AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1120 PM EST TUE DEC 27 1999 CLOUDS AND PRECIP FROM CLIPPER SYSTEM ON THE MOVE. WILL UPDATE FORECAST TO REFLECT INCREASING CLOUDS OVERNIGHT. SKIES WILL CLOUD UP FIRST ACROSS NORTHERN CWA...THEN QUICKLY REACH SOUTHERN CWA. IN THE NORTH...STILL A COUPLE OF HOURS COOLING REMAINING...ALTHOUGH NOT LIKELY TO DROP MUCH MORE THAN A FEW DEGREES. ACROSS SOUTH...STILL SEVERAL HOURS OF COOLING. WILL UPDATE TEMPS TO REFLECT THIS. WILL ALSO ADD 30 PERCENT POPS TO BAY...MIDLAND...SAGINAW COUNTY ZONE FOR SNOW BEFORE SUNRISE. LATEST ETA/NGM/RUC MODELS INDICATE THAT 30 TO 50 MB CPDS...ROUGHLY IN LINE WITH LEADING EDGE OF PRECIP...TO FAR NORTHWEST CWA BY 12Z. SO WILL UPDATE TO ADD CHANCE POPS THERE. .DTX...GALE WARNING...LAKE HURON...LATE TONIGHT AND TUESDAY. GALE WARNING LAKE ST CLAIR TUESDAY. OKEEFE mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1050 PM EST MON DEC 27 1999 00Z RAOBS SHOW PERSISTENT HI AMPLITUDE WRN RDG/ERN TROF OVR NAMERICA. ETA 0HR ANAL SHOWS 180KT H3 JET/SHRTWV DROPPING SWD E OF RDG AXIS INTO ERN TROF...AND WELL DEFINED QUICK MOVG CLD LEAF WITH TOP TEMPS NR -60C APRNT ON IR IMAGERY IN VCNTY OF 145KT H3 WND RPRT FM YPL. 995MB SFC LO OVR WRN ONTARIO ASSOCIATED WITH THIS SHRTWV... AND PRES FALLS AS GREAT AS 12MB/3HRS RPTD NR LK WINNIPEG THIS EVNG. OBS SHOW AN AREA OF MDT SN OVR SW ONTARIO IN VIGOROUS H85-5 QVECTOR CNVGC ASSOCIATED WITH H5 PVA AHD OF SHRTWV AND ISENTROPIC LIFT DEPICTED ON 285-290K SFCS OVRRNG SHARP WARM FNT STRETCHING SWD FROM LO TO ND. PCPN RATES ALSO ENHANCED BY MSTR ADVCTN ASSOCIATED WITH 50KT H85 WNDS AND PW 0.50-0.60" (CLIMATOLOGICALLY HI FOR CLIPPER TYPE SYS) FM KBIS TO CYQD. LEADING EDGE OF SN JUST REACHED YQT AT 03Z AND ON TRACK TO REACH NW ZNS BY MIDNIGHT EST. IR LOOP SHOWS CLD AHD OF SHRTWV HAS OVRSPRD ENTIRE CWA. SFC TEMPS/DWPTS GENERALLY 5 TO 15F/0 TO 5F OVR FA. MAIN FCST CONCERN TNGT IS IMPENDING SN AND NEED FOR HEADLINES. EARLIER MODELS WOEFULLY UNDERDID MSL PRES FALLS WITH LO PRES...WITH 12Z AVN F12 SLP ALMOST 10MB TOO HI. 00Z H85 WNDS ALSO HIER THAN FCST GIVEN STRGR SFC PRES GRADIENT. SO LEANED TOWARD LATEST RUC GUIDANCE...WHICH SHOWS 992MB SFC LO REACHING NE LK SUP BY 12Z. ALTHOUGH TRACK OF STORM SYS NOT FVRBL FOR CWA...RUC IN AGREEMENT WITH EARLIER MODELS SHOWING A 6 HR PD OF VIGOROUS H85-5 QVECTOR CNVGC CROSSING CWA NW-SE OVRNGT AS H5 SHRTWV APRCHS. FAIRLY IMPRESSIVE LO LVL MSTR CNVGC UNDER UPR LVL DVGC IN EXIT RGN OF UPR JET ALSO PRESENT...WITH GREATEST DIFFERENTIAL DVGC OVR ZNS BORDERING LK SUP CLOSER TO SFC LO TRACK. 2-3G/KG AVBL BTWN H75-7 WOULD EQUATE TO 2-3" SN IN 6 HR PD BASED ON IMXR TECHNIQUE. BUT WITH COLD/DRY AIRMASS IN PLACE...XPCT 20 TO 1 SN/WATER RATIO AND UP TO 6". BEST CHANCE FOR THESE AMTS IN KEWEENAW CLOSER TO SFC LO TRACK AND SCHOOLCRAFT COUNTY...WHICH MIGHT BENEFIT FM SOME MOISTENING OFF LK MI WITH MORE SSWLY TRAJECTORY TO S OF QUICK MOVG STORM. SO HAVE DECIDED TO GO WITH ADVY FOR NRN TIER ZNS/SCHOOLCRAFT CLOSER TO STORM TRACK AND BEST DIFFERENTIAL DVGC. CONFIDENCE INCRSD BY MDT RISK OF 4 INCH SN AMTS ACRS ECNTRL CWA MENTIONED IN LATEST HVY SN DISCUSSION...CLIMATOLOGICALLY HI PW UPSTREAM...RATHER IMPRESSIVE CLD LEAF...50 KT H85 WNDS AND VERY DEEP SFC LO/PRES FALLS. HAVE ALSO ADDED BLSN WORDING TO ADVY IN NW ZNS/SCHOOLCRAFT DUE TO BETTER EXPOSURE NR LKS...BUT MENTIONED BLSN ALL ZNS WITH LLJ PROGGED TO CROSS CWA DURG NGT. BUT HI STABILITY IN WAD WL PREVENT COMPLETE MIXING. BLO ADVY SN AMTS WL FALL ACRS THE SRN TIER FARTHER FM SFC LO/BETTER DIFFERENTIAL DVGC. STRG WAD/CLD COVER MEANS MOST STNS WL REACH LO TEMPS EARLY...NOT FAR FM PRESENT READINGS...WITH TEMPS RISING LATER. COORDINATED WITH APX. .MQT...SN AND BLSN ADVY OVRNGT MIZ001>003. SN ADVY TNGT MIZ004-005. SN ADVY LATE TNGT-EARLY TUE MIZ006-007. SN AND BLSN ADVY LATE TNGT-EARLY TUE MIZ014. GALE WRNG LK SUP OVRNGT. KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 1020 AM EST MON DEC 27 1999 SFC AND 850 RIDGE OFF TO THE WEST IS GIVING THE AREA NORTH FLOW FOR THE MORNING AND EARLY AFTERNOON. THIS WILL BEGIN TO CHANGE BACK TO THE NORTHWEST DURING THE LATE AFTERNOON AND EARLY EVENING AS THE RIDGE DROPS TO THE SOUTH. 12Z RUC AND 06Z MESOETA BOTH HAVE TIMING OF THE WIND DIRECTION CHANGE OCCURRING GRADUALLY BETWEEN 16Z AND 21Z THIS AFTERNOON. THIS WILL BEGIN TO CHANGE THE ORIENTATION OF THE SNOW BANDS FROM THE NORTH ORIENTATION CURRENTLY OBSERVED ON KAPX TO THE NORTHWEST AND THEN THE WEST BY 06Z TONIGHT. ZONES OUT BY 16Z. APX...LAKE EFFECT SNOW ADVISORY... THIS AFTERNOON...MIZ008-015-021-026-027-032. LUTZ mi AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 1047 AM CST MON DEC 27 1999 THE LATEST RUC...ETA AND NGM SHOW THE SFC HIGH PRES RIDGE SLIDING ACROSS NE SD AND WC MN THROUGH THE DAY WITH WINDS GOING FROM N TO SW FAIRLY QUICKLY THIS AFTERNOON. THEREFORE...AS THIS OCCURS THE LOW CLOUDS ACROSS C AND NC SD WILL ADVECT EASTWARD BRINGING MOSTLY CLOUDY SKIES BACK TO NE SD AND WC MN. ALSO...PLENTY OF MID AND HIGH CLOUDS ADVECTING IN FROM THE NW THIS AFTERNOON. THE BIG CHALLENGE WILL BE THE HIGH TEMPS TODAY. COLD AIR ACROSS NE SD AND WC MN WILL MOVE QUICKLY OUT OF THE AREA AS WAA BEGINS THIS AFTERNOON. THEREFORE ...WITH A SHARP TEMP GRADIENT ACROSS THE CWA AND LOW CLOUDS...TEMPS WILL VARY SIGNIFICANTLY FROM AROUND 15 IN FAR NE SD AND WC MN TO 45 IN JONES COUNTY BY LATE AFTERNOON. HAVE UPDATED FORECAST TO MAKE MANY CHANGES. .ABR...NONE MOHR sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 503 PM EST MON DEC 27 1999 SATELLITE IMAGERY SHOWS EXTENSIVE AREA OF CLOUDS OVER NORTHERN NEW YORK MAKING EASTWARD PUSH INTO VERMONT. LONGER LOOP OF WATER VAPOR IMAGERY SHOWS SHORTWAVE TROUGH MOVING EAST ACROSS SOUTHERN QUEBEC. TAIL END OF THE SHORTWAVE APPEARS TO HAVE HELPED ENHANCE TO CLOUDS OVER THE NORTHERN ADIRONDACKS. RUC DATA HAS DEPICTED THIS SHORTWAVE WELL. RUC FORECAST SOUNDINGS ALSO HOLDING ONTO LOWER LEVEL MOISTURE OVER THE FORECAST AREA THROUGH LATER TONIGHT...UNTIL DRYING TAKES PLACE AFTER MIDNIGHT. HAVE ALREADY UPDATED NEW YORK ZONES EARLIER AND WILL NOW ADD MORE CLOUDS INTO FORECAST FOR FIRST PART OF TONIGHT IN VERMONT. EVENSON .BTV...NONE. vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 905 PM EST MON DEC 27 1999 CUR SIT...KAKQ 88-D SHOWS A BAND OF SN ACRS VA NRN NECK WHIT -SN BEING REPORTED IN ACCOMACK AND PARTS OF THE MIDDLE NECK. TRENDS THE PAST 1/2 HR HAS SHOWN THAT THE AREA IS DEC IN COVERAGE HOWEVER WL WATCH CLOSELY AND ASSESS IF AN ADVISORY IS NEEDED. REPORTS INDICATE THAT IN NORTH UMBERLAND AND LANCASTER CNTYS HAVE ARND A 1/2 IN ACCUM ATTM. BOTH MESO ETA AND RUC SHOW A WK S/W AT H700 ACRS NRN VA AS WELL AS A 500 AND 300 JETS ACRS ERN VA. BELIEVE THAT THE COMBO OF THESE FEATURES ARE FUELING THE SN DEV. HOWEVER AM PROBLEMS FNDG SOMETHG ON THE MICRO AND MESO SCALE FOR THE LOCALIZED ENHAMCMENT. FOR THE REMAIDER OF THE AREA. THE S/W TROF WL CONT TO ROTATE S ACRS THE REGION AS THE MAIN WAVE IN NRN MS AND AL MVS INTO GA AND SRN AL. MODELS SHOW LOW AND MD LVL MOIST ACRS THE NRN HALF OF CWA THRU THE NIGHT SO WL KEE FLURRIES FOR MUCH OF NRN PART OF FA. BELEIVE THE S WL REMAIN DRY THOUGH. TEMPS LOOK OK FOR NOW. NO SIG CHANGES IN THE MARINE. .AKQ...NONE. SHADE va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 952 AM EST MON DEC 27 1999 WEAK RIDGING ACROSS THE AREA THIS MORNING ALRDY GIVING WAY TO NEXT FAST MOVING CLIPPER AS SATL SHOWS LEADING EDGE OF CLDNS INTO WRN WVA. MAIN QUES THIS AFTN WITH HOW FAR SE TO BRING MENTION OF -SN GIVEN ECHOES NOW ALONG THE OH/WVA BORDER. WITH THE LATEST MESO-ETA/RUC INDICATING PRECIP INTO THE FAR NWRN ZONES BY 00Z AND STILL ENOUGH LOW LVL UPSLOPE RH IN PLACE...WILL INTRO A LATE AFTN LOW CHC MAINLY SE WVA GROUP. ELSW ACROSS THE MTNS WITH MID CLDNS ON THE INCRS...PLAN TO OPT FOR INCRSG CLDNS BUT WITHOUT ANY PRECIP MENTION. THINK CAN HOLD PIEDMONT ZONES TO MNLY PC WITH LEE CI EARLY AND ONLY A GRDL INCRS IN MID DECK BY LATE AFTN. MAY NEED TO ADJUST TEMPS UP SLGTLY OUT EAST BASED ON MORN THICKNESS AND OFFSET OF WEAK CAA BY DOWNSLOPE OTRW GOING FCST GNRLY ON TRACK. .RNK VA...NONE. WV...NONE. NC...NONE. JH va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTH PLATTE NE 1243 PM CST MON DEC 27 1999 ...CHALLENGE CONTINUES TO BE TEMPS AND WINDS... SATELLITE INDICATING LOWS CLOUDS SLOWLY ERODING FROM BOTH EAST AND WEST...WITH SURFACE OBS INDICATING WINDS HOLDING IN THE 10 TO 20 MPH RANGE ACROSS THE CWA. ALL MODELS INITIALIZED SIMILAR WITH STRONG UPPER HIGH OVER NORTHWEST CONUS...TROUGH IN EAST. AT THE SURFACE...LOW OVER QUAD CITIES REGION...WITH HIGH PRESSURE EXTENDING INTO NORTHERN PLAINS. MODEL SOLUTIONS VERY SIMILAR THROUGH 48 HOURS. RIDGE IN WEST TO WEAKEN AND FLATTEN AS SHORTWAVE MOVES ACROSS ALASKA INTO NORTHERN BRITISH COLUMBIA BY 48 HOURS. WITH HIGH PRESSURE HOLDING TIGHT OVER WESTERN CONUS...LOW PRESSURE TO REMAIN EMBEDDED IN TROUGH IN EAST. TONIGHT...STRONG SUBSIDENCE AND DRYING OF THE ATMOSPHERE WILL LEAVE CWA WITH CLEAR SKIES. 15Z RUC INDICATES THAT LOW CLOUDS WILL ERODE QUICKLY AND WON'T BE A CONCERN TONIGHT. ALL MODELS INDICATING LOW MOVING TOWARD GREAT LAKES DEEPENING AS HIGH OVER WEST BUILDS. THIS WILL INCREASE PRESSURE GRADIENT OVER AREA...KEEPING WINDS A FACTOR OVERNIGHT. WITH MIXING WINDS AND STRONG WARM AIR ADVECTION...TEMPS TO BE A BIT TRICKY. WILL SEE TEMPS COLDEST BEFORE MIDNIGHT...THEN WARMING SLOWLY BY DAYBREAK. TUESDAY...WITH SUNSHINE...WINDS WILL MIX EARLY...AND WILL SEE BREEZY CONDITIONS WEST...WINDY EAST. THEN AS SURFACE LOWS LIFTS TO THE EAST...PRESSURE GRADIENT WEAKENS...AND WINDS WILL BEGIN TO SUBSIDE FROM WEST TO EAST LATE IN THE DAY. BIG CONCERN IS TEMPS ON TUESDAY. WITH VERY SLIGHT WESTERLY COMPONENT OF WIND STRONGEST IN PANHANDLE AND SOUTHWEST...EXPECT WARMEST THERE WITH WEAK DOWNSLOPE COMPONENT. 850 MB TEMPS TO 9 C IN FAR SOUTHWEST AND 4-5 C IN NORTHEAST. THIS EQUATES TO SURFACE TEMPS IN LOWER 60S SOUTHWEST...TO MID 50S N NORTHEAST...SLIGHTLY BELOW GUIDANCE. WITH A MORE NORTHERLY FLOW THAN PREVIOUS MODEL RUNS INDICATED...WILL GO THIS ROUTE. TUESDAY NIGHT...WEAK NORTHWEST FLOW CONTINUES...WITH ATMOSPHERE REMAINING DRY. WITH GRADIENT WEAKENING...WINDS TO DECOUPLE ALLOWING TEMPS TO FALL A BIT MORE. LOWS GENERALLY IN THE MIDS 20S TO AROUND 30 WITH LIGHT WESTERLY WINDS. WEDNESDAY...SHOULD BE WARMER THAN TUESDAY. WITH MORE WESTERLY FLOW... GOOD DOWNSLOPE. HOWEVER...WINDS NOT AS STRONG. WITH 850 MB TEMPS RANGING FROM 11 C IN SOUTHWEST TO 8 C IN NORTHEAST...EQUATES TO MID TO UPPER 60S SOUTHWEST...AROUND 60 NORTHEAST CWA. EXTENDED...DRY THROUGH PERIOD. COOL DOWN BEGINS THURSDAY AS CLIPPER DRAGS DRY FRONT THROUGH EARLY WITH ALASKAN HIGH SETTLES INTO REGION. THICKNESSES FROM 552 THURSDAY DROP TO 534 FRIDAY INTO SATURDAY. FMR TEMPS LOOK REASONABLE. HIGHS IN 50S THURSDAY...30S FRIDAY AND SATURDAY. LOWS 20S THURSDAY...TEENS FRIDAY...INTO THE SINGLE DIGITS SATURDAY. .LBF...NONE M. MUTCHLER ne AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 201 PM EST MON DEC 27 1999 MESOHIGH OVER NE SC ATTM SHIFTED WINDS TO LIGHT ESE OVER E CENTRAL SC...MESOHIGH DRIFTING SLOWLY NE AND FILLING...SO EXPECT WINDS TO BECOME W OVER NEXT FEW HOURS AS INDICATED BY RUC. LITTLE CHANGE IN MODELS FROM PREV RUNS...AND MODELS IN CLOSE AGREEMENT. EXPECT MAINLY DRY CONDITIONS THROUGH END OF WEEK. POSSIBLY A FEW CLOUDS TONIGHT AS UPR LVL VORT AND SFC TROF/WEAK COLD SURGE/FRONT PASSES BY. VERY DRY AND SLIGHTLY COOLER BEHIND SFC BOUNDARY SO SLIGHTLY COOLER HIGH TEMPS TUE. PERSISTENT RIDGE OVER THE W US FINALLY BREAKS DOWN MIDWEEK AND OVERALL FLOW BECOMES MORE ZONAL. ANOTHER SYSTEM W OF THE AREA THU SHIFTS LLVL WINDS TO SW AND RAPID WARMUP EXPECTED THU AND FRI WITH WELL ABOVE NORMAL TEMPS AND POSSIBLY SOME CLOUDS FRI BEFORE SYSTEM PASSES BY SAT. CWF...UPR IMPL MOVES ACRS AREA TNGT/EARLY TUE DRIVING NXT CDFNT/TROF ACRS WATERS. WINDS SHUD STAY BLO SCA CRITERIA...BUT WILL MENTION SCEC FOR OFFSHORE GA WATERS WHERE NW WINDS 15-20 KT AND SEAS IN THE 4-6 FT RANGE EXPECTED LTR TNGT THRU TUE NGT. NW-W WINDS NR 15 KT EXPECTED ACRS SC WATERS WITH SEAS 3-4 FT. HIGH PRES BLDS ACRS RGN ON WED WITH SOME REDUCTION IN WS AS SFC RIDGE APCHS THE SE CST. HI MOVES EAST ON FRI AS SFC TROF DVLPS TO THE W. PRES GRAD TGTNS FOR FRI AND WINDS CUD APCH SCA CRITERIA...SPLY ACRS SC WATERS...BUT WON'T MENTION FOR NOW AS MARGINAL AT BEST. WK CDFNT SHUD MOVE INTO WATERS LT FRI NIGHT THRU SAT MORN. SCA CONDS NOT EXPECTED WITH THE FNT AT THIS TIME. .CHS... SC...NONE. GA...NONE. JAC/SLB sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 630 AM EST TUE DEC 28 1999 SNOW RAPIDLY DIMINISHING FROM WEST AS EVIDENT ON MQT 88D RETURNS...WITH BACK EDGE THROUGH ALL BUT ERN COUNTIES. BEST ISENTROPIC ASCENT AND MSTR FOR HEAVY SNOW HAS MOVED EAST OF FA AND OUT AHD IN WRM SECTOR OF RAPIDLY DEEPENING 987 MB SFC LOW NOW CENTERED EAST NE OF LAKE SUPERIOR. SFC LOW CONTINUES TO MOVE RAPIDLY SEWD SLIGHTLY FASTER THAN WHAT 00Z MODELS HAD PROJECTED AT 12 HRS. PREFER ETA AND RUC ON DETAILS WHICH DIGS SERIES OF STG VORT MAXES WEST AND SOUTH OF FA TODAY MORE IN LINE WITH WHAT WV LOOP IS INDICATING ATTM. THIS DIGGING OF VORT MAXES TO WEST WILL DRIVE SFC-8H LOW ON MORE SSE TRACK DOWN TOWARD GEORGIAN BAY THIS EVENING PER RUC...ALLOWING FOR MORE DIRECT NLY PUSH OF ARCTIC AIR INTO FA PER ETA. CONCERNS TODAY WILL BE SNOW AND BLOWING SNOW IN STG CAA BEHIND SFC LOW. ETA FCST SNDGS SHOW STEEP LAPSE RATES FM SFC-850 MB WITH MAX 25 KNOTS OF WND OVR WEST THROUGH MIXED LYR AND 30 KNOTS IN EAST. WITH SYNOPTIC SNOW DONE THIS MORNING HAVE EXPIRED SNOW ADVISORIES. HWVR...STG WNDS MAY CREATE HAZARDOUS TRAVEL DUE TO BLOWING AND DRIFTING OF FALLEN SNOW TODAY. HAVE STRESSED THIS ELEMENTS IN ZFP AND WSW EXPIRATION. THIS AFT AND EVNG LOOK FOR LES TO KICK IN WITH GOOD CAA BEHIND DEPARTING LOW...ESPECIALLY OVR ERN COUNTIES WHERE INV HGTS WILL REMAIN A BIT HIGHER AND GOOD CYCLONIC LLVL FLOW NOTED WITH LAKE INDUCED TROF. LAKE DELTA-T INCREASING TO 17-20C THIS AFT YIELDS 1-3 INCHES THIS AFT AND THEN ANOTHER 1-3 TONIGHT FOR ALGER-LUCE-NRN SCHOOLCRAFT PER DECISION TREE. WENT 1-2 INCHES TODAY AND 1-2 MORE THIS EVNG OVR ONT-CMX WHERE STG WNDS AND SLIGHT BACKING OF NW FLOW WILL LIMIT RESIDENCE TIME FOR COLD AIR TO PICK UP MSTR OVR LAKE SUPERIOR. FETCH FAVORED OVR ERN MQT COUNTY TO PICK UP 1-2 INCHES OF LES TODAY...AND THEN 1-2 INCHES THIS EVNG. ETA INDICATING FLOW BACKING AND BECOMING MORE ANTICYCLONIC LATE TONIGHT WHICH SHOULD HELP SHUT OFF LES MACHINE. ANOTHER IN SERIES OF SHRTWVS TO MOVE IN FM NW LATE WED ALTHOUGH MODELS NOT SHOWING THIS SYSTEM QUITE AS STG OR MOIST AS LAST. HVWR... MODELS HAVE TENDED TO UNDER ESTIMATE PUNCH OF CLIPPERS OF LATE. WITH GOOD QG FORCING AND ISENTROPIC LIFT WENT WITH CAT POPS FOR -SN WED AFT. FWC TEMPS WAY TO HIGH TODAY GIVEN CAA FCST...THUS HAVE UNDERCUT BY AS MUCH AS 5-10 DEGREES. LOWS LOOK A TAD BIT ON COOL SIDE TONIGHT GIVEN MODERATING ONSHORE FLOW MOST OF NIGHT. .MQT...GALE WRNG LK SUP TODAY. VOSS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 955 AM EST TUE DEC 28 1999 AS EXPECTED BY PREVIOUS SHIFT... IR SAT PIX SHOW DENSE SCU NOT SURVIVING TRIP OVER APPS THIS MRNG. THIN BAND OF AC/CI DISSIPATING ON SRN END. WILL CONTINUE MOSNY FCST. UA ANALYSIS SHOWS TROF MOVING ACROSS CAROLINAS W/ DOWNSLOPE FLOW SPREADING E. FLOW SHOULD OFFSET WEAK CAA IN PLACE PER MSAS ANALYSIS. LOCAL SCHEMES GIVE LWR-MID 50S ACROSS CWA THIS AFTN & WILL MAKE ADJUSTMENTS BASED ON 16Z READINGS. WIND DIRECTIONS MAY NEED TWEAKING AS WELL AS MTRS SHOW N TO NE WINDS ATTM. BUT NW MAY STILL BE FLAVOR OF THE DAY. CWF: WINDS LGT NRLY ALONG CSTL STATIONS BUT W 10-15 OFFSHORE W/ MESO- LO ANALYZED OFF CLKN7. MSAS SHOWS BEST CAA CURRENTLY DOWN S W/ RUC & MESO-ETA STILL HOLDING ONTO 20KT THIS AFTN. WILL SPLIT AT STATE LINE W/ SLIGHTLY HIGHER WINDS OVER SC WATERS BUT WILL REMAIN BELOW SCA CRITERIA. WILL REMOVE GUSTY WORDING AS H95 WIND SPEEDS REMAIN AOB 25KT. FINAL DIRECTIONS WILL BE BASED ON 15Z-16Z OBS. .ILM...NONE. LGE nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 234 PM EST TUE DEC 28 1999 ZFP/MODELS: MAIN CONCERNS OVER THE SHORT RANGE PERIOD WILL BE MIN TEMPS WITH POTENTIAL FREEZE WARNING AND LONG DURATIONS OF LOW RH DURING THE AFTERNOONS. MODELS IN FAIR AGREEMENT WITH LARGE SCALE FEATURES. LONG WAVE TROUGH CURRENTLY AT IT/S MAXIMUM AMPLITUDE WILL LIFT NE ALLOWING A MORE ZONAL FLOW TO SET UP ACROSS THE SE STATES WHICH WILL BRING A MODERATING TREND IN TEMPS. AT THE SURFACE...A RIDGE OF HIGH PRESSURE ESTABLISHES ITSELF FROM THE SW N ATLC ACROSS FL INTO THE GULF AS CYCLOGENESIS OCCURS ACROSS OKLAHOMA. TIME/HEIGHT XSECS INDICATE VIRTUALLY NO CLOUDS ACROSS THE CWFA THROUGH THU. FWC/FAN TEMPS GUIDANCE GENERALLY SIMILAR AND WILL GENERALLY BE FOLLOWED. THIS PRESENTS A CONCERN FOR TONIGHT/S MINS. WHILE IT APPEARS MANY AREAS WILL REACH 32 DEGREES...IT WILL BE FOR A SHORT DURATION. EXCEPTIONS WILL BE PLACES LIKE CEW AND TLH AIRPORT THAT ARE EXPOSED AND NORMALLY RADIATE WELL. PLAN TO HOLD OFF ON ISSUING FREEZE WARNING ATTM...BUT WILL MENTION BELOW FREEZING TEMPS IN NORMALLY COLDER LOCATIONS. SLIGHTLY MILDER TEMPS INDICATED FOR WED NIGHT INDICATING THE CONTINUANCE OF MODERATING TREND THAT WILL EXTEND INTO THE HOLIDAY WEEKEND. MARINE: NEWEST SET OF MODEL SOUNDINGS CONTINUE TO INDICATE THAT WE WILL SEE WINDS INCREASING ACROSS THE WATERS THIS EVENING BEFORE DROPPING OFF TOWARD MORNING. THE EXTENT OF THIS INCREASE IS IN QUESTION WITH ETA/AVN INDICATING SCEC CONDITIONS AND NGM SHOWING SCA WINDS. LATEST RUC SUPPORTS NGM NUMBERS...BUT WITH GENERAL WEAKENING OF THE GRADIENT INDICATED BY THE MODELS (INCLUDING NGM) WILL STAY JUST BELOW SCA ON OFFSHORE LEGS FOR NOW. FIRE WEATHER: RED FLAG EVENT VERIFYING THIS AFTN. LOOKS LIKE A MARGINAL EVENT FOR WED AND WILL GO WITH WATCH INLAND ZONES ONCE AGAIN. EXTENDED: BEAUTIFUL START TO THE NEW MILLENNIUM ON TAP AS THE ZONAL FLOW CONTINUES TO BRING MILD AIR TO THE REGION. A WEAK DRY FRONTAL PASSAGE ON NEW YEAR/S DAY WILL HAVE LITTLE IMPACT ON OUR WEATHER. TEMPS WILL BE IN THE 40S BY NIGHT AND UPPER 60S TO LOWER 70S BY DAY. PRELIM NUMBERS... TLH 30 63 33 69 0000 PFN 39 61 40 64 0000 DHN 35 58 38 65 0000 ABY 32 60 35 67 0000 VLD 33 60 36 66 0000 .TLH... FL...RED FLAG WARNING UNTIL SUNSET INLAND FL COUNTIES. ...FIRE WEATHER WATCH WED AFTN INLAND FL COUNTIES. ...SCEC SUWANNEE TO DESTIN OUT 60 NM. AL...NONE. GA...NONE. MAW fl AREA FORECAST DISCUSSION...CORRECTED WARNINGS SECTION. NATIONAL WEATHER SERVICE JACKSONVILLE FL 955 AM EST TUE DEC 28 1999 ZONES...WV IMAGERY SHOWS THE UPR IMPULSE MOVING ACROSS CNTRL FL AND A DRY SLOT/UPR TROF AXIS DROPPING ACROSS CNTRL GA AND THE BIG BEND. THIS FEATURE WILL MOVE ACROSS THE FA THIS AFTN WITH THE MID-HIGH DECK BEING DEPRESSED TO THE SE. CURRENT ZONES REFLECT THIS TREND WELL AND WILL AMD FOR WORDING AROUND 11 AM. NEXT COLD FRONT/TROF OVER N-CNTRL GA AND SHOULD GO THROUGH ARND NOON/EARLY AFTN. THIS FEATURE SHOULD BE MARKED BY AN INCREASE IN WIND SPEEDS. WIND SPEEDS OVER THE INTERIOR LOOK TO DROP OFF TO NOTHING BY WED AM AND WITH CLEAR SKIES LOOKS LIKE A GOOD RADIATIONAL COOLING NIGHT FOR HTE SUWANNEE VALLEY/INTERIOR SE GA. MARINE...GRAYS REEF CURRENTLY WNW 16 KT SEAS 2 FEET AND SAUF1 NW 10 KT. FLY IN THE OINTMENT IS THAT WE HAVE A SHIP...KGTH...78 NM ESE OF FLAGLER BEACH REPORTING WINDS W 28KT...WIND WAVES 2-3 FT....W SWELL 6-7 FT. SINCE THE WINDS ARE LIKELY TAKEN FROM THE TOP OF A MAST 60- 80-100-? FEET ABOVE THE WATERLINE AM NOT OVERLY CONCERNED ABOUT THE WIND SPEED....BUT WILL INCREASE THE SEAS IN THE OFFSHORE PORTION TO 5-7 FEET DUE TO THE SWELL REPORT. THIS WILL REACH SCA CRITERIA FOR THE OFFSHORE WATERS. LOOKING AT THE MODEL RUNS RUC SEEMS TO HAVE CAUGHT ON TO THIS REPORT THE BEST...WITH MESO-ETA A CLOSE SECOND. WILL TEND CLOSER TO THE MESO-ETA HANDLING OF COASTAL WINDS THIS AFTN/TNGT AS IT SEEMS TO BE HANDLING THE NEXT TROF/FRONT BETTER. FIRE WX...FIRE WX FORECASTER IS MONITORING MIN RH'S AND A RED FLAG WARNING MAY...REPEAT MAY...BECOME NECESSARY FOR THE PORTIONS OF SE GA AND THE SUWANNEE VALLEY THIS AFTN. THANKS FOR THE COORD KMLB...KCHS. .JAX... GA...FIRE WX WATCH TODAY. SCA ALTAMAHA SOUND-FERNANDINA BEACH 20-60 NM OFFSHORE. FL...FIRE WX WATCH TODAY. SCA FERNANDINA BEACH-FLAGLER BEACH 20-60 NM OFFSHORE. SANDRIK fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 230 PM CST TUE DEC 28 1999 LATEST SFC/MSAS ANALYS SHOWS LOW PRESSURE NORTH OF LAKE HURON WITH FRONT INTO EASTERN ILLINOIS. SURGE OF WARM AIR ADVECTION HAS PASSED TO THE EAST OF CWA WITH TEMPS WARMING WELL INTO THE 30S/40S. SECONDARY FRONT /BACKDOOR/ EXTENDS FROM NORTHEAST MINNESOTA INTO NORTHERN WISCONSIN. WEAK COLD AIR ADVECTION BROUGHT LOW CLOUDS INTO MINNESOTA AND WISCONSIN THIS MORNING WHILE INCREASING NORTHWEST WINDS IN CYCLONIC FLOW HAS HELPED TO SEND THESE LOW CLOUDS SPILLING SOUTH OVER MUCH OF CWA. CONCERNS A PLENTY AND INCLUDE POTENTIAL FOR FOG AND FREEZING DRIZZLE OVERNGT INTO WEDS MORNING...TEMPS AND CLOUDS THROUGHOUT...AND PCPN CHCS WITH 1) SECONDARY SHOT OF WARM AIR ADVECTION WEDS AND 2) FROPA EARLY THURS. 00Z MODELS INITIALIZED FAIRLY WELL AND ADVERTISE TRANSITION TO NEARLY ZONAL UPPER FLOW. NET RESULT WILL BE SWITCH TO GENERALLY DRY AND SOMEWHAT MILD PATTERN FOR THE FORESEEABLE FUTURE AS ZONAL FLOW KEEPS CANADIAN AIR BOTTLED UP WELL TO OUR NORTH. IN SHORT TERM...VISIBLE IMAGERY SHOWS SOME BREAKS DEVELOPING IN LOW CLOUDS WITH LATEST RUC INDICATING SOME DRYING IN LOWEST LEVELS TAKING PLACE LATE THIS AFTN/EVE. ETA SEEMS TO HAVE BEST HANDLE ON LOW LEVEL MOISTURE AND SHOWS DRYING IN H7-H9 LAYER FROM NORTH TO SOUTH BETWEEN 00Z-06Z AS WEAK SFC RIDGE BUILDS INTO AREA. NGM/AVN ALSO HINT AT THIS SCENARIO BUT TO A LESSER EXTENT. CONCERN THEN SHIFTS TO POTENTIAL FOR LOW CLOUD/FOG/FREEZING DRIZZLE DEVELOPMENT OVERNIGHT. EVEN THOUGH WEAK SUSBIDENCE BUILDS IN LATER TONIGHT DON/T BELIEVE THIS WILL BE ENOUGH TO SCOUR OUT LOW LEVEL MOISTURE ESPECIALLY WITH ONGOING SNOWMELT AIDING IN SENDING MOISTURE SKYWARD. MODEL FORECAST SOUNDINGS SHOW AN INVERSION SETTING UP OVERNIGHT WITH ETA MORE PRONOUNCED ON STRENGTH OF INVERSION AND ABUNDANCE OF LOW LEVEL MOISTURE. FEEL ETA LOOKS MORE REPRESENTATIVE THUS LOW CLOUDS AND PATCHY FOG A REAL POSSIBILITY. CAN/T RULE OUT PATCHY FREEZING DRIZZLE LATE TONIGHT INTO EARLY WEDS MORNING AS ETA FORECAST SOUNDINGS REVEAL CHARACTERISTICS OF A FREEZING DRIZZLE SOUNDING WITH MOIST LOW LEVELS AND PLENTY OF DRY AIR NOTED ABOVE 700 MBS. ISENTROPIC UPGLIDE ASSOCIATED WITH NEXT SHOT OF WARM AIR ADVECTION IS FORECAST TO SWEEP ACROSS THE REGION LATE TONIGHT INTO WEDS MORNING. ANY DECREASE IN CLOUDS THIS EVENING SHOULD BE HALTED AS ALL MODELS POINT TO WARM AIR ADVECTION CLOUDS DEVELOPING OVER THE PLAINS AND SURGING EAST BACK INTO THE AREA TOWARD MORNING. WHETHER IT BE LOW CLOUDS DEVELOPING OR WARM AIR ADVECTION CLOUDS...SHOULD SEE PLENTY OF CLOUDS AROUND LATER TONIGHT INTO WEDS MORNING AFTER SOME DECREASE THIS EVENING. TEMPS WILL BE TRICKY. FWC VERIFYING POORLY AT 18Z WITH 3 HRLY TEMPS RUNNING 5 TO 10 DEGS WARMER THAN FWC INDICATES. SAME APPLIES TO MOISTURE...THOUGH NOT DOING AS POORLY...ONLY AROUND 5 DEGS TOO LOW. BRUNT OF ANY DRYING WITH BACKDOOR FRONT SHOULD REMAIN TO OUR EAST SO WILL ADJUST MINS UP CLOSER TO CURRENT DEWPTS. ON WEDNESDAY...SHOT OF WARM AIR ADVECTION AND ASSOCIATED CLOUDS SWEEP THRU DURING FIRST HALF OF DAY WITH MODELS INDICATING SOME DRYING IN THE AFTERNOON...THOUGH AVN KEEPS THINGS FAIRLY MOIST IN LOW LEVELS. ISENTROPIC INSPECTION OF 290K SFC SHOWS WEAK UPGLIDE SHIFTING ACROSS REGION EARLY WITH CONDENSATION PRESSURE DEFICITS OF 30 TO 50 MBS SHIFTING ACROSS NORTHEAST IOWA AND NORTHERN ILLINOIS. WOULD NOT BE SUPRISED TO SEE SOME LIGHT PCPN IN THESE AREAS THOUGH MEASURABLE LOOKS VERY SLIM TO NIL. FAVOR BLEND OF FWC/FAN ON TEMPS. SNOW FIELD DISSIPATING AND LOSING AFFECT ON TEMPS. MODELS SHOW NEXT FRONT FOR LATE WEDS NIGHT INTO THURSDAY. PCPN CHCS LOOK MEAGER. AREA CAUGHT IN BETWEEN WITH SPLIT FLOW AS NORTHERN ENERGY DROPS INTO MINNESOTA AND WISCONSIN...WHILE SOUTHERN ENERGY EJECTS OUT FROM SOUTHERN ROCKIES INTO PLAINS. AVN HINTING AT SOME LIGHT (TRACE) AMOUNTS OF PCPN THURS EVE...BUT WITH BEST FORCING TO REMAIN WELL TO OUR NORTH AND SOUTH WILL OPT TO REMOVE...HATE TO FLIP FLOP. SOME COOLING IN BEHIND THIS FRONT FOR THURSDAY NIGHT AND FRIDAY...THOUGH DOESN/T LOOK AS COLD. ...EXTENDED... LATEST MRF SHOWS NEARLY ZONAL UPPER FLOW THRU PERIOD. UKMET SHOWS A MORE AMPLIFIED FLOW AND GREATLY DIVERGES IN UPPER PATTERN LATE IN WEEKEND SHOWING LONGWAVE TROF OVER WESTERN US WITH RIDGING FROM OHIO VALLEY INTO SOUTHEAST US AND TROF OVER NEW ENGLAND. ECMWF APPEARS TO BE TRENDING TOWARD MORE AMPLIFIED /TROF/RIDGE/TROF SOLUTION ALTHOUGH A TAD SLOWER THAN UKMET WHILE CANADIAN ENSEMBLE FORECASTS ALSO LEANING TOWARD UKMET SOLUTION. EVEN WITH MODEL DIFFERENCES OVERALL THEME IS MODERATING TEMPS OVER LATTER HALF OF WEEKEND INTO EARLY NEXT WEEK. MRF NOT AS AGRESSIVE WITH COOL DOWN FOR NEW YEARS DAY AND QUITE A BIT WARMER BEYOND WITH H85 TEMPS ABOUT 8-12 DEG WARMER THAN PREVIOUS RUN. LATEST FMR GUIDANCE REFLECTS THIS AND IS ROUGHLY 7 DEGS WARMER FOR NEW YEARS DAY AND DRAMATICALLY WARMER FOR MONDAY BY ABOUT 15 DEGS. WILL TWEAK TEMPS UP A NOTCH FOR NEW YEARS DAY AND CONTINUE TREND THRU MONDAY. AS FOR PCPN...DPROG/DT FROM MRF SHOWS A TREND IN SPEEDING UP REMNANTS OF WEST COAST LOW WITH SYSTEM NOW SLATED BY MRF TO SHIFT TO OUR SOUTH ACROSS MISSOURI ON SUNDAY. WITH NORTHERN STREAM ENERGY WELL NORTH AND REMNANTS TO OUR SOUTH WILL LIKELY REMOVE MENTION OF PCPN FOR SATURDAY AS WERE CAUGHT IN THE MIDDLE ONCE AGAIN. COULD SEE LEAVING IT IN FOR SOUTHERN ZONES THOUGH. COORD WITH KDMX .DVN... IA...NONE. IL...NONE. MO...NONE. 05 il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PADUCAH KY 200 PM CST TUE DEC 28 1999 LAST IN THE SERIES OF CLIPPER SYSTEMS WILL MOVE SOUTHEAST FROM THE GREAT LAKES TO THE MIDDLE OHIO VALLEY THIS EVENING. AN ASSOCIATED SURFACE COLD FRONT WILL CROSS THE LOWER OHIO VALLEY EARLY THIS EVENING. MAIN FORECAST CONCERN IS ONCE AGAIN POST FRONTAL LOW CLOUDINESS AND TEMPERATURES. 19Z SATELLITE IMAGES SHOW LEADING EDGE OF LOW CLOUDS NEAR KSPI-KEVV LINE. NGM/ETA/RUC ALL INDICATE A CONTINUED SOUTHWARD PROGRESSION OF LOW CLOUDS...WITH LEADING EDGE REACHING MDH-PAH-HOP LINE AROUND 03Z. DESPITE COLD ADVECTION OVERNIGHT...WILL NOT UNDERCUT MOS LOWS BY MUCH...RELYING HEAVILY ON THE CLOUDS TO KEEP TEMPS UP. CHANGE TO ZONAL FLOW PATTERN BEGINS WEDNESDAY AS EASTERN U.S. TROUGH LIFTS OUT. MAIN FORECAST CONCERN IS HOW QUICKLY THE WARMUP WILL TAKE PLACE. ETA/NGM INDICATE LOW LEVEL FLOW WILL STILL BE NORTHWEST AT 12Z WEDNESDAY...WITH WEAK COLD ADVECTION. FLOW RAPIDLY BACKS AROUND TO THE SOUTHWEST DURING THE MORNING...AND WARM ADVECTION BEGINS IN EARNEST DURING THE AFTERNOON. WILL USE A COMPROMISE BETWEEN COLDER NGM MOS AND WARMER AVN MOS FOR HIGHS WEDNESDAY. EXPECT PLENTY OF SUNSHINE IN THE AFTERNOON AS SOUTHWEST FLOW SWEEPS OUT ANY REMAINING LOW CLOUDS. FAST MOVING SHORTWAVE EMBEDDED IN THE ZONAL FLOW PATTERN WILL APPROACH THE OHIO VALLEY THURSDAY. ASSOCIATED COLD FRONT WILL CROSS MISSOURI DURING THE DAY. MODELS STILL INDICATE VERY LITTLE MOISTURE AVAILABLE TO THIS SYSTEM...SO FORECAST WILL REMAIN DRY. FOR THE EXTENDED PERIOD...LATEST MRF RUN HAS BACKED OFF SOMEWHAT ON THE STRENGTH OF THE COLD AIR FRIDAY...AND BEGINS SOUTHWEST RETURN FLOW SOONER. MRF IS IN REASONABLE AGREEMENT WITH ECMWF AND NOGAPS... SO WILL BUMP UP TEMPS IN THE EXTENDED. A SOUTHERN STREAM SHORTWAVE IS PROGGED TO APPROACH THE FA SUNDAY. DESPITE SOME CONCERNS ABOUT MOISTURE AVAILABILITY...WILL MENTION PRECIP FOR DAY 5 IN LINE WITH MRF MOS POPS. .PAH...NONE. MY ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 220 AM CST TUE DEC 28 1999 LATEST 11-3.9 MICRON IR IMAGERY SHOWS CLEARING LINE MOVING THROUGH JONESBORO AND SHOULD APPROACH THE MS RIVER BY ZONE ISSUANCE. CIGS CURRENTLY RANGE FROM 4400 FT IN TUP TO 2500 FT IN MKL. 07Z SFC ANALYSIS SHOWED SFC HIGH CENTERED ACROSS SW TEXAS W/ RIDGE AXIS NOSING INTO NRN AR AND NW TN. DECENT PRESSURE FALLS SHOULD MOVE INTO THE OHIO VALLEY LATER TODAY AS LOW DEEPENS VCNTY LAKE SUPERIOR. THIS WILL SUPPRESS RIDGE AXIS SOUTH TOWARD THE GULF AND WILL KEEP A DECENT SFC GRADIENT ACROSS THE AREA. 00Z ETA/06Z RUC AGREE IN PUSHING NARROW...SFC-925 MB MOISTURE AXIS EAST THROUGH THE MORNING HOURS. SE PORTION OF THE CWA MAY BE THE SLOWEST TO CLEAR...BUT EVEN THERE MSUNNY SKIES SHOULD BE EXPECTED BY EARLY AFTN. LOW LEVEL THICKNESS PROG OFF THE ETA SUPPORT MAX TEMPS IN THE L/M 40S ACROSS THE AREA TODAY. OTHERWISE...FAIRLY BENIGN WEATHER AND GENERAL WARMING TREND IN STORE OVER THE NEXT SEVERAL DAYS AS UPPER FLOW BACKS IN RESPONSE TO LOWERING HEIGHTS ACROSS SW CANADA. 00Z AVN INDICATES THAT S/W ENERGY FROM THE REMNANTS OF AN ERN PACIFIC CUTOFF LOW WILL MOVE INTO THE MS VALLEY ON THU. AVN HINTS AT SOME MOISTURE RETURN AHEAD OF ATTENDANT SFC TROUGH...BUT WILL CONTINUE W/ DRY EXTENDED FCST ATTM. MEM 044/031 052/040 000 MKL 040/026 049/036 000 JBR 046/031 050/039 000 TUP 043/029 051/037 000 .MEM...NONE. CBD tn