AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE EUREKA CA 405 PM PDT SAT MAY 01 2004 .SHORT TERM... REMAINS OF MORNING FOG AND STRATUS HAS MEANDERED BACK AND FORTH BETWEEN THE OCEAN AND COASTAL AREAS TODAY WITH MOSTLY SUNNY CONDITIONS ACROSS THE FORECAST AREA AT THIS TIME. TEMPERATURES INLAND CONTINUE TO CLIMB AS THE DRY AIRMASS IN PLACE CONTINUES TO WARM. THE RUC40...WHICH DID VERY WELL WITH THE MARINE LAYER YESTERDAY...HAS NOT BEEN HELPFUL TODAY. WHILE THE 12Z MESOETA INITIALIZED WELL...IT...TOO...DID NOT HANDLE FEATURES ALONG THE COAST WELL TODAY. THE 18Z MESOETA DOES APPEAR TO BE DOING FAIRLY WELL WITH THE PLACEMENT AND COVERAGE OF THE MARINE LAYER BASED ON THE BOUNDARY LAYER RELATIVE HUMIDITY FIELD...SO HAVE FOLLOWED THIS FOR THE SHORT TERM. TODAY DEWPOINTS ALONG COASTAL AREAS HAVE RISEN INTO THE LOWER 50S SIMILAR TO WHAT OCCURRED YESTERDAY WITH ARRIVAL OF MARINE SURGE FROM THE SOUTH...SO EXPECT THAT...AS WINDS DIMINISH AT THE COAST THIS EVENING...FOG WILL AGAIN BEGIN TO FORM. HAVE INTRODUCED 10% POPS DUE TO LOCALLY DENSE NATURE OF THE FOG AND POSSIBILITY OF TERRAIN AND BOUNDARY LAYER SHEAR INDUCED DRIZZLE. EXPECT FOG TO BE CONFINED TO SIMILAR AREAS AS LAST NIGHT SINCE NOT MUCH HAS CHANGED. SLOW MOVING STRATUS CURRENTLY ABOUT 70NM OFFSHORE IS EXPECTED TO MAKE IT ONTO THE COAST BY MORNING AS THE SHORTWAVE TO THE NORTH BENDS THE SURFACE RIDGE AXIS THIS WAY. TOMORROW MODEL FORECAST SOUNDINGS FROM THE MESOETA INDICATE THAT PROLONGED ONSHORE FLOW WILL THICKEN THE MARINE LAYER TO 1500 TO 2000 FEET THICK AS COMPARED TO TODAY'S 500 FEET THICK LAYER...SO EXPECT A CLOUDIER AND COOLER DAY ACROSS THE NORTH COAST. OVER INTERIOR AREAS MODELS CONTINUE TO SHOW A 1C TO 5C TEMPERATURE INCREASE BETWEEN 925 AND 850MB SO HAVE CONTINUED WITH FORECAST WARM-UP. TEMPERATURES COULD POSSIBLY EXCEED FORECAST VALUES SINCE HAVE LEANED MORE TOWARD THE ETA RATHER THAN THE GFS SOLUTION. THE INTERESTING POINT REGARDING TOMORROW'S WEATHER IS THAT INCREASED WARMING ACROSS THE INTERIOR WILL STRENGTHEN THE INVERSION ALONG THE COAST...SO INCREASING WINDS OVER THE COASTAL WATERS ARE UNLIKELY TO MIX THE MARINE LAYER OUT. .LONG TERM... SUNDAY NIGHT INTO MONDAY MESOETA NOW INDICATES...AS IT DID BEFORE YESTERDAY...ENOUGH COOLING AT THE TOP OF THE BOUNDARY LAYER TO MIX OUT THE MARINE LAYER FROM NORTH TO SOUTH. ON MONDAY TEMPERATURES WILL LIKELY COOL SUBSTANTIALLY EVEN INLAND AS UPPER RIDGE FLATTENS AND SHIFTS EASTWARD IN RESPONSE TO A TROUGH DROPPING SOUTH OUT OF THE GULF OF ALASKA. THIS TROUGH WILL DRIFT TOWARD THE AREA THROUGHOUT THE WEEK WITH AN INCREASING CHANCE OF RAIN BEGINNING TUESDAY. WHILE THE EUROPEAN AND GFS MODELS HAVE BEEN IN VERY GOOD AGREEMENT WITH THIS FEATURE ON A DAILY BASIS...TODAY'S RUNS INDICATE LESS ENERGY DROPPING SOUTH INTO THIS WAVE AND MORE EJECTING OUT OF IT INTO THE NORTHERN ROCKIES AND CENTRAL CANADA PRIOR TO IT'S ARRIVAL INTO OUR AREA. THUS...LOW BEGINS TO CLOSE OFF FURTHER WEST OF THE AREA LEAVING US ON THE EASTERN EDGE OF THE DECAYING TROUGH. SNOW LEVELS AND PRECIPITATION TIMING STILL DIFFICULT TO PINPOINT DUE TO THESE DEVELOPMENTS. HOWEVER...WITH COOLING TEMPERATURES ALOFT...FAVORABLE JET SUPPORT...AND ONSHORE FLOW EXPECTED ESPECIALLY OVER THE NORTHWESTERN PORTION OF THE FORECAST AREA...HAVE CONTINUED THE GENERAL CHANCE OF RAIN ACROSS THE NORTH UNTIL DETAILS BECOME CLEARER. LUTZ && .SYNOPSIS...SURFACE HIGH PRESSURE WILL STRENGTHEN OFFSHORE THROUGH SUNDAY ALLOWING HIGH TEMPERATURES TO CONTINUE TO CLIMB OVER INTERIOR PORTIONS OF NORTHERN CALIFORNIA. HOWEVER...A MARINE PUSH WILL RETURN AREAS OF LOW CLOUDS AND PATCHY FOG TO THE COAST FOR TONIGHT INTO EARLY MONDAY. NEXT WEEK...AS A LOW PRESSURE TROUGH SWINGS SOUTH OUT OF THE GULF OF ALASKA...TEMPERATURES WILL COOL THROUGHOUT THE FORECAST AREA WITH AN INCREASING CHANCE OF RAIN ACROSS THE NORTH. && .EKA WATCHES/WARNINGS/ADVISORIES... NONE. && $$ DISCUSSION: BTL SYNOPSIS: TA/BTL ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1013 AM CDT SAT MAY 1 2004 .DISCUSSION... LATEST SURFACE ANALYSIS PLACES SURFACE STATIONARY FRONT JUST SOUTH OF SOUTHEAST CWA. LATEST 1445Z IR SATELLITE PLACES PLENTY OF CLOUDS ACROSS THE GREAT LAKES REGION SOUTHWEST INTO SOUTHERN PLAINS STATES. LATEST 1503Z KILX RADAR SHOWS SHOWERS ACROSS CENTRAL AND SOUTHEAST ILLINOIS WITH A BRIEF AREA OF NO PCPN FROM SPI-ILX. EXPECT PERIODS OF SHOWERS TO CONTINUE FOR THE REMAINDER OF THE DAY. WILL UPDATE ZONES FOR WORDING AND ADJUST TEMPERATURES SLIGHTLY. && .PREV DISCUSSION... FORECAST MODELS TRENDING FURTHER NORTH AND HIGHER WITH QPF FIELD ACROSS CENTRAL IL TODAY. SIDING WITH THE ETA MODEL WHICH IS FURTHEST NORTH WITH QPF AND AGREES BEST WITH CURRENT RADAR MOSAIC. GOOD ISENTROPIC LIFT DEVELOPING TODAY AND FRONTAL BOUNDARY NEARBY WITH AMPLE DEEP LAYER MOISTURE TO WORK WITH. FORECAST CHALLENGE IS IF FLOOD WATCH NEEDED TODAY ACROSS AREAS ALONG AND SOUTH OF I-70. SHORT TERM...TODAY THROUGH MONDAY... WIDESPREAD CONVECTION ON ILX CWFA DOORSTEP JUST SOUTH AND WEST OF CENTRAL IL AND MOVING NE. THIS IN RESPONSE TO 1011 MB LOW PRESSURE ALONG THE AR/MO BORDER AND MOVING NE ALONG A STRONG FRONTAL BOUNDARY EXTENDING ACROSS SE PARTS OF MO/IL FROM JUST SE OF FLORA TO JUST NW OF TERRE HAUTE. THIS FRONT THEN EXTENDS NE ACROSS CENTRAL INDIANA TO 1009 MB LOW PRESSURE IN SE LOWER MICHIGAN. TEMPS RANGE FROM 45 TO 50 DEGREES FROM CHARLESTON/MATTOON NW TOWARD THE QUAD CITIES...TO THE MID 50S TO LOWER 60S FROM I-70 SE. QUITE WET AND MUCH COOLER TODAY ACROSS CENTRAL AND SE IL. RUC AND ETA TAKES SURFACE LOW PRESSURE NE INTO SE IL BY 18Z AND ETA THEN TAKES LOW TO DAYTON OHIO BY 00Z/SUN OR SUNSET TODAY. GOOD ISENTROPIC LIFT ALONG AND SE OF THE IL RIVER TODAY WHERE CATEGORICAL POPS OF SHOWERS. LIKELY CHANCE FAR NW BY KNOX AND STARK COUNTIES THIS MORNING. SPC KEEPS SLIGHT RISK MOSTLY SE OF ILX CWA WHILE GENERAL RISK OF THUNDER AS FAR NW AS A TAYLORVILLE TO DECATUR TO CHAMPAIGN LINE TODAY. HEAVY RAINS OF 1 TO 2 INCHES LIKELY ALONG AND SOUTH OF I-70 TODAY WHERE BEST INSTABILITY AND DEEPEST MOISTURE PRESENT CLOSER TO THE FRONTAL BOUNDARY THAT CONTINUES TO PRESS SE ACROSS SE IL. FLASH FLOOD GUIDANCE VALUES RANGE FROM 2 TO 3 INCHES IN 3 HOURS ACROSS SE 8 COUNTIES...WHICH ARE FAIRLY HIGH DUE TO LACK OF RAINFALL RECENTLY. SO DID NOT ISSUE A FLOOD WATCH FOR SE COUNTIES TODAY. POPULATED WITH HPC QPF FIELDS TODAY AND COOLED HIGHS NORTH OF I-70 TO THE MID 50S WITH LOW TO MID 60S FROM I-70 SOUTH. MAY EVEN BE A FEW DEGREES COOLER IN THE LOWER 50S NORTH OF I-70 WITH CLOUDY SKIES...THE RAIN AND NORTH BREEZES. RAIN SHOULD START DIMINISHING LATER THIS AFTERNOON FROM THE IL RIVER WEST AND THEN DIMINISHING FROM THE IL RIVER EAST TO THE INDIANA BORDER DURING THIS EVENING AS THE FRONTAL BOUNDARY AND LOW PRESSURE SYSTEM PULL AWAY FROM IL. COOLER LOWS TONIGHT IN THE UPPER 30S AND LOWER 40S. STRONG UPPER LEVEL TROF DIGS INTO IL SUNDAY WITH UNSTABLE CONDITIONS BY SUNDAY AFTERNOON WITH STEEP LAPSE RATES. SPC DAY2 HAS GENERAL RISK OF THUNDER SUNDAY AFTERNOON INTO SUNDAY EVENING. ALREADY HAVE CHANCE OF SHOWERS BY SUNDAY AFTERNOON INTO THE EVENING...AND NEXT SHIFT MAY WANT TO ADD CHANCE OF THUNDER. A FAIRLY STRONG SHORT WAVE PIVOTS AROUND THE BASE OF THE TROF INTO SOUTHERN IL BY SUNDAY EVENING WHERE BEST CHANCE OF CONVECTION. EVEN COOLER MONDAY NIGHT WITH LOWS IN THE MID TO UPPER 30S AS CANADIAN HIGH PRESSURE MOVES SE TOWARD IL BY 12Z/MON. TEMPS BEGIN TO MODIFY A BIT MONDAY WITH MORE SUNSHINE BUT 850 MB TEMPS STILL AT OR JUST BELOW 0C. LONG TERM...TUESDAY THROUGH FRIDAY... TEMPS WARM BACK TO NORMAL TUE AS HIGH PRESSURE SHIFTS EAST OF IL MON NIGHT AND TUE WITH INCREASING SOUTHERLY WINDS. NORTHERN STREAM SHORT WAVE IN WNW UPPER LEVEL FLOW TO GIVE AREA NORTH OF I-70 A RISK OF SHOWERS TUE. ANOTHER NORTHERN STREAM SHORT WAVE POSSIBLE WED AND AGAIN FRI TO GIVE SLIGHT CHANCE OF SHOWERS NORTH OF I-70. NEW MEX AGREE WITH WARMER TEMPS DURING MID AND LATE WEEK WITH HIGHS BACK INTO THE 70S. && .ILX WATCHES/WARNINGS/ADVISORIES... IL...NONE. && $$ KH/13 il AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE GOODLAND KS 917 AM MDT SAT MAY 1 2004 .DISCUSSION...WILL BE ISSUING AN UPDATE SHORTLY. WILL BE TAKING OUT MORNING WORDING. LATEST RUC CATCHING CLOUD AND WIND FIELD NICELY AND WILL UPDATE WITH IT. LATEST GUIDANCE SHOWING TEMPERATURES ARE LOOKING CLOSE TO CURRENT FORECAST AND WILL NOT TOUCH MAXES. HOWEVER WILL BE TWEEKING TRENDS ON TEMP AND DEWPOINT GRIDS. $$ .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ BULLER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1048 AM EDT SAT MAY 1 2004 .DISCUSSION... UPR AIR ANALYSIS SHOWS DEEPENING TROF IN THE CENTRAL PLAINS (WITH SOME PHASING WITH THE CLOSED LOW WHICH CAME OUT OF THE SRN ROCKIES)...AND CONFLUENT SW FLOW PERSISTING OVER THE UPPER GREAT LAKES TO THE EAST OF THIS TROF. ANY LIGHT SPRINKLES ASSOCIATED WITH LAST NIGHT'S WEAK FRONTAL PASSAGE HAVE DEPARTED TO OUR EAST... LEAVING MOSTLY CLEAR SKIES EXCEPT FOR SOME HIGHER CLOUD IN THE FAR SE ASSOCIATED WITH A WAVE WELL TO OUR SOUTH IN THE MID MISSISSIPPI / LOWER OHIO VALLEYS. NOT ANTICIPATING ANY CHANGES TO THE GOING FORECAST. COLDEST AIR ALF (H5 TEMP OF -33C AT KBIS/12Z) ASSOCIATED WITH TROF IN THE CENTRAL PLAINS SHOULD REMAIN TO OUR WEST TODAY. WOULD THUS EXPECT DIURNAL SHOWER ACTIVITY TO MAKE IT INTO MN/IA/WRN WI ONLY. THOUGH COOLER AIR ALF WILL JUST BEGIN TO MAKE IT INTO THE WRN U P LATER TODAY... SHORTWAVE ENERGY WILL BE DIVING TO OUR S. SOME LOWER CLOUD (AND SOME IFR CIGS) TO OUR N HAS PUSHED SOMEWHAT ACROSS LAKE SUPERIOR...BUT WHEREAS THE ETA WAS TOO ABUNDANT WITH LOW LEVEL MOISTURE OVER THE U P AT 12Z...THE RUC SEEMS TO HAVE A BETTER HANDLE ON THINGS AS IT TAKES THIS LOW LEVEL RH TO OUR N AND SHIFTS IT EWD AS SFC HIGH BUILDS IN. LATEST VIS IMAGERY WOULD INDICATE THAT THE RUC IS ON TRACK...AND LAST EVENING'S INL SOUNDING SHOWS THE DEGREE OF DRY AIR WE ARE TALKING ABOUT. SOME DIURNAL CU IS JUST STARTING TO DEVELOP OVER THE NWRN U P...AS THERE IS SOME LINGERING LLVL MOISTURE IN PLACE (DEWPTS OF LWR/MID 20S). WE MAY VERY WELL SEE A FLAT BKN CU FIELD DEVELOP...BUT AGAIN AS WE BECOME DRIER WOULD EXPECT THIS TO DIMINISH OR BECOME MORE SCATTERED AS THE AFTN PROGRESSES. OVERALL A DRY FORECAST FOR TODAY LOOKS GOOD. REGARDING TEMPS...FCST HIGHS OF UPR 30S ALONG THE LAKE SUPERIOR SHORE TO AROUND 50F IN THE SOUTH SHOULD SUFFICE. TEMPS HAVE RISEN TO THE LOWER 40S ALREADY AT THE MQT OFFICE...BUT WITH CU BEGINNING TO DEVELOP AND CAA UNDERWAY...WOULD EXPECT VERY LITTLE RISE FROM THIS POINT ON. WILL UPDATE GRIDS TO ACCOUNT FOR THIS TREND...BUT AGAIN THE FORECAST HIGHS LOOK FINE. WILL ALSO UP WINDS SLIGHTLY AS IMPROVED MIXING THIS MORNING HAS KICKED SPEEDS TO 10-20 MPH RANGE ALREADY IN THE CENTRAL AND EAST WHERE THE GRADIENT IS TIGHTEST. WILL SEND UPDATE SHORTLY TO REMOVE MORNING SPRINKLE WORDING...AND TO TWEAK WINDS. JKL REMAINDER OF PREVIOUS DISCUSSION (ISSUED 350 AM)... AXIS OF CNTRL CANADA/N PLAINS TROUGH ACCOMPANIED BY H5 TEMPS NEAR -30C PROGGED TO AFFECT UPR GREAT LAKES ON SUN. WITH CONVECTIVE TEMPS ONLY IN MID 30S OFF FCST SOUNDINGS SKIES SHOULD QUICKLY BECOME MOSTLY CLOUDY WITH WDLY SCT-SCT INSTABILITY SHOWERS DEVELOPING. 1000-850MB THICKNESSES WELL BLO 1300M...ESPECIALLY NW INTERIOR SO SNOW ONLY PTYPE THERE. FARTHER S AND E THE LOWER ELEVATION MAY ALLOW RAIN TO MIX IN. LOWER LEVELS ARE DRY AT THIS TIME THOUGH WITH TD AROUND 20F SO ONLY EXPECT A FEW HUNDREDTHS OF LIQUID PCPN AT BEST...WITH ANY SNOW AMOUNTS WELL UNDER AN INCH. N FLOW OFF LAKE SUPERIOR ALONG WITH H85 TEMPS AROUND -10C MAY TRY TO CONTRIBUTE SOME LOWER LEVEL MOISTURE TO INSTABILITY SHOWER REGIME. THUS...EXPECT BEST PCPN COVERAGE OVR NCNTRL UPR MI WHERE UPSLOPE FLOW WILL BE PRESENT. MIXING TO H9/H85 TEMPS ONLY YIELDS MID 30S-LWR 40S FOR MAX T SO HAVE TRIMMED TEMPS A BIT MORE FOR SUN. ITS POSSIBLE THAT TEMPS MAY STRUGGLE TO REACH 35F IN UPSLOPE NCNTRL UPR MI. NWS REC LOW MAX T FOR THE 2ND OF MAY OF 35F COULD BE IN JEOPARDY. A VERY CHILLY DAY INDEED. NW FLOW AND TEMPS AT TOP OF INVERSION AROUND -8C MAY ALLOW CLOUDS AND LAKE EFFECT FLURRIES (THIS IS MAY RIGHT?) TO PERSIST OVR E CWA SUN NIGHT. ALTHOUGH LATEST GFS SHOWS UPR LOW TRYING TO SLIGHTLY CUTOFF OVR GREAT LAKES...IT STILL APPEARS UPR HEIGHTS WILL RISE ENOUGH ON MON INTO MN/UPR MI TO KEEP PCPN OUT OF FCST. N STREAM TROUGH CROSSES UPR MI MON NIGHT. RIBBON OF THETA-E ADVECTION PUSHING N IN ADVANCE OF TROUGH AND INCREASING ELEVATED INSTABILITY (SI/S AROUND ZERO) MAY ALLOW AN ISOLATED TS ALONG THE TROUGH ALONG WITH SOME SHRA. NOSE OF H85 JET ALONG WITH BEST THETA-E RIDGING OCCURS MAINLY OVR S MN/WI SO WILL JUST KEEP SCT SHRA GOING FOR NOW. NO CHANGES MADE BEYOND MON NIGHT. COORD WITH APX. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && $$ JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1011 AM EDT SAT MAY 1 2004 .UPDATE... UPDATE TO FRESHEN WEATHER AND WIND WORDING. SURFACE FRONT HAS CLEARED THROUGH SOUTHEAST LOWER...WITH PHN/DET/TTF/LSCM4 ALL NORTHWEST AS OF 13Z. WIDESPREAD SHOWERS HAVE CLEARED EAST OF THE CWA BEHIND THE FIRST SURFACE WAVE OVER SOUTHEAST ONTARIO. NEXT WAVE ALONG THE BOUNDARY UPSTREAM IS MOVING INTO THE LOWER OHIO VALLEY...WITH NEXT ROUND OF WIDESPREAD PRECIP MOVING INTO CENTRAL INDIANA. PLENTY OF LOW-LEVEL MOISTURE LINGERS ACROSS THE CWA BETWEEN THESE WAVES...WITH A NUMBER OF SITES STILL IFR. WILL KEEP LOW CHANCE POPS GOING DURING THE DAY WITH THE AVAILABLE LOW-LEVEL MOISTURE AND SOME WEAK CONVERGENCE...THEN DEFINITE BY EVENING WITH NEXT ROUND. LINEAR EXTRAPOLATION OF CURRENT TIMING AND 12Z RUC FORECAST BRING PRECIP INTO THE SOUTHERN CWA BY 21Z...RIGHT NEAR THE END OF THE PERIOD. WILL BRING IN PERIOD OF RAIN LATE IN THE SOUTH. THERE HAVE BEEN SOME LIGHTNING STRIKES ACROSS SOUTHERN INDIANA...BUT NOTHING FARTHER NORTH IN THE MORE STABLE AIR/STRATIFORM RAIN BEHIND THE FRONT /WITH FGEN AND DEFORMATION FORCING/. ETA/RUC CONTINUE TO KEEP THE BEST INSTABILITY GRADIENT JUST SOUTHEAST OF THE STATE. IT WILL BE CLOSE AND WILL KEEP THUNDER OUT OF THE GRIDS FOR NOW...BUT WILL TAKE A CLOSER LOOK THIS MORNING WITH THE SEVERE WEATHER CHECKLIST. && BRAVENDER .PREV DISCUSSION...300 AM EDT SAT MAY 1 2004 A LOOK BACK...QUASI-STATIONARY BOUNDARY WAS ABLE TO SLIP FURTHER SOUTH INTO THE TRI-CITIES WHICH ALLOWED FOR THE COLDER TEMPERATURES (AS DISCUSSED YESTERDAY). IN FACT, THE ONLY MODEL THAT SEEMED TO HAVE A GOOD HANDLE OF THIS WAS THE TAQ RUC TO BE FOLLOWED BY THE LOCALLY PRODUCED ETA-XX. THE CONFIDENCE FACTOR WAS LOW WITH LITTLE SUPPORT SUGGESTING A MOVEMENT THIS FAR SOUTH...EITHER WAY THIS FRONT WILL SLIP SOUTH DURING THE DAYLIGHT MORNING HOURS TODAY. WITH NO SATELLITE DATA THIS MORNING ON AWIPS, DIFFICULT TO ASCERTAIN UPPER LEVEL FEATURES AND PROPAGATION...SOME ONLINE RESOURCES HAVE BEEN HELPFUL. NEVERTHELESS, MODELS APPEAR TO HAVE COME INTO AGREEMENT WHICH PAINTS A VERY SOGGY FORECAST THE NEXT 24-36 HOURS. WITH RAINFALL DEFICITS BETWEEN 2-3 INCHES FOR LAST MONTH (APRIL), AND RFC GUIDANCE NUMBERS INCLUDING AHPS INFORMATION QUITE HIGH, WE SHOULD HAVE NO HYDRO ISSUES WITH THIS UPCOMING EVENT. UPPER TROF CONTINUES TO AMPLIFY WITH SURFACE WAVE ENTERING INTO SOUTHWEST LOWER EARLY THIS MORNING. THIS WAVE WILL PIVOT ON THRU THE REGION THIS MORNING WITH AN EXTENSIVE AREA OF RAIN WITH SOME EMBEDDED THUNDER...MAINLY ON THE LEADING EDGE. MODEL ELEVATED 850MB LIFTED INDEX (SHOWALTER) SHOW NEAR 0C WHICH MAKES IT AS FAR NORTH AS THE M59 CORRIDOR. THIS SHOULD QUICKLY PASS BY TO THE EAST LATE THIS MORNING WITH DEPARTING WAVE AND BOUNDARY SLIPPING SOUTH OF THE STATE LINE. UPSTREAM, THAT FOUR CORNERS LOW WILL BECOMING ENTRAINED INTO DEEPENING TROF WHICH MOVES OUT INTO THE LOWER MISSISSIPPI RIVER VALLEY LATE TODAY. WITH TIGHT BAROCLINIC BOUNDARY AND STRENGTHENING UPPER JET (RIGHT ENTRANCE REGION), EXCELLENT AGEOSTROPHIC RESPONSE WITH 850-700MB 2-D FGEN INCREASING ALONG WITH DEFORMATION DYNAMICS TO BRING MUCH NEEDED RAINFALL TO THE FORECAST AREA. IMPRESSIVE PLAN VIEW OMEGA FIELDS BRING THE FIRST SHOT OF RAIN TO THE SOUTHERN HALF LATE THIS AFTERNOON THEN OVERSPREADS THE REMAINDER OF THE CWA TONIGHT. MODEL QPF FIELDS HINT TOWARD 1" OF RAIN OVERNIGHT...WHICH IS WELL BELOW FLOOD GUIDANCE. AS SURFACE LOW DEEPENS EAST OF THE STATE LATE TONIGHT, COOLER AIR WILL FILTER SOUTH WHICH BRINGS THE POTENTIAL FOR SOME SNOW (WELCOME TO MAY). 1000-850MB THICKNESSES SUGGEST MIDLAND COUNTY COULD SEE SOME SNOW VERY LATE TONIGHT BUT FOR NOW WE WILL LEAVE AS LIQUID WITH UPSTREAM TEMPS/DEWPOINTS STILL INTO THE 40S AND 30S RESPECTFULLY. A FULL LATITUDE TROF EVOLVES ACROSS THE EASTERN CONUS DURING SUNDAY WITH MODEL TRENDS TOWARD A CLOSED 500MB LOW OVER THE GREAT LAKES. THIS WILL SET UP STEEPING LAPSE RATES WITH MAY SUNSHINE ALONGSIDE COLD 850MB TEMPS IN THE SUB-ZERO CELSIUS ADVECTING INTO THE STATE. BOUNDARY LAYER LOOKS WARM WITH WET BULB ZERO HEIGHTS ABOVE 2000 FEET FOR THE CHANCE OF RAIN SHOWERS. WITH NORTHWEST FLOW, WE TEND TO SEE SOME DRYING UP OF THE PRECIP THE FURTHER SOUTH TOWARD THE BORDER WE GO... AS WE APPROACH SUNDAY NIGHT, WITH AFOREMENTIONED BOUNDARY LAYER FLOW, DRY AIR ADVECTS INTO THE CWA. WITH THE LOST OF THE DIURNAL ASPECT AND SURFACE RIDGE ATTEMPTING TO BUILD INTO THE STATE, WE COULD SEE TEMPS DIP TOWARD THE FREEZING MARK...COULD BE LOWER TOWARD THE TRI CITIES INCLUDING FLINT. MAY 3RD RECORDS ARE 28-DTW, 26 FOR FNT AND MBS. WE WILL HIGHLIGHT THIS IN OUR HWO AS FROST/FREEZE HEADLINES ARE POSSIBLE (LOCAL GUIDELINES IS AFTER MAY 1). SURFACE HIGH IS IN CONTROL EARLY NEXT WEEK AS TROF FILLS AND LIFTS NORTHEAST AWAY FROM THE GREAT LAKES REGION. && .DTX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ BGM EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 530 AM CDT SAT MAY 1 2004 .DISCUSSION...THE AREA OF THUNDERSTORMS ALONG THE SW LA COAST HAS BEEN SLOWLY MOVING TOWARD THE CWA. RUC40 SHOWS WINDS HAVE BECOME A LITTLE MORE SOUTHWESTERLY...SO THE SYSTEM WILL PROBABLY CONTINUE TO SPREAD OVER SOUTHERN AREAS THROUGH THE MORNING. WITH THE MESO HIGH OVER THE EASTERN HALF OF THE CWA DO NOT EXPECT MUCH DEVELOPMENT. LIGHTNING AND STRENGTH OF ECHOES CONTINUE TO DECREASE AS THE THUNDERSTORMS GET CLOSER. HAVE ISOLATED-SCATTERED POPS FOR THE MORNING AND LIKELY-DEFINITE POPS FOR THE AFTERNOON. MODELS WERE SHOWING THE BEST PRECIP OVER THE AREA BY AFTERNOON...MAY HAVE AMEND ZONES TO REMOVE AFTERNOON WORDING. IT MAY TURN OUT TO BE MORE LIKE MID MORNING WHEN WIDESPREAD SHOWERS AND THUNDERSTORMS MOVE INTO THE AREA. CONTINUED SEVERE WORDING AND ADDED TO NORTHWEST FOR THIS MORNING AND AFTERNOON. EXPECT ANY DEVELOPMENT TO STAY ALONG AND AHEAD OF FRONT...SO LEFT SOUTHEAST ZONES OUT OF SEVERE WORDING. MODELS WERE SHOWING A SEVERAL WAVES DEVELOPING ALONG THE FRONT...WITH THE HEAVIEST PRECIP STAYING SOUTH OF THE CWA. STILL MAINTAINED HEAVY RAIN WORDING FOR THE AFTERNOON AND EVENING. SINCE CWA HAS NOT RECEIVED AS MUCH RAIN AS SURROUNDING AREAS OVER THE LAST 2 DAYS...WILL NOT ISSUE ANY FFA. WILL CONTINUE HEAVY RAIN/POSSIBLE FLOODING WORDING IN THE HWO. USED OF A BLEND OF THE MODELS...MAINLY LEANING TOWARD THE AVN...HOWEVER DID NOT JUMP ON SLOWING OF BOUNDARY AND REDEVELOPMENT/BULLSEYE OF PRECIP FOR THE SOUTHEAST BY SUNDAY MORNING. 1 HOUR FFA WAS AROUND 1-1.5 INCHES FOR THE SOUTH...SO IF HEAVY RAIN DEVELOPS THIS AREA WILL BE MORE LIKELY TO SEE A FFA AT THIS POINT. ALL OTHER AREAS WERE CLOSE TO 2 INCHES. SHEAR DID NOT LOOK ALL THAT GREAT ON MODEL SOUNDINGS...BUT UPPER JET INCREASES AS IT PASSES NORTHWEST OF THE AREA...SO DAMAGING WIND WORDING SHOULD BE GOOD...MAY ALSO SEE SOME HAIL. BEYOND SUNDAY DO NOT EXPECT TO MUCH IN THE WAY OF RAIN BEFORE NEXT WEEKEND. DID NOT ADD RAIN TO THE ZONES...BUT THE GFS WAS GENERATING SOME PRECIP FOR SATURDAY. DID NOT KNOW EXACTLY WHY...SO DECIDED TO MAINTAIN PARTLY CLOUDY SKIES AND INCREASING TEMPS THROUGH THE WEEK. COLD FRONT SHOULD BRING SOME COOLER DRIER AIR INTO THE REGION...BUT WITH CLEAR SKIES BY TUESDAY...TEMPS MAY GET SLIGHTLY WARM THAN EXPECTED. ANYWAY DID NOT MAKE ANY MAJOR CHANGES TO THE FORECAST...ADJUSTED ORIENTATION OF POPS FOR THE NEXT FEW DAYS. ALSO INCREASED TEMPS A DEGREE OR TWO BY THE END OF THE WEEK...GOT A LITTLE CLOSER TO MEX GUIDANCE. OTHERWISE FORECAST WAS OK. JACKSON 77 60 68 48 / 70 80 40 10 MERIDIAN 79 62 67 49 / 60 80 50 10 && .JAN WATCHES/WARNINGS/ADVISORIES... AR...SVR THUNDERSTORM WATCH ARZ074-075 LA...SVR THUNDERSTORM WATCH LAZ007 MS...NONE. && $$ ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OH 940 PM EDT SAT MAY 1 2004 .DISCUSSION... CONVECTION INTENSIFIED AND BECAME SVR LATE THIS AFTN/THIS EVENING AS THE COLD FRONT SLOWLY PASSED THRU THE CWFA. THE FRONT IS NOW ENTIRELY SOUTH OF THE CWFA...HOWEVER A WAVE HAS DEVELOPED ALONG THE FRONT OVER SW OH/NRN KY WHICH IS HELPING TO KEEP SHOWERS AND THUNDERSTORMS GOING ON THE COOL SIDE OF THE FRONT ACROSS THE ENTIRE CWFA. ALTHOUGH THE INTENSITY OF THESE THUNDERSTORMS HAVE DIMINISHED OVER THE PAST SVRL HOURS...THE FACT REMAINS THAT LOCALLY HVY RAINFALL IS STILL POSSIBLE WITH AREA OF PCPN AS IT MOVES OVER THE CENTRAL CWFA. WILL THEREFORE CONTINUE WITH CAT POPS EVERYWHERE. THERE IS A RISK OF FLOODING TONIGHT AS PARTS OF THE CWFA HAVE SEEN OVER AN INCH OF RAIN ALREADY THIS EVENING. SOME LOCALIZED AREAS HAVE SEEN 1-1.5 INCHES OF RAIN THIS EVENING...AND GIVEN THAT 6 HR FFG ACROSS MUCH OF THE AREA IS ONLY 2-3 INCHES...WILL NEED TO WATCH THE RAIN THAT MOVES FROM SW OH VERY CLOSELY. OTHERWISE...THINK THAT THE RISK FOR SVR WX HAS DIMINISHED DUE TO THE ATMOSPHERE BEING WORKED OVER FROM EARLIER CONVECTION AND THE LOSS OF DAYTIME HEATING. WILL THEREFORE REMOVE ALL SVR MENTION IN THE ZONES. WILL ALSO REMOVE ANY THUNDER CHANCES FROM THE TOL GROUP AS THAT AREA IS FARTHER BACK INTO THE COLD AIR AND FURTHEST AWAY FROM THE SFC BOUNDARY. ZFP UPDATE OUT BY 1015 PM. && .PREV DISCUSSION... CONVECTION IS INTENSIFING FROM YNG TO NEAR CMH THIS AFTERNOON WITH CAPES AROUND 1000 J/KG WHICH IS MUCH HIGHER THAN MODEL GUIDANCE OF EITHER THE RUC/ETA OR GFS RUNS. SPC SUPERCELL PARAMETER HAS INCR TO ABOUT 1 NEAR KNOX COUNTY WHICH MEANS CONDITIONS ARE BECOMING FAVORABLE FOR SUPERCELL DEVELOPMENT. SFC WINDS ARE BACKING IN ADVANCE OF THE SFC LOW PRESSURE WAVE THAT IS MOVING NE TOWARD THE REGION. THIS WILL INCREASE LOW LEVEL HELICITY AND AID IN STORM ROTATION AND INCREASE THE LIKELYHOOD OF DAMAGING WINDS AND LARGE HAIL. BUFKIT SOUNDINGS OVER THE THREAT AREA SHOWS THE SFC DELTA THEATA-E TO BE AROUND 15C LATE THIS AFTERNOON WHICH SHOULD AID IN DOWNBURST POTENTIAL OF STORMS. THE MAIN THREAT AREA CONTINUES TO BE FROM SOUTHEAST CRAWFORD PA SOUTHWEST THROUGH YNG AND TO KNOX COUNTY. THE THREAT WILL PERSIST UNTIL THE SFC WAVE MOVE NE OF THE REGION PERHAPS AROUND 02 UTC. THERE IS SOME CONCERN ABOUT FLOODING AS RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE IN THE HEAVIER DOWNPOURS. THE SURFACE LOW WILL TRACK NE OF THE REGION SUNDAY AS COOLER AND MORE STABLE AIR OVERSPREADS THE REGION. BOTH THE ETA AND GFS ARE SLOWER THAN YESTERDAY'S RUN IN MOVING THE SHORT WAVE EAST OF THE REGION. CONSEQUENTLY...THE PCPN WILL LINGER TO PERHAPS MIDDAY NOW ACROSS MOST OF THE AREA. GRADUAL CLEARING WILL PROGRESS EWD SUNDAY AFTERNOON. COOL HIGH PRESSURE WILL BUILD INTO THE REGION MONDAY SO THERE IS SOME CONCERN ABOUT FROST. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. && $$ MRD (DISCUSSION) REL (PREV DISCUSSION) oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OH 315 PM EDT SAT MAY 1 2004 .DISCUSSION... CONVECTION IS INTENSIFING FROM YNG TO NEAR CMH THIS AFTERNOON WITH CAPES AROUND 1000 J/KG WHICH IS MUCH HIGHER THAN MODEL GUIDANCE OF EITHER THE RUC/ETA OR GFS RUNS. SPC SUPERCELL PARAMETER HAS INCR TO ABOUT 1 NEAR KNOX COUNTY WHICH MEANS CONDITIONS ARE BECOMING FAVORABLE FOR SUPERCELL DEVELOPMENT. SFC WINDS ARE BACKING IN ADVANCE OF THE SFC LOW PRESSURE WAVE THAT IS MOVING NE TOWARD THE REGION. THIS WILL INCREASE LOW LEVEL HELICITY AND AID IN STORM ROTATION AND INCREASE THE LIKELYHOOD OF DAMAGING WINDS AND LARGE HAIL. BUFKIT SOUNDINGS OVER THE THREAT AREA SHOWS THE SFC DELTA THEATA-E TO BE AROUND 15C LATE THIS AFTERNOON WHICH SHOULD AID IN DOWNBURST POTENTIAL OF STORMS. THE MAIN THREAT AREA CONTINUES TO BE FROM SOUTHEAST CRAWFORD PA SOUTHWEST THROUGH YNG AND TO KNOX COUNTY. THE THREAT WILL PERSIST UNTIL THE SFC WAVE MOVE NE OF THE REGION PERHAPS AROUND 02 UTC. THERE IS SOME CONCERN ABOUT FLOODING AS RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE IN THE HEAVIER DOWNPOURS. THE SURFACE LOW WILL TRACK NE OF THE REGION SUNDAY AS COOLER AND MORE STABLE AIR OVERSPREADS THE REGION. BOTH THE ETA AND GFS ARE SLOWER THAN YESTERDAY'S RUN IN MOVING THE SHORT WAVE EAST OF THE REGION. CONSEQUENTLY...THE PCPN WILL LINGER TO PERHAPS MIDDAY NOW ACROSS MOST OF THE AREA. GRADUAL CLEARING WILL PROGRESS EWD SUNDAY AFTERNOON. COOL HIGH PRESSURE WILL BUILD INTO THE REGION MONDAY SO THERE IS SOME CONCERN ABOUT FROST. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...NONE. PA...NONE. && $$ REL oh AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 928 PM EDT SAT MAY 1 2004 .UPDATE... UPPER LEVEL TROUGH OVER CENTER OF NATION TO PROGRESS...WHILE SHORTWAVE ENERGY ROUNDING TROUGH PROVOKES CONVECTION AS IT CLIMBS W SIDE OF RIDGE OVER W ATLANTIC. CONVECTION HAS MOVED NE AND OUT OF AREA THIS EVENING. ANOTHER BATCH OF CONVECTION IN S AL IS MOVING THIS WAY...AND IF IT SURVIVES... COULD REACH THE SAVANNAH RIVER VALLEY AFTER MIDNIGHT. HAVE LOWERED POPS AND CLOUD COVER FOR LATE EVENING...THEN REALIGNED POPS FOR EARLY OVERNIGHT TO FAVOR SAVANNAH RIVER VALLEY. FRONT STILL EXPECTED TO ARRIVE AT SMOKIES BY 12Z...SO FAVORED HIGHEST POPS W LATE OVERNIGHT ...BUT LOWERED POPS TOWARD MAV AND NEIGHBORING OFFICES. WITH INSTABILITY LIMITED...KEPT THUNDER CHANCES RATHER LOW. TEMPERATURES AND DEW POINTS RUNNING ABOVE EXPECTATIONS....AND CLOSE TO MAV GUIDANCE. RAISED MINIMUM TEMPERATURES ABOUT TWO DEGREES... THEN TRENDED DEW POINTS CLOSER TO TEMPERATURES AS NIGHT PROGRESSES. WIND RATHER LIGHT AT THIS TIME...AND POPULATED WITH 21Z RUC WINDS...TRIMMING SPEED A KNOT OR TWO. PLENTY OF FOG AROUND LAST NIGHT...AND WITH MOISTURE INCREASING...EXPECT AT LEAST PATCHY FOG LATE TONIGHT. && .PRELIMINARY POINT TEMPS/POPS... GSP 64 72 50 70 / 50 90 40 20 AND 64 73 50 71 / 50 90 40 20 CLT 63 74 53 68 / 50 90 60 20 HKY 62 70 49 66 / 60 90 50 20 AVL 60 69 46 62 / 70 100 20 20 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ JAT sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 250 PM EDT SAT MAY 1 2004 .SHORT TERM... RUC SHOWING H5 VORT MAX CURRENTLY OVERHEAD...THIS MAY BE THE REASON FOR THE CLUSTER OF CONVECTION OVER THE UPSTATE. THROUGH THE EVENING...WILL EXPECT NUMEROUS SMALL SHOWERS TO DRIFT NE ACROSS THE FA. I AM IMPRESSED TO SEE THE GFS HANDLING THE MCS OFF THE SC COAST AND OVER LA VERY WELL. LOOKING AT THE GFS FUTURE OF THE LA MCS...STRONG CONVECTION WILL BEGIN TO MIGRATE NE OVER MS/AL AROUND 0Z TONIGHT. CURRENT RADAR SHOWING MCS HAS DEVELOPED A COOL POOL AND IS PROCEEDING SE TOWARD THE GULF...BELIEVE THE GFS OUTPUT IS OVERDONE 3-6HRS IN THE FUTURE. WOULD TEND TO TRUST THE ETA SOLUTION MORE...AS IT KEEPS THE HEAVIER PRECIP ALONG THE FRONT. HOWEVER...A STRENGTHENING LLVL JET OF 40KTS OR MORE WOULD CARRY ANY CONVECTION THAT WOULD DEVELOP OVER POOLING CAPES IN NRN GA TONIGHT. WITH A COMBINATION FOR PRE-FRONTAL DEVELOPMENT...UPSLOPE FLOW.. AND FRONTAL SQUALL WILL FORECAST CATE POPS OVER THE MTNS TONIGHT. WILL STEP CAT EAST SUN AS FRONT PUSHES EAST. AGAIN LOW CLOUDS AND RAIN COOLED AIR WILL LIMIT INSTABILITY AHEAD OF THE FRONT SUNDAY. HOWEVER...MOISTURE CONVERGENCE/LIFT ALONG THE FRONT LOOKS RATHER STRONG AND SHEAR IS MARGINAL FOR ORGANIZATION. SPC HAS PLACED THE MAJORITY OF THE FA IN THE DY2 SLGT RISK...HIGHLIGHTING THE CHC OF ISO WIND DAMAGE WITH FRONTAL SQUALL. IN ADDITION...1 TO 3 INCHES MAY COLLECT OVER THE MTNS WITH AN INCH OR MORE EAST BY 0Z MON. ETA AND GFS PUSH THE FRONT EAST AND WILL TIME THE SHOWERS TO END FROM WEST TO EAST SUN NIGHT. DURING THE DAY MON...MODELS CARRY A 30+ UNIT VORT OVER THE WESTERN CAROLINAS BRING A FEW SHOWERS A FAR EAST AS THE TN BORDER. HOWEVER...WITH TEMPS IN THE U60S TO L70S AND POWERFUL VORT OVERHEAD MIXING HEIGHTS WILL LIKELY EXCEED 750 MB. WILL EXPECT A BREEZY AND GUSTY DAY AS HIGH PRESSURE BUILDS EAST AND WINDS MIX DOWN. MONDAY NIGHT...HIGH PRESSURE BECOMES CENTERED OVER THE NC MTNS WITH H85 TEMPS JUST ABOVE 0C. WITH MOSTLY CLEAR SKIES AND LIGHT WINDS MODEL GUIDANCE SHOWS TEMPS FALLING AT TO JUST BELOW FREEZING ACROSS A SIGNIFICANT PORTION OF THE TN BORDER COUNTIES. WILL EXPECT TO SEE TEMPS AS LOW AS THE U20S IN THE HIGHER VALLEYS. HAVE ISSUED A FREEZE OUTLOOK FOR TUESDAY MORNING TO HIGHLIGHT. .LONG TERM... ECMWF AND GFS SHOW LOW PRESSURE EXITING MANITOBA LATE MON AND MOVING ALONG THE INTERNATIONAL BORDER TO NEW ENGLAND BY THU. WITH MUCH OF THE ENERGY AND MOISTURE REMAINING NORTH...EXPECT TO LITTLE MORE THAN SOME CLOUDS OVER THE FA ON WED. H5 HEIGHTS RISE THROUGH THE REST OF THE FORECAST PERIOD...YIELDING A INCREASE IN TEMPS FROM PREVIOUS FORECAST. ANOTHER COLD FRONT BEGINS TO DROP SOUTH OUT OF CANADA LATE THU...GFS SHOWS THIS FRONT BECOMING QUASI-STATIONARY OVER THE OHIO RIVER VALLEY FRI PM. WITH HEIGHTS RIDGING NEAR 590DAM WOULD EXPECT FRONT TO REMAIN NORTH...LEAVING THE FA IN A MOSTLY CLEAR WARM AIR MASS. BY LATE IN THE WEEK...WILL PLAN ON TEMPS TO REMAIN ABOVE AVERAGE...MAXING OVER THE UPPER SAVANNAH IN THE MID 80S. && .PRELIMINARY POINT TEMPS/POPS... GSP 62 72 50 70 / 70 90 40 20 AND 62 73 50 71 / 70 90 40 20 CLT 61 74 53 68 / 70 90 60 20 HKY 60 70 49 66 / 70 90 50 20 AVL 58 69 46 62 / 100 100 20 20 && .GSP WATCHES/WARNINGS/ADVISORIES... GA...NONE. NC...NONE. SC...NONE. && $$ NED sc AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 318 PM CDT SAT MAY 1 2004 .DISCUSSION... 12Z UPPER AIR OBSERVATIONS INDICATED CWA UNDER COLD H500 TROUGH WITH RIDGING BUILDING OVER THE WEST COAST AHEAD OF NEXT TROUGH. BOTH THE ETA/GFS STRUGGLED INITIALIZING THE TROUGH OVER NORTHERN PLAINS AND WERE NEITHER DEEP NOR COLD ENOUGH. ETA WAS PARTICULARLY BAD AT H850...INITIALIZING FAR TO WARM ACROSS THE PLAINS. MODELS ALSO EVIDENTLY HAVING PROBLEMS WITH EMBEDDED SHORTWAVES IN THE TROUGH. 16Z RADAR MOSAICS INDICATING SHOWERS DEVELOPING ACROSS EASTERN CWA...DUE TO THE ORIENTATION LOOKS TO HAVE SOME KIND OF UPPER FORCING. RUC SEEMED TO PICK UP ON THE WAVE THE BEST AT 16Z. DESPITE ALL THE INITIALIZATION PROBLEMS...MODELS SEEM TO BE IN RATHER GOOD AGREEMENT THROUGH TUESDAY WITH RESPECT TO THE SYNOPTIC PATTERN EVOLUTION. FIRST CONCERN WILL BE LINGERING INSTABILITY SHOWERS THAT ARE ONGOING ACROSS THE CWA AT THE MOMENT. THESE WILL SLOWLY FADE AS SFC HEATING IS LOST AND COLD CORE SLIDES EAST. WEAK SHORTWAVE IS PROGGED TO SLIDE DOWN THE BACKSIDE OF THE TROUGH IN 03-09Z TIMEFRAME AND ADDED A FEW ISOLATED SHOWERS ACROSS THE SOUTHWEST TO ACCOUNT FOR THIS. LOWS ARE GOING TO BE VERY TRICKY TONIGHT...DRY LOW LEVELS...CLOUDS AND WEAK BACKDOOR COLD FRONT WILL PLAY A LARGE ROLE IN TEMPS TONIGHT. RESULT IS AN UNUSUAL TEMP GRADIENT WITH WARMEST READINGS LIKELY IN THE NORTHEAST WHERE WEAK FRONT WILL BRING IN SOME LOW CLOUDS AND STRONGER WINDS. ON SUNDAY...COLD POCKET ALOFT WILL BE ALMOST COMPLETELY OUT OF AREA BY SUNDAY MORNING...BUT STEEPER LAPSE RATES WILL LINGER OVER THE FAR EAST AND A FEW SHOWERS MAY SPARK INITIALLY WITH SFC HEATING BUT SYSTEM SHOULD BE QUICK TO CLEAR THE AREA SO THE MOST OF THE CWA WILL BE DRY. LOW LEVEL RIDGING WILL BE IN CONTROL OF THE REST OF THE AREA WHICH WILL KEEP HIGHS ON THE COOL SIDE AS MIXING WILL BE WEAK. MONDAY LOOKS TO BE A WARM AND WINDY DAY AS SOUTHWEST WINDS REALLY GET GOING AHEAD OF SFC TROUGH. WENT WELL ABOVE GUIDANCE AS SHOULD HAVE NO PROBLEM MIXING DOWN THE WARMER TEMPS WITH THE STRONG FLOW. MAY NEED TO KEEP AN EYE ON MONDAY WITH RESPECT TO FIRE WX...BUT FOR NOW LOOKS LIKE THE STRONGEST WINDS WILL BE WITH THE COOLER TEMPS AND HIGHER AFTERNOON DEWPOINTS. BOTH ETA/GFS HINT AT SOME SORT OF SHORTWAVE CLIPPING THE AREA...WITH THE BEST MOISTURE TO THE NORTH. BUT AS BOTH MODELS INITIALIZED A TAD TO STRONG WITH THE RIDGE...WOULDNT BE SURPRISED IF ENERGY WAS A BIT FARTHER SOUTH SO ADDED SOME SHOWERS TO THE NORTHEAST LATE MONDAY INTO TUESDAY MORNING. EXTENDED...MEDIUM RANGE MODELS CONTINUE TO SHOW A PATTERN SHIFT THROUGH THE EXTENDED AS FLOW GOES FROM COOL NORTHWEST TO WEST/SOUTHWEST AT H500 AS WEST COAST TROUGH DIGS OFF THE PACIFIC. MAIN CONCERN THROUGHOUT THE EXTENDED WILL BE TEMPS AND PRECIP CHANCES. ADDED CHANCE OF TSRA FOR LATE WEDNESDAY AND THURSDAY NIGHT AS SOME MOISTURE RETURN AND WAA MAY BE ENOUGH TO TAP IN SOME WEAK INSTABILITY...ONLY PLACED THEM IN THE EASTERN ZONES THOUGH. BIG QUESTION IS THE COLD FROPA ON THURSDAY OR FRIDAY. 00Z GFS WAS MUCH MORE AGGRESSIVE BRINGING THE FRONT THROUGH ON THURSDAY. THIS WAS A PRETTY BIG CHANGE FROM YESTERDAYS AND THE 06Z RUN WHICH BRING THE FRONT THROUGH ON SUNDAY. SEVERELY ENSEMBLE MEMBERS ALSO FAVOR SLOWER SOLUTION. DECIDED TO USE A COMPROMISE OF YESTERDAYS 00Z GFS AND TODAYS 06Z GFS FOR FROPA AS IT HAS BEEN MORE CONSISTENT AND THEREFORE WILL PUT TSRA FRIDAY AFTERNOON AND KEEP TEMPS WARM. FOR TEMPS...MEX GENERALLY SEEMS TO COLD THROUGH ALL PERIODS AND WENT ABOVE GUIDANCE FOR MOST PERIODS. && .FSD...WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. && $$ JRM sd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tx SOUTH TEXAS FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 545 AM CDT SAT MAY 1 2004 UPDATED ZONES TO INCLUDE SEVERE THUNDERSTORM WATCH THRU NOON FOR ALL OF SOUTH TEXAS. REFER TO SVR TSTM WATCH 142 ISSUED BY SPC FOR DETAILS. .SHORT-TERM (TODAY AND TONIGHT)...COLD FRONT ALONG A LINE FROM JUST NORTH OF AUSTIN TO DEL RIO. SHOWERS AND THUNDERSTORMS ORGANIZING ALONG FRONT AND ELEVATED BEHIND AS STRONG COLD POOL SURGES SOUTH. STRONG 3 HR PRESS RISES BEHIND FRONT WILL ALLOW FRONT TO ACCELERATE DOWN THE RIO GRANDE APPROACHING NORTHWEST COUNTIES OF CRP CWA AROUND 11-12Z. FURTHER EAST...INCREASINGLY MOIST AND UNSTABLE INFLOW OFF GULF OF MEXICO HAS RESULTED IN SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS UPR TX COAST. FAVORABLE SHEAR PROFILES AND LLVL CONVERGENCE HAS RESULTED IN AN INCREASING THREAT FOR TORNADOES OVER THE HGX CWA AND SPC HAS ISSUED BOX FOR THIS. RUC PICKED UP WELL ON THIS AND SHOWS AREA OF INFLOW AND CONVERGENCE SHIFTING SOUTHWEST OVER THE NEXT FEW HOURS. MSAS SFC PRESS ANALYSIS SHOWS FALLS HAVE SHIFTED FURTHER WEST...FROM AUSTIN COUNTY SOUTH THRU VICTORIA AND CALHOUN COUNTIES. EXPECT THE POSSIBILITY OF ISOL/SCT SHOWERS AND THUNDERSTORMS TO BEGIN DEVELOPING ACROSS THE NE COUNTIES AND STREAM NORTH AHEAD OF ADVANCING COLD FRONT. COLD FRONT WILL SWEEP NW TO SE THRU CWA THROUGH THE MORNING AND EARLY AFTERNOON HOURS. EXCELLENT DIVERGENCE ALOFT AND MODEST CAPES SUPPORT ISOL THREAT FOR SEVERE. BIGGER THREAT WILL BE HEAVY RAINFALL AND HAVE DECIDED TO GO AHEAD AND ISSUED FLASH FLOOD WATCH FOR ENTIRE CWA THRU 7 PM...WITH MAIN THREAT BEING ACROSS THE COASTAL BEND. LIKELY WATCH MAY BE DROPPED OUT WEST BEFORE 7 PM. FRONT SWEEPS OFFSHORE INTO THE LATE AFTERNOON AND MAY SEE ELEVATED SHOWERS AND THUNDERSTORMS CONTINUE THRU EARLY EVENING. BRISK NORTH WINDS OVER THE WATERS WILL RESULT IN SCA CONDITIONS. EXPECT PRECIP TO TAPER OFF BY MIDNIGHT. && .LONG-TERM (SUNDAY THROUGH FRIDAY)...MID LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH SOUTHEAST TEXAS AND THE COASTAL BEND SUNDAY MORNING. EXPECT CLOUDS TO DIMINISH DURING THE MORNING HOURS. WITH HIGH PRESSURE BUILDING INTO SOUTH TEXAS AND DECENT COLD AIR ADVECTION OVER THE WATERS...WILL CONTINUE SMALL CRAFT ADVISORY CONDITIONS OVER THE GULF WATERS THROUGH MOST OF THE DAY SUNDAY. CLEAR SKIES AND LIGHT WINDS WILL PREVAIL SUNDAY NIGHT AS THE RIDGE OF HIGH PRESSURE SETTLES OVER SOUTH TEXAS. VERY COOL READINGS EXPECTED MONDAY MORNING WITH POSSIBLE RECORD LOW AT CRP. THE WEAK UPPER LOW WILL REMAIN WEST OF BAJA CALIFORNIA THROUGH WEDNESDAY SO EXPECT A GRADUAL WARMING TREND FOR THE WEEK WITH LOW LEVEL MOISTURE RETURN INCREASING BY THURSDAY. THE GFS AND ECMWF SHOW THE WEAK UPPER LOW MOVING ACROSS MEXICO THURSDAY AND INTO SOUTH TEXAS FRIDAY. TOO EARLY TO BE VERY CONFIDENT ON THE TRACK OF THIS UPPER LOW. WILL KEEP THE FORECAST DRY FOR FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 77 59 76 52 79 / 80 50 10 00 00 VICTORIA 75 55 75 48 79 / 90 50 10 00 00 LAREDO 76 58 78 55 83 / 70 30 05 00 00 ALICE 77 57 77 51 81 / 80 50 10 00 00 ROCKPORT 77 59 76 57 78 / 90 60 10 00 00 COTULLA 75 53 76 50 82 / 80 30 05 00 00 && .CRP WATCHES/WARNINGS/ADVISORIES... FLOOD WATCH FOR FLASH FLOODING ALL ZONES THRU 7 PM SCA EXPECTED OVER BAYS AND WATERS TONIGHT. && $$ 76/JR...SHORT-TERM 89/TMT...LONG-TERM tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 1003 AM EDT SAT MAY 1 2004 .DISCUSSION... ANOTHER NICE DAY ON TAP FOR THE REGION TODAY. TEMPS STARTING TO REBOUND NICELY FROM MORNING LOWS. CLD DEBRIS FROM SHORTWAVE MVG ALONG COLD FRONT MVG THRU CWA THIS MORNING. ANY PLACES WHERE BREAK IN CLD COVER SHOULD SEE NICE JUMPS IN TEMPS TDY...ALMOST NEAR YESTERDAY/S. LIGHT SCATTERED RW MVD THRU FA EARLY THIS MORNING. AREA RADARS SHOW LIGHT PRECIP JUST NORTH OF CWA. SOME LIGHT PRECIP SHOWING UP ACROSS CENTRAL NY AND LK ONTARIO. WILL OPT NOT TO UPDATE ZONES THIS MORNING. TEMPS LOOK WELL ON TRACKS FOR FORECASTED HIGHS. W/ SCATTERED CLD DEBRIS MVG OVER CWA DURING COURSE OF DAY...PT SUNNY LOOKS GOOD. W/ LIGHT PRECIP STILL DEVELOPING OVER NY...WARM TEMPS...AND MOISTER AIR W/ DEWPTS IN THE 50S...POSSIBLE FOR CHANCE OF TS TO POP UP THIS AFTERNOON AND CURRENT ZONES HAVE THIS COVERED. && .PREVIOUS DISCUSSION... CF (ALONG WITH A WK WAVE OF LOW PRESS) TO STAY TO THE WEST OF THE FA TODAY. ANOTHER...STRONGER WAVE OF LOW PRESS TO RIDE UP THIS CF TONITE...THEN THESE SYSTEMS TO MOVE ACRS THE FA ON SUN/SUN NITE AND TO THE EAST OF THE FA ON MON. UPR TROF TO START TO MOVE IN ACRS THE FA ON MON FROM THE WEST. 00-02Z 20KM "DEVELOPMENT" RUC SHOWS TEMPS TO GET UP INTO THE M60S TO NEAR 80F TODAY WITH SOUTHERLY SFC WINDS AT 10-15G20 KTS. T1MAX TEMPS ARE IN THE U70S-L80S TODAY. FEW TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON THIS DATA. RUC SHOWS PTSUNNY SKIES ACRS THE FA TODAY WITH SCT PCPN BY THIS AFTERNOON. BUFCAN/88D MOSAIC SHOWS A FEW -SHRA MOVING NE ACRS MUCH OF THE WRN/CENTRAL ZONES ATTM. WK H85 WAA TO TAKE PLACE ACRS THE FA TODAY THRU SUN...THEN CAA TO AFFECT THE FA ON SUN NITE/MON. SOME LOW-LVL MSTR ADVECTION TO TAKE PLACE ACRS THE FA TODAY AND TONITE. LOW-LVL MSTR TO INCREASE ACRS THE FA TODAY AND TONITE...WITH GOOD LOW-LVL MSTR ACRS THE FA ON SUN AND MUCH OF SUN NITE AND INTO EARLY ON MON. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA THIS AFTERNOON AND ON MON AFTERNOON. MID-LVL LAPSE RATES TO BE HI ACRS THE FA TODAY. SOME MID-LVL MSTR TO AFFECT THE ENTIRE FA TONITE THRU SUN NITE AND THE ERN ZONES EARLY ON MON. PW VALUES ACRS THE FA LOOK TO BE 0.8-1.4" TODAY THRU SUN...THEN DROP TO AROUND AN INCH ON SUN NITE...AND AOB 0.5" ON MON. NOTED FA IN SPC GEN TSTM OUTLOOK TODAY AND TONITE. CAPES ACRS THE FA TO BE 1-600 J/KG TODAY AND AOB 300 J/KG ON SUN. HAVE TAPERED POPS FROM WEST (HIGHEST) TO EAST (LOWEST) ACRS THE FA TODAY. FEEL THAT WITH A LACK OF ANY REAL TRIGGER AFFECTING THE FA TODAY THAT NOT MUCH WILL END UP HAPPENING. INSTABILITY LOOKS BETTER ACRS THE FA TODAY THAN ON SUN...WITH THE WIND FIELD ALOFT LOOKING BETTER ACRS THE FA ON SUN. WILL HANG ONTO THE MENTION OF THUNDER ACRS THE FA THIS AFTERNOON THRU SUN FOR NOW. WILL CONT WITH CHC POPS ACRS THE FA TONITE. LIKELY POPS BY LATER IN THE DAY ON SUN AND INTO SUN NITE LOOK LIKE A GOOD IDEA WITH FRONTAL SYS AFFECTING THE FA THEN. SOME LINGERING PCPN EXPECTED ACRS THE FA MOSTLY EARLY ON MON...ESPECIALLY ACRS THE ERN ZONES. T1MAX TEMPS ARE BASICALLY 75-80F ACRS THE FA ON SUN AND WILL GO BLO THESE VALUES BASED ON EXPECTED CLD COVER/PCPN THEN. NO CHANGES TO THE GOING FCST BEYOND MON FOR NOW. WRK ZONES AND PRELIM ISC GRIDS AVAILABLE. FINAL ZFP BY 4 AM. .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ NEILSON vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 1246 AM MDT SUN MAY 2 2004 .DISCUSSION...WATER VAPOR/RUC ANALYSIS SHOWING SHORT WAVE DIVING SOUTH ACROSS NORTHEAST KANSAS. COLD AIR WILL BE DRAWN SOUTH...LIMITING HIGHS ACROSS THE EASTERN ZONES. ETA 850 MB TEMPERATURES SUPPORT HIGHS VERY SIMILAR TO YESTERDAY IN THE HILL CITY AND MCCOOK AREAS WITH SOME WARMING IN THE WEST. OVERALL...VERY LITTLE CHANGES EXPECTED THROUGH THE SHORT TERM PERIODS AS AMPLIFIED RIDGE OVER THE SOUTHWEST FLATTENS AND MOVES INTO THE SOUTHERN PLAINS BY MID WEEK. CURRENT WARMING TREND LOOKS ON TRACK WITH ONLY SOME MINOR ADJUSTMENTS TO TEMPERATURES. DAYS 4 THROUGH 7 APPEAR ON TRACK WITH NO SIGNIFICANT CHANGES PLANNED. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ MWM ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 320 AM CDT SUN MAY 21 2004 .DISCUSSION... TWIST OVER SOUTH CENTRAL MN SHOWING SIGNS OF SINKING S A LITTLE MORE RAIN NOT TOO WIDE SPREAD BUT CONCENTRATED IN A SMALL MINI DEFORMATION ZONE. LATEST RUC ALSO PICKING UP ON A SMALL AREA OF MID LEVEL FRONTOGENESIS. THIS SLOWLY WEAKENS DURING THE MORNING AND SINKS INTO IOWA...WITH STEEP LAPSE RATES ALSO ENDING UP OVER IOWA. OTHERWISE CLEARING OVER THE NW CWA AS RIDGING MOVES IN...WITH CLOUDS LINGERING SE CWA IN CYCLONIC CURVATURE. PACIFIC FRONTAL SYSTEM MOVES IN ON MONDAY..WITH STRONG S WINDS OUT AHEAD. WILL KEEP WARMER TEMP IDEA IN SW CWA BUT HIGH CLOUDS COULD COULD LIMIT THIS. FIRE WEATHER PARAMETERS WILL BE CLOSE BUT TEMPS PROBABLY THE LIMITING FACTOR. PRECIPITABLE WATER INCREASES LATE AFTERNOON AND EVENING...AND QG FORCING RATHER WELL DEFINED. THICKNESS DIFFLUENCE AIMED AT NW MN BY AFTERNOON WHICH GRADUALLY DEVELOPS SOUTH BY EVENING. ETA SHOWING FAIRLY STRONG DIFFERENTIAL TEMP SIGNATURE SHOWING UP AS WELL..ESPECIALLY OVER WI AFTER 00Z. LOW LEVEL MOISTURE VERY LIMITED...AND NOT REAL UNSTABLE..SO THUNDER PROBABLY ISOLATED. FWC TEMPS LOOK A LITTLE LOW FOR MONDAY NIGHT WITH FRONT JUST EXITING THE AREA. FLIP-FLOPPING GFS IN LATER PDS OF COMING WEEK NOW SHOWING WEAKER NWLY FLOW POST WEAK FRONTAL BOUNDARY MOVING THRU ON THU. AHEAD OF SAID BOUNDARY...STRONG THETA-E ADVECTION AND A BIT MORE MOISTURE MAY TRIGGER A FEW -SHRA OVER NRN FORECAST AREA ON WED...BEFORE NOCTURNAL THREAT SETS UP OVR SRN MN WED NGT INTO THU MRNG. LAST TWO RUNS OF GFS LONG RANGE TRENDING TWD WARMER SOLUTION WITH AMPLIFICATION OF LONG WAVE TROF OVR WRN U.S. HENCE WARMER TEMPS LKLY BUT DEEP MOISTURE CUT OFF DUE TO SWLY FLOW ACRS CENTRAL PLAINS. ENOUGH MOISTURE TO MOST LKLY BRING PSBL CONVECTION...ESPECIALLY AT NGT. LATEST CANADIAN MORE IN LN WITH WARMER GFSLR SOLUTION BUT UKMO STILL HINTING AT COOLER SCENARIO WITH BOUNDARY WELL SOUTH. NEEDLESS TO SAY...CONFIDENCE LOW AT THIS POINT...AND NEED TO SEE MORE CONSISTENCY IN LONG RANGE GUIDANCE. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ JPR/MPK mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 316 AM EDT SUN MAY 2 2004 COORD WITH GYX...THANX FOR THE CALL. WAVE OF LOW PRESS TO RIDE UP ALONG A CF JUST TO THE WEST OF THE FA TODAY. THIS FRONTAL SYS TO MOVE SLOWLY EAST ACRS THE FA TONITE AND ON MON AS MORE WAVES OF LOW PRESS RIDE UP ALONG IT. ANOTHER WAVE OF LOW PRESS TO RIDE UP THIS CF TO THE EAST OF THE FA ON MON NITE...THEN HI PRESS TO START TO BUILD IN ACRS THE FA ON TUE. UPR TROF TO MOVE ACRS THE FA ON MON NITE/TUE. 00-02Z 20KM "DEVELOPMENT" RUC SHOWS TEMPS TO GET UP INTO THE M60S-L70S TODAY WITH SOUTHERLY SFC WINDS AT 5-15G25 KTS. T1MAX TEMPS ARE BASICALLY 75-80F TODAY. FEW TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON THIS DATA. LATER SHIFTS WILL NEED TO WATCH TEMPS IN THE ST LAW VLY TODAY...FOR IF THE CF SAGS FAR ENUFF TO THE SE IT COULD BE SIGNIFICANTLY COOLER IN THIS PART OF THE FA. RUC/ETA/NGM/GPS IPW SITES SHOW PW VALUES TO BE 1-1.4" ACRS THE FA TODAY AND INTO TONITE. RUC SHOWS ONLY WIDELY SCT PCPN ACRS THE FA TODAY WITH MOCLDY SKIES OTRW. BUFCAN/88D MOSAIC SHOWS THAT MUCH OF THE PCPN ASSOCIATED WITH THE NEXT FRONTAL SYS IS BEHIND IT. WK H85 WAA TO TAKE PLACE ACRS THE FA TODAY...THEN CAA TONITE...AND WK CAA ON MON THRU TUE. H85 TEMPS TO GO NEGATIVE ACRS THE FA BY AROUND 12Z TUE. SOME LOW-LVL MSTR ADVECTION TO TAKE PLACE ACRS THE FA TONITE AND ON MON. LOW-LVL MSTR TO CONT TO LINGER ACRS THE FA TODAY THRU TUE. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA ON TUE. SOME MID-LVL MSTR TO AFFECT THE FA TODAY...THEN BETTER MID-LVL MSTR ACRS THE FA TONITE THRU MON NITE. PW VALUES ACRS THE FA LOOK TO BE AROUND AN INCH ON MON...0.5-1" ON MON NITE...AND BLO 0.5" ON TUE. RUC/ETA CAPES TO BE AOB 500 J/KG ACRS THE FA TODAY. NOTED PARTS OF THE WRN FA IN SPC DAY ONE SLIGHT RISK OF SVR TSTMS. ENVIRONMENT ACRS THE FA INTO TONITE APPEARS TO BE MODERATELY TO HIGHLY SHEARED WITH LOW INSTABILITY AND WET-BULB ZERO HTS AROUND 10 KFT. WITH LACK OF GOOD LOW AND MID-LVL INSTABILITY AND GOOD MID-LVL DRY AIR ACRS THE FA FEEL THAT CHC FOR SVR WX IS MINIMAL INTO TONITE. WILL CONT WITH THE MENTION OF NON-SVR TSTMS IN THE FCST INTO TONITE. HAVE TAPERED POPS FROM WEST (HIGHEST) TO EAST (LOWEST) TODAY...WITH THE OPPOSITE TAPERING ON MON. HIR POPS IN THE GOING FCST FOR TONITE LOOK PRETTY GOOD. WILL GO WITH SOME LINGERING PCPN ACRS THE ENTIRE FA (AND MOSTLY CHC POPS) ON MON NITE FOR NOW. LATER SHIFTS WILL NEED TO WATCH FOR A FURTHER TREND TO LINGER THE PCPN ACRS THE FA LONGER. IF IT ENDS UP LINGERING TOO LONG...WE/LL NEED TO START TO WORRY ABOUT SOME P-TYPE ISSUES EVENTUALLY. T1MIN TEMPS ARE IN THE M40S-50S TONITE AND BASICALLY AROUND 30F ON MON NITE. T1MAX TEMPS ARE BASICALLY 55-65F ON MON. NO CHANGES TO THE GOING FCST BEYOND TUE FOR NOW. PRELIM WRK ZONES AND ISC GRIDS AVAILABLE. FINAL ZFP BY 4 AM. .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ MURRAY vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 10 AM EDT SUN MAY 2 2004 ...CONCERN FOR STRONG TO SEVERE THUNDERSTORMS AGAIN THIS EVENING... .DISCUSSION... CURRENT OBS AND ADAS MESOSCALE ANALYSIS SHOWS SOUPY ATM IN PLACE WITH SOLAR HEATING CONTRIBUTING TO STRONG INSTABILITY DURING THE AFTERNOON. RUC40 SHOWS FORECAST LI -8 ACROSS OUR NORTHERN HALF OF FA. SCATTERED SHOWERS EXPECTED TO DEVELOP BY MIDDAY...MOVE NORTHWARD AND DEVELOP INTO THUNDERSTORMS AS CONVECTION DEEPENS. WITH A MORE SOUTHERLY FLOW IN THE LOW LEVELS TODAY...WE EXPECT A SLOWER EAST COAST SEA BREEZE PENETRATION WITH SEA BREEZE COLLISION OCCURRING A LITTLE FARTHER EAST THAN LAST COUPLE DAYS...ON THE EAST SIDE OF THE PENINSULA. ADDITIONAL BOUNDARIES FROM OVERNIGHT CONVECTION ARE LIKELY LURKING WITH A PRE-FRONTAL BAND OF CONVECTION MOVING QUICKLY EAST ACROSS THE EASTERN GULF OF MEX. HOWEVER...THIS LINE APPEARS TO BE WEAKENING AS IT MOVES OUT FROM UNDERNEATH THE UPPER SUPPORT. THE MAIN SHOW WILL HOLD OFF UNTIL THE EVENING WHEN THE SEA BREEZE COLLISION OCCURS. PRIMARY CONCERN IS FOR STRONG TO SEVERE CONVECTION CONTAINING DAMAGING WINDS...HAIL AND EXCESSIVE LIGHTNING MAINLY NORTH OF A LINE FROM CAPE CANAVERAL TO KISSIMMEE. VERY HEAVY RAIN CAN ALSO BE EXPECTED. LAKE COUNTY HAS HAD ABUNDANT RAINS LAST COUPLE NIGHTS AND THEY ARE MUCH MORE SUSCEPTIBLE TO FLOODING SHOULD HEAVY RAINS RETURN. HOWEVER...THE COLLISION IS EXPECTED TO OCCUR EAST OF LAKE COUNTY WHERE NOT AS MUCH ANTECEDENT RAINFALL HAS OCCURRED. WILL UPDATE GRAPHICAL AND TEXT FORECAST TO INDICATE STRONG STORMS THIS EVENING AND INCREASE POPS FROM DAB TO MCO...OVER TO TIX. && MARINE... SMALL CRAFT EXERCISE CAUTION WILL BE CONTINUED AS TREND OF WIND AND SEAS HAS CONTINUED WITH BUOY 009 INDICATING SOUTH WINDS AT 14 GUSTING 18 KNOTS AND 5FT SEAS WITH A 5 TO 6 SECOND PERIOD. RUC40 INDICATES WINDS SHOULD BE SUSTAINED IN THE 15 TO 20 KT RANGE THIS AFTERNOON IN RESPONSE TO TIGHTENING PRESSURE GRADIENT AHEAD OF THE APPROACHING FRONT AND THE DEVELOPMENT OF A STRONG SEA BREEZE. SEAS SHOULD STAY IN THE 5 TO 6 FOOT RANGE WHICH COMBINED WITH THE SHORT PERIOD WILL MAKE FOR ROUGH CONDITIONS FOR SMALL CRAFT. SCATTERED THUNDERSTORMS MAY MOVE OUT OF THE COASTAL WATERS NORTH OF CAPE CANAVERAL BY LATE AFTERNOON OR EARLY EVENING. && .MLB WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SHORT TERM...KELLY LONG TERM....HAGEMEYER fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1130 AM EDT SUN MAY 2 2004 .UPDATE... 12Z RAOBS/WATER VAPOR LOOP SHOW UPPER TROUGH OVER THE WESTERN GREAT LAKES...WITH 300MB JET JUST OVER LOWER MICHIGAN. SURFACE ANALYSIS SHOWS WAVE JUST WEST OF THE APPALACHIANS...LIFTING INTO THE LOWER GREAT LAKES. DECENT NORTHERLY GRADIENT REMAINS BEHIND THIS LOW. REGIONAL RADARS SHOW A LARGE AREA OF LIGHT PRECIP HOLDING ON ACROSS SOUTHEAST MICHIGAN. UPDATE FOCUS WILL BE WITH DIMINISHING PRECIP CHANCES AS THIS SYSTEM CONTINUES NORTHEAST. GOOD LIFT ACROSS SOUTHEAST MICHIGAN FROM FGEN/UPPER DIVERGENCE. 12Z RUC SHOWS THE BETTER BAND OF 850MB FRONTOGENESIS ALIGNED WITH THE CURRENT AREA OF PRECIP...AND WEAKENS THIS FEATURE DURING THE DAY AS IT LIFTS NORTHEAST WITH THE SYSTEM. THIS STILL SEEMS REASONABLE AS INTENSITY OF REFLECTIVITIES HAS BEEN VERY SLOWLY DIMINISHING DURING THE MORNING. CEILINGS HAVE CONTINUED TO DROP AND REMAIN MVFR ACROSS MUCH OF THE CWA. HOWEVER WITH BETTER SUBSIDENCE/DRYING UPSTREAM...WESTERN LOW HAS SCATTERED OUT NOT EVEN LOW CLOUDS BUT ALSO MUCH OF THE MID CLOUDS. COLD AIR CONTINUES TO FILTER ACROSS THE STATE...AND EVEN WITH SOME DRY ADVECTION TEMP/DEWPOINT PROFILES STILL SUPPORT ADDITIONAL CU...AND POTENTIAL FOR A SHOWER OR TWO. OVERALL THE FORECAST LOOKS ON TRACK...AND WILL JUST UPDATE TO FRESHEN TIMING AND WORDING FOR PRECIP. TEMPERATURES HAVE STRUGGLED TO CLIMB THIS MORNING WITH CLOUDS AND WEAK COLD ADVECTION CONTINUING ACROSS THE CWA...AND ARE NEARLY 20F BELOW NORMAL. IT ACTUALLY FEELS WORSE...WITH A 15MPH NORTH WIND AND A COLD RAIN. CURRENT HIGH TEMP GRID GENERALLY RANGES FROM THE MID 40S NORTH TO NEAR 50 SOUTHEAST. TEMPERATURES AT DETROIT HAVE REMAINED PRETTY STEADY NEAR 40F. EXPECT SOME RECOVERY ONCE PRECIP ENDS...BUT STILL WILL CUT HIGHS BACK A FEW DEGREES BASED ON THE LOW-LEVEL THERMAL TROUGH FINALLY REACHING THE FAR SOUTHEASTERN CWA. && BRAVENDER .PREV DISCUSSION...325 AM EDT SUN MAY 2 2004 AN EXTENSIVE AREA OF RAIN, AS EXPECTED, OVER THE SOUTHERN HALF OF THE STATE WITH A SHARP CUT OFF ACROSS NORTHERN LOWER. DEWPOINTS ARE LOWER NORTH OF THE CWA WHICH COULD ADVECT SOUTH AND BRING A LITTLE WET SNOW TO SPOTS ACROSS THE FAR NORTH. OTHERWISE, DEPARTING JET RESULTING IN DIVERGENCE ACROSS SOUTHEAST LOWER WILL LINGER THROUGH THE EARLY MORNING WITH A GRADUAL TAPERING OFF FROM WEST TO EAST. THIS WILL BE OUR FIRST ISSUE WITH TIMING THE DEPARTURE OF THIS RAIN. NEARLY A FULL LATITUDE TROF HAS EVOLVED (THIS IS MAY, RIGHT?) AND NEW MODEL TRENDS TOWARD A CUT OFF LOW AS WE HEAD INTO MONDAY OVER THE GREAT LAKES. SURFACE WAVE LIFTING NORTHEAST TOWARD UPSTATE NEW YORK WITH DEFORMATION AXIS ACROSS SOUTHEAST LOWER WILL GRADUALLY MIGRATE EAST THIS MORNING. WITH SUCH A DEEP TROF, IT MAY TAKE AWHILE FOR THIS RAIN TO EXIT THE CWA. MODEL SOLUTIONS ARE IN AGREEMENT AND WE WILL SLOWLY TAPER THINGS OFF DURING THE COURSE OF THE MORNING. AS POSITION OF UPPER JET TRANSLATES EAST AND DEEP CYCLONIC FLOW SETS UP ACROSS THE REGION, THE CHANCE OF SHOWERS WILL REMAIN THIS AFTERNOON. TEMPERATURES WILL BE TRICKY AS THICKNESSES SUGGEST A NEARLY STEADY/SLOW CLIMB... IN OTHER WORDS HOLDING INTO THE 40S. SOUNDINGS FOR TONIGHT ARE QUITE MOIST AND WITH GOOD REASON. FLOW OFF LAKE HURON AND CONSIDERABLE WET GROUND WOULD SUPPORT MORE STRATUS. FURTHERMORE, BOUNDARY LAYER THRU 60 AGL CONDENSATION PRESSURE DEFICITS REMAIN BELOW 10MBS BUT SURFACE WINDS APPEAR TO REMAIN A BIT HIGH TO PRECLUDE WIDESPREAD FOG. SO CLOUDS WILL PERSIST AND TEMPS OVERNIGHT WILL FALL BUT HOLD JUST ABOVE THE FREEZING MARK FOR MOST LOCATIONS. SINCE IT WILL BE CLOSE, WE WILL CONTINUE WITH THE PATCHY FROST IN THE GRIDS BUT HEADLINES EXPECTED AT THIS TIME. AS UPPER LOW COMES OVERHEAD, 500MB TEMPS OF -30C AND VERTICAL TOTALS INTO THE MID 20S CELSIUS (HIGHEST VALUES TOWARD THE SOUTHERN STATE LINE) SHOULD BE ENOUGH FOR THE CHANCE OF DIURNAL SHOWERS AND AN ISOLATED THUNDERSTORM. ETA SOUNDINGS SHOW STEEP LOW LEVEL LAPSE RATES WITH SURFACE BASED CAPES BETWEEN 100-200 J/KG AND EQUILIBRIUM LEVELS CLIMBING TOWARD 700MB TAPPING INTO SUB -20C AIR. MONDAY NIGHT WITH RIDGING BUILDING IN AT ALL LEVELS, WE SHOULD BE ABLE TO SHED SOME OF THIS CLOUD COVER AND THIS MIGHT SET THE STAGE FOR A COLD NIGHT... WELL AT LEAST INITIALLY. THERE WILL BE A BRIEF PERIOD WHERE DECOUPLING WILL OCCUR TO ALLOW TEMPS TO DROP OFF TO AT OR BELOW FREEZING NORTH AND WEST OF METRO DTW. WE WILL ADD IN PATCHY FROST IN THE GRIDS FOR NOW. WARM ADVECTION REGIME UNFOLDS QUICKLY OVERNIGHT MONDAY INTO TUESDAY WITH THE CHANCE FOR SHOWERS AND THUNDERSTORMS. && .DTX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ BGM EXPERIMENTAL GRAPHICAL FORECASTS ARE AVAILABLE ONLINE AT HTTP://WWW.CRH.NOAA.GOV/DTX (ALL LOWER CASE) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1110 AM EDT SUN MAY 2 2004 .UPDATED... RATHER COMPLEX WEATHER PATTERN FOR THE NEXT 24HRS. THE ISSUES ARE THE UPPER COLD POOL AND THE ASSOCIATED CONVECTION (LINE OF THUNDERSTORMS EAST OF STL)...THE JUXTAPOSITION OF THE UPPER JET CORE...AND THE DEPARTING SURFACE SYSTEM AND IT'S RAINFALL PATTERN. AT 1430Z RADAR LOOPS SHOW AN AREA OF CONVECTION ASSOCIATED WITH IL SHORTWAVE FROM WI INTO W CNTL IL MOVING TO THE SOUTH SOUTHEAST. IT WAS SNOWING AT MSN AT 14Z ON THE NORTH SIDE OF THE SHORTWAVE WHILE THERE WAS A LINE OF THUNDERSTORMS EAST OF STL MOVING EAST. THERE WAS THE LARGE ARE OF SYSTEM RELATED RAIN OVER OH AND THE EASTERN 1/3 OF LOWER MICHIGAN WHICH WAS MOVING LARGELY TO THE EAST. SKIES HAVE CLEARED OVER THE WRN CWA WHILE LAYER CLOUDS REMAIN OVER THE EASTERN CWA. FROST/FREEZE ISSUE IS STILL THERE. I HAVE NOT RESOLVED THE CLOUD OVER ISSUE TONIGHT WHICH WILL BE THE DIFFERENCE BETWEEN LOWS BELOW FREEZING AND A FREEZE OR LOWS IN THE MID TO UPPER 30S. SO FOR NOW WILL HAVE PARTLY CLOUDY WEST AND MOSTLY CLOUDY EAST AND CALL THAT GOOD. I AM LEANING IN THE DIRECTION OF A FREEZE WEST AND PATCHY FROST EAST TOWARD MORNING BASED ON THE RUC AND LATEST ETA DATA (WESTERN SECTIONS ON THE COLD SIDE OF THE UPPER JET RESULTING IN SUBSIDENCE AND DRY AIR). FOR NOW I WILL NOT ISSUE A FREEZE WARNING NOW BUT I AM LEANING TOWARD ONE FOR TONIGHT WEST. THIS AFTERNOON...THE WESTERN CWA WILL BE ON THE COLD SIDE OF THE JET CORE AND WILL HAVE CONSIDERABLE SUBSIDENCE (AS SEEN ON THE GRB 12Z SOUNDING BETWEEN 900 AND 700 MB). THE RUC CU ROUTINE SUGGEST LIMITED CU OVER THE WESTERN CWA AS 850MB DEW POINT PLUNGE TO BELOW -20C! HARD TO GET MUCH FROM THAT. THAT WILL ALSO LIMIT ANY CONVECTION FROM THE SHORTWAVE OVER IL MOVING EAST WITH THE UPPER TROUGH AND UPPER COLD POOL MOVING IN (VERTICAL TOTAL REACH 27C BY 00Z OVER THE LAKE SHORE COUNTIES). OVER THE EASTERN CWA...I WILL KEEP SCT SHOWERS IN THE FORECAST SINCE MODEL SOUNDING SUGGEST IF THE SFC TEMP GETS INTO THE LOWER 50S IT WOULD NOT BE OUT OF THE QUESTION TO GET CONVECTIVE CLOUDS HIGH ENOUGH TO RESULT IN SHOWER. AS FOR SFC HIGHS TODAY...WILL GO 50 TO 55 WEST CNTL AND 45 TO 50 NEAR THE LAKE SHORE...NORTH AND EAST. THIS IS BASED ON FORECAST CLOUD OVER...RUC SFC TEMPS...AND 1000/925MB THICKNESS TOOL. && .GRR...WATCHES/WARNINGS/ADVISORIES...SMALL CRAFT ADVISORY ENTIRE LAKESHORE THIS AFTERNOON. && WDM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 1128 AM EDT SUN MAY 2 2004 IN SHORT-TERM, SHARP COLD FRONT CONTINUES TO MOVE EASTWARD AT 10 MPH THROUGH THE UPPER OHIO VALLEY. BY 15Z/11AM EDT/ COLD FRONT HAD REACHED KFKL-KBVI-KPKB. BY 21Z/5 PM/ THE COLD FRONT SHOULD REACH KDUJ-KLBE-KMGW. PER RUC, RADAR CONTINUES TO SHOW MOST OF THE PRECIPITATION IS POST-FRONTAL. HOWEVER PER RUC, PRE-FRONTAL DAYTIME HEATING SHOULD INITIATE ENOUGH INSTABILITY TO FIRE THUNDERSTORMS IN CONVERGENCE AHEAD OF THE FRONT...AND THERE IS FAVORABLE WIND FLOW FOR SEVERE WIND GUST POTENTIAL. SEE SPC DISCUSSION. SO CONTINUE TO MENTION FOR POINTS EAST OF KYNG-KPKB LINE...THE POSSIBILITY OF THUNDERSTORMS THIS AFTERNOON WITH GUSTY/DAMAGING WIND GUSTS AND HEAVY DOWNPOURS. BEHIND FRONT...RAIN AND SHARPLY COOLER TEMPERATURES...DROPPING INTO THE 40S. TONIGHT, KEPT MENTION OF RAIN ENDING EARLY WITH PATCHES OF DRIZZLE AND FOG POSSIBLE LATE. REST UNCHANGED. ...GIORDANO .PBZ WATCHES/WARNINGS/ADVISORIES... PA...NONE. OH...NONE. WV...NONE. MD...NONE. && $$ pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 950 AM EDT SUN MAY 2 2004 .PUBLIC...VERY ACTIVE DAY EXPECTED THIS AFTERNOON WITH ALL THE INGREDIENTS EXPECTED TO COME TOGETHER. THERE WILL BE INCREASING DIVERGENCE ALOFT AHEAD OF AN APPROACHING JET STREAK...DEEP MOISTURE WITH PWATS OVER AN INCH AND A HALF IS IN PLACE...IMPRESSIVE LOW LEVEL CONVERGENCE ESPECIALLY ALONG THE COAST AND EXPECTED RESULTANT SEA BREEZE LATER TODAY...AND LARGE AMOUNTS OF INSTABILITY. CHS AND JAX SOUNDINGS THIS MORNING SHOW LIS ALREADY AROUND -6. AFTER MODIFYING THE SOUNDING IT SHOWS CAPES APPROACHING 3000 J/KG AND LIS OF -7. THIS IS IN GOOD AGREEMENT WITH THE RUC WHICH SHOWS LIS APPROACHING -8 AND CAPES AOA 2000 J/KG LATER THIS AFTERNOON. WITH ONLY SMALL AMOUNTS OF SHEAR...LOCALLY HEAVY RAIN...HAIL AND DAMAGING WINDS WILL BE THE PRIMARY THREATS THIS AFTERNOON. WILL SEND OUT UPDATES TO GRIDS AND ZONES SHORTLY MAINLY TO INCREASE POPS LATER TODAY AND POSSIBLY MENTION THE POTENTIAL FOR SEVERE STORMS. && .MARINE...WINDS AND SEAS WILL CONTINUE TO INCREASE THROUGH THE AFTERNOON AHEAD OF THE APPROACHING COLD FRONT. CURRENT FORECAST LOOKS GREAT THIS MORNING...WITH ONLY A FEW MINOR CHANGES EXPECTED TO THE MARINE GRIDS OR FORECASTS THIS MORNING. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...SMALL CRAFT ADVISORY AMZ374. SC...SMALL CRAFT ADVISORY AMZ330-350. && $$ JR sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 955 AM EDT SUN MAY 2 2004 .DISCUSSION... SCATTERED SHOWERS CURRENTLY FALLING ACROSS THE CWA W/ HEAVIEST CONCENTRATIONS OVER THE DACKS WEST INTO THE ST LAW. VALLEY. NO LIGHTNING BEING DETECTED IN ANY OF CURRENT ONGOING PRECIP MVG NORTH THRU REGION. CD FRONT CURRENTLY MEANDERING OVER WESTERN NY W/ SHORT WV MOSTLY ALONG FRONT IN WESTERN NY/PA. MOST PRECIP STILL LOCATED BEHIND FRONT. TEMPS ACROSS REGION MAINLY IN 60S W/ FEW RANDOM 70S. KMSS IN THE 50S WHICH IS JUST ON/BEHIND CURRENT POSITION OF FRONT. WILL HAVE TO UPDATE ZONES TO CLEAN UP WORDING AND ADJUST TEMPS/WINDS...ESPECIALLY IN ST LAW VALLEY WHERE WND SHIFT IS TIGHT. WINDS THERE SHOULD SHIFT AROUND A BIT AS SHORT WV MVS NORTH ALONG FRONT DURING THE DAY. BREAKS IN CLDS OVER THE NORTHEAST SHOULD PROVIDE SOME WARMING IN AREAS W/ THE POSSIBILITY OF MAKING ATMOSPHERE UNSTABLE FOR A POSSIBLE TS...SO WILL KEEP MENTION IN ZONES. && .PREVIOUS DISCUSSION... COORD WITH GYX...THANX FOR THE CALL. WAVE OF LOW PRESS TO RIDE UP ALONG A CF JUST TO THE WEST OF THE FA TODAY. THIS FRONTAL SYS TO MOVE SLOWLY EAST ACRS THE FA TONITE AND ON MON AS MORE WAVES OF LOW PRESS RIDE UP ALONG IT. ANOTHER WAVE OF LOW PRESS TO RIDE UP THIS CF TO THE EAST OF THE FA ON MON NITE...THEN HI PRESS TO START TO BUILD IN ACRS THE FA ON TUE. UPR TROF TO MOVE ACRS THE FA ON MON NITE/TUE. 00-02Z 20KM "DEVELOPMENT" RUC SHOWS TEMPS TO GET UP INTO THE M60S-L70S TODAY WITH SOUTHERLY SFC WINDS AT 5-15G25 KTS. T1MAX TEMPS ARE BASICALLY 75-80F TODAY. FEW TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON THIS DATA. LATER SHIFTS WILL NEED TO WATCH TEMPS IN THE ST LAW VLY TODAY...FOR IF THE CF SAGS FAR ENUFF TO THE SE IT COULD BE SIGNIFICANTLY COOLER IN THIS PART OF THE FA. RUC/ETA/NGM/GPS IPW SITES SHOW PW VALUES TO BE 1-1.4" ACRS THE FA TODAY AND INTO TONITE. RUC SHOWS ONLY WIDELY SCT PCPN ACRS THE FA TODAY WITH MOCLDY SKIES OTRW. BUFCAN/88D MOSAIC SHOWS THAT MUCH OF THE PCPN ASSOCIATED WITH THE NEXT FRONTAL SYS IS BEHIND IT. WK H85 WAA TO TAKE PLACE ACRS THE FA TODAY...THEN CAA TONITE...AND WK CAA ON MON THRU TUE. H85 TEMPS TO GO NEGATIVE ACRS THE FA BY AROUND 12Z TUE. SOME LOW-LVL MSTR ADVECTION TO TAKE PLACE ACRS THE FA TONITE AND ON MON. LOW-LVL MSTR TO CONT TO LINGER ACRS THE FA TODAY THRU TUE. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA ON TUE. SOME MID-LVL MSTR TO AFFECT THE FA TODAY...THEN BETTER MID-LVL MSTR ACRS THE FA TONITE THRU MON NITE. PW VALUES ACRS THE FA LOOK TO BE AROUND AN INCH ON MON...0.5-1" ON MON NITE...AND BLO 0.5" ON TUE. RUC/ETA CAPES TO BE AOB 500 J/KG ACRS THE FA TODAY. NOTED PARTS OF THE WRN FA IN SPC DAY ONE SLIGHT RISK OF SVR TSTMS. ENVIRONMENT ACRS THE FA INTO TONITE APPEARS TO BE MODERATELY TO HIGHLY SHEARED WITH LOW INSTABILITY AND WET-BULB ZERO HTS AROUND 10 KFT. WITH LACK OF GOOD LOW AND MID-LVL INSTABILITY AND GOOD MID-LVL DRY AIR ACRS THE FA FEEL THAT CHC FOR SVR WX IS MINIMAL INTO TONITE. WILL CONT WITH THE MENTION OF NON-SVR TSTMS IN THE FCST INTO TONITE. HAVE TAPERED POPS FROM WEST (HIGHEST) TO EAST (LOWEST) TODAY...WITH THE OPPOSITE TAPERING ON MON. HIR POPS IN THE GOING FCST FOR TONITE LOOK PRETTY GOOD. WILL GO WITH SOME LINGERING PCPN ACRS THE ENTIRE FA (AND MOSTLY CHC POPS) ON MON NITE FOR NOW. LATER SHIFTS WILL NEED TO WATCH FOR A FURTHER TREND TO LINGER THE PCPN ACRS THE FA LONGER. IF IT ENDS UP LINGERING TOO LONG...WE/LL NEED TO START TO WORRY ABOUT SOME P-TYPE ISSUES EVENTUALLY. T1MIN TEMPS ARE IN THE M40S-50S TONITE AND BASICALLY AROUND 30F ON MON NITE. T1MAX TEMPS ARE BASICALLY 55-65F ON MON. NO CHANGES TO THE GOING FCST BEYOND TUE FOR NOW. PRELIM WRK ZONES AND ISC GRIDS AVAILABLE. FINAL ZFP BY 4 AM. .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ JN vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 341 PM CDT SUN MAY 2 2004 .DISCUSSION... AT 20Z...SCATTERED THUNDERSTORMS WERE FOUND ACROSS MUCH OF MISSOURI...AS THE UPPER COLD POOL/VORT MAX NOSED INTO WESTERN MISSOURI. RUC BEST LI VALUES ACROSS THE FORECAST AREA WERE GENERALLY -1 TO -3. THIS AREA OF UPPER LEVEL INSTABILITY WILL GRADUALLY TRANSLATE EASTWARD FOR THE REMAINDER OF THE AFTERNOON...AND LINGER OVER MY FAR EASTERN COUNTIES DURING THE EVENING. SMALL HAIL HAD BEEN REPORTED THE STORMS OVER SOUTHWEST MISSOURI...HOWEVER STRONG WINDS WERE THE MAIN THREAT...AS DAMAGE WAS REPORTED IN THE JOPLIN AREA. THIS IS NOT SURPRISING...AS THE KTOP 12Z SOUNDING SHOWED AN INVERTED V-TYPE SOUNDING. WILL TWEAK GRIDDED POPS FOR THIS AFTN/EVE WITH CURRENT RADAR TRENDS. ANY LINGERING PRECIPITATION SHOULD END THIS EVENING ACROSS SOUTH-CENTRAL MISSOURI...AS INSTABILITY DECREASES AND SUBSIDENCE BEHIND THE SYSTEM INCREASES. TEMPERATURES WILL BE THE MAIN FORECAST CHALLENGE OVERNIGHT. GOOD RADIATIONAL COOLING IS EXPECTED OVER THE FORECAST AREA...AS HIGH PRESSURE BUILDS AT THE SURFACE...BRINGING LIGHT WINDS AND CLEARING SKIES. LOOKING AT THE NUMERICAL GUIDANCE...MET/MAV/FWC ALL SHOW LOWS IN THE MIDDLE TO UPPER 30S. PREVIOUS GRIDS HAD A GOOD HANDLE ON THIS...I ONLY TWEAKED TEMPERATURES DOWN A DEGREE IN MOST SPOTS. WITH MOST LOCATIONS NOT DROPPING INTO THE LOWER 30S...IT LOOKS LIKE FROST WILL BE PATCHY LATE TONIGHT...WITH THE GREATEST LIKELIHOOD OF FROST IN LOW-LYING AREAS. THEREFORE...DECIDED AGAINST A FROST ADVISORY...BUT WILL INCLUDE PATCHY FROST WORDING IN THE ZONES. THE REMAINDER OF THE WEEK LOOKS DRY WITH A NICE WARMING TREND. NUDGED TEMPERATURES UPWARD A FEW DEGREES BY MID-WEEK...AS HIGHS ACROSS SOUTHEAST KANSAS AND THE MISSOURI OZARKS LOOK TO BE WELL INTO THE 80S. && .AVIATION... SCATTERED CONVECTION WILL AFFECT THE FORECAST AREA THROUGH THE REMAINDER OF THE AFTERNOON...BUT SHOULD COME TO AND END AT THE KJLN AND KSGF SITES BY 00Z. CEILINGS WITH THE STORMS ARE GENERALLY 2 TO 3 THOUSAND FEET WITH VISIBILITIES OF 2 TO 3 MILES. AFTER THE STORMS PASS...VFR CONDITIONS ARE EXPECTED FOR THE FORESEEABLE FUTURE. && .SGF WATCHES/WARNINGS/ADVISORIES... .MO...NONE. .KS...NONE. $$ WFO SGF mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 125 PM EDT SUN MAY 2 2004 .DISCUSSION... TONIGHT...ETA IS A LITTLE SLOWER WITH THE FRONT THAN THE GFS...AND THE ETA HAD A BETTER POSITION OF THE FRONT SLIGHTLY FARTHER WEST. WILL LEAN TOWARD THE ETA AND SHOW A BAND OF CONVECTION ALONG THE SURFACE FRONT CROSSING THE AREA BETWEEN MIDNIGHT AND SUNRISE. RUC INDICATES CAPE APPROACHING 1000 J/KG AHEAD OF THE FRONT...0-1 KM HELICITY NEAR 200 M2/S2...AND EHI VALUES NEAR 2...INDICATING A SUPERCELL/POTENTIAL TORNADO THREAT THROUGH THE EVENING. FLASH FLOODING MAY ALSO BE A THREAT AS A DEEP SOUTHWEST FLOW MAY LEAD TO TRAINING OF CELLS. TOMORROW/TUESDAY...WILL CARRY LIKELY POPS IN THE EAST IN THE MORNING AS THE FRONT BE SLOW TO MOVE EAST. THE 850 MB TROUGH LAGS THE SURFACE FRONT...CROSSING THE AREA IN THE LATE AFTERNOON. LAPSE RATES STEEPEN WITH COOLING 500 MB TEMPS ALONG WITH PVA AHEAD OF THE STRONG VORT MAX...THOUGH THE COOLEST MIDLEVEL TEMPS AND MOX VORTICITY PASS JUST TO OUR NORTH. WITH SOME PARTIAL CLEARING IN THE MORNING TO AID IN DESTABILIZATION...EXPECT SOME ELEVATED CONVECTION IN THE AFTERNOON...SO WILL HAVE HIGH CHANCE POPS AT THAT TIME. CLEARING SKIES MONDAY NIGHT AND TUESDAY AS THE UPPER TROUGH PASSES. TEMPS COOL BEHIND THE FRONT TO HIGHS IN THE MID/UPPER 60S TOMORROW AND TUESDAY...LOWS IN THE MID/UPPER 40S TOMORROW NIGHT. WEDNESDAY THROUGH SUNDAY...FRONT APPROACHES FROM THE NORTH ON WEDNESDAY WITH LIMITED MOISTURE IN A NORTHWEST FLOW ALOFT. PREFER THE HPC AND 06Z GFS SOLUTIONS WHICH KEEP THE FRONT TO OUR NORTH. THUS WILL HAVE TEMPS WEDNESDAY AND THURSDAY ABOVE 00Z GFS MOS GUIDANCE...MID/UPPER 70S WED TO NEAR 80/LOWER 80S THU. DOWNSLOPE FLOW AND 1000-850 THICKNESS VALUES BETWEEN 1385M AND 1400M GIVES HIGHS IN THE MID/UPPER 80S FOR FRIDAY THROUGH SUNDAY. RIDGE ALOFT AND SURFACE HIGH TO OUR SOUTH WILL BE SLOW TO MOVE...SO IT LOOKS LIKE AN EXTENDED WARM AND DRY PERIOD IS ON THE WAY. && .RAH WATCHES/WARNINGS/ADVISORIES... NC...NONE. && $$ DGS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 326 PM EDT SUN MAY 2 2004 .DISCUSSION... FOR TONIGHT, RADAR DATA AND RUC SHOW POST-FRONTAL RAIN BAND WILL CONTINUE MOVING EAST AT 10 MPH. SO EXPECT RAIN TO END OVER MOST OF THE UPPER OHIO VALLEY EARLY TONIGHT. ACROSS NORTHWEST PENNSYLVANIA AND THE APPALACHIAN MOUNTAINS, PATCHY DRIZZLE MAY LINGER PAST MIDNIGHT. ALSO LATE TONIGHT, PATCHY FOG WAS MENTIONED FOR THE ENTIRE UPPER OHIO VALLEY, DUE TO THE EXPECTED LOW LEVEL SATURATED CONDITIONS ASSOCIATED WITH THE LATE DAY RAIN AND COOL DOWN. FOR MONDAY, ETA AND GFS CONTINUE TO SHOW A DEEP UPPER TROUGH MOVING THROUGH THE UPPER OHIO VALLEY. HOWEVER, ETA SOUNDINGS SHOW MID-LEVEL LAPSE RATES FAIRLY STABLE. SO EXPECT BROKEN TO OVERCAST STRATOCUMULUS, BUT ANY DAYTIME-HEATING-INDUCED SHOWERS IN THE AFTERNOON SHOULD BE LITTLE MORE THAN SPRINKLES. FOR MONDAY NIGHT, SKIES WILL BE CLEARING, AND WITH TEMPERATURES DROPPING INTO THE 30-35 RANGE, SCATTERED FROST WAS MENTIONED IN THOSE AREAS THAT HAVE STARTED THE GROWING SEASON, THAT IS, GENERALLY WEST AND SOUTH OF PITTSBURGH. FOR THE LONG-TERM, STARTING TUESDAY, THE UPPER JET FLOW BECOMES MORE ZONAL, WITH THE PACIFIC COAST RIDGE BUILDING INTO THE CENTRAL PLAINS BY THE WEEKEND. CONSEQUENTLY, THERE SHOULD BE A LATE WEEK WARM UP. THE GFS SHOWS WEAK SYSTEMS BRINGING A CHANCE OF SHOWERS LATE TUESDAY INTO WEDNESDAY, AND AROUND SUNDAY. ...GIORDANO .PBZ WATCHES/WARNINGS/ADVISORIES... PA...NONE. OH...NONE. WV...NONE. MD...NONE. && $$ pa AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE CHARLESTON SC 100 PM EDT SUN MAY 2 2004 .UPDATE...WILL SEND UPDATE FOR SEVERE THUNDERSTORM WATCH FOR INLAND-MOST ZONES OF SC/GA UNTIL 2300Z...AKA 7PM. && .PUBLIC...VERY ACTIVE DAY EXPECTED THIS AFTERNOON WITH ALL THE INGREDIENTS EXPECTED TO COME TOGETHER. THERE WILL BE INCREASING DIVERGENCE ALOFT AHEAD OF AN APPROACHING JET STREAK...DEEP MOISTURE WITH PWATS OVER AN INCH AND A HALF IS IN PLACE...IMPRESSIVE LOW LEVEL CONVERGENCE ESPECIALLY ALONG THE COAST AND EXPECTED RESULTANT SEA BREEZE LATER TODAY...AND LARGE AMOUNTS OF INSTABILITY. CHS AND JAX SOUNDINGS THIS MORNING SHOW LIS ALREADY AROUND -6. AFTER MODIFYING THE SOUNDING IT SHOWS CAPES APPROACHING 3000 J/KG AND LIS OF -7. THIS IS IN GOOD AGREEMENT WITH THE RUC WHICH SHOWS LIS APPROACHING -8 AND CAPES AOA 2000 J/KG LATER THIS AFTERNOON. WITH ONLY SMALL AMOUNTS OF SHEAR...LOCALLY HEAVY RAIN...HAIL AND DAMAGING WINDS WILL BE THE PRIMARY THREATS THIS AFTERNOON. WILL SEND OUT UPDATES TO GRIDS AND ZONES SHORTLY MAINLY TO INCREASE POPS LATER TODAY AND POSSIBLY MENTION THE POTENTIAL FOR SEVERE STORMS. && .MARINE...WINDS AND SEAS WILL CONTINUE TO INCREASE THROUGH THE AFTERNOON AHEAD OF THE APPROACHING COLD FRONT. CURRENT FORECAST LOOKS GREAT THIS MORNING...WITH ONLY A FEW MINOR CHANGES EXPECTED TO THE MARINE GRIDS OR FORECASTS THIS MORNING. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...SMALL CRAFT ADVISORY AMZ374. SEVERE THUNDERSTORM WATCH 146 GAZ087-088-099-100-114-115. SC...SMALL CRAFT ADVISORY AMZ330-350. SEVERE THUNDERSTORM WATCH 146 SCZ040. && $$ JR sc