AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 830 PM EST SAT JAN 29 2000 WEAK LOW SOUTH OF THE WESTERN PANHANDLE WILL MOVE NORTHEAST TO NORTH FLORIDA EARLY SUNDAY AND ACCELERATE TO THE MID ATLANTIC COAST LATER SUNDAY. AN ASSOCIATED COLD FRONT WILL MOVE TO CENTRAL FLORIDA LATER SUNDAY AND TO SOUTH FLORIDA EARLY MONDAY AND WILL PASS SOUTH OF THE STATE MONDAY AFTERNOON. IN THE SHORT TERM...THE 00Z RAOB SHOWS A LITTLE BIT MORE MOISTURE BELOW 850 MB THAN THIS MORNING BUT ONLY .87 INCHES OF PW. THE LASTEST RUC HAS THE MRH OF THE 1000-700 MB LAYER DRYING OUT LATER THIS EVENING AND THE SATELLITE TREND SHOWS THIS ALREADY WITH THE CLOUDS ERODING NEAR THE COAST. FOR THE PM UPDATE...WILL ONLY MAKE MINOR CHANGES TO THE ZONES. AM RELUCTANT TO REMOVE ALL POPS FROM SE ZONES. WILL LOWER WINDS SOMEWHAT AND DROP PALM BEACH COUNTY TO <20%. THE WINDS IN THE CWF WILL BE LOWERED SOME WITH THE RIDGE NEAR SOUTH FLORIDA. .MIA...NONE. fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 245 PM EST SAT JAN 29 2000 FORECAST CHALLENGE -- RAIN CHANCES THROUGH MONDAY MORNING. CURRENTLY -- WATER VAPOR IMAGES SHOW SPLIT FLOW PATTERN ALOFT...WITH THE POLAR JET LOCATED OVER NRN CANADA AND A STRONG SUBTROPICAL JET OVER THE SRN STATES. AN UPPER LOW BETWEEN THESE TWO JETS IS VERY SLOWLY TRANSLATING E. EXIT REGION OF STRONG EWD-MOVING JET STREAK IS CURRENTLY OVER MS/AL. THIS FEATURE HAS NOT BEEN WELL REPRESENTED BY THE MODELS. RADAR AND LIGHTNING DATA SHOW THUNDERSTORMS CONFINED TO OUR COASTAL WATERS ALONG COLD FRONT EXTENDING FROM SURFACE LOW SE OF KPNS. THERE IS ALSO AN AREA OF RAIN OVER OUR NRN ZONES IN AREA OF BEST LOW-LEVEL ISENTROPIC LIFT AND UPPER JET SUPPORT. MANY METAR STATIONS OVER OUR CWA ARE REPORTING BR AND SEEING POSITIVE THETA-E ADVECTION AS WARM FRONT E OF LOW CONTINUES TO LIFT N. --FORECAST-- TONIGHT - WARM FRONT WILL CONTINUE LIFTING N THROUGH CWA WHILE UPPER VORT LOBE ROTATES NE AROUND UPPER LOW AWAY FROM CWA. LATEST RUC CONFINES PRECIPITATION TO COASTAL WATERS IN WARM SECTOR AND IN NRN GA ZONES N OF LIFTING WARM FRONT. WILL THEREFORE KEEP HIGHEST POPS OVER NRN ZONES...WITH MENTION OF FOG MANY AREAS. SUNDAY/SUNDAY NIGHT - SURFACE LOW TO STRETCH NE WHILE COLD FRONT PUSHES THROUGH AREA. WINDS DO NOT LOOK PARTICULARLY STRONG IN WAKE OF THIS FRONT. EXPECT A VERY GRADUAL W-E DECREASE IN CLOUDS THROUGH THE DAY...WITH ERN ZONES LIKELY STAYING CLOUDY ALL DAY. A SECONDARY COLD FRONT MONDAY MORNING SHOULD FINALLY DRY OUT LOWER LEVELS. MONDAY - AM THINKING ABOUT LEFTOVER POPS EARLY WITH FRONTAL PASSAGE... FOLLOWED BY DECREASING CLOUDS. AGREE WITH GUIDANCE ON MAKING THIS DAY COLDER THAN SUNDAY FOR EASTERN ZONES. MARINE - SURFACE LOW HAS ALREADY WEAKENED WINDS OVER OUR COASTAL ZONES...AND EXPECT THIS TO CONTINUE TO BE THE CASE. AS THE PENSACOLA BUOY SHOWS WINDS AND SEAS STILL TRENDING DOWN...WILL KEEP EXERCISE CAUTION MENTIONED TONIGHT FOR FIRST PERIOD FOR OUTER WATERS W OF KAQQ. NEXT CHANCE FOR A SMALL CRAFT ADVISORY WILL BE SUNDAY NIGHT. EXTENDED -- (MONDAY NIGHT THROUGH THURSDAY) AFTER BRIEF RESPITE FROM MENTIONABLE POPS THROUGH TUESDAY...MEDIUM RANGE MODELS PROG NEXT BATCH OF UPPER SUPPORT TO COME WITH AMPLIFYING SRN STREAM SHORTWAVE TROUGH THAT SHOULD CROSS CWA WED AND EXIT THURSDAY. WILL KEEP MENTION OF THUNDERSTORMS FOR END OF EXTENDED. TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW CLIMATOLOGY. THANKS FOR COORDINATION FFC. ADDITIONAL INPUT IS WELCOME. PRELIMINARY NUMBERS... TLH 054/061 038/058 551- PFN 057/064 042/056 421- DHN 048/054 034/051 43-- ABY 043/054 035/051 5421 VLD 051/066 038/054 5421 .TLH... .AL...NONE. .GA...NONE. .FL...NONE. TJT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 935 AM EST SAT JAN 29 2000 A FEW LIGHTNING STRIKES APPEARING S OF KPNS ALONG COLD FRONT...AND ALSO NE OF KMGM AHEAD OF WELL-DEFINED UPPER JET STREAK MOVING E OVER THE WRN GULF STATES AT THIS TIME. SURFACE DATA SHOW LOW JUST SW OF KPNS WITH WARM FRONT LIFTING N OVER THE ERN GULF TOWARD OUR COAST. THIS CURRENT POSITION OF LOW AND COLD FRONT IS SLIGHTLY AHEAD OF THE TIMING OF THE MANUAL PROGS FROM LAST NIGHT/S MODEL RUNS. 12Z RUC PROGS ADDITIONAL STRENGTHENING OF WARM FRONT TODAY WHILE IT LIFTS N INTO THE CWA THANKS TO INDIRECT CIRCULATION AHEAD OF APPROACHING JET STREAK. LIFT FROM UPPER JET SUPPORT TO BE COMPLEMENTED BY INCREASING LOW-LEVEL ISENTROPIC LIFT...PARTICULARLY OVER NRN ZONES WHERE HIGHEST DEEP LAYER RH VALUES RESIDE. RADAR AND METARS ALREADY SUPPORT THIS WITH LIGHT RAIN OVER OUR NRN GA ZONES. ALTHOUGH CURRENT TRENDS SUGGEST POPS COULD BE LOWERED OVER SOME OF OUR SRN ZONES...WILL WATCH RADAR AND SATELLITE TRENDS A WHILE LONGER BEFORE ZONE UPDATES TO SEE IF WARM FRONTOGENESIS AND APPROACHING JET STREAK CAN INCREASE PRECIPITATION COVERAGE BY EARLY THIS AFTERNOON. MARINE: SURFACE LOW PROGGED BY RUC TO OCCUPY OUR WRN COASTAL WATERS BY THIS AFTERNOON...RESULTING IN LIGHTER WINDS. PENSACOLA SOUTH BUOY STILL SHOWS 7 FT SEAS...SO WILL EXTEND SMALL CRAFT ADVISORY FOR OUR WATERS W OF KAQQ. INPUT ALWAYS WELCOME. .TLH... .AL...NONE. .GA...NONE. .FL...SMALL CRAFT ADVISORY TO 60 NM APALACHICOLA TO DESTIN. TJT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 800 PM CST SAT JAN 29 2000 FORECAST HAS BEEN UPDATED TO LOWER TEMPERATURES SLIGHTLY...BASED ON DELAY IN WARM ADVECTION AND LIMITED CLOUDINESS. LATEST RUC SUPPORTS THIS...OTHERWISE FORECAST IS GOOD SHAPE. .MSP...NONE SCOTT mn AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 853 AM MST SAT JAN 29 2000 88D SHOWS PRECIP WINDING DOWN AS WK VORT OVR WRN NE DRIFTS S. RUC SHOWS SECOND WK WV OVR SE SD MOVING SLOWLY W ALONG WITH ENHANCED CLD TOPS ON IR. LEFT -SN OVR ERN ZONES ALONG WITH FG...BUT DROPPED PRECIP TO FLURRIES IN WRN SD AND NONE IN NE WY. WNDS AND TEMPS STILL LOOKED IN THE BALL PARK...SO DIDN'T ADJUST THOSE. .UNR...NONE. BAILEY sd DEEP SOUTH TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE BROWNSVILLE TX 955 AM CST SAT JAN 29 2000 CLOUD COVER CONTINUES OVER THE AREA AS SOUNDING THIS MORNING INDICATED 20 TO 30 KNOT SOUTHERLY WINDS OVERRIDING THE COLD AIR AT THE SURFACE. RADAR IS FINALLY STARTING TO SHOW SOME VERY WEAK RETURNS UNDER 20 DBZ. SURFACE DEWPOINTS HOWEVER ARE DRY ENOUGH THAT IT MAY TAKE SEVERAL HOURS FOR THE LOWER ATMOSPHERE TO SATURATE. IF THIS OCCURS WE WILL LIKELY DROP INTO THE 30S BECAUSE OF THE EVAPORATIVE COOLING. THE INCREASE IN RETURNS IS LIKELY IN RESPONSE TO AN APPROACHING WEAK S/W TROF MOVING EAST ACROSS MEXICO. WITH TEMPERATURES A FEW DEGREES LOWER THAN YESTERDAY AT THIS TIME...WILL GO AHEAD AND INCLUDE SOME MIDDLE 40S FOR HIGH TEMPERATURES. WILL ALSO LOWER WINDS A BIT AS MORNING SOUNDING SHOWS WIND SHOULD STAY IN THE 15 KNOT RANGE. WILL ALSO INCLUDE WORDING OF CURRENT WINDCHILLS. WILL KEEP THE SCEC UP FOR THE BAY AND OFFSHORE AS BUOY IS STILL IN THE 5 FOOT RANGE AND LATEST RUC AND ETA SHOW WINDS SHOULD STAY BELOW SCA CRITERIA. 69 .BRO...NONE. tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 955 PM CST SAT JAN 29 2000 HAVE MADE SOME WHOLESALE CHANGES TO GOING ZFP PACKAGE. BEST WAA/ISENTROPIC LIFT PCPN IS SHIFTING TO THE EAST AND NORTHEAST OF CWA. BEST MOISTURE ON THE 285K SFC BEING SHUNTED QUICKLY OFF TO THE EAST. DRY SLOT ASSOCIATED WITH UPR LOW SPINNING OVR IL WRAPING INTO NE/E CENTRAL IL AND NW IND. 00Z MODELS AND MOST RECENT RUC INDICATE BEST LIFT/UVV DECREASING OVER NEXT SEVERAL HOURS...AND COMBINED WITH CURRENT SMATTERING OF SNOWFALL REPORTS...HAVE ADJUSTED TOTAL SNOWFALL AMOUNTS DOWN A CATEGORY OVER NRN HALF OF CWA. SO FAR...AMOUNTS RANGED FROM 4 TO 5 INCHES IN FORD/IROQUOIS/KANKAKEE COUNTIES...WHERE DRY SLOT HAS ENDED ANY SIG ACCUMULATION...TO ONLY AN INCH IN ROCKFORD AND FAR NORTHERN AREAS. UPDATED WSW TO FOLLOW SHORTLY. .CHI...SNW ADVZY TNGT AND SUN AM ENTIRE FCST AREA RATZER il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1005 PM EST SAT JAN 29 2000 SNOW PATTERN REALLY STRUGGLING IN ITS APPROACH AT SE LOWER LATE THIS EVENING. REGIONAL RADAR AND SURFACE OBS SHOWS MAIN AREA OF LIGHT TO OCCASIONALLY MODERATE SNOW SOUTH OF A LINE FROM KSBN TO KGSH TO KDFI. WEAK SURFACE LOW JUST MOVING INTO WC IN WITH STRONG VORT MAX EVIDENT ON WV/IR IMAGERY JUST TO THE WEST OF SURFACE LOW. KDTX RAOB AT 00Z SHOWED MONSTER DRY LAYER BETWEEN 950 AND 700 MB. THUS, LIFT OCCURRING OVER SRN SECTIONS THIS EVENING PER IR IMAGERY AND MID LEVEL RETURNS HAVE ONLY ACTED TO SLOWLY LOWER THE CEILINGS. NEXT RAOB TO THE S THOUGH (KILN) WAS NEARLY SATURATED IN THE VERTICAL WHICH SUGGESTS STRONG HORIZONTAL MOISTURE GRADIENT JUST TO THE SOUTH. LEADING EDGE OF SNOW MATCHES UP PRETTY WELL WITH ETA 30 CPD PROG AT 00Z ON THE 290K SFC. THIS ALONG WITH OTHER PROGGED PARAMETERS FROM 18Z ETA RUN/LATEST RUC SUGGESTS THINGS WILL STILL BE COMING TOGETHER FOR SOME LIGHT TO MODERATE SNOW ACROSS SOUTHEAST LOWER AROUND AND AFTER MIDNIGHT. ISENTROPIC ASCENT PICKS UP AROUND 06Z WITH CPDS REALLY STARTING TO CRASH FROM S TO N AS VORT MAX LIFTS NE TOWARD THE REGION. THINK SNOW WILL GET ITS ACT TOGETHER ACROSS SW SECTIONS AROUND MIDNIGHT AND THEN SPREAD SLOWLY N ACROSS REMAINDER OF REGION THROUGH THE OVERNIGHT HOURS. APPEARS THAT ACCUMULATING SNOW WILL BE ABOUT OVER ACROSS SOUTHERN SECTIONS SHORTLY AFTER SUNRISE AS MID LEVELS DRY. STILL LOOKS LIKE QUICK SHOT OF SNOW ADVERTISED IN AFTERNOON PACKAGE IS ON TRACK AND 2 TO 3 INCH AMOUNTS NOT OUT OF THE QUESTION OVER SOUTHERN SECTIONS WHERE BEST MOISTURE AND LIFT WILL PERSIST THE LONGEST. LATE EVENING UPDATE WILL MAINLY BE JUST A WORD REFRESHER. .DTX...NONE. JW mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 245 AM EST SUN JAN 30 2000 THE ETA SHOWS H5 DIFFLUENCE AND PVA THROUGH 18Z WITH LIFT INCREASING BETWEEN 12Z AND 18Z TODAY. SATELLITE SUPPORTS THIS WITH COOLING TOPS OCCURRING OVER AL AND N GA. EXPECT PCPN WILL BECOME MORE WIDESPREAD. PCPN SHOULD DIMINISH LATE THIS AFTERNOON AS THE UPPER DYNAMICS LIFT NORTH OF THE AREA AND THE H85 ADVECTION BECOMES COLD. PLAN TO USE THE ETA SURFACE WET BULB TEMPERATURE FORECAST AS A BASIS FOR CONTINUING THE WINTER STORM WARNING/ADVISORY. EXPECT PCPN WILL REMAIN FREEZING RAIN INTO THE AFTERNOON OVER THE PIEDMONT PLUS CHESTERFIELD COUNTY SO PLAN TO CONTINUE THE WINTER STORM WARNING FOR ALL OF TODAY FOR THAT AREA. SOUTH OF THIS AREA FROM MCDUFFIE COUNTY TO LEE/SUMTER COUNTIES PLAN TO CONFINE THE WINTER STORM WARNING TO THIS MORNING. THE LATEST RUC ALSO SUPPORTS CONFINING THE WARNING TO THIS MORNING AND SHOWS SURFACE WET BULB TEMPERATURES INCREASING ABOVE 32 BY 15Z. PLAN TO CONTINUE THE WINTER WEATHER ADVISORY FOR THE REMAINDER OF THE FORECAST AREA FOR THIS MORNING. SINCE THE H85 ADVECTION HAS BECOME WEAK AND THE ETA SHOWS IT REMAINING SO...BELIEVE PCPN WILL REMAIN LIGHT. THE ETA QPF IS BELOW ONE-QUARTER OF AN INCH TODAY. PLAN TO FORECAST TOTAL ICE ACCUMULATIONS AROUND ONE-QUARTER INCH IN THE PIEDMONT PLUS CHESTERFIELD AND ONE-TENTH TO ONE-QUARTER OF AN INCH FOR THE AGS-CAE-SSC AREA. DRY HIGH PRESSURE BUILDS INTO THE AREA TONIGHT AND MONDAY. PLAN TO CUT THE GUIDANCE TEMPERATURES ABOUT 6 DEGREES TODAY DUE TO THE WEDGE AND PCPN AND ALSO CUT A FEW DEGREES MONDAY DUE TO THE ICE COVER. .CAE...WINTER STORM WARNING FOR SEVERE ICING TODAY GAZ040-SCZ015-016- 018-020-021-025-026. WINTER STORM WARNING FOR SEVERE ICING THIS MORNING GAZ063-064- 065-022-027>031-037. WINTER WEATHER ADVISORY FOR FREEZING RAIN THIS MORNING GAZ077- SCZ035-036-038-041. RJL sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 939 PM EST SAT JAN 29 2000 TEMPS CONT AT OR BELOW FREEZING FROM SSC TO CAE TO AGS ON NORTH. TEMPS 33 TO 34 TO THE SOUTH. LATEST MSAS SHOWS BEST PRESSURE FALLS OFF THE NC COAST..SO LOOKS LIKE LOW PRESSURE WILL DEVELOP OFF THE COAST. LATEST RUC SOUNDINGS HAS SFC TEMPS GOING ABV FREEZING AROUND 09Z AT AGS AND AROUND 12Z EDGEFIELD..CAE..CAMDEN. SO FAR..NO PROBLEMS IN THE AGS AREA. DNL AT 32 DEGREES AND AGS AT 33. CURRENT FCST HAS FZRA CHANGING TO RAIN AROUND MIDNIGHT AT AGS. PLAN TO DROP ICE STORM WARNING FOR THE AGS AREA BUT STILL MENTION SOME POCKETS OF FREEZING RAIN BUT NO ACCUMULATION AND ISSUE A WINTER WEATHER WX ADVISORY. REST OF THE WARNINGS WILL STAY UP. .CAE...ICE STORM WARNING FOR TONIGHT...SCZ018- 015>016- 020>022- 025>031-GAZ040. WINTER WEATHER ADVISORY TONIGHT GAZ063>065. ICE STORM WARNING FOR SUNDAY MORNING...SCZ015>16-20>022. LM sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 320 AM EST SUN JAN 30 2000 06Z SOUNDINGS COLDER THAN PROGGED AND EVEN COOLED IN A LAYER FROM H9 TO H8 FROM 00Z WITH HEAVY BAND OF PRECIP. RUC SOUNDINGS SEEM TO HAVE COME CLOSEST TO MATCHING 06Z. ON THE SURFACE...GREATEST PRESSURE FALLS CONTINUE TO BE IN THE MYR AREA...WITH REDEVELOPMENT FINALLY ORGANIZING JUST SOUTH. WV AND IR IMAGERY SHOWING JETLET TURNING WINDS SOUTHWEST FROM MS TO TN WITH SOME ENHANCEMENT OF CLOUDS SEEN. MODELS DEVELOP THIS AREA NICELY INTO SECOND BATCH OF HEAVIER PRECIP AND TRACK IT UP ALONG APPALACHIANS. WESTERN AND NORTHERN NRV AND GREENBRIER VALLEYS SHOULD SEE MOSTLY SNOW FROM THIS FEATURE. NORTHERN MOUNTAINS AND SOUTHERN NRV WILL SEE A MIX BEFORE GOING BACK TO SNOW BEFORE ENDING. BIG PROBLEMS REMAIN WITH ICING POTENTIALS FOR THE EAST...AND THIS IS WHERE THE HEAVIEST QPF IS PROGGED FOR TODAY. PRECIP OVERNIGHT HAS BEEN IN THE FORM OF SNOW/SLEET WITH 1 TO 3 INCHES REPORTED. DAN HAS JUST GONE OVER TO -FZRA IN THE LAST HOUR. ALL FROM THE BLUE RIDGE EAST WILL HAVE A PERIOD OF MOSTLY FZRA TODAY WITH SIGNIFICANT ICING. MAY BE SOME QUICK CHANGE TO SLEET AND SNOW BEFORE ENDING LATE TODAY OR EARLY TONIGHT. WIND TONIGHT WILL COULD MAKE MATTERS WORSE. EXPECT STRONG CAA BEHIND SYSTEM TO CRANK UP TO 15 TO 25 MPH. .RNK VA...WINTER STORM WARNING THIS MORNING VAZ007-009-010-012. WINTER STORM WARNING ALL DAY REMAINDER. WV...WINTER STORM WARNING MERCER AND SUMMERS THIS MORNING. WINTER STORM WARNING ALL DAY GREENBRIER AND MONROE. NC...WINTER STORM WARNING ALL ZONES. NOGUEIRA va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 910 PM EST SAT JAN 29 2000 SNOW NOW REPORTED AS FAR EAST AS THE ROA VALLEY WITH MAIN AXIS FROM THE NRV INTO SE WVA. BEST SNOWFALL RATES GNRLY ALONG BACK EDGE OF ENHANCEMENT OFF IR PICS WITH CONVECTIVE BURSTS OR 2-3INCH/HR SEEN IN PARTS OF SW VA/SE WVA. ISOTHERMAL COOLING ALF THE BIG PLAYER AS PRECIP TENDING TO MIX BACK TO PL ONCE HEAVIER BANDS MOVE ACROSS. CONCERNS OVRNGT WITH QPF AMTS AND P-TYPE AS BEST UPR DIFFLUENCE BEGINS TO SHIFT TWD THE ERN ZONES AND WWA ALF CONTS SRN SECTIONS. LATEST REGIONAL RADARS ALSO SHOWING PRECIP GETTING QUITE SPOTTY SW ZONES AND YET TO REACH THE SERN CORNER. KEY PLAYER BY MORNING WITH TIMING OF CSTL LOW AND HOW LONG IT CAN HOLD HEAVIER QPF OVER THE REGION WHILE INCRSG CAA ALOFT WEST BY MORN. LATEST MESO-ETA GIVING A LITTLE MORE PRECIP WITH 2ND AREA OF UPR DIFFLUENCE AS CSTL GETS GOING EARLY SUNDAY BUT EXPECT BEST OVER THE WEST EARLY ON. THUS MAY TWEAK SNOW AMTS BACK A BIT FAR SW ZONES GIVEN LACK OF PRECIP AND MIX PTNL PER RNK RAOB...BUT PLAN TO HANG ONTO THE WARNING FOR NOW. OTHER PROBLEM OVER THE PIEDMONT ZONES WHERE GSO RAOB GNRLY CLOSE TO RUC FCST SOUNDINGS WITH WARM LYR ALF ESPCLY WHEN BEST PRECIP LKLY ARRIVES EARLY SUNDAY. MAY EMPHASIZE FREEZING RAIN PTNL THERE A BIT MORE...OTRW OTHER THAN TO LOWER TEMPS NO HUGE CHANGES PLANNED ATTM. THANKS GSP FOR COORD. .RNK VA...WINTER STORM WARNING OVERNIGHT AND SUNDAY ALL ZONES. WV...WINTER STORM WARNING OVERNIGHT AND SUNDAY ALL ZONES. NC...WINTER STORM WARNING OVERNIGHT AND SUNDAY ALL ZONES. JH va AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 930 AM CST SUN JAN 30 2000 MAIN PRBLM TDAY IS HOW FAST...OR IF AT ALL...THE LOW CLDS WL CLEAR OUT OF CWA. CONFIDENT THAT THE FOG WL EVENTUALLY LIFT...WITH BETTER VSBY TO THE WEST...AND SFC WINDS FM THE NNW. HOWEVER...LOW CLDS IN THE RANGE OF 1000-2000 FT REALLY EXPAND ALL THE WAY BACK TO THE WY AND MT BORDERS. WITH 925 MB WINDS CRNTLY FM THE N AND NNW...AND THE RUC PROGS A WRLY COMPONENT OF THIS WIND TO CONT THRU THE DAY. THERE IS QUITE A BIT OF LLVL DRY AIR IN MN...BUT WITH THE 925 MB NOT FM THE NE...THIS MAY HAVE TROUBLE BACKING INTO CWA. THEREFORE...WL CONT TO MONITOR THE CLD COVER...WHICH COULD HAVE A BEARING ON TEMPS. ALTHOUGH THE TEMPS DO LOOK PRETTY GOOD EVEN IF WE KEEP THE CLDS IN A LITTLE LONGER. .FSD...NONE sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 1000 AM EST SUN JAN 30 2000 ***WINTER STORM WARNING*** CLASSIC FREEZING RAIN SOUNDINGS THIS MORNING. WARM LAYER EXISTS BETWEEN 850-800 MB...+1 DEG C AT RNK...+4.4 AT GSO. BOTH SOUNDINGS SUPPORT POTENTIAL FOR ELEVATED CONVECTION...CAPES 30-80 J/KG. LAPSE RATES MAY EVEN STEEPEN A BIT MORE AS COLDER AIR COMES IN ALOFT. VERY STRONG JET STREAK ROTATING AROUND THE 500 MB LOW THIS MORNING WITH BAROCLINIC LEAF FORMING OVER THE EASTERN U.S. GREATEST PRESSURE FALLS ARE OCCURRING OVER THE MID ATLANTIC...AND 12 UTC RUC SUGGEST ANOTHER 10-15 MILLIBARS OF PRESSURE FALLS TO OCCUR OVER ERN VA/NC BY 00 UTC THIS EVENING. THIS SUPPORTS RAPID DEVELOPMENT AND ACCELERATION OF SFC LOW WHICH HAS BEEN NEARLY STATIONARY OVER THE NE GULF COAST. CENTER OF THE LOW PROGGED TO BE OVR ERN VA BY 00 UTC THIS EVENING. LATEST RADAR TRENDS SHOW INCREASE IN AREAL COVERAGE OF PRECIPITATION OVER WRN NC/VA AND WV. SIGNIFICANT ICING HAS ALREADY BEEN REPORTED THIS MORNING...AND A QPF OF ANOTHER THREE QUARTERS OF AN INCH DOES NOT BODE WELL FOR THE AREA. FREEZING RAIN WILL LIKELY BECOME MODERATE AT TIMES...WITH SLEET OCCURRING OVR THE NRV AND GBV WHERE THE BL AIR IS COLDER AND DEEPER. DYNAMIC COOLING FROM CONVECTION COULD EASILY CHANGE PRECIP BACK OVER TO SNOW IN THE WRN TIER COUNTIES...ALONG WITH A LITTLE THUNDER...AND HAS ALREADY BEEN OBS AT BKW THE LAST HR. FOR THIS REASON...WILL CONTINUE TO MENTION ADDITIONAL ACCUMULATIONS OF SNOW THERE...ESP THE GBV OF WV. WINTER STORM WARNINGS WILL CONTINUE OR BE EXTENDED...ALL ZONES...ALL DAY...WITH ICE ACCUMULATIONS OF ONE HALF TO ONE INCH B4 EVENING. SFC TEMPERATURES WILL NOT CHANGE MUCH WITH READINGS AOB 32 DEG F. .RNK VA...WINTER STORM WARNING TODAY. WV...WINTER STORM WARNING TODAY. NC...WINTER STORM WARNING TODAY. PM va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 944 AM EST SUN JAN 30 2000 LATEST SFC ANALYSIS SHOWING COASTAL LOW JUST E OF CHARLESTON SC. 12Z RUC APPEARS TO ANALYZE SFC LOW SLIGHTLY E OF SFC ANALYSIS POSITION. RUC CARRIES SFC LOW TO NEAR GSB BY 21Z AND OVER ORF BY 00Z...IN GENL AGREEMENT WITH LAST NIGHTS MODEL RUNS. THIS FCST TRACK WILL ALLOW FOR ENOUGH WARM AIR TO CHANGE PRECIP TO RAIN OVER THE ERN HALF OF NORTHEAST NORTH CAROLINA...THE HAMPTON ROADS AREA BY 16Z. WITH THIS IN MIND WILL CONSIDERING DROPPING WINTER WX ADVY FOR THOSE AREAS WITH THE UPDATE PACKAGE. TEMPS HV WARMED TO 32-35F ACROSS THOSE AREAS. PLAN TO KEEP WINTER WX ADVY UP FOR VA PORTION OF ERN SHORE AND WORCESTER COUNTY MD GIVEN TEMPS HOVERING AOB 30F. QUICK LOOK AT AREA RAOBS INDC WARM NOSE BTWN 750-850 MB CREEPING INTO RNK RAOB AND MARGINAL 750-850 MB TEMPS AT WAL. THIS REFLECTED IN ANALYZED 1544-1548M 850-700 MB THICKNESSES AT RNK/WAL RAOBS. ETA 2 M TEMPERATURES LOOK THE BEST FOR DEPICTING COLD AIR DAMMING AND VERIFIED WELL AT 12Z. CRITICAL FCST PROBLEM REMAINS PRECIP TYPE. HOWEVER IT APPEARS WE'RE NARROWING IN ON A SOLUTION TO THIS FCST PROBLEM. MODELS HANDLED SURGE OF 850-700 MB WARM NOSE WELL. THIS SURGE ESSENTIALLY RULES OUT SNOW ACROSS THE FA WITH THE NEXT ROUND OF PRECIP SURGING NEWD. LOOKS MORE LIKE A SLEET AND FREEZING RAIN EVENT FOR MUCH OF THE CWA WEST OF A RZZ-AKQ-NORTHERN NECK-DORCHESTER LINE. RUC QPF...INCRG COVERAGE IN UPSTREAM RADAR RETURNS PLUS INCRG ENHANCMNT OF MID/HI LVL CLDS IN APPCHG LEFT FRONT QUAD OF JET STREAK SUGGESTS WE COULD EASILY SEE A HALF INCH OR GREATER LIQUID PRECIP...HENCE WARNING CRITERIA FOR FREEZING RAIN AND WILL LEAVE WINTER STORM WARNING AS IS. ADDITIONAL CONCERN EXISTS THAT RECENT COLD SNAP WILL ALLOW FOR ICE ACCRETION ON OBJECTS TO CONTINUE A LITTLE AFTER FREEZING MARK IS ECLIPSED. PROPOSAL IN WWA SHORTLY. CWF...MINOR TWEAKS TO WIND DIRECTION...OTRW ADVY SECTIONS REMAIN UNCHANGED. CALLED CBBT AND RECEIVED REPORT OF 1 FOOT WAVES. .AKQ...WINTER STORM WARNING...TODAY...CENRTAL VA...ERN VA PIEDMONT NRN NECK AND PORTIONS OF MD ERN SHORE WINTER WEATHER ADVISORY...TODAY...VA ERN SHORE ZONES AND COASTAL MD ZONE. SMALL CRAFT FOR SEAS...ATLC COASTAL WATERS. COBB va AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO IL 221 PM CST SUN JAN 30 2000 AT 18Z ONLY RUC HAD GOOD HANDLE ON THE VORT MAXES IN AREA WITH MAIN 1 W OF FWA AND ANOTHER WKR 1 E OF UIN. MORE IMPORTANT FEATURE WAS THE 850 CIRCULATION SE OF IKK STILL PRODUCING -SHSN OVER N 1/4 IL. INTERESTING TO WATCH TODAY THE STUFF PINWHEEL ARND CIRC ALL DAY. IN ANY CASE ALL WILL ACCELERATE E TNGT AS TROF FROM NW PUSHES SE. CLRG TNGT NW-SE WITH NW IN LAST TO SEE IT. SOME HI CLDS AGAIN MON WITH NW VORT. NOT A REAL COLD AIRMASS BEHIND THIS NEXT FRONT MON NGT. MDLS THEN SHOW LO LVL MOISTURE PART OF MON NGT BEFORE SUN TUE. AS SYSTEM MOVS AWAY TNGT WNDS TO PICK UP FROM WNW TO BLOW AWAY THE HZ/BR IN AREA THIS AFTN. TEMPS LOOK OK. FAVOR SLIGHTLY WRMR FWC MON. .CHI...NONE AF il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 954 AM EST SUN JAN 30 2000 A TRICKY TEMP FCST WITH TROF LINGERING JUST OFF SC CST. 00Z ETA MODEL AND LATEST RUC BRINGS TROF JUST INLAND ALG N CST. EXPECT TEMPS MAY WARM TO THE MID 50S FOR THE CSTL CNTYS...BUT FOR INLAND SXNS WITH CLD CVR AND PRIMARILY W-NW WINDS ANTICIPATE MAX TEMPS MAY BE A LTL COOLER THAN FSCT. WILL LWR TEMPS UP TO 5 DEGREES ALL BUT CSTL SXNS. COMPLEX OF RAIN AND TSRA MOVG INTO WRN SXNS OF CWA ATTM WILL TRAVERSE CWA DURG THE AFTN...WITH TSRA PSBLY HOLDING TOGETHER ALL THE WAY TO THE CST. CAT POPS LOOKS GOOD FOR THIS AFTN ACRS ENTIRE CWA. AREAS OF FOG WILL PERSIST UNTIL RAIN AND PSBL TSRA MOVES THROUGH. CWF...TROF HAS PRETTY MUCH BECOME ELONGATED LO OFF THE SC COAST AHEAD OF SECONDARY LO NR FLA BIG BEND AREA. WINDS AND SEAS RATHER GUSTY ON E SIDE OF TROF...SEAS REMAIN HIGH IN ALL LOCATIONS. WILL NEED TO INIT WINDS TO VAR CLOSE TO THE COAST BECMG W THIS AFTN. S WINDS OFFSHORE GA WATERS BECMG W LATE. WILL MAINTAIN CURRENT HEADERS AS THEY ARE. .CHS... SC...SMALL CRAFT ADVISORY SOUTH SANTEE RIVER TO SAVANNAH OUT 20 NM EXCLUDING CHARLESTON HARBOR. GA...SMALL CRAFT ADVISORY SAVANNAH TO ALTAMAHA SOUND OUT 60 NM. JAC/MJR sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 925 AM EST SUN JAN 30 2000 PRECIPITATION FILLING BACK IN FROM SRN AL NORTHEAST THROUGH MUCH OF CWA ATTM...IN RESPONSE TO STRONG MID/UPPER JET PUNCHING EAST ACROSS THE NRN GULF COAST STATES AND TN...AND INCREASING DPVA AHEAD OF VORTICITY MAXIMUM ROTATING AROUND CLOSED LOW IN MID MS RVR VALLEY. PRESSURE FALLS AND ENHANCED CLOUD TOPS OFF THE SC/GA COAST INDICATE THAT THE SFC LOW PROGGED BY THE MODELS IS IN A DEVELOPMENTAL STAGE...RIGHT ON QUEUE. AREA SOUNDINGS SHOW FREEZING RAIN AND SLEET SHOULD BE PREDOMINANT P-TYPE EAST OF MTNS. BNA SOUNDING IS WELL BELOW ZERO AT ALL LEVELS. 06Z ETA AND LATEST RUC SHOW 850-700 THICKNESSES FALLING THROUGH THE DAY...CHANGING ANY PRECIPITATION OVER TO SNOW IN THE MTNS. RECENT CALLS TO COUNTIES REVEAL THAT SNOW AND SLEET IS ALREADY FALLING IN THE NRN MTNS...AND A FREEZING RAIN/SLEET MIXTURE ELSEWHERE. SLEET IS ACTUALLY QUITE ABUNDANT IN THE BRIGHTER REFLECTIVITIES. FAR SW NC IS ACTUALLY ABOVE FREEZING WITH NO PRECIP FALLING ATTM. DRIER AIR PUNCHING IN WITH PASSAGE OF JET...SO WILL SEE THIS PRECIP BAND SHIFTING EAST THIS AFTERNOON. PLAN TO DROP AT LEAST A FEW COUNTIES IN SW NC FROM THE WARNING AT ISSUANCE. WILL WAIT AND SEE HOW PRECIP IS DOING. WILL KEEP TEMPS NEARLY STEADY AND WILL TWEAK SOME OF THE PRECIP WORDING IN THE ZONES TO ACCOUNT FOR EXPECTED CONDITIONS. .GSP...WINTER STORM WARNING NCZ033>037-048>050-052>O57-063>072-082 WINTER STORM WARNING ALL GA AND SC ZONES. MOYER sc AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 320 PM CST SUN JAN 30 2000 MAIN PRBLMS AGAIN ARE IN THE SHORT TERM AND EXTENDED. SAT LOOP SHOWS LOW CLDS THINNING...DECREASING RAPIDLY ACROSS SD. ONE CLEARING LINE IS ADVANCING FM THE JAMES VALLEY TOWARD I 29...WITH THINNING CLOUDS OVER CNTRL SD. RUC 925MB CONTS TO SHOW A GNRL TREND OF DRYING IN THE CWA THRU TNGT. BUT SOME PATCHY SC KEEPS DVLPING IN THE CLEARING ZONE OVR THE JAMES VALLEY AND TOWARD THE MO RIVER. IN THE EAST...CLOUDS WL TAKE AWHILE TO CLEAR OUT. WORDED ZONES ACCORDINGLY TO THESE TRENDS. WITH THE CLEARING SKIES AND RELATIVELY MOIST SFC DEW PTS...FOG MAY AGAIN DVLP HERE AND THERE TNGT ESPECIALLY OVER THE SNOW COVER. WINDS SHOULD TURN ARND TO THE SW BUT LIGHT ACRS THE ENTIRE CWA TNGT AS THE NIGHT PROGRESSES...AHD OF NXT SFC TROF/CDFNT MOVG SOUTH. RH TIME SECTIONS SHOW DRY AIR MONDAY THRU TUESDAY. HOWEVER SOMETHING A BIT CONCERNING IS THE NGM SHOWS A POCKET OF HIGH RH NR THE SFC AS MONDAY NIGHT PROGRESSES. ACTS LIKE IT IS TRYING TO ADVECT MSTR IN WITH THE LIGHT NORTH WINDS BUT NOT SURE FM WHERE. AVN/ETA TIME SECTIONS ARE MOIST NR THE SFC THRU THE ENTIRE PD BUT USUALLY ARE ANYWAY...SO HARD TO TELL WHAT IS GOING ON. FUTURE SHIFTS MAY WANT TO WATCH THIS TO SEE IF FOG OR LOW CLDS MAY DVLP LATER MON NIGHT. LEFT OUT FOR NOW. MDLS SIMILAR IN BRINGING FAST MOVG CDFNT THRU TO THE EAST ON MONDAY. WL CLIP THE BKX TO SPW AREAS THE MOST...SO KEPT SKIES PARTLY CLOUDY IN THE EAST AND TEMPS RATHER COOL. NXT CANADIAN HIGH THEN MOVES DOWN BEHIND THE FNT MONDAY NIGHT AND TUESDAY...WITH VERY LIGHT NRLY WINDS. MAY HAVE TROUBLE WARMING UP AGAIN IN THE EAST ON TUESDAY WITH LIGHT...COOL WINDS...AND SNOW COVER. WEST SHOULD WM UP STILL...AS HON IS 30 ALREADY RIGHT NOW WITH NO PROBLEM AT ALL. IN THE EXTENDED...FINALLY GOOD AGREEMENT BETWEEN THE NEW AVN AND LAST NIGHT'S MRF VALID WED MRNG. COULD BE A DECENT WARMUP AHD OF NXT DEVELOPING SYSTEM DURING MID WEEK WITH VERY WM 850 TEMPS. THE NXT SYSTEM THEN MOVES INTO THE WRN US ON THURSDAY...WITH LAST NIGHTS MRF VALID THURSDAY EVENING SHOWS CENTER OF TROF SLIGHTLY FURTHER W THAN PREVIOUS RUN. BUT A HUGE DIFFERENCE EXISTS IN HOW MUCH MORE ENERGY THE NEW MRF PUTS INTO THE NRN STREAM OVER THE PAC NW THAN THE PREVIOUS RUN. IF THIS TREND CONTS...NRN STREAM WL LIKELY REALLY TAKE OVER ON FRIDAY PRODUCING SOME CD FRONTAL -SHSN...BUT NOT MUCH ELSE... TYPICAL LA NINA. SFC INVERTED TROF TOO FAR W AND N TO AFFECT CWA ON THURSDAY. .FSD...NONE FUHS sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 245 PM EST SUN JAN 30 2000 LATEST SFC ANALYSIS INDC SFC LOW INVOF FAY...GENLY IN LINE/SLIGHTLY W OF 12Z RUC MODEL. TEMPS RISING TO THE LOWER 40S ACROSS NE N.C. UPR 30S HAMPTON ROADS AND GENLY ABV FREEZING E OF AN AVC-PTB-RIC-TAPPAHANNOCK LINE. RECEIVING SOME REPORTS OF ICE ACCRETION ON TREES AND POWER LINES AND EVEN ISOLATED POWER OUTAGES NORTH OF RICHMOND. ICE ACCRETION LIKELY APPCHG OR EXCEEDING WARNING CRITERIA IN THE VA PIEDMONT. REGIONAL RADAR LOOPS SHOWING FIRST BATCH OF PRECIP ALREADY BEGINNING TO EXIT FA...SECOND BATCH ALG VA/N.C. BORDER POISED TO SWEEP ACROSS FA NEXT SVRL HRS. BACK EDGE OF PRECIP SHIELD WELL DEFINED INDC AN ABRUPT CUTOFF TO PRECIP. THIS ALSO INDC IN MODEL T-SXNS AS WELL. MODELS NOT IN AGREEMENT WI 18Z POSN OF SFC LOW. AVN/NGM HV SFC LOW IN N-CNTRL S.C. THE ETA APPEARS TO HV THE BEST HANDLING OF SFC LOW... WI AN 18Z POSN NR ILM...THOUGH THIS IS STILL 90 NM SE OF CURRENT POSN. BOTTOM LINE THE MODELS ARE SLOW WI THIS FTR. THUS AM LEANING TWD ENDING PRECIP ACROSS THE FA AROUND 22Z IN THE FAR SW TO AROUND 02Z IN THE NE SXNS OF THE FA...SVRL HRS FASTER THAN TIMING OF ETA. MAIN FCST PROBLEM IS IN THE FIRST PERIOD WI REFINEMENT OF PRECIP TYPE. FCST PARTIAL THICKNESS SUPPORT A SHAPR R/ZR/S LINE AT THE END OF THE PRECIP...THEREFORE LOOKING AT PRECIP ENDING AS A BRIEF PERIOD OF SNOW GENLY W OF A FVX-LKU LINE. RECIEVED REPORTS OF THUNDER FROM COORD WI RAH...BANDED NATURE TO PRECIP IN FAVORABLE REGION NORTH OF SFC LOW/WARM FRONT IS SUGGESTIVE OF POSSIBLE GRAVITY WAVE ENHANCEMENT TO PRECIP. WILL MENTION ISOLATED THUNDER IN SOME OF THE SOUTHERN ZONES. WILL CONTINUE WI WINTER STORM WARNINGS FOR THE SAME ZONE GROUPINGS AS PREVIOUS AND ADD A BUFFER ZONE FOR WINTER WX ADVY. THIS ALL FOR THE EVENING TIMEFRAME. BEYOND THIS EVENING...THE FCST SIMPLIFIES AND GENLY LOOKING AT GOOD MIXING ON MON. DOWNSLOPE COMPONENT TO WINDS ON MON WILL AID IN RAISING TEMPS TO FAN VALUES...IE LOWER-MID 40S ACROSS THE FA. CWF...SMALL CRAFT ADVY TONIGHT CST AND BAY/CST MON. .AKQ...WINTER STORM WARNING THIS EVENING...CENTRAL VA. WINTER WEATHER ADVISORY THIS EVENING...INTERIOR NORTHERN NECK...INTERIOR MIDDLE PENINSULA AND SOUTHERN VA ZONES. SMALL CRAFT ADVY...ATLC COASTAL WATERS TONIGHT AND BAY/CSTL WTRS MON. COBB va