EAST CENTRAL FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 835 PM EST WED DEC 6 2000 CURRENT WEATHER...500MB TROUGH MOVING ACROSS MISSISSIPPI RIVER VALLEY AND TOWARD SOUTHEAST STATES. SURFACE LOW FORMING OVER NORTHWEST GULF OF MEXICO. RIDGE OF HIGH PRESSURE EXTENDS FROM NEAR LITTLE ROCK TO OFFSHORE CAPE CANAVERAL. LATEST CAPE SOUNDING RECORDED NORTH TO NORTHWEST WINDS UP TO AROUND 2000 FEET THEN WINDS QUICKLY BACKED TO THE SOUTHWEST ABOVE THAT. SURFACE DEW POINT TEMPERATURES RANGED FROM AROUND 40 AT SOME OF THE INTERIOR AG SITES TO THE MID 50S AT THE COAST. INFRARED SATELLITE LOOP SHOWED AN AREA OF STRATOCUMULUS TRYING TO WORK ITS WAY UP THE PENINSULA. OFFSHORE WEATHER BUOYS WERE RECORDING NORTHWEST WINDS AT 5 TO 10 KNOTS AND 6 TO 7 FOOT SEAS...OF WHICH MOST WAS A NORTHEAST SWELL. PUBLIC ZONES...STRATOCUMULUS WAS HAVING A HARD TIME TRYING TO MAKE IT NORTH OF CENTRAL FLORIDA DUE TO A DRY SLOT OF AIR FROM 850-500MB. LATEST RUC UPDATE CYCLE SHOWS INCREASING 850-500MB MOISTURE AHEAD OF THE TROUGH WHICH IS CROSSING THE MS RIVER VALLEY AND FORECAST TO CLEAR CENTRAL FLORIDA THURSDAY AFTERNOON. MID AND UPPER CLOUDS MAY DECREASE FOR A WHILE BUT WILL THICKEN AS MOISTURE AHEAD OF ADVANCING 500MB TROUGH REPLACES CURRENT DRY POCKET OF AIR OVER NORTH FLORIDA AND THE UPPER PORTION OF CENTRAL FLORIDA AROUND SUNRISE. CURRENT MID AND UPPER LEVEL WIND TRAJECTORIES AND IR SATELLITE LOOK APPEAR TO TAKE MOST OF THE MID/UPPER MOISTURE SOUTHWEST AND SOUTH OF CENTRAL FLORIDA. WILL CHANGE SKY CONDITIONS WORDING. MARINE ZONES...SHORT RANGE GUIDANCE INDICATES THAT WINDS WILL STAY OUT OF THE NORTHWEST OVER THE COASTAL WATERS OVERNIGHT. PLAN TO KEEP SMALL CRAFT ADVISORY FOR SEAS IN THE GULF STREAM AND SMALL CRAFT EXERCISE CAUTION STATEMENT FOR THE REMAINDER OF THE COASTAL WATERS. .MLB...SMALL CRAFT ADVISORY FOR SEAS IN THE GULF STREAM. PUBLIC/MARINE...WIMMER AVIATION/FIRE WX...GLITTO fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 735 PM EST WED DEC 6 2000 ISENTROPIC LIFT SEEMS TO BE SLOWLY INCREASING OVER S FLA AS INDICATED BY CURRENT RUC. PROCESS EXPECTED TO CONTINUE TONIGHT INTO THU. RIGHT REAR QUAD OF JET OVER AREA PROVIDING SOME UPPER DIVERGENCE AS WELL SO ENOUGH UPWARD VELOCITIES SHOULD BE GENERATED TO SQUEEZE OUT SOME SHOWER ACTIVITY INTO THU. BYX/AMX 88-DS PAINTING SOME WIDELY SCATTERED SHOWERS OVER S FLA COASTAL WATERS AND MAINLAND AREAS AS WELL SLOWLY MOVING N TO NE AS UPPER LEVEL SW WINDS LOWER TO AROUND 7K CATCHING TOPS OF SHOWERS AND STEERING THE PRECIPITATION. CHANCE OF PRECIPITATION LEAST IN PALM BEACH ...HENDRY AND GLADES COUNTIES TONIGHT AS ISENTROPIC LIFT REALLY WEAK BUT COULD STRENGHTEN TOWARDS MORNING THIS SECTION OF CWA. WILL ONLY AMEND PUBLIC ZONES IF FORECASTED LOW TEMPERATURES TONIGHT APPEAR IN JEOPARDY DUE INCREASING CLOUDS. SCOURING FIRE WEATHER RAWS STATIONS AND UF FAWN WEATHER NETWORK... DEWPOINTS RUNNING IN THE UPPER 50S TO LOWER 60S CURRENTLY IN INTERIOR S FLA INCLUDING AREAS AROUND THE LAKE. UNLESS SOMETHING REALLY BREAKS IN THE NEXT 2 HOURS...WILL PROBABLY INCH MINIMUMS UPWARD A SMIDGE. IN THE COASTAL ZONES...WINDS APPEAR TO BE VEERING IN RESPONSE TO LOW PRESSURE OVER N CENTRAL GUFMEX. SPEEDS APPEAR OK BUT DIRECTIONS NEED TO BE ADJUSTED SOME. EVEN WITH SHIFTING WINDS...SMALL CRAFT SHOULD CONTINUE TO EXERCISE CAUTION IN THE GULF STREAM TONIGHT. .MIA...NONE. fl SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 930 PM EST WED DEC 6 2000 3.9 MICRON IR IMAGERY INDICATING THIN SPOTS AND SOME HOLES IN CLOUD COVER OPENING UP NEAR AND NORTH OF SAGINAW VALLEY...AIDED BY OROGRAPHIC DOWNSLOPING OF VEERING WINDS. EARLIER MESOETA AND LATEST RUC SHOW RATHER PRONOUNCED DRYING OVERNIGHT ALOFT AND CONSIDERABLE DECAY OF MOISTURE IN LOW LEVELS AS WELL...MOST PARTICULARLY NORTHERN AND CENTRAL COUNTIES OF FORECAST AREA...AS WEAK BUT DEEP SUBSIDENCE SETS IN. WILL THUS ALTER CLOUD WORDING A BIT OVER ALL BUT SOUTH PART OF SOUTHEAST MI OVERNIGHT FOR MORE BREAKS. WILL ALSO ADJUST WINDS MOST ZONES TO GRADUALLY VEER INTO WEST AS THEY LIGHTEN. WEATHER SERVICE RADARS SHOW MODEST LIGHT SNOW RETURNS OVER FORECAST AREA PULLING SOUTHEAST...SHOULD PERSIST MAINLY SOUTH HALF OF FORECAST AREA UNTIL A BIT PAST MIDNIGHT WITH FLURRIES ENDING NORTH BY MIDNIGHT. RUC SHOWS LITTLE IN WAY OF PRECIPITATION ANYWHERE PAST 06Z...ESPECIALLY NOT IN THE NORTH...EXCEPT WILL RETAIN CHANCE MENTION HURON COUNTY OVERNIGHT. UPDATE FOR THESE TRENDS WILL BE ISSUED BEFORE 10 PM EST. .DTX...NONE. DWD mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 902 PM EST WED DEC 6 2000 ...PLAN ON ALLOWING LAKE EFFECT SNOW WARNINGS TO EXPIRE THIS EVE... THE LATEST SFC ANALYSIS INDICATES ARCTIC FRONT HAS NOW SLIPPED SOUTH OF THE PELLSTON/CHEBOYGAN AREAS AND ON THE DOORSTEP OF GAYLORD AND ALPENA. WINDS HAVE QUICKLY TURNED NORTHERLY BEHIND THE TROUGH ACROSS ONTARIO AND UPPER MICHIGAN AS HIGH PRESSURE BUILDS INTO THE REGION...AND GIVEN THE DEGREE OF COLD AIR FILTERING IN...EXPECT A DEVELOPING LAND BREEZE COMPONENT TO RESULT IN SURFACE WINDS TURNING MORE NORTHEAST ACROSS THE PORTION OF ONTARIO BORDERING BOTH LAKE SUPERIOR AND HURON. AS NORTH TO EVENTUALLY NE WINDS FILTER SOUTH THROUGH ERN UPR AND NRN LWR MI...IT WILL RESULT IN AN END TO THE W/NW FLOW LAKE EFFECT SNOW (LES)...AND ALLOW FOR AT LEAST PARTIAL CLEARING ACROSS ERN UPR MI AND PORTIONS OF NC LOWER MI. THEREFORE...WILL ALLOW THE LES WARNINGS PREVIOUSLY IN PLACE FOR THE EVENING HOURS TO EXPIRE WITH THE NEXT ZONE ISSUANCE. 18Z ETA AND THE LATEST (00Z) RUC HINT AT DEVELOPING N/NNE LES BANDS POTENTIALLY CLIPPING SHORELINE AREAS FROM LEELANAU COUNTY SOUTH THROUGH MANISTEE COUNTY. FURTHERMORE...GIVEN THE LIGHTER WIND SPEEDS MOVING IN OVERNIGHT...BOTH THE ETA AND THE RUC SHOW A WEAK TROUGH DEVELOPING ACROSS LAKE MICHIGAN AS A RESULT OF THE DEVELOPING LAND BREEZES OFF ERN WI AND WRN MI (...AND THUS A CONVERGENCE ZONE NEAR MID-LAKE. WHETHER OR NOT THE LAND BREEZE COMPONENT WILL ALLOW THESE LES BANDS STAY OFFSHORE WILL BE SOMETHING TO WATCH OVERNIGHT... HOWEVER IN ANY EVENT GIVEN THE LATE DEVELOPMENT OF THESE BANDS (SHORT DURATION) ALONG WITH INVERSIONS DROPPING/STRENGTHENING TO AROUND 5500 FEET...EXPECT ONLY LIGHT ACCUMULATIONS. N/NNE WINDS WILL ALSO LIKELY YIELD AT LEAST LAKE CLOUDS (POTENTIALLY LIGHT LES/FLURRIES) ACROSS NE LOWER MI. HOWEVER...WITH THE DRY AIRMASS FILTERING IN FROM ONTARIO ALONG WITH THE LIMITED LAKE FETCH WITH THESE WINDS (ESP NORTH OF ALPENA)...WOULD EXPECT LITTLE IF ANY NEW ACCUMULATION. .APX...NONE. HURLEY mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 225 PM EST WED DEC 6 2000 REPORTS OF 2 TO 4 INCHES OF SNOW COMING FROM NORTHERN ONTONAGON COUNTY PER SNOW/STORM OBSERVERS. VSBY OBS OF 1/2 MI FROM THE SS JOHN G MUNSON AND ZERO FROM THE ONTONAGON PAPER PLANT ALSO INDICATE HEAVY SNOW. SNOW BANDS ORIGINATING OFF LAKE SUPER IN NRLY FLOW WHICH DVLPD AS LOW PRESSURE OVR THE ERN LAKE SLIPPED SWD. CLD TOPS TEMPS TO MINUS 35 INDICATE THAT TOPS MAY BE AS HIGH AS 17K FEET PER MORG SNDGS...INVERSION HAS PERHAPS LOWERED A BIT IN WAKE OF S/WV... BUT OBVIOUSLY NOT ENUF! ETA/RUC INDICATE CONTD H95 CONVERGENCE IN THIS AREA THRU ERLY EVENING. HAVE GONE AHD AND HOISTED ADVISORY FOR ONTONAGON COUNTY... AN ADDITION 1 TO 3 INCHES IS LIKELY THIS AFTERNOON UNDER THE HEAVIST BANDS. ANOTHER 1 TO 3 INCHES TONIGHT...THOUGH HIGHEST AMNT LIKELY FARTHER S AS BEST CONVERGENCES SHIFTS SLIGHTL. .MQT...LAKE EFFECT SNOW ADVISORY THIS AFTERNOON MIZ001-003. LAKE EFFECT SNOW ADVISORY THROUGH THIS EVEVING 002. DESROSIERS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1115 AM EST WED DEC 6 2000 MAIN FCST CONCERS THIS MORG ARE SYNOPTIC SNOW...LES ACRS THE KEWEENAW AND TEMPS. KMQT RADAR AND METARS SHOW AN AREA OF SYNOPTIC LIGHT SNOW RACING ACS SRN WRN AND SNR UPR MI AND NRN WI. VISIBILITIES HAVE BEEN 1-2SM AT THE LOWEST WITH THIS AREA. ENHANCED COLD CLD TOPS ACRS NRN WI SUGGEST HEAVIEST SNOW THERE... BUT AN INCH OR TWO XPCTD FOR UPR MI WITH THE GREATEST ALG THE WI BORDER. SNOW IS BEING DRIVEN BY H7/H5 QVECTOR FORCG ASSOC W/ S/WV NEAR THUNDER BAY AND H3 LFQ SPEED AND DIRECTIONAL DIVERGENCE AHD OF 150KT JET CORE. RUC FCSTS SHOW THIS FORCING MOVING SE OF THE FA BY LATE AFTN. LES BAND AS BEEN NEARLY STATIONARY FM W OF THE KEWEENAW ACRS STANNARD ROCK TO NEAR WHITEFISH POINT THIS MORNING. THIS BAND HAS BEEN LARGELY DRIVEN BY LOW LVL CONVERGENCE ASSOC W/ LOW OVR ERN LAKE WHICH XTNDS BACK TO E CNTRL MN. THIS LOW IS A LTL STRONGER THAN LAST NGT/S MODELS INDICATED...LIKELY DUE TO SLIGHTLY STRONG S/WV AND UPR DIVERGENCE. IN ADTN...UVM HAS LIFTED INVERSION TO ARND 17K FEET (WHICH AT CWPL IS ACTUALLY THE TROPOPAUSE!!) STRENGTH OF CONVERGENCE AND DEEPER MIXING WORKING TO OVERCOME DRY AIR (CWPL PW STL ONLY 0.04 AND KINL 0.09) W/ RADAR SHOWING A NARROW BAND OF 28DBZ IN CORE OF BAND. LES DECISION TREE YIELDS 3-5 INCHES FOR 6 HOURS SO WL CONT THAT FOR KEWEENAW. OUT EAST...AS LOW GRADUALLY MOVES SE... BAND WL SINK SE AND WL CONT 2-5 INCH FORECAST THERE. HAVE ADJUSTED TEMPS DOWN CONSIDERABLY...SPCLY IN THE SOUTH. CRNT READINGS RMN IN THE SINGLE DIGITS (XCP AT COPPER HARBOR) AND W/ LTL SUNSHINE AND NO WAA AREA WL SEE NO MORE THAN A CPL DEG RISE. .MQT...LAKE EFFECT SNOW ADVISORY TODAY MIZ001-003. DESROSIERS mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 910 PM CST WED DEC 6 2000 IN THE SHORTTERM... THE LATEST MODEL RUNS OFF THE ETA AND RUC INDICATED THAT THE SFC LOW WILL ADVANCE FURTHER WEST THAN PREVIOUS MODEL RUN. THE 6 HOUR MEAN SEA LEVEL PRESSURE CHANGE HAD A NARROW WEDGE OVER THE CENTRAL DAKOTAS INTO CNTRL NEBRASKA. THE SURFACE LOW SHOULD MOVE INTO WEST CENTRAL MN AFTER 12Z THURSDAY...AND SOUTHEAST INTO SOUTH CNTRAL MN BY AFTN. UPPER LEVEL ANALYSIS SHOWED AN OPEN WAVE...EXPECT A QUICK BURST OF SNOW OVER CNTRL MN INTO WESTERN WISCONSIN BY MIDDAY THURSDAY. THE LATEST RADAR COMPOSITE IMAGERY SHOWED LARGE SWATH OF SNOW EXTENDING OVER EASTERN NORTH DAKOTA INTO EXTREME WEST CENTRAL WISCONSIN. SNOW SHOULD CONTINUE TO SPREAD SOUTH AND EAST OVERNIGHT. ONLY MINOR CHANGES TO NEEDED TO PREVIOUS FORECAST...WL FRESHUP THE WORDING AND FINE TUNE SNOW AMOUNTS. WL HOLD OFF FROM ISSUING A WINTER WEATHER ADVISORY. WITH THE MODELS DIVERGING ON SOLUTIONS FROM PREVIOUS RUNS...THERE STILL REMAIN A BIT UNCERTAINTY. .MSP...NONE. JVM mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE JACKSON MS 700 PM CST WED DEC 6 2000 RADAR INDICATES THAT PRECIPITATION IS RAPIDLY DIMINISHING OVER THE SOUTHERN ZONES. PER RUC AND WATER VAPOR...AS SHORTWAVE PULLS AWAY RAIN SHOULD END SOON...AND WILL BE UPDATING SHORTLY ONCE LAST REMNANTS OF PRECIPITATION MOVES OUT. SOME BREAKS IN CLOUDS OVER NORTHWEST ZONES AND POINTS NORTHWEST. HOWEVER...WOULD EXPECT A TENDENCY TO FILL BACK IN WITH LOWER CLOUDS AS EVENING GOES ON WITH LOW LEVEL RELATIVE HUMIDITY HIGH...SO WILL STICK WITH MOSTLY CLOUDY FOR NOW. REST OF ZONES OK AT THIS POINT. .JAN... AR...NONE. LA...NONE. MS...NONE. 08 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 931 PM EST WED DEC 6 2000 SURFACE LOW PRESSURE OVER GEORGIAN BAY IS HOLDING A SOUTHWESTERLY FLOW OVER LAKES ERIE AND ONTARIO WITH LAKE EFFECT SNOW NORTH OF BUFFALO AND WATERTOWN. THERE AREA ALREADY INDICATIONS ON THE THE KBUF 88D RADAR OF THE LAKE SNOW BAND SHIFTING A LITTLE FARTHER SOUTH TOWARD THE CITY OF BUFFALO AND THE EASTERN SUBURBS. THE SURFACE LOW WILL MOVE EASTWARD TO THE ST LAWRENCE VALLEY BY THURSDAY MORNING. THERE IS A DISAGREEMENT AMONG THE MODELS ON HOW MUCH WITH WINDS WILL SHIFT TO THE NORTHWEST OR NORTH FOLLOWING THE PASSAGE OF THE LOW...THE 18Z ETA BRINGS IN A NORTHERLY WIND OVER THE WESTERN COUNTIES BY 12Z THURSDAY BUT THE OTHER MODELS INCLUDING THE RUC KEEP THE WINDS MORE NORTHWESTERLY..EVEN A WESTERLY WIND ON THE ETA. THE COLDEST H8 AIR WILL BE COMING THROUGH AFTER MIDNIGHT AND WILL FURTHER ENHANCE LAKE SNOWS...ESPECIALLY EAST OF LAKE ONTARIO. ADDITIONAL ACCUMULATIONS WILL BE SUBSTANTIAL EAST OF LAKE ONTARIO AND OVER PARTS OF WESTERN NY...AN ADDITIONAL FOOT OF SNOW IS NOT OUT OF THE QUESTION. THE CURRENT WARNING/ADVISORY MATRIX LOOKS OK AND WILL NOT NEED TO CHANGE MUCH. A GENERAL SNOW IS EXPECTED THURSDAY NIGHT AND FRIDAY MORNING AS ANOTHER LOW MOVES FROM WISCONSIN TO THE EASTERN LAKES BY FRIDAY. ANOTHER COUPLE OF INCHES OF WIDESPREAD SNOW WILL ADD TO THE EXISTING COVER OF THE LAKE EFFECT SNOWS...BUT NOT MUCH POTENTIAL FOR ADDITIONAL LAKE EFFECT SNOW THURSDAY NIGHT OR FRIDAY. .BUF...LAKE EFFECT SNOW WARNING TONIGHT NYZ010>012 ERIE GENESEE WYOMING COUNTIES. LAKE EFFECT SNOW WARNING LATE TONIGHT NYZ019-020 CHAUTAUQUA AND CATTARAUGUS COUNTIES. LAKE EFFECT SNOW WARNING TONIGHT NYZ007 JEFFERSON COUNTY. LAKE EFFECT SNOW ADVISORY THURSDAY MORNING NYZ006 OSWEGO LAKE EFFECT SNOW ADVISORY LATE TONIGHT AND THU MORNING NYZ008 LEWIS LAKE EFFECT SNOW ADVISORY THROUGH 3AM NYZ001-002. HIBBERT ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 900 PM EST WED DEC 6 2000 FIRST AREA OF JET ASSCD HI CLDNS IS MOVG THRU CWA AT THIS TIME...AND MAY SHIFT SOMEWHAT EWD NEXT FEW HRS IN VIEW OF STLT IMAGERY AND RUC. EVEN IF IT DOES SO THE UPSTREAM AREA OF UVV ASSCD WITH S/WV SHUD QUICKLY FOLLOW AND KEEP MOCLDY SKIES GOING. WL MAINTAIN A MENTION OF SNOW FLURRIES FAR NWRN ZONES BUT SAY "LATE" AS NOTHING IS IMMINENT. NO CHGS TO LATER TIME PDS AT THIS POINT...EXCEPT TO ADJUST 7TH DAY TO BLEND IN WITH SURROUNDING ZONES BETTER. TEMPS...DID A LTL TWEAKING TO SOME ZONES...MAINLY TO EXTEND THE RANGE DOWN JUST A DEG OR TWO IN VIEW OF CURRENT TEMPS. WL MAINTAIN HEADLINE IN MARINE FCST THAT SCA MAY BE NEEDED THU SINCE IT/S STILL A BIT EARLY RIGHT NOW. .PHI...NONE. pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 915 PM EST WED DEC 6 2000 SATELLITE SHOWS MID CLOUDINESS WILL CONTINUE FOR MUCH OF TONIGHT... BUT PROBABLY DIMINISH BEFORE SUNRISE SINCE THE RUC SHOWS THE APPROACHING H5 SHORTWAVE MOVING EAST OF THE FORECAST AREA BY 09Z. BASES ON CURRENT TEMPERATURES...DECREASED CLOUDINESS...AND THE MAV GUIDANCE PLAN TO LOWER TONIGHT/S LOWS ONE CATEGORY. NO OTHER CHANGES PLANNED. FCSTID = 5 CAE 28 55 31 62 / 5 0 0 0 AGS 28 57 29 63 / 5 0 0 0 SSC 29 56 31 63 / 5 0 0 0 OGB 29 56 32 62 / 5 0 0 0 .CAE... GA...NONE. SC...NONE. RJL sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 310 PM EST WED DEC 6 2000 UPDATED DISCUSSION BECAUSE I DECIDED TO MENTION FLURRIES FOR ENTIRE CWA FOR TONIGHT. SHORT WAVE TO CROSS THE AREA TONIGHT SHOULD KEEP SKIES CLOUDY UNTIL LATE. THERE COULD BE SOME FLURRIES....MAINLY THIS EVENING. THE LATEST RUC CONTINUES TO SHOW THE SHORT WAVE WEAKENING AND IR CLOUD TOPS UPSTREAM HAVE BEEN WARMING THE PAST COUPLE OF HOURS. THE REMAINDER OF THE FORECAST PERIOD OUR FLOW ALOFT WILL GRADUALLY BECOME NEARLY ZONAL. TEMPS WILL WARM A BIT ALOFT AND WEAK DISTURBANCES WILL MOVE ACROSS FROM TIME TO TIME... WITH LITTLE ORGANIZATION. HIGH PRESSURE WILL BUILD OVER THE SOUTHEASTERN U.S. LATER IN THE WEEK. THE FLOW COMING AROUND THE WEST SIDE OF THE HIGH WILL MODERATE TEMPS SOME BEGINNING FRIDAY. MOISTURE WILL GRADUALLY INCREASE THIS WEEKEND ALSO... AS THE SOUTHWEST FLOW EVENTUALLY STARTS TAPPING INTO THE GULF. FCSTID = 69 GSP 28 50 30 58 / 10 0 0 0 AND 27 51 30 59 / 10 0 0 0 CLT 26 49 30 57 / 10 0 0 0 HKY 25 46 28 55 / 10 0 0 0 AVL 23 43 27 52 / 10 0 0 0 .GSP... GA...NONE. NC...NONE. SC...NONE. sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 215 PM EST WED DEC 6 2000 SHORT WAVE TO CROSS THE AREA TONIGHT SHOULD KEEP SKIES MOSTLY CLOUDY UNTIL LATE. THERE COULD BE SOME FLURRIES....MAINLY THIS EVENING BUT WILL ONLY MENTION IN THE NC MTNS... WHERE THEY WILL BE MOST LIKELY. THE LATEST RUC CONTINUES TO SHOW THE SHORT WAVE WEAKENING AND IR CLOUD TOPS UPSTREAM HAVE BEEN WARMING THE PAST COUPLE OF HOURS. THE REMAINDER OF THE FORECAST PERIOD OUR FLOW ALOFT WILL GRADUALLY BECOME NEARLY ZONAL. TEMPS WILL WARM A BIT ALOFT AND WEAK DISTURBANCES WILL MOVE ACROSS FROM TIME TO TIME... WITH LITTLE ORGANIZATION. HIGH PRESSURE WILL BUILD OVER THE SOUTHEASTERN U.S. LATER IN THE WEEK. THE FLOW COMING AROUND THE WEST SIDE OF THE HIGH WILL MODERATE TEMPS SOME BEGINNING FRIDAY. MOISTURE WILL GRADUALLY INCREASE THIS WEEKEND ALSO... AS THE SOUTHWEST FLOW EVENTUALLY STARTS TAPPING INTO THE GULF. FCSTID = 69 GSP 28 50 30 58 / 10 0 0 0 AND 27 51 30 59 / 10 0 0 0 CLT 26 49 30 57 / 10 0 0 0 HKY 25 46 28 55 / 10 0 0 0 AVL 23 43 27 52 / 10 0 0 0 .GSP... GA...NONE. NC...NONE. SC...NONE. sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MORRISTOWN TN 840 PM EST WED DEC 6 2000 AREA WSR-88DS SHOW WEAK RETURNS DIMINISHING RAPIDLY ACROSS THE REGION THIS EVENING. THESE RETURNS AND ENHANCED CLOUDS HAD EXITED EASTWARD INTO NC/VA. UNCERTAIN JUST HOW MUCH PCPN ACTUALLY REACHED THE SURFACE...AS FLURRIES IN MRX AREA WERE BARELY VISIBLE AND MAINLY VIRGA WAS NOTED AT CHA. THE LATEST RUC MODEL RUN INDICATES NEUTRAL TO WEAK COLD AIR ADVECTION (CAA) FROM 850-700 MBS OVERNIGHT...AND SHORT RANGE MODELS DEPICT WEAK SINKING MOTION ON A SYNOPTIC SCALE. HOWEVER...ABUNDANT MOISTURE REMAINS IN PLACE BELOW 700 MB LEVEL WITH VERY WEAK WESTERLY UPSLOPE LOW LEVEL FLOW AS WELL. SATELLITE PICS AND RUC ALSO TRACK A FAST MOVING VORT MAX SE FROM SRN ILLINOIS. THUS...I WILL LIKELY LEAVE IN AT LEAST A MENTION OF FLURRIES FOR THE MTN ZONES AND ANY OTHER HIGHER TERRAIN AREAS. OTHERWISE...CURRENT TEMPS APPEARED TO BE RUNNING ABOUT 1-3 DEGREES BELOW MOS AT 8PM EST...SO I WILL CHECK FOR A POSSIBLE NEED TO LOWER MIN TEMP FORECAST IN A FEW GROUPS. UPDATED ZONES WILL FOLLOW IN ABOUT AN HOUR OR SO...ALLOWING TIME FOR THE EVENING TO OFFICIALLY END AND REMOVE THAT WORDING. .MRX... NC...NONE. TN...NONE. VA...NONE. TG tn DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 810 PM CST WED DEC 6 2000 SHORT TERM...11-3.9 MICRON SATL IMAGERY SHOWS THE LAST OF THE SC EXITING THE CWA. RUC AND MESO-ETA GUIDANCE SHOWS PLENTY OF NVA AND CAA PREVAILING THROUGH THE NIGHT AS SURFACE HIGH PRESSURE BUILDS IN THE WAKE OF THE COLD FRONT. THE COMBINATION OF CLR SKIES... DIMINISHING WINDS AND FALLING DEWPOINTS WILL ALLOW TEMPS TO FALL INTO THE LOWER TO MIDDLE 40S ACROSS THE EASTERN CWA AND POSSIBLY INTO THE MID TO UPPER 30S ACROSS THE WESTERN AND NORTHERN SECTIONS. ACCORDINGLY...WILL LEAVE MOST OF THE CURRENT ZFP AS IS...BUT WILL MAKE A QUICK AMENDMENT TO DECREASE SURFACE WINDS A BIT. MARINE...SURFACE WINDS ACROSS THE BAY WATERS REMAIN BELOW SCA CRIT ATTM...AND WILL LIFT THE SCA FROM GMZ130 AS MESO-ETA SURFACE WIND FIELDS APPEAR TO BE OVERESTIMATING WIND STRENGTHS OVER THE BAY WATERS. HOWEVER...BUOY019 AND 002 SHOW A STRONG NW FLOW PREVAILING OVER THE GULF WATERS FROM 25 TO 30 KTS WITH SWELLS INCREASING TO NEAR 10 FT AT BUOY019. SO WILL CONTINUE SCA FOR OFFSHORE WATERS. OTHERWISE...NO OTHER CHANGES REQUIRED IN THE CURRENT CWF. SYNOPTIC...60/MESO...MARTINEZ .BRO...SCA FOR GMZ150-155-170-175. tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 920 AM EST WED DEC 6 2000 WITH CLOUDS AT MID LEVELS THICKENING TEMPERATURES WILL HAVE A DIFFICULT TIME WARMING MUCH THIS AFTERNOON. SHORT RANGE MODELS ALSO INDICATE THAT MAXIMUM TEMPERATURES THIS AFTERNOON WILL NOT BE ABLE TO WARM MUCH. RUC SOUNDING SHOWS CENTRAL AND NORTHERN MOUNTAINS MAY NOT GET OUT OF TEENS IN MANY AREAS. WILL ADJUST MAXIMUM TEMPERATURES DOWN. REMAINDER OF FORECAST LOOKS OK SO ONLY MINOR TWEAKING THERE. .RLX... WV...NONE. VA...NONE. KY...NONE. OH...NONE. .END / AAR wv AREA FORECAST DISCUSSION...UPDATED. NATIONAL WEATHER SERVICE SPRINGFIELD MO 259 AM CST THU DEC 7 2000 MAIN CONCERNS ARE SHORT TERM TEMPERATURES. TEMPERATURES HAVE BEEN NEARLY STEADY THE LAST FEW HOURS...AND HAVE EVEN BEGUN TO RISE ACROSS THE WESTERN CWA. STRONG WARM AIR ADVECTION PATTERN DEVELOPING OVER THE CENTRAL U.S. AS 08Z RUC 85H TEMPS OVER THE NORTHERN U.S ABOVE 10C IN CENTRAL NEBRASKA. 85H TEMPS ALREADY ABOVE ZERO ACROSS THE SE KS AND MOST OF THE MISSOURI OZARKS. WATER VAPOR SHOWING NEXT SHORT WAVE THAT WILL PUSH A COLD FRONT THRU THE AREA WAS ACROSS WESTERN CANADA. MODELS CONTINUE TO BE CONSISTENT IN THE SHORT TERM WITH 85H THERMAL RIDGE MOVING THRU THIS AFTN WITH 85H TEMPS FROM 8 TO 10C. MAIN CIRRUS SHIELD SHOULD REMAIN NE OF CWA SO CLOUD COVER SHOULD NOT BE A PROBLEM FOR MAXIMUM HEATING. CURRENT ZONES LOOK GOOD WITH NEAR 60 IN SE KS...TO AROUND 50 IN SOUTH CENTRAL MO. LATER TONIGHT AS COLD FRONT MOVES IN...LOW LEVEL MOISTURE WILL INCREASE...HOWEVER DEPTH OF MOISTURE IS LIMITED (LOWER 5000 FEET)... SO DONT EXPECT ANY PRECIPITATION. ALTHOUGH QPF INDICATING 0.01 OVER THE OZARKS ON FRIDAY MORNING. THIS MAY BE AN INDICATION OF DRIZZLE OR MAYBE FREEZING DRIZZLE DEPENDING UPON WHEN IT DEVELOPS. WILL NOT ADD ATTM...BUT WILL ADVISE LATER SHIFT ON THE POTENTIAL. IN THE EXTENDED...BROAD W/SW FLOW SHOULD KEEP ARCTIC SURGE FROM DIVING TOO FAR SOUTH UNTIL LATE IN THE EXTENDED. STRONG WARM AIR ADVECTION PATTERN DEVELOPS ON SUN/MON...AND RELATIVELY DRIER ATMOSPHERE IN THE LOW LEVELS...THIS COULD MEAN HIGHER TEMPS THAN HAS BEEN ADVERTISED...BUT WILL NOT CHANGE ATTM. FCSTID = 25 SGF 55 29 38 24 / 0 0 20 0 JLN 57 30 39 24 / 0 0 20 0 UNO 51 32 38 24 / 0 0 20 0 VIH 53 29 37 22 / 0 0 20 0 .SGF... MO...NONE. KS...NONE. JLT mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON, NC 300 AM EST THU DEC 7 2000 RUC ANALYSIS PRETTY MUCH AGREES W/ SATL DEPICTION OF A CONGLOMERATE OF VORT CENTERS W/ IN WEAK UPPER TROF ACROSS THE ERN CONUS. ONE VORT EXPECTED TO MOVE ACROSS SC AND WEAKEN...WHILE A BIT STRONGER VORT PROGRESSES ACROSS VA BY 15Z TODAY. WILL CONTINUE TO SEE MAINLY MID-LVL CLOUDINESS AS THESE FEATURES MOVE BY. MAYBE A FEW FLURRIES ACROSS NERN NC? A MORE DEFINED S/WV SEEN ACROSS THE N CENTRAL GULF OF MEXICO WILL STAY FAR TO OUR S AND WEAKEN LATER TODAY. FLOW ALOFT EVENTUALLY BECOMES ZONAL LATER TODAY. SFC WINDS WILL BACK W TO SW IN RESPONSE TO HIGH PRESSURE BUILDING ACROSS THE DEEP S TODAY AND FRI...THEN VEER NW TO NE LATE FRI AND SAT AS A COLD FRONT MOVES BY. ANOTHER S/WV RIDING THE WLIES OVER THE PLAINS ON SAT MAY SPREAD BETTER LIFT ACROSS THE AREA BY SUN. MODELS DIFFER W/ THIS SYSTEM...THE ETA A LTL MORE AMPLIFIED AT 60H COMPARED TO THE AVN. MSTR DIFFS EXIST TOO. AT ANY RATE...SWLY H85 FLOW WILL BEGIN TO STEER MSTR INTO THE REGION LATE FRI NIGHT AND EARLY SAT MORNING W/ POSSIBLE OVER-RUNNING -RA SAT PERSISTING INTO SUN. PRECIP COULD BE ENHANCED SUN DEPENDING ON THE INFLUENCE OF THE PLAINS S/WV. PREVIOUS FCST APPEARS TO HAVE A GOOD HANDLE THIS SCENARIO. FWC NUMBERS FOR TODAY ARE IN VERY GOOD AGREEMENT W/ T1 AND THICKNESS SCHEMES. OTHER GUIDANCE SUPPORTS THESE NUMBERS AS WELL. LGT SWLY FLOW SHOULD PREVENT TEMPS FROM DROPPING TO MUCH TONIGHT. A RANGE IN THE LOWER AND MID 30S ARE EXPECTED. BY EARLY NEXT WEEK IT LOOKS AS IF THE UPPER PTN IS GOING TO UNDERTAKE A MAJOR CHANGE AS A DEEP UPPER LOW EVOLVES ACROSS THE WRN US...FORCING AN UPPER RIDGE AXIS NWD ALONG THE E COAST. WILL TAKE A LOOK AT THE NEW MRF BEFORE MAKING FINAL DECISIONS ON THE EXTENDED. IN THE LEAST A WARMING TREND IS EXPECTED NEXT WEEK. CWF: W-NW FLOW WILL BACK TO A W-SW DIR OVERNIGHT THEN SHIFT BACK TO THE NW LATE FRI AS THE CF MOVE THROUGH. FLOW WILL VEER FURTHER TO A N-NE DIR SAT. SPEEDS SHOULD REMAIN 20 KTS OR LESS THROUGH THE FP. FCSTID = 29 ILM 54 35 63 41 / 0 0 0 - LBT 53 33 63 39 / 0 0 0 - FLO 55 34 64 40 / 0 0 0 - MYR 53 37 64 42 / 0 0 0 - .ILM... NC...NONE. SC...NONE. PFAFF nc AREA FORECAST DISCUSSION...CORRECTED FOR PUNCTUATION NATIONAL WEATHER SERVICE NASHVILLE TN 300 AM CST THU DEC 7 2000 FORECAST QUANDARIES...CLOUD COVER TRENDS ON FRIDAY...TEMPERATURES. CURRENT ASOS/AWOS OBSERVATIONS AND REGIONAL SATELLITE IMAGERY DEPICTING LOW LEVEL CLOUDINESS ACROSS THE MID STATE. MSAS/SURFACE HAND ANALYSES SHOWING LOW LEVEL CLOUDINESS RESULTING FROM INVERTED SURFACE TROUGH OVER REGION AND LINGERING MOISTURE ASSOCIATED WITH SE ONTARIO LOW PRESSURE SYSTEM. SW-W SURFACE WINDS ALSO ADVECTING MOISTURE INTO THE AREA. RUC/UPPER AIR CHART ANALYSES SHOWING MAIN TROUGH AXIS WELL TOO OUR EAST WITH PROGRESSIVE NWLY FLOW OCCURRING. 00Z THU REGIONAL MODEL WEATHER PATTERN EVOLUTION THROUGH 12Z SAT IN GOOD AGREEMENT...ESPECIALLY IN THE UPPER LEVELS. ETA BEST INITIALIZED AT 00Z THU...WITH THE 06Z MESO-ETA INITIALIZED WELL WITH CURRENT INVERTED SURFACE TROUGH SITUATION. THUS...WILL LEAN TOWARD AN ETA/MESO-ETA SOLUTION FOR THE UPCOMING FORECAST PERIOD. LOOK FOR THE MID STATE TO REMAIN DRY THROUGH THE FORECAST PERIOD AS MIDWEST LOW PRESSURE SYSTEM EXPECTED TO MOVE ACROSS THE OHIO VALLEY REGION TODAY AND INTO NEW ENGLAND BY 12Z SAT...WITH HIGH PRESSURE INFLUENCES OVER THE SOUTH DEVELOPING. HIGH PRESSURE WILL BE RE-ENFORCED ON FRI AS NORTHERN ROCKIES HIGH PRESSURE SYSTEM MOVES SEWD. DE-AMPLIFYING NWLY UPPER LEVEL FLOW WILL OCCUR THROUGH THE FORECAST PERIOD...WITH FLOW BECOMING ZONAL. MAIN SHORTWAVE PASSAGES IN UPPER LEVEL FLOW SHOULD REMAIN WELL TO OUR NORTH. CURRENT LOW LEVEL MOISTURE REGIME SHOULD ERODE FROM THE WEST AS THE MORNING HOURS PROGRESS...WITH SKIES BECOMING PARTLY CLOUDY AND REMAINING PARTLY CLOUDY THROUGH TONIGHT. MAIN FORECAST QUANDARY CENTERS AROUND ADDITIONAL CLOUD COVER ON FRI...EVEN-THOUGH SURFACE HIGH PRESSURE PATTERN EXPECTED TO STRENGTHEN. AS OHIO VALLEY LOW PRESSURE SYSTEM MOVES TO NEAR LAKE ERIE BY 12Z FRI...A TRAILING DRY COLD FRONT COULD PUSH INTO THE REGION PROVIDING ADDITIONAL LOW LEVEL MOISTURE. ZONAL FLOW COULD USHER IN UPPER LEVEL MOISTURE ASSOCIATED WITH A SHORTWAVE PASSAGE. MOS GUIDANCE AND ETA/MESO-ETA MODEL DEPICTIONS DIFFER ON AMOUNT OF CLOUD COVER DEVELOPMENT...WITH MOS GUIDANCE THE WETTER. WILL ADDRESS THIS QUANDARY BY CONTINUING WITH MOSTLY CLOUDY SKY CONDITIONS FRI THROUGH FRI NIGHT. TEMPS...AVN MOS NUMBERS SEEM REASONABLE FOR HIGHS TODAY. ETA IN HOUSE BOUNDARY TEMPERATURE SCHEME VALUES MAY BE TOO WARM WITH AN EXPECTED HIGHS IN THE LOW TO MID 50S. WITH POTENTIAL CLOUD COVER DEVELOPING IN THE EARLY MORNING HOURS ON FRI...BELIEVE THAT FAN LOWS IN THE MID TO UPPER 30S APPROPRIATE. WILL GO WITH A COMPROMISE SOLUTION BETWEEN MOS AND BOUNDARY LAYER TEMPERATURE SCHEME VALUES ON FRI AND FRI NIGHT. PRELIMINARY NUMBERS FOR COORDINATION PURPOSES ONLY... BNA 048/037/046/032 0000 CSV 041/033/044/028 0000 .BNA...NONE. 14 JBW tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1030 AM EST THU DEC 7 2000 ...WILL DOWNGRADE WARNING TO ADVISORY THIS AFTERNOON... LATEST TREND ON SATELLITE AND RADAR IMAGES CONFIRMS 12Z RUN OF ETA AND RUC WITH SHOW THE TRACK OF THE BEST SNOWFALL WILL BE CLOSER TO I-94 THAN WE THOUGH EARLIER. THE BEST 850 WAA... ISENTROPIC LIFT... AND SFC PRESSURE FALLS TRACK ACROSS INDIANA. UNLIKE YESTERDAYS MODEL RUNS THERE IS LESS AGEOSTROPHIC FLOW INTO THE COLD AIR OVER SOUTHWEST MICHIGAN. THIS ALSO DECREASES THE LAKE ENHANCEMENT OF THE EVENT. WE HAVE HAD REPORTS AS HIGH AS 3 INCHES IN WESTERN OTTAWA COUNTY AND 6 INCHES IN WAYLAND (ALLEGAN) AND PAW PAW (VAN BUREN). THE ETA SHOWS THE INTENSITY OF THE SNOW WILL DECREASE WITH TIME THIS AFTERNOON OVER THE ENTIRE CWA. WITH ALMOST NO SNOWFALL FORECAST AFTER 00Z. BASED ON THIS... I ONLY EXPECT ANOTHER 1 TO 3 INCHES ON TOP OF THE SNOW THAT ALREADY FELL. THUS I WILL DOWNGRADE THE WARNING TO AN ADVISORY FOR THIS AFTERNOON ONLY. ALSO I WILL TAKE OCEANA... NEWAYGO...MONTCALM AND CLINTON COUNTY OUT OF THE ADVISORY. .GRR...SNOW ADVISORY THIS AFTERNOON...WEST CENTRAL...SOUTHWEST AND SOUTH CENTRAL LOWER. (MIZ050-056>058-064>067-071>074) WDM mi SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 950 AM EST THU DEC 7 2000 SNOW ADVISORIES WILL REMAIN IN PLACE ACROSS THE SOUTHERN HALF OF THE CWA. NO UPPER AIR REPORT FROM HERE (EQUIPMENT PROBLEMS) BUT WAS ABLE TO ACCESS ACARS INFORMATION. SOUNDINGS REMAIN ALL COLD FOR A SNOW EVENT. 250/300MB WINDS ARE VERY STRONG THIS AM, AROUND 160KTS, DIVING TOWARD SOUTHEAST MICHIGAN. UPSTREAM SOUNDINGS TOWARD CHICAGO COULD BE A PROBLEM FOR TONIGHT...MORE ON THAT IN A BIT. 88D IN CLEAR AIR MODE SHOWING INCREASING REFLECTIVITIES ACROSS SOUTHERN MICHIGAN. ASOS REPORTS SHOW VISIBILITIES DROPPING QUICKLY TO NEAR A MILE ACROSS WESTERN PORTIONS OF THE STATE AND MAKING ITS WAY INTO THE DETROIT METRO AREA. A SEPARATE BAND OF SNOW WAS DEVELOPING ACROSS THE NORTH NEAR KMBS. THIS IS IN ASSOCIATION WITH THE STRONG JET, LFQ, AS THIS SHOULD BE MOVING EAST. DEFORMATION AXIS MIGHT SET UP JUST NORTH OF THE CWA. LATEST RUN OF THE RUC MODEL SHOWS BEST ISENTROPIC LIFT (290-295K SURFACE) ACROSS THE SOUTHERN HALF (MAX BULLET JUST SOUTH OF THE MICHIGAN BORDER). USING THE GARCIA METHOD, WOULD EXPECT 1-3 INCHES TOWARD EVENING WITH SLIGHTLY HIGHER AMOUNTS NEAR THE OHIO/MICHIGAN BORDER. THE ISSUE WILL BE THE FAST MOVEMENT OF THIS SYSTEM WHICH MAY CUT DOWN ON SNOW TOTALS. WITH SUCH IMPRESSIVE 850/700 THETA-E ADVECTION AND Q-VECTOR CONVERGENCE, AM RELUCTANT TO TAKE DOWN ADVISORIES AND ACCUMULATIONS ALONG AND NORTH OF M59. IN ADDITION, 300MB DIVERGENCE INCREASES AS POWERFUL JET RRQ WILL BE OVER THE CWA THIS PM. OKAY, AS WITH UPSTREAM SOUNDINGS/ACARS DATA, QUICK DRYING IN THE MID LAYERS IS APPARENT ABOVE 700MB. ICE GROWTH FORMATION WILL BECOME LESS FAVORABLE AS THE EVENING WEARS ON. WITH LOW LEVEL MOISTURE REMAINING IN PLACE AND BELOW FREEZING, SOME FREEZING DRIZZLE COULD BE THE RESULT. WE WILL MONITOR THIS FOR AFTERNOON PACKAGE. MEANWHILE, SNOW WILL OVERSPREAD THE CWA AND COULD BE LOCALLY HEAVY SOUTH. QUESTIONS OR COMMENTS ARE WELCOME. ZONES AROUND 1030 TO MONITOR TRENDS AND TO TAKE A LOOK AT 12Z GUIDANCE. .DTX...SNOW ADVISORY THIS AFTERNOON AND EVENING FOR MIZ063-068>070-075-076-082-083. BGM mi AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE NASHVILLE TN 627 AM CST THU DEC 7 2000 "CLEARING LINE" APPROACHING THE PLATEAU. 11Z RUC AND LAMP GUIDANCE SHOWING DECREASED MOISTURE POTENTIAL BEHIND THIS LINE THAN PREVIOUSLY THOUGHT. WILL ELIMINATE MORNING CLOUDINESS WORDING FROM ZONES AND ADDRESS SKY CONDITIONS AS MOSTLY SUNNY. .BNA...NONE 14 JBW tn