM MST SAT DEC 2 2006 .SHORT TERM... (TONIGHT AND SUNDAY) AFTER AN EARLY AFTERNOON LULL...SNOW APPEARS TO BE INCREASING ACROSS THE AREA AS UPWARD MOTION FROM THE UPPER TROUGH MOVES INTO SOUTHERN COLORADO. STARTING TO SEE SOME ENHANCEMENT IN IR SATELLITE IMAGERY OVER THE CENTRAL MOUNTAINS...WITH RADAR SHOWING AN INCREASE IN SNOWFALL INTENSITY ALONG THE ARKANSAS RIVER FROM SALIDA EAST TO JUST NORTH OF PUEBLO. KPUX VAD WINDS ARE EAST TO SOUTHEAST THROUGH 10K FEET AGL...WHICH IS A GOOD DIRECTION FOR HEAVY SNOW OVER THE SOUTHWEST PORTIONS OF COLORADO SPRINGS AND THE AREA ALONG HIGHWAY 115 FROM FORT CARSON SOUTH INTO FREMONT COUNTY. LATEST RUC AND NAM SUGGEST SNOW WILL PERSIST THROUGH 03Z...WITH BEST LIFT SHIFTING TOWARD THE SANGRES BETWEEN 03-06Z. TROUGH AXIS DRAGS THROUGH THE AREA BY 06Z...WHICH SHOULD SHUT PRECIP DOWN FAIRLY QUICKLY. ADDITIONAL ACCUMS GENERALLY IN THE 1-2 INCH RANGE...THOUGH SRN EL PASO/NRN PUEBLO/ERN FREMONT COUNTY AREA COULD SEE ANOTHER 2-4 AS HEAVIER BAND REMAINS ANCHORED TO CHEYENNE MOUNTAIN/SOUTH SLOPE OF PIKES PEAK. INCREASED SNOW AMOUNTS SLIGHTLY IN THE GRIDS FOR THE EVENING HOURS...AND NUDGED LOW TEMPS OVER FRESHLY SNOW COVERED AREAS. MUCH NICER DAY ON SUNDAY WITH CLEARING SKIES...BUT MAX TEMPS WILL STRUGGLE TO GET ABOVE FREEZING IN SNOW COVERED AREAS. MADE SOME MINOR DOWNWARD TWEAKS TO THE MAX TEMP GRID...OTHERWISE GRIDS APPEAR TO BE IN GOOD SHAPE. --PETERSEN .LONG TERM... (SUNDAY NIGHT THROUGH NEXT SATURDAY) FAIRLY QUIET WEATHER PATTERN SETTING UP OVER THE AREA...DEPICTED BY BOTH NAM AND GFS SOLUTIONS. SUNDAY NIGHT...WILL BE QUITE COLD WITH CLEAR SKIES AND SNOW COVER...AND LOW DEW POINTS. LOOK FOR READINGS IN THE LOWER TEENS IN PARTS OF THE PLAINS...WITH THE REST OF THE AREA GENERALLY IN THE SINGLE DIGITS ABOVE AND BELOW ZERO. MONDAY AND TUESDAY...UPPER FLOW TRANSITIONS FROM NORTHWEST TO WEST NORTHWEST...USHERING IN MILDER AIR ALOFT. EVEN WITH SOME AREAS HAVING A GOOD DEAL OF SNOW COVER...MODELS STILL ADVERTISING GOOD WARM UP. LOWERED TEMPERATURES JUST A BIT ON MONDAY...BUT WITH MORE MIXING ANTICIPATED TUESDAY...ALONG WITH HIGHER TEMPERATURES ALOFT... AND TO BLEND BETTER WITH DDC AND GLD...RAISED HIGHS. TUESDAY NIGHT THROUGH THURSDAY...THERE HAVE BEEN SEVERAL SOLUTIONS TO THE MIDWEEK SHORTWAVE OVER THE PAST COUPLE OF DAYS. THE LATEST IS A STRONGER SHORTWAVE PASSING NORTH AND EAST OF OUR CWFA. THE GFS DOES BRING SOME MOISTURE OVER OUR PLAINS LATE WEDNESDAY NIGHT INTO THURSDAY. NO ONE HAS BIT ON THIS SOLUTION ATTM...SO FOR NOW...A DRY FORECAST. FRIDAY AND SATURDAY...THE TROUGH MOVES OUT AND A SHORTWAVE RIDGE MOVES IN...BRINGING A SIGNIFICANT UPTURN TO MID LEVEL TEMPERATURES...SOME 5-7 DEGREES C. THAT PROBABLY WILL NOT TRANSLATE TO THE SURFACE...BUT LOOK FOR HIGHS MOSTLY IN THE 50S IN THE PLAINS AND 30S TO 40S IN THE MOUNTAINS AND HIGH VALLEYS. && .PUB WATCHES/WARNINGS/ADVISORIES... SNOW ADVISORY UNTIL 8 PM MST THIS EVENING FOR COZ074-075-079>088. && $$ 10/13 co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1045 AM CST SAT DEC 2 2006 .DISCUSSION... FORECAST LOOKS ON TRACK TODAY WITH JUST MINOR TWEAKS TO THE HOURLY GRIDS. A MOSTLY SUNNY DAY WITH SW WINDS 5 TO 15 MPH. HIGHS TO RANGE FROM THE UPPER 20S TO NEAR 30F OVER DEEPER SNOW PACK ALONG AND WEST OF I-55 TO THE UPPER 30S AND LOWER 40S OVER EASTERN IL WITH LITTLE OR NO SNOW COVER. 16Z/10 AM SURFACE MAP SHOWS 1033 MB HIGH PRESSURE OVER SOUTHERN IL AND ARCHING FROM THE CENTRAL PLAINS NW TO THE PARENT 1047 MB ARCTIC HIGH PRESSURE OVER NORTHERN SASKETEWAN PROVINCE. A 1018 MB LOW WAS OVER WESTERN LAKE SUPERIOR WITH A COLD FRONT EXTENDING ACROSS EASTERN WI TO NEAR THE IA/IL BORDER AND OVER NW MO. SUNNY SKIES ACROSS MUCH OF CENTRAL AND SE IL WITH PATCHES OF MID LEVEL CLOUDS STREAMING ENE FROM NORTHERN/CENTRAL MO INTO WESTCENTRAL IL AND DISSIPATING IN THE VERY DRY AIR MASS OVER IL. TEMPS RANGE FROM THE UPPER TEENS OVER DEEPER SNOW COVER FROM I-55 WEST TO THE LOWER 30S SE OF I-70. RUC AND NAM/WRF BRING COLD FRONT SE TOWARD AREAS NW OF THE IL RIVER LATE TODAY AND SLIDE SE THROUGH CENTRAL IL THIS EVENING. THIS TO MOVE THROUGH DRY AND REINFORCE COLDER AIR MASS OVER CENTRAL IL TONIGHT AND SUNDAY. TODAY HIGHS IN THE UPPER 20S/30 FROM I-55 WEST AND UPPER 30S/LOWER 40S FROM I-57 EAST. && .PREV DISCUSSION... MAIN CHALLENGE WITH THIS FORECAST PACKAGE WILL BE HOW COLD TO GO WITH TEMPS OVER THE SNOW-COVERED WESTERN HALF OF THE KILX CWA OVER THE NEXT FEW DAYS. 07Z SURFACE MAP INDICATES WEAK RIDGING ACROSS ILLINOIS...LEADING TO CLEAR SKIES AND LIGHT WINDS. EXCELLENT RADIATIONAL COOLING CONDITIONS HAVE HELPED TEMPS DIP INTO THE SINGLE DIGITS AND TEENS ACROSS LOCATIONS WITH A SIGNIFICANT SNOW-COVER. MEANWHILE...NEXT PUSH OF CANADIAN AIR ALREADY EVIDENT DROPPING THROUGH THE DAKOTAS. SHORT TERM...TODAY THROUGH MONDAY... SURFACE RIDGE WILL SHIFT EASTWARD TODAY...ALLOWING SW WINDS TO BRING SLIGHTLY WARMER AIR INTO THE REGION. DESPITE THE WAA...TEMPS OVER THE SNOW-PACK WILL LIKELY HOVER BELOW THE FREEZING MARK. NUMERIC GUIDANCE CONTINUES TO BE WAY TOO WARM...SO WILL UNDERCUT THE NUMBERS...ESPECIALLY ACROSS THE WESTERN HALF OF THE KILX CWA. HAVE TWEAKED READINGS UP JUST A BIT ALONG AND EAST OF I-57...WHERE LITTLE OR NO SNOW COVER EXISTS. SKIES SHOULD BE MOSTLY SUNNY...HOWEVER LOCATIONS ALONG AND SOUTH OF I-72 WILL SEE SCT-BKN MID-CLOUDS FROM TIME TO TIME...AS WEAK WAVE AND 120KT JET STREAK TRANSLATES ACROSS THE AREA. BY TONIGHT...SECONDARY COLD FRONT ACROSS THE DAKOTAS PUSHES INTO ILLINOIS...RESULTING IN WINDS SWITCHING BACK TO W/NW. SIGNIFICANT CAA IN STORE FOR SUNDAY...WITH NAM-WRF INDICATING 850MB TEMPS DROPPING INTO THE -12 TO -14C RANGE. THIS WILL RESULT IN A GOOD 5 TO 10 DEGREE DROP IN HIGH TEMPS FROM SATURDAY TO SUNDAY. CANADIAN HIGH PRESSURE BUILDS INTO THE REGION SUNDAY NIGHT...SETTING UP WHAT COULD BE THE COLDEST NIGHT OF THE WINTER SEASON THUS FAR. WILL CONTINUE TO UNDERCUT GUIDANCE ACROSS THE SNOW-PACK...WITH READINGS POSSIBLY DROPPING TO NEAR ZERO IN A FEW LOCATIONS. LONG TERM...TUESDAY THROUGH FRIDAY... NORTHWEST UPPER FLOW PATTERN PROGGED TO DOMINATE MUCH OF THE CENTRAL AND EASTERN CONUS THROUGH THE EXTENDED...RESULTING IN BELOW NORMAL TEMPS AND PRECIP. WILL ONLY SEE SUBTLE CHANGES IN TEMPS...AS A SERIES OF WAVES MOVE ACROSS THE AREA. AT THIS POINT...MEDIUM RANGE MODELS ARE SUGGESTING RATHER WEAK FEATURES...WITH BEST DYNAMICS FOR ANY PRECIP REMAINING FURTHER NORTH ACROSS THE GREAT LAKES. WILL THEREFORE MAINTAIN CURRENT COOL AND DRY FORECAST THROUGH THE END OF NEXT WEEK. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ HUETTL/BARNES il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 515 PM EST SAT DEC 2 2006 .DISCUSSION... LES EVENT CONTINUES TO BE A CHALLENGE. MAIN FCST CONCERNS ARE OBVIOUSLY SNOW AMOUNTS AND HEADLINES TONIGHT/SUN. WATER VAPOR IMAGERY/RUC ANALYSIS AND 12Z RAOBS SHOW CLOSED MIDLEVEL LOW OVER NRN MN WITH A SHORTWAVE TROF EXTENDING SE THRU UPPER MI. NEARLY COINCIDENT WITH CENTER OF MIDLEVEL LOW...12Z KINL SOUNDING SHOWED A DEEP MOIST PROFILE TO 600MB WITH TEMPS BTWN 800-650MB DOWN 4-6C IN THE LAST 12HR. 850MB TEMP WAS -15C. SO...A FAVORABLE AIRMASS FOR LES WILL PASS ACROSS THE LAKE WITH SYSTEM. AT THE SFC... CONVERGENCE ZONE HAS SET UP A BIT FARTHER N THAN MOST OF THE PREVIOUS MODEL RUNS HAD INDICATED...AND IN GENERAL SFC WINDS ARE STRONGER. ILL-DEFINED MESOLOW AT 21Z APPEARS TO BE LOCATED JUST W OF ISLE ROYALE WITH CONVERGENCE ZONE RUNNING ACROSS ISLE ROYALE TO JUST N OF THE KEWEENAW THEN SE TOWARD GRAND MARAIS. CONVERGENCE HAS REALLY STRENGTHENED IN THE LAST HR OR SO. ACROSS ISLE ROYALE...ROCK OF AGES HAS A WIND OF 240 AT 25G29KT WHILE PASSAGE ISLAND IS 070 AT 23G26KT. THUNDER BAY RADAR SHOWS HVY SNOW OCCURRING OVER ISLE ROYALE IN THE STRONG CONVERGENCE. TO THE SE... STANNDARD ROCK WIND IS 280 AT 23KT WHILE WHITEFISH POINT IS 130 AT 8KT. IN THE SW FLOW ACROSS WRN LAKE SUPERIOR...SW TO NE ORIENTED LES BANDS HAVE DEVELOPED AND ARE IMPACTING THE KEWEENAW PER SATELLITE IMAGERY/SFC OBS AND WEB CAMS. OTHERWISE...DECENT SWATH OF MOSTLY -SN HAS SPREAD ACROSS MUCH OF UPPER MI TODAY IN ASSOCIATION WITH SHORTWAVE TROF MOVING ACROSS THE AREA. APPEARS SOME LAKE ENHANCEMENT OFF LAKE MICHIGAN HAS BRIEFLY OCCURRED OVER THE FAR ERN FCST AREA...AND RADAR IMAGERY SUGGESTS A POSSIBLE MESOLOW MOVING ENE ACROSS LUCE COUNTY ATTM. KERY OB REPORTED 1/4SM SN AT 2058Z AND 2115Z. 12Z GFS/NAM CONTINUE TO SHOW VERY FAVORABLE TEMP/MOISTURE PROFILES FOR HVY LES TONIGHT/SUN MORNING WITH DEEP MOISTURE UPWARDS OF 15KFT (SIMILAR TO 12Z KINL SOUNDING) AND FAVORABLE INTERSECTION OF UPWARD MOTION WITH BEST DENDRITIC SNOW GROWTH TEMPS. IN ADDITION...IR/WATER VAPOR IMAGERY SUGGEST HEALTHY FORCING/DEEP MOISTURE WRAPPING AROUND N SIDE OF MIDLEVEL LOW ALONG AND JUST N OF MN/ONTARIO BORDER. THIS WILL BE SLIDING ESE TONIGHT...FURTHER SUPPORTING THE DEEP MOISTURE PROFILES INDICATED BY THE MODELS. QUESTION CONTINUES TO REVOLVE AROUND LOW-LEVEL WIND FIELDS AND RESULTANT CONVERGENCE. MOST OF THE 12Z MODELS HAVE A DECENT HANDLE ON CURRENT WIND FLOW OVER LAKE SUPERIOR AND SURROUNDING AREAS...BUT 12Z REGIONAL CANADIAN MODEL LOOKS TO HAVE THE BEST FIT AT 18Z. WITH ITS SOLUTION...AN ELONGATED CONVERGENCE ZONE EVOLVES IN ASSOCIATION WITH MESOLOW THIS EVENING...SNAKING NE FROM NEAR THE APOSTLES TO THE TIP OF THE KEWEENAW AND THEN SE TOWARD WHITEFISH POINT. GFS/NAM/RUC13/LOCAL HI RESOLUTION WRF RUN HAVE SIMILAR PATTERNS...JUST SLIGHTLY DIFFERENT TIMING OF THE PROGRESSION. IN ANYCASE...THEY ALL SUGGEST THE SAME END RESULT...THAT BEING A BAND OF VERY HVY SNOW. WOULD NOT BE SURPRISED TO SEE 2-4IN/HR SNOW RATES IN THE MAIN SNOW BAND THAT WILL IMPACT MOST OF THE COUNTIES BORDERING LAKE SUPERIOR. AFTER CONVERGENCE MOVES ONSHORE...N WIND FAVORED SNOWBELTS WILL SEE MDT TO OCCASIONALLY HVY SNOW THRU SUN MORNING. WARNING ON THE KEWEENAW LOOKS TO BE IN GOOD SHAPE SINCE THAT AREA IS SEEING SW FLOW LES NOW. ONCE WINDS SHIFT TO THE N LATER TONIGHT...SNOW SHOULD DIMINISH SIGNIFICANTLY THERE. 18Z RUC SUGGESTS WARNING MAY NEED TO BE EXTENDED PAST 06Z AS CONVERGENCE ZONE IS JUST REACHING THE TIP OF THE KEWEENAW AT 06Z. THIS WILL NEED TO BE WATCHED. OTHERWISE...WILL START WARNINGS FOR ONTONAGON/GOGEBIC MID/LATE EVENING AND RUN THRU THE DAY SUN UNDER FAVORABLE N OR NNW FLOW. WIND SHIFT WILL ARRIVE LATER THAN PREVIOUSLY EXPECTED FOR THE NCNTRL COUNTIES. WILL BEGIN WARNING FOR BARAGA AT 06Z AND MARQUETTE AT 10Z AND RUN BOTH THRU THE DAY SUN. SOME SPOTS IN THE WARNING AREAS SHOULD SEE A FOOT OR MORE OF SNOW. WIND SHIFT SHOULD REACH ALGER AROUND 12Z...HAVE OPTED FOR AN ADVY THERE ON SUN WITH HIGH END ADVY TOTALS. FETCH ACROSS LAKE SUPERIOR INTO LUCE COUNTY IMPROVES SUN...BUT BEST FORCING WILL HAVE PASSED BY THEN. NO HEADLINES ANTICIPATED AT THIS TIME. ANOTHER SHORTWAVE WILL PASS ACROSS THE AREA MON FOLLOWED BY ANOTHER TUE NIGHT/WED MORNING. BOTH SHOULD BRING A PERIOD OF MDT/BRIEFLY HVY LES TO MAINLY THE AREAS FAVORED BY NW WINDS. EXPECT ONLY SOME -SN ELSEWHERE WITH BOTH SYSTEM. WED THRU SAT...TYPICAL EARLY DEC WEATHER WILL BE THE RULE FOR THE FIRST HALF OF THIS TIME FRAME WITH LES OFF LAKE SUPERIOR...AND TEMPS BLO NORMAL AS GENERAL MEAN TROF POSITION WILL BE OVER ERN NAMERICA. AT THE END OF THIS FCST PERIOD AND INTO NEXT WEEK...LOOKS LIKE A TRANSITION WILL OCCUR TO A MORE TYPICAL EL NINO TYPE PATTERN WITH SPLIT FLOW ACROSS NAMERICA. NRN STREAM WILL LIFT INTO CANADA... ALLOWING PACIFIC AIRMASSES TO BECOME MORE DOMINANT ACROSS MUCH OF THE COUNTRY. UKMET/ECWMF/CANADIAN/GFS ARE IN GENERAL AGREEMENT ON THE PATTERN DISCUSSED ABOVE...BUT HAVE OPTED TO FOLLOW THE ECMWF GIVEN ITS RECENT CONSISTENCY FOR THE LAST HALF OF THE WEEK. PLUS...GFS IS COMING AROUND TOWARD THE ECWMF SOLUTION OF HAVING ONE LAST SIGNIFICANT SHORTWAVE AND ASSOCIATED SHOT OF ARCTIC AIR FOR WED. SHOULD PROVIDE FOR A BRIEF PERIOD OF DECENT LES AS 850MB TEMPS DROP TOWARD -20C. NW FLOW AREAS WILL BE FAVORED...BUT THERE MAY BE A QUICK SHOT OF NRLY FLOW INTIALLY BEHIND COLD FROPA. BUILDING AREA OF SFC HIGH PRES WILL THEN SETTLE SE OVER THE PLAINS THU AND MOVE E FRI. SO...A LIGHTER PURE LES REGIME SHOULD PREVAIL THU FOR NW AND THEN W FLOW AREAS AS WINDS BACK. EXPECT A DIMINISHING TREND AS WELL AS 850MB TEMPS BEGIN TO MODERATE WITH INVERSIONS LOWERING. WAA KICKS INTO HIGH GEAR THU NIGHT WITH ENOUGH WARMING TO END LES BY FRI MORNING. PACIFIC AIRMASS AND DRY WEATHER WILL BE THE RULE FOR FRI/SAT WITH TEMPS RETURNING TO AND THEN ABOVE NORMAL. && .MQT WATCHES/WARNINGS/ADVISORIES... LES WARNING MIZ001-003 UNTIL 06Z SUN. LES WARNING MIZ002-009 FROM 03Z TO 24Z SUN. LES WARNING MIZ004 FROM 06Z TO 24Z SUN. LES WARNING MIZ005 FROM 10Z TO 24Z SUN. LES ADVY MIZ006 FROM 12Z TO 24Z SUN. && $$ ROLFSON mi