AREA FORECAST DISCUSSION...CORRECTED SYNOPSIS NATIONAL WEATHER SERVICE PHOENIX AZ 255 PM MST MON SEP 19 2005 SOUTHWEST AND SOUTH-CENTRAL ARIZONA...AND SOUTHEAST CALIFORNIA FORECAST DISCUSSION .SYNOPSIS... A LOW PRESSURE SYSTEM OFF THE SOUTHERN CALIFORNIA COAST WILL MOVE NORTHEAST TONIGHT AND TUESDAY. MOISTURE FROM THE SOUTH OF OUR AREA WILL INCREASE...BRINGING A SLIGHT CHANCE OF PRECIPITATION. THE LOW PRESSURE SYSTEM WILL MOVE NORTHEAST ACROSS NEVADA ON WEDNESDAY. THIS WILL LIMIT THE SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO THE HIGHER TERRAIN NORTH AND EAST OF THE PHOENIX AREA WEDNESDAY. A LARGE LOW PRESSURE SYSTEM FROM THE GULF OF ALASKA WILL BRING COOLER AND BREEZY WEATHER BY THE END OF THE WEEK...AND ESPECIALLY THIS COMING WEEKEND. THE AUTUMNAL EQUINOX WILL OCCUR THIS THURSDAY AT 323 PM. && .DISCUSSION... LOWER LEVELS STILL RATHER DRY ALTHOUGH THE DEW POINTS HAVE COME UP SOMEWHAT IN THE LAST FEW HOURS AT PHOENIX. 18Z SOUNDING INDICATED PRECIP WATER HAS JUMPED TO .88 INCH WITH SOUTHWEST FLOW ALOFT CONTINUING. SURROUNDING AREAS MOISTENED UP AS WELL...AND 88D DATA FROM SE ARIZONA SHOWED THE BULK OF THE PRECIP ACROSS COCHISE COUNTY. AND ISOLATED TSTMS ALSO REPORTED IN THAT AREA BY 20Z. RUC PICKED UP ON AN AREA OF UVV AT 700MB AND GENERATED SOME PRECIP TO THE SOUTH OF PHOENIX BY 00Z. PLENTIFUL MOISTURE CONTINUES ACROSS MEXICO AND BY 06Z WINDS ALOFT LIKELY TO BACK AROUND FURTHER AND MAY SHOW SOME COMPONENT FROM THE SOUTHEAST. WITH MAX TEMPERATURE UP TO NEAR 103 THIS AFTERNOON WE COULD GET AN ISOLATED TSTM OR TWO BY 00Z. GFS STILL SHOWS THE CLOSED LOW OFF THE CALIFORNIA COAST AND THE CENTER OF THE RIDGE OVER TEXAS TONIGHT. BY TUESDAY AFTERNOON RIDGE STAYS NEARLY STNRY WHILE THE LOW LIFTS TO THE NORTHEAST. NO STRONG SYSTEM PROGGED TO ROTATE INTO OUR CWA FROM MEXICO...AND I AM VERY HESITANT TO GO HOG WILD WITH POPS LIKE THE ETA MOS SHOWS FOR KPHX TONIGHT. WILL ALSO KEEP THE GENERAL TRENDS INTACT FOR TUESDAY AND WEDNESDAY AS THE TROF PUSHES EASTWARD AND A DRIER SW FLOW ALOFT IS EXPECTED. HOWEVER...UPPER FLOW IS STRONGER ACROSS N-CENTRAL ARIZONA ON WEDNESDAY AND WITH BETTER JET DYNAMICS...THERE COULD BE AND A BETTER CHANCE OF TSTMS WITH CONTINUED LOW LEVEL MOISTURE IN PLACE. WESTERLY FLOW BECOMES MORE PRONOUNCED BY 12Z FRIDAY MAINLY DUE TO AN APPROACHING SHORT WAVE OVER NORTH CALIFORNIA COAST. THIS SYSTEM CLOSES OFF OVER NEVADA AND NORTHERN CALIFORNIA BY 12Z SATURDAY AND OUR FLOW ALOFT BACKS SOMEWHAT ON SUNDAY. WE WILL NOT INTRODUCE POPS YET FOR THAT PERIOD...ALTHOUGH PORTIONS OF EASTERN AZ LOOK MORE FAVORABLE FOR SOME ACTIVITY. && .AVIATION... DISCUSSION FOR 00Z TAFS. TAFS ADEQUATELY DEPICT CURRENT WEATHER. SEE TAFS PHXTAFPHX...PHXTAFIWA...PHXTAFYUM...LAXTAFBLH AND LAXTAFIPL FOR MORE DETAILED INFORMATION. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && $$ NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT WEATHER.GOV/PHOENIX SIPPLE az AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HANFORD CA 900 AM PDT MON SEP 19 2005 .SHORT TERM FOR THE CENTRAL CALIFORNIA INTERIOR...MAIN FOCUS THIS MORNING REMAINS THE THREAT OF PRECIPITATION OVER THE DISTRICT ON TUESDAY. BEFOREHAND...SOUTHERLY FLOW RESULTING FROM THE CUT OFF LOW OFF THE WEST COAST WILL ADVECT WARM AIR INTO THE DISTRICT TODAY. THIS WARM AIR ADVECTION WILL ONLY ALLOW TEMPERATURES TO RISE A FEW DEG-F ABOVE NORMAL OVER MUCH OF THE CWFA BEFORE TEMPERATURES BEGIN FALLING ON TUESDAY. WINDS WILL NOT BE MUCH OF A FACTOR TODAY AS GRADIENTS FROM SFO TO LAS REMAIN NEAR 1-3MB THIS AFTERNOON AND MOSTLY OFF-SHORE. FURTHERMORE...WHILE THE ATMOSPHERE OVER THE CWFA REMAINS STABLE TODAY...THE TREND IS FOR INCREASING INSTABILITY GOING INTO TUESDAY WITH THE SOUTHERLY SURGE OF SUBTROPICAL MOISTURE. CURRENT FORECAST HAS MOSTLY SUNNY SKIES TODAY WITH PARTLY CLOUDY WORDING OVER THE KERN DESERTS AND MOUNTAINS THIS AFTERNOON. WILL MAINTAIN THIS WORDING OF INCREASING CLOUD COVER BASED ON RUC AND SATELLITE WATER VAPOR ANALYSIS FROM THIS MORNING. OTHERWISE...WILL MAKE NO CHANGES TO THE FORECAST THIS MORNING AS ALL WEATEHR ELEMENTS REMAIN ON TRACK FOR TODAY AND TOMORROW/S EVENTS. && .PREV DISCUSSION...ON TUES...THE UPPER LOW WILL BEGIN TO PUSH INLAND. MODELS IN GOOD AGREEMENT IN THIS...AND SPREAD SCATTERED PRECIP INTO THE REGION FROM SOUTH TO NORTH...WITH THE BEST CHANCES IN THE MTNS. HAVE BUMPED UP POPS ALL AREAS...BUT STAYED BELOW MOS UNTIL SAT PIX ACTUALLY BEGIN TO SHOW MOISTURE GETTING ENTRAINED INTO THE LOW. MODEL QPF/S VARY QUITE A BIT...BUT RANGE FROM 1/2-3/4 INCHES IN THE KERN MTNS...TAPERING OFF FARTHER NORTH. FOR THE VALLEY...QPF/S ARE FROM 1 TO 2 TENTHS. THE LOW WILL MOVE INTO THE GREAT BASIN TUES NITE AND WED...ENDING PRECIP THREAT. TEMPS TUESDAY PROBLEMATIC AND WILL GREATLY DEPEND ON EXTENT OF CLOUDS/PRECIP. HAVE FAVORED THE LOWER GFS NUMBERS AT THIS TIME. SLIGHTLY WARMER WED AS RIDGE BEGINS TO BUILD IN FROM THE WEST. && .AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH AT LEAST 18Z TUESDAY. SPECIFIC DETAILS CAN BE FOUND IN THE TAFS FOR KMCE...KFAT AND KBFL. && $$ WWW.WEATHER.GOV/HANFORD /USE ALL LOWER CASE/ MOLINA/BINGHAM ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 935 AM EDT MON SEP 19 2005 .DISCUSSION... ...RITA FORECAST TO MOVE THROUGH THE FLORIDA STRAITS/KEYS TUE... CURRENTLY/TODAY...WATER VAPOR LOOP AND RUC ANALYSIS SHOW VERY DRY AIR ALOFT WITH MID LEVEL ANTICYCLONE COVERING LOUISIANA/EAST TEXAS AND RIDGE EXTENDING ACROSS NORTH FLORIDA. MORNING SOUNDINGS REFLECT THIS DRIER THAN NORMAL AIR MASS WITH PRECIPITABLE WATER ABOUT 1.35 INCHES. EAST/NORTHEAST GRADIENT FLOW CONTINUES TO TIGHTEN AS TROPICAL STORM RITA MOVES THROUGH THE CENTRAL BAHAMAS. A FEW CONVERGENCE LINES WERE NOTED OVER THE ATLANTIC WATERS BUT RADAR HAS JUST BEEN SHOWING A FEW SHOWERS WITH THE CLOUD LINES...INDICATING THAT DRY AIR CONTINUES TO DOMINATE. BREEZY CONDITIONS SHOULD START TO DEVELOP ALONG THE COAST...ESPECIALLY IN SOUTHERN SECTIONS. CURRENT FORECAST WHICH HAS SLIGHT CHANCE POPS FOR MARTIN/ST LUCIE LOOKS GOOD. ANY SHOWERS THAT OCCUR ELSEWHERE WILL HAVE COVERAGE OF LESS THAN 10 PERCENT AND PLAN TO HANDLE WITH SHORT TERM FORECASTS. DON'T PLAN ANY CHANGES TO THE ZONES. && .MARINE...DETERIORATING BOATING CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS. ONSHORE FLOW WILL GRADUALLY INCREASE DURING THE DAY. WILL BE ADDING SCEC TO THE NORTHERN ZONES. SCA REMAINS IN EFFECT SOUTH OF COCOA BEACH. THE INCREASING WAVE ACTION IS EXPECTED TO LEAD TO A MODERATE RIP CURRENT THREAT...ESPECIALLY SINCE THERE ARE EXISTING CUTS IN THE SANDBARS DUE TO THE HIGH SURF EVENT ABOUT A WEEK AGO. && .MLB WATCHES/WARNINGS/ADVISORIES... ...SMALL CRAFT ADVISORY COCOA BEACH TO JUPITER INLET OUT TO 60 NM THIS AFTERNOON THROUGH TUESDAY EVENING. ...SMALL CRAFT ADVISORY FLAGLER BEACH TO COCOA BEACH OUT TO 60 NM THIS EVENING THROUGH TUESDAY EVENING. && $$ SHORT TERM...LASCODY LONG TERM...HIRSCH fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL 628 AM CDT MON SEP 19 2005 .AVIATION DISCUSSION FOR 12Z TAFS... MAIN AVIATION CONCERN IS THUNDERSTORM TRENDS TODAY. VIGOROUS SHORT WAVE PUNCHING THROUGH MID/UPPER MISSISSIPPI VALLEY THIS MORNING...WITH IMPRESSIVE THERMAL/MOISTURE ADVECTION INTO FORECAST AREA. PROFILER PLOTS AT 850 HPA INDICATES 40-50 KT LOW LEVEL JET ORIENTED FROM SOUTHERN PLAINS INTO MO/IL. BAND OF ELEVATED THUNDERSTORMS IN REGION OF STRONG MOIST CONVERGENCE/THETA-E ADVECTION ON NOSE OF LOW LEVEL JET TO MOVE ACROSS TERMINALS THIS MORNING...WITH LATEST RUC FORECASTS SHIFTING MAIN CONVERGENT AXIS NORTHEAST OF THE AREA AROUND MID MORNING...ALONG WITH CONTINUED VEERING AND GRADUAL WEAKENING OF LOW LEVEL JET. THUS WILL CARRY A FEW HOURS OF VCTS/TEMPO TS FOR ALL TAF SITES THROUGH ABOUT 15 UTC. THEN EXPECT LULL AS MORNING ACTIVITY LIFTS OUT. FORECAST AREA WILL BE IN WARM SECTOR HOWEVER...WITH SFC LOW MOVING ACROSS WI AND TRAILING COLD FRONT NOT ARRIVING UNTIL LATER THIS AFTERNOON. MET/RUC FCST SOUNDINGS INDICATE SIGNIFICANT INSTABILITY TO DEVELOP IF WE CAN GET SOME SUN...WITH SFC DEWPOINTS 65-70 DEG F AND WELL MIXED BOUNDARY LAYER SUPPORTING SBCAPES ON THE ORDER OF 3000 J/KG. SECOND MID LEVEL SHORT WAVE TROUGH AXIS/VORT LOBE APPROACHES CONCURRENT WITH COLD FROPA LATER TODAY...SO HAVE INCLUDED ANOTHER VCTS GROUP FROM ABOUT 21 UTC THROUGH FROPA AT 23-00 UTC. DRYING/SUBSIDENCE SHOULD CLEAR SKIES FAIRLY RAPIDLY BEHIND FRONT THIS EVENING. STRONG GRADIENT AND WELL MIXED BOUNDARY LAYER EXPECTED TO SUPPORT S/SW WINDS GUSTING TO 25 KTS THIS AFTERNOON. WINDSHIFT TO WEST WITH FROPA...THEN VEERING TO 320-340 DEG THIS EVENING BEHIND FRONT. RATZER && .PRELIMINARY DISCUSSION FOR MORNING PACKAGE... MAIN CONCERN THIS PACKAGE THE TS COMING THRU TODAY. AT 05Z MAIN TS STILL WAY BACK IN W IA BUT SCATTERED STUFF DEVELOPING W OF MLI WITH A STRONG VORT LOBE IN CENTRAL IA WITH GOOD 850-700 WARM AIR ADVECTION. MODELS SHOW TWO ENERGY PACKAGES TO COME THRU NEXT 24 HOURS WITH TS CHANCES, THE ONE IN IA NOW AND ONE POSSIBLY THIS EVENING WITH SOME 850-700 COLD AIR ADVECTION ALOFT. LONGER RANGE PICTURE IS ONE OF CONTINUED WARM TEMPS WITH 850 TEMPS 12 OR HIGHER THRU PERIOD WITH ALMOST ALL 16 OR HIGHER AS JET HOLDS TO OUR N WITH A W FLOW AND BY END OF FORECAST TROF DIGS ALONG W COAST TO BRING OUR UPPER FLOW BACK TO SW. NEXT CHANCE OF PRECIP LOOKS THURSDAY INTO FRIDAY. IN SHORT TERM LOOKS LIKE MAIN PUSH TS THRU IN MORNING ENDING BY MIDDAY THEN GOOD SUBSIDENCE BEHIND THE VORT LOBE. HOWEVER, BY EVENING THE NEXT WEAKER LOBE COMES OVERHEAD WITH THE FRONT STILL IN THE AREA AND STILL DECENT 925 CONVERGENCE INDICATED ON THE ETA, 700-500 LAPSE RATES OVER VERY UNSTABLE 7-7.5, WITH A DECENT NE-SW LOBE OF 100-850 MOISTURE CONVERGENCE ON ETA AND EVEN NGM, AND -7 LI ON GFS. SO WILL HAVE CATEGORIAL POPS THIS MORNING AND THEN CHANCE THIS EVENING WITH FROPA AND 2ND UPPER LEVEL TROF. THINKING OF LEAVING THE NW COUNTIES OUT OF THE EVE TS THREAT AS IT LOOKS MAIN CONVERGENCE AND LIFT JUST TO THE E OF THEM. LAST MINUTE DECISION ON THIS. TEMPERATURES REAL TRICKY TODAY DEPENDING ON SOON SUN COMES OUT BEHING THE FIRST BATCH OF TS. && .LOT WATCHES/WARNINGS/ADVISORIES... .IL...NONE. .IN...NONE. .LK MI...NONE. $$ il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 310 PM EDT MON SEP 19 2005 .SHORT TERM (TONIGHT - TUESDAY)... CURRENT VIS SAT SHOWING NEARLY CLEAR SKIES ACROSS ENTIRE REGION. THIS IS IN RESPONSE TO MID-LEVEL WARMING...WHERE ACARS DATA OUT OF SDF IS SHOWING 700MB 10 DEGREE CELSIUS CAP. WARM FRONT PUSHING NORTHEASTWARD NEAR IL/IN BORDER...AND DEWPOINTS ARE INCREASING AND WINDS ARE GUSTING BEHIND IT IN WARM SECTOR. MAIN SHORTWAVE OVER SOUTHERN MINNESOTA IS TRAVERSING EASTWARD HELPING TO FIRE STORMS ALONG COLD FRONT OVER IA/MO BORDER. WATER VAPOR/RUC ANALYSES DATA SHOWING WEAK SHORTWAVE OVER CENTRAL MO TOO...SEEN AS WEAK SPEED MAX VIA PROFILER DATA. ONLY MID-LEVEL CLOUDINESS IS LOCATED OVER SOUTHERN IL. IT IS POSSIBLE...HOWEVER NOT LIKELY THAT IF SHORTWAVE OVER CNTRL MO DEVELOPS AS IT MOVES EASTWARD...IT COULD COMBINE WITH INSTABILITY OVER WESTERN PORTIONS OF CWA AND GENERATE A FEW ISOLATED CELLS BEFORE SUNSET. WITH SOME SFC CONVERGENCE CURRENTLY OVER SW IN...HAVE SLT CHC POPS OVER IN COUNTIES THROUGH THIS EVENING. MAIN SHOW FOR CWA WILL BE WITH COLD FRONT AS THAT MOVES SE TOWARD REGION OVERNIGHT. EXPECT A LARGE LINES OF SHWRS/STRMS TO DEVELOP OVER THE NEXT FEW HOURS ALONG COLD FRONT. AS UPPER-LEVEL JET IS PROGGED TO MOVE EASTWARD...PARTS OF CENTRAL IL/IN WILL BE UNDER RIGHT ENTRANCE REGION OF JET. AS WEAK LOW-LEVEL JET DEVELOPS AND NOSES INTO FA AFTER MIDNIGHT...COULD SEE THIS LOW LEVEL CONVERGENCE/UPPER LEVEL DIVERGENCE HELP SUSTAIN THE LINE OF PRECIP EXPECTED ALONG THE COLD FRONT. MOST OF THE FORCING WILL BE TO THE NORTH HOWEVER...BUT WITH INCREASED MOISTURE AHEAD OF THE FRONT AND INCREASING SHEAR...HAVE 50 POPS NORTH AND 30S SOUTHEAST OVERNIGHT. LOW-LEVELS WILL LIKELY BE STABLE BY THE TIME THE SQUALL LINE REACHES CWA...BUT GIVEN THE 0-3KM SHEAR OF NEARLY 40 KTS...COULD SEE DAMAGING STRAIGHT-LINE WINDS. BEST CHCS FOR THIS RESIDE IN CENTRAL AND SOUTH-CENTRAL INDIANA. AS COLD FRONT PUSHES THROUGH AREA IT BECOMES MORE WEST TO EAST AS OPPOSED TO BEING ORIENTED FROM NE TO SW. WITH 850MB WSW JET...FLOW WOULD GENERALLY BE PARALLEL TO LINE AND WITH UPPER-LEVEL DIVERGENCE STILL AROUND...COULD SEE HEAVY RAINFALL SUNRISE AND LATER BUT ONLY IF THE LINE HOLDS TOGETHER THAT LONG. GIVEN PAST FRONTAL PASSAGES THIS SUMMER...DO NOT HAVE THAT MUCH CONFIDENCE THAT LINE WILL HOLD TOGETHER SO HAVE 50 POPS MAX. DECREASE POPS NW BY NOON TUESDAY...WITH SLT CHCS OVER SE TOMORROW AFT AS FRONT SLOWS A BIT. WENT NEAR GUIDANCE FOR HIGHS TOMORROW (MID 80S) AS TEMPS SHOULD STILL REBOUND NICELY AS SKIES CLEAR BEHIND FROPA. AL .LONG TERM (TUESDAY NIGHT - MONDAY)... WITHIN POST FRONTAL AIRMASS...WE SHOULD SEE DEWPOINTS DROP INTO THE 50S TUE NIGHT WITHIN LIGHT N/NELY FLOW. MAY STILL BE ENOUGH LOW LEVEL MOISTURE FOR PATCHY FOG IN SRN KY BY WED MORNING...HOWEVER WINDS IN LOWEST 500FT AGL ARE FCST TO REMAIN TOO MIXY FOR ANYTHING WIDESPREAD. REMAINDER OF PERIOD DEFINED BY RIDGING COVERING MUCH OF THE CNTRL/ERN CONUS SOUTH OF FAST WESTERLIES ALONG THE US/CAN BORDER. STRONG JET STREAK PASSES THROUGH THIS FLOW INTO ONTARIO AND QUEBEC THU-FRI...LEAVING A TRAILING SFC FRONT ACROSS THE MIDWEST-GREAT LAKES. APPEARS AS THOUGH THIS FRONT AND ASSOC WX WILL REMAIN N OF THE CWA GIVEN DECENT UPPER RIDGING OVER SRN/ERN CONUS...BUT SOMETHING TO KEEP AN EYE ON. TPC INDICATING HRCN RITA INTO NWRN GULF OF MEX SAT WITH GFS/ECMWF DEPICTING REMNANT CIRCULATION TO LIFT N/NWWD AROUND THE WRN PERIPHERY OF UPPER RIDGE OVER CONUS. THERE ARE SIGNIFICANT DIFFERENCES IN THIS TRACK HOWEVER...WITH LATEST SETS OF ECMWF... CANADIAN...AND NOGAPS MODELS MUCH FURTHER TO THE WEST THAN RECENT GFS RUNS WHICH BRING CIRCULATION UP THROUGH THE MISS RIVER VALLEY CLOSER TO THE CWA. GFS SOLUTIONS WOULD BRING BETTER CHANCES FOR TSRA TO THE AREA SUN-MON. AM INCLINED FOR NOW TO CONTINUE WITH CURRENT DRY FCST FOR THE LATER SECTIONS OF THE LONG TERM PERIOD...GIVEN UNCERTAINTY IN PATH OF TROPICAL CYCLONE. WITH UPPER RIDGING IN PLACE...850MB TEMPS NEARING +20C AT 00 UTC/FRI SO SFC TEMPS WILL GET FAIRLY WARM FOR LATE SEPTEMBER...PARTICULARLY IN THE WED-FRI TIMEFRAME WHERE WIDESPREAD MIDDLE TO UPPER 80S LIKELY...WITH CAPPING NOTED IN BUFKIT FCST SOUNDINGS. CS && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 1104 AM EDT MON SEP 19 2005 .DISCUSSION... CURRENT WATER VAPOR IMAGERY AND RUC ANALYSES SHOWING RIDGING OVER GULF STATES WITH NUMEROUS SHORTWAVES ROTATING AROUND THIS HIGH...TWO DEEP TROUGHS OVER THE ROCKIES AND NORTHERN MINNESOTA...AND A SECONDARY ONE DEVELOPING OVER NE IL. THE LATTER SHORTWAVE IN CONJUNCTION WITH LOW-LEVEL JET AND WARM AIR ADVECTION IS HELPING TO GENERATE CONVECTION ACROSS MUCH OF INDIANA WITH A FEW CELLS EXTENDING INTO ILLINOIS. SFC WARM FRONT SEEMS TO EXTEND FROM NEAR THE IA/IL BORDER DOWN TO NEAR THE SOUTHERN IL/IN BORDER (JUST NW OF FA). THIS SEEMS TO BE VERIFIED LOOKING AT THE 850MB DEWPOINT FIELD ANALYZED BY THE RUC. RECENT ACARS DATA OUT OF SDF SHOWING 700MB TEMP OF AROUND 11 DEGREES CELSIUS...WITH ILX AND PAH ACARS DATA SHOWING MUCH COOLER TEMPS. THUS FA IS STILL CAPPED BUT THAT IS ERODING WEST OF THE REGION. AS DAY PROGRESSES...THE REGION SHOULD GET INTO THE WARM SECTOR...HOWEVER THE FRONTAL AND UPPER-LEVEL FEATURES STAYING OFF TO THE NORTH AND WEST. PERHAPS OUTFLOW FROM ONGOING INDIANA CONVECTION COULD BE ENOUGH TO SPARK STORMS OVER EXTREME NORTHERN CWA...BUT REALLY THINK ALL PRECIP WILL HOLD OFF UNTIL THE CHANCES INCREASE OVERNIGHT TONIGHT/TUESDAY MORNING WITH APPROACHING COLD FRONT (NOW OVER NW MO). SO WILL KEEP SLT CHC OVER SOUTH-CENTRAL INDIANA COUNTIES AND WILL REMOVE FROM ALL KY COUNTIES UNTIL THIS EVENING. AFTERNOON CU WILL LIKELY DEVELOP...BUT WILL TRIM BACK CLOUD COVERAGE IN THE GRIDS AS WELL. EVERYTHING ELSE LOOKS ON TRACK...AND NEAR 90 DEGREES WILL BE LIKELY OVER MOST PLACES. UPDATE OUT SHORTLY TO ALSO TAKE OUT MORNING FOG WORDING...AS IT HAS BURNED OFF EVERYWHERE. AL && .LMK WATCHES/WARNINGS/ADVISORIES... KY...NONE. IN...NONE. && $$ ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 1004 AM EDT MON SEP 19 2005 .DISCUSSION... PATCHY FOG NOW BURNING OFF OUR ERN MOST AND DEEPEST VALLEYS. SAT PIC SHOW OTHERWISE CLR SKY. AREA OF SHRA/TSRA WITH ASSOC CLOUD COVER PROGRESSING THRU IN/OH. PCPN MOVING INTO INCREASINGLY STABLE AIR AS IT MOVES EAST AND ESP SE. STILL THINK POSSIBLE SLGHT CHC FOR PCPN INTO OUR NRN COUNTIES SO WILL ADD THERE. AT THE VERY LEAST EXPECT ADDITIONAL CLOUD COVER NORTH. UPDATE WILL REMOVE MENTION OF FOG AND ADD NRN POP/CLOUD. TEMPS LOOK ON TRACK...EVEN WITH CLOUDS MOVING INTO NRN COUNTIES...TEMPS THERE A COUPLE DEG COOLER THAN FARTHER SOUTH. FOR ISC CONCERNS...WILL ADD POP TO OUR WRN/NRN COUNTIES A LITTLE EARLIER TONIGHT THAN ORIGINALLY PLANNED. AFTN FCST WILL REVISIT TIMING TONIGHT WITH SYSTEM TO DROP OUT OF NRN PLAINS. && .PREV DISCUSSION... 454 AM EDT MON SEP 19 2005 SHORT TERM (TODAY-WEDNESDAY NIGHT)... TIMING OF POPS AND THE FRONTAL PASSAGE ARE THE MAIN CHALLENGES FOR THE SHORT TERM. HIGH PRESSURE WILL CONTINUE TO SLIDE TO THE EAST TODAY. ONCE THE FOG BURNS OFF DURING THE MORNING HOURS...SKIES WILL BE MOSTLY SUNNY...DESPITE SOME CIRRUS CLOUDS STREAMING OVERHEAD. THE CIRRUS MAY KEEP TEMPERATURES DOWN A DEGREE OR TWO...BUT WITH 850 TEMPS AROUND 20C...HIGHS SHOULD BE IN THE UPPER 80S TO THE LOWER 90S FOR MOST OF THE CWA. WE SHOULD SEE A NEW RECORD HIGH AT JKL (RECORD IS 86)...BUT LOZ (RECORD IS 92) WILL FALL A FEW DEGREES SHORT. THE NAM AND GFS HAVE COME IN TO MUCH BETTER AGREEMENT ON THE TIMING OF THE FRONT AND POPS TONIGHT AND TUESDAY. BEST DYNAMICS SHOULD STAY TO THE NORTH...HOWEVER WITH LLJ DEVELOPING ACROSS OHIO AND DIVERGENCE ALOFT FROM THE RIGHT ENTRANCE AREA OF THE 300 MB JET...BUMPED UP POPS IN THE BLUEGRASS TO 50% TONIGHT. BUMPED UP POPS TO 50% FOR THE REST OF THE AREA TUESDAY...AS THE FRONT MOVES ACROSS THE AREA. DON'T EXPECT ANY SEVERE TONIGHT...DUE TO THE TIMING OF THE FRONT...AS THE LATEST SOUNDINGS ARE NOT AS IMPRESSIVE. SPC HAS ALSO REMOVED THE SLIGHT RISK FROM THE CWA. THE FRONT WILL PUSH THROUGH THE STATE BY TUESDAY AFTERNOON. HIGH PRESSURE WILL SETTLE INTO THE REGION ON TUESDAY NIGHT...AS THE COLD FRONT PUSHES WELL SOUTH OF THE STATE. CLEARING SKIES AND LIGHT WINDS COMBINED WITH LINGERING LOW LEVEL MOISTURE SHOULD LEAD TO THE DEVELOPMENT OF PATCHY DENSE FOG OVER THE AREA. EXTENDED GRIDS WERE IN GOOD SHAPE...NO CHANGES WERE NECESSARY AT THIS TIME. SFC HIGH PRESSURE WILL PROVIDE ANOTHER PLEASANT NIGHT ACROSS E KY. LATEST SAT PICS SHOW HIGH CLOUD COVER DROPPING SOUTH AND DISSIPATING ACROSS THE AREA AS TRAVERSING S/W RESPONSIBLE FOR THE CLOUDS DAMPENS AND EXITS. ANOTHER COMPLEX OVER NE MO AND WRN PART OF IL WILL LIKELY WEAKEN AS IT COMES EAST...AND ANY LEFTOVER HIGH CLOUD COVER SHOULD BE PRETTY THIN BY THE TIME IT ENCROACHES ON US. WILL GO AHEAD AND USE MOSTLY CLEAR WORDING FOR ALL ZONES. ALL OTHER FORECAST ASPECTS LOOK GOOD AND WILL ONLY TWEAK A FEW PARAMETERS TO ACCOUNT FOR LATEST TRENDS. UPDATE OUT SHORTLY. 335 PM EDT SUN SEP 18 2005 SHORT TERM (TONIGHT THRU TUESDAY NIGHT)...START OF THE PERIOD WILL BE DOMINATED BY HIGH PRESSURE WHICH WILL MOVE FROM NRN WV TO OFF THE DELMARVA COAST TOMORROW AFTERNOON. UPPER HEIGHTS WILL BE RISING AS WELL AS A S/W MVG TOWARD THE GREAT LAKES FORCES RIDGING OUT IN FRONT. THIS WILL PROVIDE FOR A WARM DAY ON MON BEFORE A COLD FRONT SWEEPS THRU MON NIGHT/TUE MORNING. S/W MVG ACROSS SRN MO IS MAKING FOR A TOUGHER FORECAST TONIGHT THAN I ORIGINALLY PLANNED. RUC80 MODEL SHOWS A VORT OVER SRN IN MOVING DUE E. THIS IS PRODUCING SOME SHRA/TSRA OVER SRN IN PRESENTLY. THE VORT IS PROGGED TO MOVE E OHD WHILE DISSIPATING LATE THIS AFTERNOON AND EVENING. BELIEVE THIS SYSTEM WILL PRODUCE ENOUGH CLOUDS TO HINDER FOG FORMATION A LITTLE AND HOLD TEMPS UP A DEGREE OR TWO FROM WHAT I HAD ORIGINALLY PLANNED TO FORECAST. WILL HOLD OFF ON ANY POPS THOUGH AS SHRA SHOULD DIMINISH AS THEY MOVE INTO A STABLE ATMOSPHERE W/ A STRONG CAP ALOFT OVER THE AREA. SKIES WILL PROBABLY CLEAR IN GOOD ENOUGH TIME FOR AT LEAST PATCHY DENSE FOG TO FORM IN THE RIVER VALLEYS AND FOR TEMPS TO DROP WELL INTO THE 50S BUT HELD THEM A TAD ABOVE THE COOLEST FWC NUMBERS. SUNNY AND WARM ON MON AS WARMING TEMPS ALOFT...OVER 20C AT H85...SUPPORT MAX TEMPS WELL ABOVE CLIMO. FOLLOWED THE WARMER MET MOS GUIDANCE WHICH WILL BRING TEMPS TO NEAR OR ABOVE RECORD VALUES. TOMORROW/S RECORD MAX TEMPS ARE 86F AT JKL AND 92F AT LOZ. FRONT MOVES THRU MON NIGHT OR EARLY TUE MORNING. NAM/GEM SEEM TO BE A LITTLE QUICKER THAN THE GFS BUT ALL BRING THE FRONT THRU EARLY TUE MORNING...NOT A GOOD TIME FOR CONVECTION. MODELS DO SHOW A BAND OF CONVECTION MOVING THRU ALBEIT IN A WEAKENING FASHION AND WILL GO WITH CHANCE POPS LATE MON NIGHT/EARLY WED MORNING. MODIFIED NAM12 SOUNDING ONLY YIELDS 500 J/KG OR SO OF CAPE AND LIS OF -2C AT THAT EARLY MORNING HOUR SO EXPECT A DISSIPATING LINE OF SHRA/TSRA MOVING THRU AROUND DAWN. SPC HAS MOST OF THE AREA IN A SLT RISK BUT MENTIONS THE CONVECTION SHOULD WEAKEN DURING THE OVERNIGHT HOURS. WILL UPDATE THE HWO AND CONTINUE TO MENTION THE POSSIBILITY FOR DAMAGING WINDS WITH THE LINE EARLY TUE. WINDS WILL SHIFT AROUND TO THE NW BEHIND THE FRONT DURING THE DAY AND ATMOSPHERE DRIES OUT WITH HIGH PRESSURE AT THE SURFACE AND ALOFT BUILDING IN THRU TUE NIGHT. WENT W/ A BLEND OF GUIDANCE NUMBERS FOR MAX TEMPS ON TUE W/ SOME UNCERTAINTY ON HOW FAST THE FRONT MOVES THRU AND WENT WITH THE COOLEST NUMBERS TUE NIGHT WITH DRIER/COOLER AIRMASS FILTERING IN. EXTENDED (WEDNESDAY THRU SUNDAY)...GFS IS MODEL OF CHOICE WHICH HAS HIGH PRESS BUILDING INTO REGION BY EARLY WED. BY FRI THE HIGH SITS OVER THE CAROLINAS WITH A SW FLOW INTO ERN KY. PLAINS LOW TRACKS INTO SRN CANADA WITH A TRAILING COLD FNT TAILING BACK THRU CNTRL IL TO THE SPS AREA OF TX. THIS FNT SAGS TO AROUND THE OH RVR BY FRI EVENING AND THEN STALLS. PCPN APPEARS TO STALL WITH THE FNT AND REMAINS NORTH OF THE RIVER AS THE FNT BEGINS TO MOVE NORTH AS A WARM FNT WITH THE PCPN MOVING NORTH AS WELL. TD18 TRACKS ACROSS THE GOMEX AND BY THE WEEKEND IS BEGINNING TO PUSH GOMEX MOISTURE INTO THE LONE STAR STATE. THIS IS STILL TOO FAR AWAY TO AFFECT ERN KY BUT A PRECURSOR TO BRINGING PRECIPITABLE MOISTURE TO OUR CWFA BY THE FOLLOWING WEEK. WITH THE PERSISTENT LLVL SW FLOW OUR DWPTS WILL REMAIN ELEVATED AS THE TEMPS REMAIN IN THE UPPER 80S THRU MOST OF THE EXTENDED PD. HAVE FOLLOWED GFS/GFSLR FOR THE MOST PART FOR TEMPS/DWPTS. EXPECTING A FAIRLY GOOD DIURNAL SWING TO CLOUDS AND MORNING FOG SHOULD BE PRESENT ALMOST EVERY NITE/EARLY MORNING. && .JKL WATCHES/WARNINGS/ADVISORIES...NONE. && $$ DUSTY ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1015 AM EDT MON SEP 19 2005 .UPDATE... FORECAST IN FINE SHAPE... WILL UPDATED TEXT PRODUCTS TO REMOVE MORNING FOG WORDING. && .SHORT TERM (TODAY THROUGH TONIGHT)... WATER VAPOR LOOP SHOWS A SHORTWAVE TROUGH MOVING ACROSS THE EASTERN GREAT LAKES. THE GULF STATES RIDGE IS BUILDING NORTH INTO THE MIDWEST...WHILE THE NEXT WAVE BEGINS TO PRESS EAST FROM THE NORTHERN ROCKIES INTO THE UPPER MIDWEST. ACARS 400-250MB WIND OBSERVATIONS REVEAL A 80-100KT JET STRETCHING FROM THE CENTRAL ROCKIES THROUGH THE WESTERN GREAT LAKES AND DIPPING INTO THE OHIO VALLEY. 03Z SURFACE ANALYSIS PLACES A 1022MB ANTICYCLONE ACROSS THE OHIO VALLEY. A STATIONARY BOUNDARY EXTENDS FROM SOUTH OF THE DELMARVA SOUTHWEST TOWARDS THE MISSISSIPPI GULF COAST...THEN NORTHWEST TO A 1009MB CYCLONE ACROSS EASTERN NEBRASKA. A SECOND BOUNDARY APPEARS TO BE DEVELOPING FROM THE CYCLONE TO EASTERN IOWA...THEN SOUTH ALONG THE MISSISSIPPI VALLEY. A 1022MB ANTICYCLONE SOUTHWEST OF JAMES BAY DOMINATES THE WEATHER BEHIND A COLD/STATIONARY BOUNDARY ACROSS THE UPPER GREAT LAKES. PATCHY LIGHT RADIATIONAL FOG WILL BE QUICK TO BURN OFF AROUND SUNRISE AS THE 00Z KIAD RAOB AND RUC MODEL INDICATE THE INVERSION IS QUITE SHALLOW (LESS THAN 1KFT). EXPECTING A FEW CUMULUS TO DEVELOP DURING THE MID MORNING AS CIRRUS STREAKS FROM UPSTREAM CONVECTION STREAMS IN FOR THE MID AFTERNOON. LIGHT NORTHERLY FLOW EARLY THIS MORNING WILL BECOME SOUTH/SOUTHEAST THIS AFTERNOON AS THE HIGH PUSHES OFF THE COAST. LOWER LEVEL WARM ADVECTION SHOULD SUPPORT HIGH TEMPERATURES A FEW DEGREES HIGHER THAN THOSE RECORDED SUNDAY. MID AND UPPER LEVEL MOISTURE WILL CONTINUE TO ADVECT INTO THE REGION OVERNIGHT WITH FALLING HEIGHTS AHEAD OF THE NEXT SYSTEM. HAVE CONTINUED A 20-30 POP WEST OF THE BLUE RIDGE FOR THE POSSIBILITY THAT CONVECTION MAY BE CROSSING THE MOUNTAINS JUST BEFORE SUNRISE. GRADIENT WARM ADVECTION EXPECTED TO ALLOW FOR WIND GUSTS UP TO 30 MPH IN THE HIGHER TERRAIN ATOP THE NOCTURNAL INVERSION. THE COLD FRONT WHICH PASSED SATURDAY (AND IS CURRENTLY HUNG UP ALONG THE COAST IN THE CAROLINAS) IS EXPECTED TO RESPOND TO THE WARM ADVECTION BY MOVING NORTH/NORTHWEST AND REST FROM CHO TO BWI BY SUNRISE. AMOUNT OF TURBULENCE ATOP THE NOCTURNAL INVERSION WILL SUPPORT STRATUS INSTEAD OF DENSE FOG ALONG THE BOUNDARY (ALTHOUGH MOS GUIDANCE IS INCONSISTENT ON LOW STRATUS CAUSING SOME UNCERTAINTY DESPITE PATTERN RECOGNITION). && .LONG TERM... GDNC CONTS TO POINT TWD FROPA TUE...AND HV COME INTO MUCH BTTR AGREEMNT ON HOW THIS WL HPPN. H5 S/WV WL REMAIN WELL N OF CWFA... TRAVERSING ACRS SRN CNDA...AS WL SFC CYCLONE. HWVR...THIS WL DRAG CDFNT THRU MIDDAY/AFTN...AND LINGER ACRS SRN MD INTO ELY EVNG. AMS AHD OF CDFNT WL BE WARM AND MARGINALLY UNSTBL...SPCLY CONSIDERING TIME OF YR. W/ PRONOUNCED THTE RDG IN PLACE...DECENT UPR DIVGNC... GOOD INSTBLTY...PWAT 1.5 INCH PLUS...SFC DEWPTS IN THE 60S...AND APPCHG SFC BNDRY...FEEL POPS NEED TO BE MNTND IN THE FCST. INSTBLTY MAXIMIZED IN THE E AS TIME OF DAY FVRBL...W/ LI DWN TO -2 AND CAPES 1000-1500 J/KG. PLUS...20-30 KT H8-9 JET PRESENT TO PROVIDE SOME SHEAR. MID LVL FLOW BTTR. THIS CUD ALL COMBINE FOR ISOLD SVR TSTMS. SPC CONCURS PER DAY 2 OUTLK. CONSIDERING ABV...KEPT POPS LOW...BUT DID ADD THEM BACK INTO THE FCST GRIDS. MAV/MET MOS AGREES. MAV LWR OF THE TWO...AND FCST WL SIDE TWD IT. BUMPED CLDS UPWD AS WELL AS WAA INDUCED MID DECK AND CNVCTV CU SHUD COMBINE TO YIELD MOCLDY SKIES. AMT OF CLDS ULTIMATELY WL CNTRL AFTN HEATING...AND THUS DEGREE/CHARACTER OF TSRA. AS ALLUDED TO ABV...KEPT 20/25 POPS E OF I-95 INTO ELY EVE TIL DRIER AIR CAN ADVECT SEWD. AS DEWPTS DROP INTO THE 50S TUE NGT...SKIES WL PRTLY CLR. HIPRES WL BUILD IN TUE NGT/WED...FOR SVRL DAYS OF MOSUN/CLR SKIES AND DRY CONDS. TEMPS WL RETURN TO NRML. && .AVIATION...LIGHT PATCHY RADIATIONAL FOG WILL QUICKLY BURN OFF WITH SUNRISE. FEW-SCT CU DEVELOP DURING THE MID MORNING...WITH CLOUD BASES CLIMBING TO ABOUT 6FT FOR THE AFTERNOON UNDER STREAMING CIRRUS. LIGHT NORTHERLY WINDS AROUND SUNRISE WILL QUICKLY BECOME SE/S ABOUT 5KT...REMAINING COUPLED THROUGH THE EVENING AHEAD OF THE NEXT COLD FRONT. && .MARINE... LIGHT AND VARIABLE FLOW EARLY THIS MORNING WILL BECOME SOUTHEAST THIS AFTERNOON AS THE HIGH PUSHES OFF THE COAST. HEIGHT/PRESSURE GRADIENT INCREASES TONIGHT AS THE NEXT SYSTEM APPROACHES. WITH 80 DEGREE WATER AND 25-35KT WINDS FORECAST ATOP A NOCTURNAL INVERSION ON THE ADJACENT LAND SITES PER NAM/GFS BUFKIT FORECAST SOUNDINGS...WILL BE RAISING A SMALL CRAFT FOR 15-20KT SOUTHERLY WINDS DEVELOPING AROUND MIDNIGHT. WATER LEVELS ARE CURRENTLY RUNNING SLIGHTLY ABOVE PREDICTED VALUES. THE LUNAR CYCLE IS BEGINNING TO WANE FROM A FULL MOON. SLY FLOW WL CONT INTO TUE...W/ H10-9 WNDS ABV 20 KT THRU 18Z...SPCLY LWR PTMC/MID BAY. WL CONT SCA INTO TUE FOR THESE AREAS. IT WL BE CLOSE THO ACRS ALL WATERS. THEN...CNVCTV ELEMENTS WL ENTER THE PIX...W/ CHC TSRA AFTN-EVE. WNDS/WVS WL BE HIER...AND BASED ON WNDS AVBL TO MIX...SMW CRITERIA MAY BE MET INVOF TSRA LT TUE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FOR ANZ530>533-535-536 FROM MIDNIGHT TUESDAY TO 6 AM TUESDAY. ...SMALL CRAFT ADVISORY FOR ANZ534-537 FROM MIDNIGHT TUESDAY TO 2 PM TUESDAY. && $$ UPDATE...STRONG SHORT TERM/AVIATION FORECASTER: ROGOWSKI LONG TERM FORECASTER: HTS md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1027 PM EDT MON SEP 19 2005 .UPDATE... MAIN FCST ISSUE OVERNIGHT TURNS TO FOG POTENTIAL. WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A POTENT...VERY WELL-DEFINED SHORTWAVE EXITING ERN UPPER MI. AT THE SFC...ASSOCIATED COMPACT LOW PRES HAS RECENTLY MOVED E OF WHITEFISH BAY. VERY DYNAMIC SYSTEM BROUGHT GUSTY WINDS TO MUCH OF UPPER MI LATE THIS AFTN/EVENING...BUT WINDS ARE NOW GRADUALLY SUBSIDING FROM W TO E AS SHORTWAVE HAS MOVED E OF THE AREA AND 3HR PRES RISE MAX HAS MOVED INTO UPPER MI IN THE WAKE OF THE LOW. SCT -SHRA LINGERING OVER NCNTRL/ERN FCST AREA ARE ALSO WINDING DOWN QUICKLY. EXPECT THE LINGERING SCT -SHRA TO END OVER THE NEXT HOUR OR TWO AS SHORTWAVE CONTINUES TO SLIDE E QUICKLY. CLEARING UPSTREAM IS NOT PROGRESSING E QUITE AS FAST AS THOUGHT. BACK EDGE OF LOW STRATUS IS CLOSE TO THE WRN SHORE OF UPPER MI...BUT SCT TO BKN STRATOCU LINGERS BACK TO ROUGHLY THE W EDGE OF THE LAKE. FARTHER UPSTREAM...00Z KINL SOUNDING DID NOT REVEAL AN ESPECIALLY DRY AIRMASS WITH DWPT DEPRESSIONS ONLY 4-10C UP TO ABOUT 650MB. STILL...EXPECT A GRADUAL CLEARING TREND FROM W TO E DURING THE NIGHT AS SFC RIDGE AXIS OVER MN ARRIVES OVER UPPER MI AND FLOW BECOMES MORE ANTICYCLONIC. AS FOR FOG...WET GROUND AND DIMINISHING WINDS WITH ARRIVAL OF SFC HIGH PRES RIDGE SUPPORT AT LEAST PATCHY FOG DEVELOPMENT. HOWEVER...SINCE UPSTREAM AIRMASS DOES NOT SHOW SHARP DRYING ABOVE THE SFC TO ENHANCE RADIATIONAL COOLING...DON'T THINK WIDESPREAD FOG WILL DEVELOP...AND DENSE FOG SHOULD BE LIMITED TO A FEW SHELTERED INTERIOR LOCATIONS. GOING FCST WHICH LIMITS PATCHY FOG TO INTERIOR W HALF OF UPPER MI LOOKS ON TRACK AS 00Z RUC/NAM SHOW NW WINDS OF 20-25KT AT 950MB THRU 12Z. && .PREV DISCUSSION... DISCUSSION ISSUED AT 400 PM EDT. 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW ZONAL FLOW PREVAILING ALG THE US/CNDN BORDER TO THE N OF UPR RDG OVER THE SRN STATES. SVRL SHRTWS OF INTEREST EMBEDDED WITHIN THIS FLOW. THE FIRST OF THESE IS IN NRN WI WITHIN RRQ OF 100KT H3 JET MAX N OF LK SUP. DIFFLUENT H3 FLOW OVR THE FA AND DPVA/DEEP LYR H85-3 QVECTOR CNVGC AS WELL AS BAND OF H7-6 FRONTOGENESIS N OF SFC LO/ATTENDANT WARM FNT IN CNTRL WI HAS OVERCOME MID LVL DRY AIR SHOWN ON THE 12Z GRB SDNG TO GENERATE SHRA/ISOLD +TSRA OVER MUCH OF THE FA. RAINFALL RATES HAVE REACHED 0.50 INCH/HR AT A FEW SPOTS. PRES FALLS UP TO 4MB/3HR NOTED ACRS WI AHEAD OF THE SFC LO. SOME DRYING NOTED OVER NW WI/WRN CWA WHERE THE PCPN HAS DIMINISHED THE PAST FEW HRS...BUT ANOTHER BAND OF SHRA/TSRA HAS DVLPD OVER ERN MN WHERE DPVA AHEAD OF A TRAILING SHRTWV HAS INTERACTED WITH RICH MSTR SHOWN ON THE 12Z INL/MPX SDNGS (1.41 INCH PWAT AT MPX CLOSE TO 200 PCT OF NORMAL). THIS PCPN APRCHG THE WRN ZNS EARLY THIS AFTN. SFC HI PRES APRNT OVER THE NRN PLAINS IN ADVANCE OF SHRTWV RDG TRAILING THE PLAINS SHRTWV. 12Z BIS SDNG SHOWS IMPRESSIVE DRYING ALF...AND PLENTY OF FOG FORMED OVER THE LINGERING LLVL MSTR ACRS THE NRN PLAINS UNDER THE SFC HI EARLIER THIS MRNG. NEXT SHRTWV IN THE ZONAL FLOW ALF MOVING INTO BRITISH COLUMBIA EARLY THIS AFTN. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE PCPN TRENDS/WINDS THIS EVNG...THEN FOG COVG OVRNGT. FOR TNGT...SHORT RANGE MODELS IN GOOD AGREEMENT SHOWING SFC LO NOW IN CNTRL WI REACHING NRN LK MI BY 00Z AND THEN WRN QUEBEC BY 12Z TUE. EXPECT AN AREA OF LOCALLY HVY RA TO MARCH ACRS THE FA LATE THIS AFTN BEFORE EXITING THIS EVNG WITH DEPARTURE OF DPVA AHEAD OF SHRTWV COMPLEX/UPR DVGC/SFC LO/H7-6 FRONTOGENESIS. ALTHOUGH THERE WL BE SOME HVY RA...THE CNVCTN SHOULD BE PROGRESSIVE ENUF TO AVOID ANY HYDRO PROBLEMS. SFC LO FCST TO INTENSITY SHARPLY AS IT MOVES TO NRN LK MI...SO EXPECT SOME BRIEF GUSTY NNW WINDS OVER IN THE TIGHT CYC FLOW ARND THE LO CENTER WHERE GFS SHOWS H925 WINDS REACHING 45KT. ISALLOBARIC WIND AT 90 DEGREES TO FCST GRADIENT FLOW SHOULD MITIGATE SFC WIND SPEED INCRS. THEN PRES GRADIENT FCST TO WEAKEN QUICKLY OVRNGT IN ADVANCE OF SHRTWV RDGING FM THE W AND ARRIVAL OF SFC HI PRES. WITH DRIER AIR TO THE W ARRIVING ALF OVERNGT/CLRG SKIES OVER WET GROUND AND SFC WINDS GOING LGT WITH SFC RDG AXIS PROGGED OVER THE CNTRL ZNS BY 12Z TUE...EXPECT PTCHY FOG TO DVLP OVER AT LEAST THE W AS OBSVD UPSTREAM THIS MRNG. ALTHOUGH FOG MAY BCM LOCALLY DENSE AT SOME SHELTERED INLAND LOCATIONS OVER THE W...STRENGTH OF FCST H925 WINDS ARND 15KT THRU 12Z SHOULD LIMIT COVG OF FOG TO JUST THE INTERIOR W HALF. TUE LOOKS TO BE A DRY DAY WITH FAST ZONAL FLOW ALF DRIVING DRY AIR INTO THE UPR GRT LKS. SHRTWV NOW ENTERING BRITISH COLUMBIA PROGGED TO MOVE INTO ONTARIO JUST N OF LK SUP BY 00Z WED. BUT SHEARED NATURE OF SYS WITH DPVA/QVECTOR CNVGC TRACKING WELL TO N IN THE ABSENCE OF MUCH MSTR SUG THERE WL BE LTL IMPACT OTHER THAN PTCHY CLD OVER THE FA EVEN THOUGH ATTENDANT SFC COLD FNT/LO PRES TROF MOVES INTO THE AREA LATE IN THE DAY. MIXING TO H8 ON NAM/GFS FCST SDNGS YIELDS MAX TEMPS IN THE LOW 80S OVER THE SCNTRL WHERE LLVL WLY FLOW WL DOWNSLOPE AND WARM. EXPECT A QUIET NGT ON TUE NGT WITH HI PRES RDG BLDG OVER THE UPR GRT LKS IN WAKE OF WEAK COLD FROPA. DRY NATURE OF AIRMASS AND FAIRLY STRG H925 NW FLOW WL LIMIT DIURNAL TEMP FALL/ POTENTIAL FOR FOG. ON WED...GFS/UKMET ARE MORE PROGRESSIVE AT PUSHING SFC HI PRES RDG TO THE E. NAM HOLDS SFC HI ARND LONGER...BUT FAST ZONAL FLOW ALF SUGS GFS/UKMET SOLN PROBABLY A BETTER BET. IN FACT...GFS SHOWS RETURN SW FLOW IN THE WAKE OF THE SFC HI BOOSTING H85 DWPT UP TO 12C/SSI DOWN TO -4C BY 00Z THU UNDER DECENT ISENTROPIC LIFT AND STEEP H7-5 LAPSE RATES ARND 7C/KM. UKMET/GFS BOTH GENERATE SOME LGT PCPN OVER AT LEAST THE W HALF OF THE FA LATE IN THE DAY...SO HAVE GONE WITH A 20 POP FOR ISOLD SHRA PER GFS MOS POPS OVER THE W HALF. BUT DRY ANTECEDENT AIRMASS/PLACEMENT OF FA IN UNFVRBL RIGHT EXIT OF UPR JET TO THE NW WL RESTRICT PCPN CHCS. GFS/UKMET SHOW H85 TEMPS RISING TO 14C OR SO ALG THE WI BORDER LATE IN THE DAY ON WED...SO THINK MAX TEMPS WL RECOVER WELL INTO THE 70S AND CLOSE TO GFS MOS GUIDANCE. FOR WED NGT THRU THU...OPERATIONAL MODELS SHOW FRONTOGENESIS OVER THE UPR GRT LKS...BUT DIFFER SHARPLY ON TRACK OF WAVE THAT IS FCST TO MOVE ENE ALG THIS BNDRY. ECMWF/UKMET ARE A BIT FARTHER N THAN NAM/GFS/CNDN AND APPEAR TO TRACK A FLAT SFC LO TO NR MNM AT SOME POINT DURING THE DAY. GIVEN THE PERSISTENT RDG TO THE S...WL TEND TOWARD THE FARTHER N TRACK OF THE UKMET/ECMWF. WL GO WITH CHC POPS FOR THE WED NGT/THU PD WITH HIER POPS ACRS THE SCNTRL. FCST TEMPS AOA GFS MOS GUIDANCE. IN THE EXTENDED PD...UPR HGTS REBOUND OVER THE GRT LKS IN THE WAKE OF THU LO ON TOP OF PERSISTENT MEAN RDG ACRS THE SE CONUS AND DOWNSTREAM OF DEEPENING UPR TROF OVER THE W. EXPECT FRI TO BE DRY AND SEASONABLE WITH NE FLOW TO THE S OF HI PRES IN ONTARIO AND H85 TEMPS 8-10C. WL FOLLOW NEW ECMWF OUTPUT VS 12Z GFS (WHICH SHOWS WHAT APPEARS TO BE CONVECTIVELY INDUCED SHRTWV CAUSING PCPN OVER THE SRN TIER ALG BNDRY TO THE S). DRY WX WL LINGER INTO SAT WITH HI PRES OVER ONTARIO HOLDING ITS GRND...BUT WAD PCPN ASSOCIATED WITH SHRTWV ENTERING CONFLUENCE ZN BTWN BIG RDG TO THE S AND MORE WNW FLOW ALF ACRS CNTRL CAN WL RETURN RA CHCS BY THE AFTN. LOOK FOR RA CHCS TO LINGER INTO SUN BEFORE HI PRES BLDS BACK INTO THE AREA LATER IN THE DAY AND ON MON. GIVEN ABV NORMAL HGTS...EXPECT TEMPS IN GENERAL THE NEXT WEEK TO AVERAGE HIER THAN USUAL (ESPECIALLY MIN TEMPS). COORDINATED WITH GRB. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ROLFSON (UPDATE) KC (PREV DISCUSSION) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 400 PM EDT MON SEP 19 2005 .DISCUSSION... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW ZONAL FLOW PREVAILING ALG THE US/CNDN BORDER TO THE N OF UPR RDG OVER THE SRN STATES. SVRL SHRTWS OF INTEREST EMBEDDED WITHIN THIS FLOW. THE FIRST OF THESE IS IN NRN WI WITHIN RRQ OF 100KT H3 JET MAX N OF LK SUP. DIFFLUENT H3 FLOW OVR THE FA AND DPVA/DEEP LYR H85-3 QVECTOR CNVGC AS WELL AS BAND OF H7-6 FRONTOGENESIS N OF SFC LO/ATTENDANT WARM FNT IN CNTRL WI HAS OVERCOME MID LVL DRY AIR SHOWN ON THE 12Z GRB SDNG TO GENERATE SHRA/ISOLD +TSRA OVER MUCH OF THE FA. RAINFALL RATES HAVE REACHED 0.50 INCH/HR AT A FEW SPOTS. PRES FALLS UP TO 4MB/3HR NOTED ACRS WI AHEAD OF THE SFC LO. SOME DRYING NOTED OVER NW WI/WRN CWA WHERE THE PCPN HAS DIMINISHED THE PAST FEW HRS...BUT ANOTHER BAND OF SHRA/TSRA HAS DVLPD OVER ERN MN WHERE DPVA AHEAD OF A TRAILING SHRTWV HAS INTERACTED WITH RICH MSTR SHOWN ON THE 12Z INL/MPX SDNGS (1.41 INCH PWAT AT MPX CLOSE TO 200 PCT OF NORMAL). THIS PCPN APRCHG THE WRN ZNS EARLY THIS AFTN. SFC HI PRES APRNT OVER THE NRN PLAINS IN ADVANCE OF SHRTWV RDG TRAILING THE PLAINS SHRTWV. 12Z BIS SDNG SHOWS IMPRESSIVE DRYING ALF...AND PLENTY OF FOG FORMED OVER THE LINGERING LLVL MSTR ACRS THE NRN PLAINS UNDER THE SFC HI EARLIER THIS MRNG. NEXT SHRTWV IN THE ZONAL FLOW ALF MOVING INTO BRITISH COLUMBIA EARLY THIS AFTN. MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE PCPN TRENDS/WINDS THIS EVNG...THEN FOG COVG OVRNGT. FOR TNGT...SHORT RANGE MODELS IN GOOD AGREEMENT SHOWING SFC LO NOW IN CNTRL WI REACHING NRN LK MI BY 00Z AND THEN WRN QUEBEC BY 12Z TUE. EXPECT AN AREA OF LOCALLY HVY RA TO MARCH ACRS THE FA LATE THIS AFTN BEFORE EXITING THIS EVNG WITH DEPARTURE OF DPVA AHEAD OF SHRTWV COMPLEX/UPR DVGC/SFC LO/H7-6 FRONTOGENESIS. ALTHOUGH THERE WL BE SOME HVY RA...THE CNVCTN SHOULD BE PROGRESSIVE ENUF TO AVOID ANY HYDRO PROBLEMS. SFC LO FCST TO INTENSITY SHARPLY AS IT MOVES TO NRN LK MI...SO EXPECT SOME BRIEF GUSTY NNW WINDS OVER IN THE TIGHT CYC FLOW ARND THE LO CENTER WHERE GFS SHOWS H925 WINDS REACHING 45KT. ISALLOBARIC WIND AT 90 DEGREES TO FCST GRADIENT FLOW SHOULD MITIGATE SFC WIND SPEED INCRS. THEN PRES GRADIENT FCST TO WEAKEN QUICKLY OVRNGT IN ADVANCE OF SHRTWV RDGING FM THE W AND ARRIVAL OF SFC HI PRES. WITH DRIER AIR TO THE W ARRIVING ALF OVERNGT/CLRG SKIES OVER WET GROUND AND SFC WINDS GOING LGT WITH SFC RDG AXIS PROGGED OVER THE CNTRL ZNS BY 12Z TUE...EXPECT PTCHY FOG TO DVLP OVER AT LEAST THE W AS OBSVD UPSTREAM THIS MRNG. ALTHOUGH FOG MAY BCM LOCALLY DENSE AT SOME SHELTERED INLAND LOCATIONS OVER THE W...STRENGTH OF FCST H925 WINDS ARND 15KT THRU 12Z SHOULD LIMIT COVG OF FOG TO JUST THE INTERIOR W HALF. TUE LOOKS TO BE A DRY DAY WITH FAST ZONAL FLOW ALF DRIVING DRY AIR INTO THE UPR GRT LKS. SHRTWV NOW ENTERING BRITISH COLUMBIA PROGGED TO MOVE INTO ONTARIO JUST N OF LK SUP BY 00Z WED. BUT SHEARED NATURE OF SYS WITH DPVA/QVECTOR CNVGC TRACKING WELL TO N IN THE ABSENCE OF MUCH MSTR SUG THERE WL BE LTL IMPACT OTHER THAN PTCHY CLD OVER THE FA EVEN THOUGH ATTENDANT SFC COLD FNT/LO PRES TROF MOVES INTO THE AREA LATE IN THE DAY. MIXING TO H8 ON NAM/GFS FCST SDNGS YIELDS MAX TEMPS IN THE LOW 80S OVER THE SCNTRL WHERE LLVL WLY FLOW WL DOWNSLOPE AND WARM. EXPECT A QUIET NGT ON TUE NGT WITH HI PRES RDG BLDG OVER THE UPR GRT LKS IN WAKE OF WEAK COLD FROPA. DRY NATURE OF AIRMASS AND FAIRLY STRG H925 NW FLOW WL LIMIT DIURNAL TEMP FALL/ POTENTIAL FOR FOG. ON WED...GFS/UKMET ARE MORE PROGRESSIVE AT PUSHING SFC HI PRES RDG TO THE E. NAM HOLDS SFC HI ARND LONGER...BUT FAST ZONAL FLOW ALF SUGS GFS/UKMET SOLN PROBABLY A BETTER BET. IN FACT...GFS SHOWS RETURN SW FLOW IN THE WAKE OF THE SFC HI BOOSTING H85 DWPT UP TO 12C/SSI DOWN TO -4C BY 00Z THU UNDER DECENT ISENTROPIC LIFT AND STEEP H7-5 LAPSE RATES ARND 7C/KM. UKMET/GFS BOTH GENERATE SOME LGT PCPN OVER AT LEAST THE W HALF OF THE FA LATE IN THE DAY...SO HAVE GONE WITH A 20 POP FOR ISOLD SHRA PER GFS MOS POPS OVER THE W HALF. BUT DRY ANTECEDENT AIRMASS/PLACEMENT OF FA IN UNFVRBL RIGHT EXIT OF UPR JET TO THE NW WL RESTRICT PCPN CHCS. GFS/UKMET SHOW H85 TEMPS RISING TO 14C OR SO ALG THE WI BORDER LATE IN THE DAY ON WED...SO THINK MAX TEMPS WL RECOVER WELL INTO THE 70S AND CLOSE TO GFS MOS GUIDANCE. FOR WED NGT THRU THU...OPERATIONAL MODELS SHOW FRONTOGENESIS OVER THE UPR GRT LKS...BUT DIFFER SHARPLY ON TRACK OF WAVE THAT IS FCST TO MOVE ENE ALG THIS BNDRY. ECMWF/UKMET ARE A BIT FARTHER N THAN NAM/GFS/CNDN AND APPEAR TO TRACK A FLAT SFC LO TO NR MNM AT SOME POINT DURING THE DAY. GIVEN THE PERSISTENT RDG TO THE S...WL TEND TOWARD THE FARTHER N TRACK OF THE UKMET/ECMWF. WL GO WITH CHC POPS FOR THE WED NGT/THU PD WITH HIER POPS ACRS THE SCNTRL. FCST TEMPS AOA GFS MOS GUIDANCE. IN THE EXTENDED PD...UPR HGTS REBOUND OVER THE GRT LKS IN THE WAKE OF THU LO ON TOP OF PERSISTENT MEAN RDG ACRS THE SE CONUS AND DOWNSTREAM OF DEEPENING UPR TROF OVER THE W. EXPECT FRI TO BE DRY AND SEASONABLE WITH NE FLOW TO THE S OF HI PRES IN ONTARIO AND H85 TEMPS 8-10C. WL FOLLOW NEW ECMWF OUTPUT VS 12Z GFS (WHICH SHOWS WHAT APPEARS TO BE CONVECTIVELY INDUCED SHRTWV CAUSING PCPN OVER THE SRN TIER ALG BNDRY TO THE S). DRY WX WL LINGER INTO SAT WITH HI PRES OVER ONTARIO HOLDING ITS GRND...BUT WAD PCPN ASSOCIATED WITH SHRTWV ENTERING CONFLUENCE ZN BTWN BIG RDG TO THE S AND MORE WNW FLOW ALF ACRS CNTRL CAN WL RETURN RA CHCS BY THE AFTN. LOOK FOR RA CHCS TO LINGER INTO SUN BEFORE HI PRES BLDS BACK INTO THE AREA LATER IN THE DAY AND ON MON. GIVEN ABV NORMAL HGTS...EXPECT TEMPS IN GENERAL THE NEXT WEEK TO AVERAGE HIER THAN USUAL (ESPECIALLY MIN TEMPS). COORDINATED WITH GRB. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1148 AM EDT MON SEP 19 2005 .DISCUSSION... UPDATE CONCERNS ON QPF AMOUNTS AND WINDS CURRENT WEATHER...15Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED A LARGE UPPER LEVEL HIGH ALONG THE GULF COAST WITH NEARLY ZONAL FLOW ACROSS THE NORTHERN TIER OF THE U.S.. HOWEVER THERE IS A SHRTWV TROUGH MOVING THROUGH THIS ZONAL FLOW WHICH IS OVER MINNESOTA. IMMEDIATELY AHEAD OF THE SHRTWV WAS A LINE OF SHOWERS AND THUNDERSTORMS WHICH EXTENDS FROM THE ARROWHEAD OF MN SOUTHWARD DOWN I-35 TO HINCKLEY ON KDLH RADAR. AHEAD OF THIS LINE WAS A MORE BROAD AREA OF SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS OVER UPPER MICHIGAN. THIS AREA OF PRECIPITATION IS ASSOCIATED WITH ISENTROPIC LIFT AND MID LEVEL FRONTOGENESIS. SOME OF THE RAIN HAS COME DOWN PARTICULARLY HEAVY WITH RAINFALL AMOUNTS ALREADY APPROACHING ONE HALF OF AN INCH HERE AT THE OFFICE AT THE MOMENT. THERE DOES APPEAR TO BE SOME LET UP OF THE PRECIPITATION ACROSS NORTHERN WISCONSIN BUT WITH THE APPROACH OF THE SHRTWV...THIS WILL PROBABLY BE TEMPORARY. ANOTHER ITEM TO NOTE IS TWO UPPER LEVEL JETS. AT 250MB AT 12Z THERE WAS A 90 KT JET OVER NEBRASKA WITH ANOTHER 90 KT JET OVER INTERNATIONAL FALLS. AT THE SURFACE...LOW PRESSURE OF 1011 MB WAS LOCATED JUST TO THE EAST OF LACROSSE WITH THE BEST PRESSURE FALLS ON THE ORDER OF 1 MB/HR LOCATED NEAR APPLETON WISCONSIN. THIS AFTERNOON AND TONIGHT...SHRTWV TROUGH SHOULD CONTINUE ITS EASTWARD MOVEMENT...CROSSING UPPER MICHIGAN BETWEEN 18-00Z. MANY FACTORS ARE COMING TOGETHER TO PRODUCE A HEAVY RAINFALL EVENT. FIRST WILL BE THE DYNAMICAL FORCING AHEAD OF THE SHRTWV ITSELF. NEXT IS UPPER DIVERGENCE FROM THE TWO UPPER LEVEL JETS HEADING NORTHEASTWARD TOWARDS UPPER MICHIGAN (COUPLED JET STRUCTURE). THIRD WILL BE THE ISENTROPIC LIFT AHEAD OF THE SHRTWV TROUGH. FOURTH...PRECIPITABLE WATER IS PROGGED TO BE AROUND 1.4 INCHES WHICH IS NEARLY 200 PERCENT OF NORMAL. FINALLY...INCREASING FRONTOGENESIS WILL RESULT IN ADDITIONAL LIFT. THESE ALL APPEAR TO BE MAXIMIZED ACROSS WESTERN AND NORTH CENTRAL UPPER MICHIGAN...WHICH IS SHOWN BY THE 06Z/12Z NAM AND 12Z RUC. HAVE FOLLOWED QPF AMOUNTS SIMILAR TO THAT OF THE 12Z NAM WHICH INDICATES UPWARDS OF 1-2 INCHES OVER NORTH CENTRAL UPPER MICHIGAN BETWEEN 18-00Z. THESE FACTORS WILL ALSO AID IN DEEPENING THE SURFACE LOW AS IT MOVES TOWARDS NORTHERN LOWER MICHIGAN/STRAITS OF MACKINAC AREA. AS A RESULT...EXPECTING WINDS TO INCREASE...PARTICULARLY DURING THE 19-02Z PERIOD OVER EASTERN LAKE SUPERIOR AND NORTHERN LAKE MICHIGAN. CURRENT SMALL CRAFT ADVISORIES AND GALE WARNING ON NORTHERN LAKE MICHIGAN LOOK REASONABLE. WITH THE RAPID PROGRESSION OF THE SHRTWV TROUGH...SHOULD NOT HAVE TO WORRY ABOUT ANY FLOODING CONCERNS...ESPECIALLY SINCE A LOT OF THIS RAIN IS GOING OVER PLACES THAT HAVE BEEN PARTICULARLY DRY. ALSO...RAIN WILL PROBABLY CUT OFF QUICKLY THIS EVENING AND THIS TREND CAN ALREADY BE SEEN BEHIND THE SHRTWV WHERE EVEN SKIES CLEAR OUT PRETTY QUICK. WITH THE BIG DRYING TAKING PLACE (SEEN ON THE BIS SOUNDING)...FOG WILL BECOME A CONCERN AS IT WAS OVER NORTH DAKOTA. MAY CHANGE THE PATCHY FOG TO AREAS OF DENSE FOG ON THE NEXT FORECAST ISSUANCE. && .PREV DISCUSSION... FOR TUESDAY...LOOKS VERY WARM WITH 850 MB TEMPERATURES UP TO 14C AND MIXING THIS DOWN TO THE SFC GIVES ME LOWER 80S. THIS SEEMS POSSIBLE WITH A WEST-SOUTHWEST WIND WHICH WOULD AID IN SOME DOWNSLOPE...BUT WENT UPPER 70S FOR HIGHS AS SUN ANGLE IS WEAK THIS TIME OF YEAR AND MIGHT NOT BE ABLE TO MIX UP TO 850 MB TOO MUCH LONGER. ALSO SEEMS LIKE A WEAK DRY FRONT COMES THROUGH LATE ON TUESDAY BASED ON 1000-500 MB THICKNESS PACKING AS THICKNESSES LOWER SLIGHTLY FOR WED. FOR THIS REASON...BELIEVE TUE WILL BE THE WARMEST DAY OF THE WEEK AND SLIGHTLY COOLER TEMPERATURES FOR WED...BUT WILL STILL BE ABOVE NORMAL. PULLED POPS OUT OF THE WEST FOR EARLY WED NIGHT AS SEEMS LIKE WITH ZONAL FLOW...THE MID LEVELS WOULD START OUT DRY AND WILL TAKE SOME TIME TO MOISTEN THESE UP. PUSHED TIMING OF THE NEXT SYSTEM BACK ABOUT 6-12 HOURS BECAUSE OF POSSIBILITY OF DRY MID LEVELS. OTHER THAN THAT...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR TEMPERATURES. && .MQT...WATCHES/WARNINGS/ADVISORIES...GALE WARNING LMZ248 TONIGHT. && $$ AJ (DISCUSSION) MICHELS (PREV DISCUSSION) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 1112 AM EDT MON SEP 19 2005 .UPDATED... AT THIS POINT IT WOULD SEEM THE BEST SHOT FOR SEVERE THUNDERSTORMS WOULD BE FROM INTERSTATE 94 SOUTH. THAT IS BASED ON A COMPOSITE OF THE NAM AND RUC PLUS LOOKING AT THE AREA OF STRATUS OVER NRN IL...WI AND ERN MN BEHIND THIS LINE OF CONVECTION. EVEN MORE IMPORTANT THAN THAT IS A COMPOSITE OF THE 400 TO 200 MB DIVERGENCE FIELDS FOR THIS AFTERNOON. IT SHOWS THE BEST DIVERGENCE (SOUTHWEST OF THE JET CORE) HEADING ACROSS NRN IN INTO EXTREME SOUTHEAST MICHIGAN BY 03Z. MOST OF THE GRR CWA HAS UPPER LEVEL SINKING AS THE FRONT COMES THROUGH. THE RUC SOUNDINGS SUGGEST A STRONG SUBSIDENCE INVERSION BETWEEN 10000 AND 15000 FT MOST OF THE AFTERNOON OVER THE CNTRL AND NRN CWA. THUS I DO NOT AT THIS TIME FEEL WE HAVE MUCH CHANCE OF SEVERE HERE... MAYBE THE SOUTHERN TWO ROWS OF COUNTIES. THERE IS STILL THE 40 KNOT LOW LEVEL INFLOW AND THE 100 KNOT JET CORE HEADING EAST NORTHEAST ACROSS SOUTHERN LOWER MICHIGAN (INTERSTATE 94) AS THE FRONT COMES THROUGH. THERE IS STILL 50 TO 60 KNOTS OF DEEP LAYER SHEAR OVER ALL OF THE CWA THIS AFTERNOON. THUS I CAN NOT TOTALLY DISCOUNT THE RISK OF SEVERE ANYWHERE IN THE CWA. EVEN ON THE RUC IF WE CAN GET 80F TEMP WITH A 68F DEW POINT USING THE RUC SOUNDING THIS AFTERNOON WE COULD SEE SEVERE STORMS ON THE FRONT. SO BOTTOM LINE IS I WILL DROP AFTERNOON POP TO SCT BEHIND THIS LINE OF WARM ADVECTION PCPN NORTH OF INTERSTATE 94. THE SMALL CRAFT ADVISORY LOOKS FINE AS IS. $$ && .GRR WATCHES/WARNINGS/ADVISORIES...A SMALL CRAFT ADVISORY IN EFFECT FROM ST. JOSEPH TO MANISTEE THIS AFTERNOON THROUGH TUESDAY MORNING. && $$ BEACHLER MEADE WDM mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 328 PM CDT MON SEP 19 2005 .DISCUSSION... AFTERNOON HIGHS REACHING 94-98F OVER A WIDE AREA AS SUMMER HEAT HOLDING ON FOR A FEW MORE DAYS. MID-UPPER LEVEL MASSIVE ANTICYCLONE SITTING OVER THE LOWER MS VALLEY THIS MORNING PROGGED BY LATEST RUC RUNS TO BEGIN RETROGRADING WWD TONIGHT. WEAKER SURFACE RIDGE AXIS FROM THE SRN APPALACHIANS TO CENTRAL/SRN MS VIRTUALLY DISINTEGRATES AS 500MB SHORTWAVE TROUGH MOVES FROM NE/IA INTO THE TN VALLEY BY TUESDAY EVENING. BEST AXIS OF INSTABILITY/MID LEVEL LAPSE RATES STAYS ALONG I-40 WITH THIS TROUGH AND WILL HOLD OFF MENTIONING ANY TSRA MAKING A SWD PUSH TO THE GRENADA...STARKVILLE...COLUMBUS AREAS FOR NOW. MAY SEE SOME ADDITIONAL CLOUD COVER IN NERN CWFA TUESDAY EVENING BUT OVERALL STILL A DRY AND CLEAR FORECAST WITH HOT AFTERNOONS./40/ LONG TERM...WEDNESDAY THROUGH MONDAY. MAIN CONCERN IN THE EXTENDED IS TROPICAL STORM RITA WHICH WILL LIKELY BECOME A HURRICANE THIS EVENING ACCORDING THE NHC. IN THE MEANTIME...WITH THE UPPER RIDGE CONTINUING TO RETROGRADE SOME SLIGHTLY COOLER TEMPS WILL FILTER BACK IN ESPECIALLY AFTER A WEAK DRY FRONT SLIDES IN FROM THE NORTH BY WEDNESDAY. H850 TEMPS WILL COOL TO 18C ON WED AND THUS ALLOWING FOR HIGHS TO BE LOWER THAN 95 ACROSS MOST OF THE FORECAST AREA. THE WEAK FRONT WILL WEAKEN ON THE EAST SIDE OF THE UPPER RIDGE AS THE RIDGE RETROGRADES WITH FALLING HEIGHTS. WILL GO SLIGHTLY COOLER THAN MEX TEMPS. WILL GO A LITTLE COOLER THAN MAV IS SHOWING...ESPECIALLY IN THE NW WHERE THE MAV IS SHOWING 97 AT KGWO...THIS IS A LITTLE HIGH AND WILL CUT TEMPS BY AT LEAST 3-4 DEGREES AT MOST PLACES. THIS FRONT WILL BRING IN DRIER AIR AND THIS WILL HELP LOWS DROP BACK INTO THE UPPER 60S TO LOWER 70S ACROSS NORTHERN PORTIONS OF THE CWA WEDNESDAY THROUGH FRIDAY. AS FOR WEDNESDAY AND THURSDAY...HIGH PRESSURE AT THE SURFACE WILL HELP KEEP SKIES PARTLY CLOUDY BUT THIS ALL MAY CHANGE COME FRIDAY AS RITA MAY BEGIN TO HAVE SOME INFLUENCE ON OUR AREA...WITH RAIN AND COOLER HIGHS OVER THE AREA DUE TO CLOUD COVER. AS FOR RITA...MEDIUM RANGE AND HURRICANE MODELS HAVE SENT THE PREDICTED TRACK FARTHER NORTH DURING THE PAST FEW DAYS...WHICH HAS CAUSED THE NHC TRACK TO ADJUST ITS COURSE FARTHER NORTH. THERE ARE STILL MANY UNCERTAINTIES AS TO WHERE RITA WILL GO. AS MEDIUM RANGE MODELS AND HURRICANE MODELS HAD LANDFALL ANYWHERE FROM BROWNSVILLE TO SOUTH CENTRAL LOUISIANA BY SATURDAY. THE MAIN REASONS FOR THIS IS PROBABLY DUE TO THE FORWARD MOTION OF RITA WHICH IS A LITTLE SLOWER WITH EACH RUN. THIS ALLOWS THE RIDGE OVER THE NORTHERN GULF OF MEXICO TO RETROGRADE MORE AND WEAKEN THAN THE BUILDING OF A RIDGE OVER THE SE CONUS TO INDUCE RECURVATURE AND A FARTHER NORTH TRACK. NHC OFFICIAL TRACK HAS SHIFTED INTO THE NORTHWEST GULF OF MEXICO BETWEEN 96 AND 120 HRS FROM NOW...AND PUTS IT NEAR HOUSTON BY SATURDAY MORNING. THE 12Z ECMWF FALLS VIRTUALLY ON THE OFFICIAL TRACK AS DOES THE 12Z GFS WHICH BRINGS RITA TO GALVESTON BAY AT 18Z SATURDAY. THEN RITA MOVES NORTH OVER THE ARKLATX THEN TO NORTHEAST ARKANSAS WITH A DEEPER SURFACE LOW...BUT STILL BRINGS SOME RAIN OVER THE OUR CWFA. NOW WHAT EFFECTS WILL ALL OF THIS HAVE ON OUR FORECAST...WELL IF LANDFALL IS THIS WEEKEND AND BEING ON THE NORTH AND THEN EAST SIDE OF RITA WE WILL LIKELY SEE A DECENT SHOT OF SHRA AND TSRA ACROSS THE CWA. DEPENDING ON THE SITE OF LANDFALL WE COULD SEE SOME LOCALLY HEAVY RAINS MAINLY OVER THE WESTERN HALF OF THE FORECAST AREA AND POSSIBLE SEVERE WEATHER INCLUDING TORNADOES AS WAS SEEN IN GEORGIA WITH KATRINA. WILL CONTINUE TO KEEP A VERY CLOSE EYE ON RITA. ALL CONCERNS ONCE AGAIN NEED TO FOCUS ON RITA AS THE TREND SEEMS TO BE SETTLING IN ON THE UPPER TX COAST. SO WITH THAT IN MIND WILL KEEP TEMPS ABOUT THE SAME AND INCREASE POPS OVER THE WEEKEND./17/ && .AVIATION...VFR CONDITIONS WITH CUMULUS 4-5K FEET DISSIPATING BEFORE 00Z. VFR SHOULD CONTINUE THROUGH 05Z WHEN SOME PATCHY MVFR FOG COULD DEVELOP AT THE USUAL LOCATIONS OF KMEI...KHBG. THE FOG/HAZE SHOULD BE WIDESPREAD AT 3-4SM AGAIN BY 10Z AND COULD PERSIST A LITTLE LONGER IN THE MORNING UNTIL 15Z OR SO BEFORE CLEARING OUT. WIND FIELDS VERY WEAK THROUGHOUT THE NEXT 24 HOURS WITH A N TO S DRIFT POSSIBLE./40/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 72 98 71 94 / 0 0 0 0 MERIDIAN 67 98 67 94 / 0 0 10 10 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 254 PM CDT MON SEP 19 2005 .DISCUSSION... THE TWO PRIMARY FORECAST CHALLENGES WITH THIS ISSUANCE ARE THE AREAL COVERAGE AND INTENSITY OF CONVECTION THIS EVENING...AND THE POTENTIAL INFLUENCES OF SOON TO BE HURRICANE RITA LATE THIS WEEKEND INTO MONDAY. IN THE SHORT TERM...18Z SGF SOUNDING SHOWED A 2C CAP IN PLACE BETWEEN 700 AND 750 MB. THIS LAYER WAS ALSO VERY DRY (-17C DP)...BUT LOOKING AT THE 12Z RAOBS...IT APPEARS TO BE VERY LOCALIZED. RUC PROGS WOULD SUPPORT THIS...WITH A NARROW TONGUE OF DRY AIR IN THE 700 TO 750 MB LAYER ADVECTING NEWD INTO SW MO AROUND MIDDAY TODAY. RUC THEN TAKES THE DRY LAYER AND SWEEPS IT EASTWARD AHEAD OF THE FRONT...AND TEMPS COOL BY ABOUT 2C. THIS SHOULD BE ENOUGH TO WEAKEN THE CAP AND ALLOW UPDRAFTS TO PUNCH THROUGH WHATEVER REMAINS OF IT. SLIGHTLY ELEVATED CAPE NEAR 2000 J/KG REMAINS INTO THE EVENING...SO THE POTENTIAL EXISTS FOR CONVECTION TO LAST WELL INTO THE EVENING. A SIGNIFICANT PORTION OF THE CAPE DOES EXTEND ABOVE THE -20C LEVEL...SO LARGE HAIL IS A THREAT. MAY GET SOME MARGINALLY SEVERE WINDS BEFORE THE SURFACE COOLS THIS EVENING...AS WINDEX SHOWS GUSTS TO 59 KNOTS POSSIBLE. COLD FRONT WILL MOVE TO NEAR THE ARKANSAS LINE AFTER MIDNIGHT AS UPPER LEVEL SUPPORT MOVES QUICKLY EASTWARD. TUESDAY MAY SEE THE REMAINS OF THE SURFACE FRONT NEAR THE SOUTHERN CWA...HOWEVER WITH UPPER LEVEL SUPPORT LACKING...DO NOT THINK THAT CONVECTION WILL BE WIDESPREAD ENOUGH TO MENTION. FRONT WASHES OUT OVER THE NEXT 24 HOURS...AND SOUTHERLY FLOW RETURNS BY WEDNESDAY. IN RESPONSE TO THE FORMATION OF AN ANOMALOUSLY DEEP 500 MB TROUGH OVER THE WEST COAST...THE VERY STRONG 500 MB RIDGE OVER TEXAS IS FORECAST TO MOVE EASTWARD INTO ARKANSAS BY 12Z FRIDAY. A SHORTWAVE RIDING OVER THE RIDGE THROUGH THE UPPER MIDWEST WILL NOT LIKELY MAKE MUCH OF A DENT IN THE RIDGE AT OUR LATITUDE...AND THE ASSOCIATED COLD FRONT SHOULD STALL OVER NORTHERN MISSOURI ON FRIDAY. WELL ABOVE NORMAL TEMPS AND DRY WEATHER WILL LIKELY PERSIST THROUGH AT LEAST SATURDAY. THE NEXT BIG FORECAST CHALLENGE COMES ON SUNDAY INTO MONDAY WITH RITA. LATEST TPC LANDFALL NEAR GALVESTON WOULD STILL GIVE SW AND ESPECIALLY SOUTH CENTRAL MO A SHOT AT HEAVY RAIN AS THE REMAINS OF THE SYSTEM PASS BY. ANY FURTHER SHIFTS EASTWARD...LETS NOT EVEN THINK ABOUT THAT!...WOULD LIKELY LEAVE SW MO ON THE DRY SIDE OF THE STORM. WILL EASE INTO THIS...AND JUST GO LOW CHANCE POPS AREAWIDE FOR NOW. BROWNING && .AVIATION... 18Z TAFS...THUNDERSTORMS ARE DEVELOPING ALONG A COLD FRONT FROM SOUTHERN IA TO SOUTH CENTRAL KS. MAIN CONCERN IS HOW FAR SOUTH THE STORMS WILL DEVELOP ALONG THE FRONT. PRESENT INDICATIONS ARE THAT CONVERGENCE ALONG THE FRONT WILL BE ENOUGH TO FORCE THE ISSUE...DESPITE MODERATE CAP. FOR NOW...WILL MAINTAIN PREDOMINATELY VFR CONDITIONS WITH THE MENTION OF CB'S IN THE KSGF/KJLN TAFS LATE THIS AFTERNOON/EVENING WITH THE THINKING THAT STORM COVERAGE WILL BE BETTER NORTH AND EAST OF THE TAF SITES WHERE CAP IS EXPECTED TO BE WEAKER. FRONTAL BOUNDARY WILL MOVE THROUGH THE AREA TONIGHT WITH VFR CONDITIONS LATE TONIGHT AND EARLY TUESDAY. DSA && SGF WATCHES/WARNINGS/ADVISORIES... .MO...NONE. .KS...NONE. $$ WFO SGF mo AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BUFFALO NY 1000 PM EDT MON SEP 19 2005 .UPDATE... A WEAK LINE OF CONVECTION LIMPED ACROSS THE WESTERN COUNTIES EARLIER THIS EVENING WITH A COUPLE VERY LOCALIZED DOWNPOURS. THIS ACTIVITY CONTINUES TO WEAKEN THOUGH AS IT MOVES ACROSS THE GENESEE VALLEY AND WESTERN FINGER LAKES INTO MARGINALLY UNSTABLE AIR. IN FACT...TAMDAR SOUNDINGS OUT OF BGM, YYZ AND ERI SHOW THAT THE AIRMASS WILL NEED SOME HELP SYNOPTICALLY TO GET ANY DECENT CONVECTION GOING. THE LOWER LEVELS ARE NOT VERY UNSTABLE AT ALL... WITH THE MOST UNSTABLE LAYER FOUND FROM ABOUT 700 TO 500MB. IT WAS EARLIER BELIEVED THAT THE APPROACHING 110KT H25 JET WOULD ADD SUCH LIFT AHEAD OF THE COLD FRONT...BUT THE LATEST RUC GUIDANCE BRINGS THE AXIS OF THE JET DIRECTLY ACROSS THE FORECAST AREA. THIS WOULD KEEP THE FAVORED LEFT FRONT EXIT REGION AND RIGHT REAR ENTRANCE REGION OF THE JET ENHANCED LIFT TO OUR NORTH AND SOUTH RESPECTIVELY. THE INCOMING NAM GUIDANCE SUGGESTS THE SAME. WHILE THERE IS PLENTY OF CONVECTION CURRENTLY ONGOING ACROSS SOUTHERN LOWER MICHIGAN...THIS ACTIVITY SHOULD DRIFT TO THE EAST-SOUTHEAST DURING THE OVERNIGHT. AS A RESULT WILL TWEAK CONTINUITY TO DOWNPLAY CONVECTION FOR MOST REGIONS (IAG FRONTIER, GENESEE VALLEY, FINGER LAKES AND EASTERN LAKE ONTARIO)...BUT WILL KEEP LIKELY POPS FOR -SHRA. MEANWHILE THE LIKELY POPS FOR TSRA/SHRA ACROSS THE SOUTHERN TIER WILL BE LEFT INTACT. TEMPS WILL BE RAISED A COUPLE DEGREES IN MOST AREAS FOR THE OVERNIGHT GIVEN WAA AND RELATIVELY HIGH TD'S. RSH && .SHORT TERM (TONIGHT THROUGH THURSDAY)... LOW PRESSURE WILL TRACK TO THE NORTH OF LAKE ONTARIO TONIGHT AND EARLY TUESDAY WITH A COLD FRONT MOVING THROUGH THE REGION... ACCOMPANIED BY A PERIOD OF CONVECTIVE PRECIP. EXPECT THE ASSOCIATED PRECIP TO MOVE THROUGH DURING THE OVERNIGHT HOURS AND NOT LINGER AFTER DAYBREAK EXCEPT FOR THE THREE EASTERN LAKE ONTARIO COUNTIES...THEN OUT OF THE FORECAST AREA BY 19Z TUESDAY. AN EXPANSIVE HIGH WITH COOLER AND DRY AIR THEN BUILDS ACROSS OHIO VALLEY AND EAST TUESDAY NIGHT AND WEDNESDAY. ZONAL FLOW ALOFT WILL KEEP THE AREA FREE OF PRECIP WITH LITTLE MORE THAN HIGH THIN CLOUDS. && .LONG TERM (THURSDAY NIGHT THROUGH MONDAY)... A RATHER MODERATE ZONAL FLOW COUPLED WITH A BAROCLINIC ZONE LYING WEST TO EAST ACROSS OUR FORECAST AREA THURSDAY NIGHT INTO FRIDAY NIGHT WILL MAKE AT LEAST CHANCE POPS NECESSARY FOR THAT TIME FRAME. IT APPEARS THAT THE BAROCLINIC ZONE SHOULD SLIDE TO OUR SOUTH SATURDAY FOR AWHILE BUT EDGE NORTHWARD AGAIN SUNDAY AND MONDAY. THEREFORE WARM FRONTAL PRECIPITATION IS A POSSIBILITY. TEMPERATURES FOR THE MOST PART THROUGH THE PERIOD WILL AVERAGE ABOVE NORMAL. && .AVIATION... CONDITIONS WILL LIKELY DROP TO MVFR AS SHOWERS AND THUNDERSTORMS MOVE THROUGH OVERNIGHT THEN IMPROVEMENT TO VFR IS EXPECTED AGAIN TOWARDS MORNING. THE WIND FIELD BECOMES QUITE STRONG WITH THIS SYSTEM WITH A 40 KNOT LOW LEVEL JET PROGGED OVERNIGHT. SURFACE WINDS AT MOST TAF SITES WILL GUST OVER 25 KNOTS LATE TONIGHT AND TUESDAY MORNING. && .MARINE... VIGOROUS SYSTEM MOVING EAST FROM THE CENTRAL LAKES WILL PRODUCE RATHER WINDY CONDITIONS ACROSS LAKES ERIE AND ONTARIO LATER TONIGHT INTO TUESDAY. SMALL CRAFT ADVISORIES WILL BE NECESSARY FOR ALL SECTIONS OF OUR NEARSHORE FORECASTS. && .MARINE...SMALL CRAFT ADVISORY OVERNIGHT AND TUESDAY LEZ020-040-041 AND FOR TUESDAY LOZ042>045 AND SLZ022. $$ UPDATE...RSH SHORT TERM...HIBBERT LONG TERM/AVIATION/MARINE...SAGE ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 340 PM EDT MON SEP 19 2005 .SHORT TERM (TONIGHT THROUGH WEDNESDAY)... LOOKS LIKE PRIMO CONDITIONS SETTING UP FOR WIDESPREAD FOG...POSSIBLY DENSE TOWARD SUNRISE. A REPEAT OF THIS MONDAY MORNING...EXCEPT POSSIBLY EVEN LOWER HORIZONTAL AND VERTICAL VISIBILITIES. WILL LET EVENING SHIFT LOOK AT THE 00Z RAOB...TO AID IN A POTENTIAL DENSE FOG ADVISORY ISSUANCE. ISOLATED CONVECTION POSSIBLE AGAIN TUESDAY BUT NOT ENUF TO PLACE IN ZONES. S/W MID LEVEL TROF AND ASSOCIATED SFC FRONTAL BOUNDARY TO MOVE TO THE AREA LATE TUE INTO WED. WILL PLACE 30 POPS FOR ENTIRE FA ON WED...WITH SHRA ALONG ADJACENT WATERS LATE TUE NIGHT INTO WED MORNING. TROPICAL CYCLONE RITA TO PUSH INTO THE GULF OF MEXICO... AND WILL SEE A SMALL WINDOW OF SWELL FROM HER LATE TUE INTO WED. CULD SEE A BRIEF PERIOD OF INCREASED RIP POTENTIAL. TEMPS TO REMAIN 5 TO 10 DEGREES ABOVE NORMAL THRU THE SHORT TERM. && .LONG TERM (THURSDAY THROUGH MONDAY)... WILL CONTINUE THE 30 POPS THURSDAY INTO THURSDAY NIGHT DUE TO LEFTOVER SFC FRONTAL BOUNDARY AND SEA BREEZE INTERACTION...AND WHATS LEFT OF THE MID LEVEL S/W TROF. FOR FRIDAY THRU MONDAY...UPPER RIDGE TO BECOME THE MAIN WEATHER FEATURE THRU THIS PERIOD. CENTER OF SFC HIGH TO RESIDE ACROSS THE REGION THRU THIS PERIOD. SHULD BE CAPPING IN THE MID LEVELS...500MB TO 700 MB...TO PREVENT MUCH VERTICAL EXTENT TO THE DIURNAL CU AND LIMIT OVERALL CONVECTION THRU THIS PERIOD. ANY CONVECTION THAT DOES OCCUR WILL BE THE NOCTURNAL GULF STREAM INDUCED VARIETY. MODEL SOUNDINGS INDICATE VERY LITTLE STORM MOTION...WHICH SHULD KEEP THEM OVER THE ATLANTIC WATERS. ONLY POSSIBLE PCPN WILL BE FROM THIS NOCTURNAL ACTION THAT FORMS OVER THE ATLANTIC WATERS CLOSE ENUF TO THE COAST...WHERE STORM MOTIONS FROM FORECAST SOUNDINGS WILL ALLOW THEM TO DRIFT TO LAND. TROPICAL CYCLONE PHILIPPE SWELLS TO MAKE THEIR PRESENCE KNOWN LATE THIS WEEK AND INTO THE WEEKEND. THESE SWELLS LOOK MORE PRONOUNCED THAN RITA. THIS WILL ALSO RAISE THE RIP CURRENT POTENTIAL. TEMPS DURING THIS PERIOD TO REMAIN 5 TO AS MUCH AS 10 DEGREES ABOVE NORMAL. GFS INDICATES BY MID TO LATE NEXT WEEK...THE PASSAGE OF THE FIRST TRUE COLD FRONT THAT CULD POTENTIALLY BRING AUTUMN LIKE TEMPERATURES AND LOWER DEWPOINTS RESULTING IN LOWER RELATIVE HUMIDITES. WE SHALL SEE. && .MARINE... LATEST BUOY OBSERVATIONS CONTINUE TO DEPICT INEPT WIND MAGNITUDES ACROSS ALL OF OUR COASTAL WATERS...AND THIS TREND IS EXPECTED TO CONTINUE THROUGH THE FORESEEABLE FUTURE. WITH THE CIRCULATION FROM RITA REMAINING DISPLACED FAR ENOUGH TO THE SOUTH...SURFACE FEATURES/FORCING WARRANT KEEPING MAGNITUDES UNDER TEN KNOTS THROUGH THE FORECAST. WAVE FORECAST REQUIRES A LITTLE MORE TLC...AS GLANCING SWELL FROM RITA ARRIVES OVERNIGHT TUESDAY INTO THE DAY WEDNESDAY. GFS AND WAVEWATCH SEEM TO HAVE A GOOD HANDLE ON THE PLACEMENT...MOVEMENT OF THE TROPICAL STORM....WITH FOUR TO FIVE FEET DEPICTED BEGINNING LATE TUESDAY. THESE VALUES GET REINFORECD LATE IN THE PERIOD BY SWELL FROM PHILIPPE. && AVIATION... CONVECTION THIS AFTERNOON HAVING A HARD TIME TRYING TO FIRE. HAVE RELEGATED IT TO JUST VC WITH TEMPO GROUPS ALONG COASTAL TERMS. AGREE WITH RUC THAT FLO HAS TROUBLE GETTING IN ON THE ACTION. FORECAST TONIGHT MOSTLY PERSISTENCE ALTHOUGH THERE IS GOOD SUPPORT FROM GUIDANCE AS WELL. MOST TERMINALS SHOULD FALL TO IFR WITH FOG AND STRATUS AOA 06Z. FURTHER DETERIORATION TO LIFR WILL BE POSSIBLE AT ANY TERMINAL SHORTLY THEREAFTER AND PERSIST THROUGH THE PREDAWN HOURS. ONCE THE FOG LIFTS THE HAZE WILL STILL PERSIST, BORDERING ON MVFR AT ALMOST ANY TIME THROUGH THE REMAINDER OF THE PERIOD. && .ILM WATCHES/WARNINGS/ADVISORIES... NC...NONE. SC...NONE. MARINE...NONE. $$ MARINE...KEEBLERSTEPHEN AVIATION...BACONMARK SHORT TERM...HOEHLERDOUGLAS LONG TERM...HOEHLERDOUGLAS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 1032 AM EDT MON SEP 19 2005 .SHORT TERM (TODAY)...REMOVED SLIGHT CHANCE POPS FOR THIS AFTERNOON GIVEN VERY DRY AIRMASS ABOVE 700 MB PER 12Z MHX SOUNDING...SUBSIDENCE ALOFT AND NVA THIS AFTERNOON. HOWEVER...THE BOUNDARY LAYER WILL REMAIN VERY MOIST WITH DEWPOINTS IN THE LOW- MID 70S AND DECENT CAPE VALUES. ADDITIONALLY...THE RUC40 SHOWS E OR NE FLOW AT THE SURFACE THIS AFTERNOON WHICH WOULD FAVOR A SLOW MOVING SEABREEZE...PARTICULARLY IN NORTHERN AREAS DUE TO THE LOCAL GEOGRAPHY AND WHERE WATER TEMPS ARE A BIT COOLER. THE SURFACE WINDS APPEAR TOO WEAK...HOWEVER...FOR ANY SIGNIFICANT SEABREEZE LIFT T0 DEVELOP...AND GIVEN THE ABOVE NEGATIVE FACTORS FOR CONVECTIVE DEVELOPMENT...CONDITIONS APPEAR UNFAVORABLE TO MENTION POPS IN THE FORECAST. ALSO LOWERED SKY COVER AND UPDATED T AND TD TRENDS THROUGH THIS AFTERNOON. && .AVIATION...EXTENSIVE AREA OF STRATUS/FOG ACROSS THE INLAND CWA THIS MORNING. WITH A DRIER OVERALL SOUNDING AS COMPARED TO RECENT DAYS...ESPECIALLY ABOVE H8 THIS MORNING...ANTICIPATE THIS DRIER AIR TO MIX DOWN AND GRADUALLY ERODE THESE LOW CLOUDS OVER THE NEXT COUPLE OF HOURS...WITH GENERALLY VFR WITH SOME PERIODS OF MVFR CEILINGS THRU THE AFTERNOON. && .MARINE...VERY BENIGN CONDITIONS ALONG THE COAST THIS MORNING WITH WINDS GENERALLY LESS THAN 10 KT AND SEAS 3 FT OR LESS. WEAK WIND-SHIFT BOUNDARY HAS MOVED SOUTH TO ALONG A CAPE LOOKOUT TO KINSTON. AS A RESULT...WILL GENERALLY HAVE A NE/E WINDS ACROSS MUCH OF THE WATERS THRU THE AFTERNOON. && .RIP CURRENTS...QUITE MARGINAL AS FAR AS THE MODERATE THREAT OF RIP CURRENTS THIS AFTERNOON. DESPITE LONG PERIODS...SEAS ONLY ABOUT 2 TO 3 FT AT MOST WITH WINDS GENERALLY 10 KT OR LESS. ONLY POSITIVE FACTOR IS THE HIGH ASTRONOMICAL TIDES. WILL KEEP MODERATE...BUT WILL EXPLORE A REDUCTION TO LOW THIS AFTERNOON. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SHORT TERM...VINCENT AVIATION...COLLINS MARINE...COLLINS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 135 PM EDT MON SEP 19 2005 .AVIATION(18Z-18Z)... WARM FRONT CURRENTLY APPRAOCHING NW OH. ELEVATED STORMS HAVE DEVELOPED NR THE WARM FRONT WHICH THE MDLS REALLY DID NOT HAVE A GOOD HANDLE ON. ALTHOUGH AIRMASS IS STABLE OVER THE AREA ATTM...STRONG WARM ADVECTION AT 850MB IS HELPING TO DESTABILIZE THE MID LVLS AND CREATE THIS THUNDERSTORM ACTIVITY. IT IS UNCLEAR WHETHER THIS ACTIVITY WL MAKE IT ALL AWAY ACROSS TO ERI/CLE/YNG THIS AFTN...BUT IT SHOULD MAKE IT TO TOL AND FDY IN THE NEXT COULD OF HRS. OTHER THAN THAT...EXPECT ACTIVITY TO DEVELOP ALONG THE COLD FRONT THIS EVENING AND MOVE ACROSS THE ENTIRE REGION OVERNIGHT. WILL BRING CIGS AND VSBYS TO IFR IN TSRA...BUT THE NAM SUGGESTS RAPID CLEARING BY 15Z TMRW. && .SHORT TERM (THIS AFTERNOON)... CLOUD COVER INCREASED QUICKLY ACROSS FCST AREA THIS MORN BUT STILL APPEARS THIN IN SOME SPOTS. SHWRS AND TSTMS NOT MAKING MUCH EASTWARD PROGRESS. JUST A FEW MINOR CHANGES TO ZFP SINCE FOG HAS DISSIPATED. && .AVIATION(12Z-12Z)... CONDITIONS MVFR TO VFR THIS MORNING. IN SHORT TERM CONCERN IS WESTERN AREAS LATER THIS MORNING WITH HIGH CLDS MOVING IN FROM SHOWER AND THUNDERSTORM ACTIVITY OVER IL AND IN. BROUGHT IN POSSIBLITY OF -SHRA LATER THIS AM IN TOL AND FDY. ETA AND RUC BRING THIS AREA OF SHOWERS NE INTO MI LATER THIS AM. RADAR HOWEVER CONT TO SHOW SOME EASTWARD PROGRESSION OF SHOWERS. THINK THAT MOST OF THIS ACTIVITY WILL DISSIPATE THROUGH THE AM. WITH THAT IN MIND LEFT REMAINDER OF SITES DRY THROUGH THE AFTERNOON WITH MAINLY HIGH CLDS BUILDING EAST INTO NORTHERN OHIO. MORE SIGNIFICANT ACTIVITY EXPECTED THIS EVENING INTO OVERNIGHT HOURS BEGINNING IN TOL-FDY AROUND 00-02Z AND CONTINUING EAST THROUGH THE AREA OVERNIGHT. WINDS WILL ALSO PICK UP LATER THIS AFTERNOON AND EVENING AHEAD OF AND BEHIND THE COLD FRONT AS IT PASSES THROUGH THE AREA TONIGHT. && .PREVIOUS SHORT TERM (TODAY - TUESDAY)... HIGH PRESSURE OVER THE UPPER OH VLY ERY THIS MORNING PROVIDING MOSTLY CLEAR SKIES WITH PATCHY FOG. THE HIGH PRESSURE WILL SLIDE OFF TO THE EAST THIS MORNING. LOW PRESSURE OVER IOWA THIS MRNG WILL DEEPEN AS IT MOVES NORTHEAST THROUGH THE UPPER GREAT LAKES TONIGHT. ASSOCIATED COLD FRONT WILL MOVE THROUGH TONIGHT. COLD FRONT SHOULD MOVE INTO WESTERN OHIO EARLY TONIGHT AND MOVE JUST EAST OF THE FORECAST AREA TUE MRNG. WILL KEEP THE CHC TSTMS GOING FOR WESTERN AREA THIS AFTERNOON BUT DROP BACK TO SLGT CHC OR LOWER CENTRAL AND EASTERN AREAS FOR TODAY. BLV TSTMS SHUD BE IN FAIRLY NARROW BAND BUT THE CONCERN IS HOW FAR OUT IN ADVANCE OF THE FRONT WILL THEY SPREAD WITH THE FAIRLY STG MID LEVEL WINDS. STORMS SHOULD CONTINUE INTO TNGT WITH GOOD SUPT FROM LOW LVL JET...MSTR AND INSTAB AXIS THOUGH MAY SEE DCRSS WITH LOSS HEATING. CONT WITH A CHC LINGERING SHOWERS/TSTMS CLOSE TO FNT TUE MRNG FAR E...THEN SLGT CHC AFTN SHWRS WITH COOL FLOW AND WARM LAKE WATERS. DIDI NOT CHNG CURRENT FCST TEMPS TOO MUCH...THIS EVENING MAV GUIDANCE APPEAR TOO WARM FOR TUE AND WED. .LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)... NO CHANGES FOR NOW. PREV DISC...COLD FRONTAL PASSAGE EXPECTED TO TAKE PLACE MONDAY NIGHT OR TUESDAY WILL SET UP A COLD AIR ADVECTION PATTERN OVER THE AREA TUESDAY NIGHT. FLOW BECOMES WELL ALIGNED TUESDAY EVENING FROM THE NORTHWEST BUT SHEAR DOES DEVELOP IN THE LOWER LEVELS BASED ON GFS 06Z MODEL RUN. MOISTURE IS PROGGED TO BE LIMITED SYNOPTICALLY BUT I THINK WITH WARM WATERS ON THE LAKES THERE SHOULD BE ENOUGH MOISTURE SUPPLIED LOCALLY TO PRODUCE SOME LAKE EFFECT RAIN SHOWERS TUESDAY NIGHT. MODELS ALWAYS TRY TO END THE THREAT OF LAKE EFFECT PRECIPITATION WELL BEFORE IT ACTUALLY ENDS SO WILL PUT IN A THREAT OF 30 PERCENT CHANCE OF SHOWERS TUESDAY NIGHT. WEATHER SHOULD BE RATHER TRANQUIL WEDNESDAY AFTERNOON AND THURSDAY AS SURFACE HIGH PRESSURE AND BROAD UPPER LEVEL RIDGE DOMINATE THE AREA THROUGH THURSDAY. A COLD FRONT IS PROGGED TO MOVE EAST TOWARD THE AREA BY THURSDAY AFTERNOON AND BECOME QUASI STATIONARY BY SATURDAY ACROSS OHIO AND PENNSYLVANIA. WAVES OF LOW PRESSURE AT THE SURFACE AND WEAK UPPER LEVEL SHORTWAVES WILL MOVE EAST ALONG THE BOUNDARY FRIDAY THROUGH SUNDAY. THIS WILL SET THE STAGE FOR A RATHER WET WEEKEND ACROSS THE FORECAST AREA. I WILL INTRODUCE SHOWERS OVER THE AREA FRIDAY THROUGH SUNDAY AND I DONT ANTICIPATE ANY THUNDER AS BOUNDARY SHOULD REMAIN JUST SOUTH OF THE FORECAST AREA KEEPING OUR AREA IN THE STABLE AIR MASS. MEX GUIDANCE TEMPERATURES APPEAR TO BE ON THE WARM SIDE CONSIDERING COLD AIR ADVECTION EARLY IN THE PERIOD AND ALSO THREAT OF EXPECTED PRECIPITATION. SO WILL LOWER TEMPERATURES A BIT THROUGH THE PERIOD. && .CLE WATCHES/WARNINGS/ADVISORIES... .OH...NONE. .PA...NONE. $$ SHORT TERM...WCR/BM LONG TERM...WCR/LOMBARDY AVIATION...MRD oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 1041 AM EDT MON SEP 19 2005 .SHORT TERM (THIS AFTERNOON)... CLOUD COVER INCREASED QUICKLY ACROSS FCST AREA THIS MORN BUT STILL APPEARS THIN IN SOME SPOTS. SHWRS AND TSTMS NOT MAKING MUCH EASTWARD PROGRESS. JUST A FEW MINOR CHANGES TO ZFP SINCE FOG HAS DISSIPATED. && .AVIATION(12Z-12Z)... CONDITIONS MVFR TO VFR THIS MORNING. IN SHORT TERM CONCERN IS WESTERN AREAS LATER THIS MORNING WITH HIGH CLDS MOVING IN FROM SHOWER AND THUNDERSTORM ACTIVITY OVER IL AND IN. BROUGHT IN POSSIBLITY OF -SHRA LATER THIS AM IN TOL AND FDY. ETA AND RUC BRING THIS AREA OF SHOWERS NE INTO MI LATER THIS AM. RADAR HOWEVER CONT TO SHOW SOME EASTWARD PROGRESSION OF SHOWERS. THINK THAT MOST OF THIS ACTIVITY WILL DISSIPATE THROUGH THE AM. WITH THAT IN MIND LEFT REMAINDER OF SITES DRY THROUGH THE AFTERNOON WITH MAINLY HIGH CLDS BUILDING EAST INTO NORTHERN OHIO. MORE SIGNIFICANT ACTIVITY EXPECTED THIS EVENING INTO OVERNIGHT HOURS BEGINNING IN TOL-FDY AROUND 00-02Z AND CONTINUING EAST THROUGH THE AREA OVERNIGHT. WINDS WILL ALSO PICK UP LATER THIS AFTERNOON AND EVENING AHEAD OF AND BEHIND THE COLD FRONT AS IT PASSES THROUGH THE AREA TONIGHT. && .PREVIOUS SHORT TERM (TODAY - TUESDAY)... HIGH PRESSURE OVER THE UPPER OH VLY ERY THIS MORNING PROVIDING MOSTLY CLEAR SKIES WITH PATCHY FOG. THE HIGH PRESSURE WILL SLIDE OFF TO THE EAST THIS MORNING. LOW PRESSURE OVER IOWA THIS MRNG WILL DEEPEN AS IT MOVES NORTHEAST THROUGH THE UPPER GREAT LAKES TONIGHT. ASSOCIATED COLD FRONT WILL MOVE THROUGH TONIGHT. COLD FRONT SHOULD MOVE INTO WESTERN OHIO EARLY TONIGHT AND MOVE JUST EAST OF THE FORECAST AREA TUE MRNG. WILL KEEP THE CHC TSTMS GOING FOR WESTERN AREA THIS AFTERNOON BUT DROP BACK TO SLGT CHC OR LOWER CENTRAL AND EASTERN AREAS FOR TODAY. BLV TSTMS SHUD BE IN FAIRLY NARROW BAND BUT THE CONCERN IS HOW FAR OUT IN ADVANCE OF THE FRONT WILL THEY SPREAD WITH THE FAIRLY STG MID LEVEL WINDS. STORMS SHOULD CONTINUE INTO TNGT WITH GOOD SUPT FROM LOW LVL JET...MSTR AND INSTAB AXIS THOUGH MAY SEE DCRSS WITH LOSS HEATING. CONT WITH A CHC LINGERING SHOWERS/TSTMS CLOSE TO FNT TUE MRNG FAR E...THEN SLGT CHC AFTN SHWRS WITH COOL FLOW AND WARM LAKE WATERS. DIDI NOT CHNG CURRENT FCST TEMPS TOO MUCH...THIS EVENING MAV GUIDANCE APPEAR TOO WARM FOR TUE AND WED. .LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)... NO CHANGES FOR NOW. PREV DISC...COLD FRONTAL PASSAGE EXPECTED TO TAKE PLACE MONDAY NIGHT OR TUESDAY WILL SET UP A COLD AIR ADVECTION PATTERN OVER THE AREA TUESDAY NIGHT. FLOW BECOMES WELL ALIGNED TUESDAY EVENING FROM THE NORTHWEST BUT SHEAR DOES DEVELOP IN THE LOWER LEVELS BASED ON GFS 06Z MODEL RUN. MOISTURE IS PROGGED TO BE LIMITED SYNOPTICALLY BUT I THINK WITH WARM WATERS ON THE LAKES THERE SHOULD BE ENOUGH MOISTURE SUPPLIED LOCALLY TO PRODUCE SOME LAKE EFFECT RAIN SHOWERS TUESDAY NIGHT. MODELS ALWAYS TRY TO END THE THREAT OF LAKE EFFECT PRECIPITATION WELL BEFORE IT ACTUALLY ENDS SO WILL PUT IN A THREAT OF 30 PERCENT CHANCE OF SHOWERS TUESDAY NIGHT. WEATHER SHOULD BE RATHER TRANQUIL WEDNESDAY AFTERNOON AND THURSDAY AS SURFACE HIGH PRESSURE AND BROAD UPPER LEVEL RIDGE DOMINATE THE AREA THROUGH THURSDAY. A COLD FRONT IS PROGGED TO MOVE EAST TOWARD THE AREA BY THURSDAY AFTERNOON AND BECOME QUASI STATIONARY BY SATURDAY ACROSS OHIO AND PENNSYLVANIA. WAVES OF LOW PRESSURE AT THE SURFACE AND WEAK UPPER LEVEL SHORTWAVES WILL MOVE EAST ALONG THE BOUNDARY FRIDAY THROUGH SUNDAY. THIS WILL SET THE STAGE FOR A RATHER WET WEEKEND ACROSS THE FORECAST AREA. I WILL INTRODUCE SHOWERS OVER THE AREA FRIDAY THROUGH SUNDAY AND I DONT ANTICIPATE ANY THUNDER AS BOUNDARY SHOULD REMAIN JUST SOUTH OF THE FORECAST AREA KEEPING OUR AREA IN THE STABLE AIR MASS. MEX GUIDANCE TEMPERATURES APPEAR TO BE ON THE WARM SIDE CONSIDERING COLD AIR ADVECTION EARLY IN THE PERIOD AND ALSO THREAT OF EXPECTED PRECIPITATION. SO WILL LOWER TEMPERATURES A BIT THROUGH THE PERIOD. && .CLE WATCHES/WARNINGS/ADVISORIES... .OH...NONE. .PA...NONE. $$ SHORT TERM...WCR/BM LONG TERM...WCR/LOMBARDY AVIATION...ABE oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CLEVELAND OHIO 749 AM EDT MON SEP 19 2005 .AVIATION(12Z-12Z)... CONDITIONS MVFR TO VFR THIS MORNING. IN SHORT TERM CONCERN IS WESTERN AREAS LATER THIS MORNING WITH HIGH CLDS MOVING IN FROM SHOWER AND THUNDERSTORM ACTIVITY OVER IL AND IN. BROUGHT IN POSSIBLITY OF -SHRA LATER THIS AM IN TOL AND FDY. ETA AND RUC BRING THIS AREA OF SHOWERS NE INTO MI LATER THIS AM. RADAR HOWEVER CONT TO SHOW SOME EASTWARD PROGRESSION OF SHOWERS. THINK THAT MOST OF THIS ACTIVITY WILL DISSIPATE THROUGH THE AM. WITH THAT IN MIND LEFT REMAINDER OF SITES DRY THROUGH THE AFTERNOON WITH MAINLY HIGH CLDS BUILDING EAST INTO NORTHERN OHIO. MORE SIGNIFICANT ACTIVITY EXPECTED THIS EVENING INTO OVERNIGHT HOURS BEGINNING IN TOL-FDY AROUND 00-02Z AND CONTINUING EAST THROUGH THE AREA OVERNIGHT. WINDS WILL ALSO PICK UP LATER THIS AFTERNOON AND EVENING AHEAD OF AND BEHIND THE COLD FRONT AS IT PASSES THROUGH THE AREA TONIGHT. && .SHORT TERM (TODAY - TUESDAY)... HIGH PRESSURE OVER THE UPPER OH VLY ERY THIS MORNING PROVIDING MOSTLY CLEAR SKIES WITH PATCHY FOG. THE HIGH PRESSURE WILL SLIDE OFF TO THE EAST THIS MORNING. LOW PRESSURE OVER IOWA THIS MRNG WILL DEEPEN AS IT MOVES NORTHEAST THROUGH THE UPPER GREAT LAKES TONIGHT. ASSOCIATED COLD FRONT WILL MOVE THROUGH TONIGHT. COLD FRONT SHOULD MOVE INTO WESTERN OHIO EARLY TONIGHT AND MOVE JUST EAST OF THE FORECAST AREA TUE MRNG. WILL KEEP THE CHC TSTMS GOING FOR WESTERN AREA THIS AFTERNOON BUT DROP BACK TO SLGT CHC OR LOWER CENTRAL AND EASTERN AREAS FOR TODAY. BLV TSTMS SHUD BE IN FAIRLY NARROW BAND BUT THE CONCERN IS HOW FAR OUT IN ADVANCE OF THE FRONT WILL THEY SPREAD WITH THE FAIRLY STG MID LEVEL WINDS. STORMS SHOULD CONTINUE INTO TNGT WITH GOOD SUPT FROM LOW LVL JET...MSTR AND INSTAB AXIS THOUGH MAY SEE DCRSS WITH LOSS HEATING. CONT WITH A CHC LINGERING SHOWERS/TSTMS CLOSE TO FNT TUE MRNG FAR E...THEN SLGT CHC AFTN SHWRS WITH COOL FLOW AND WARM LAKE WATERS. DIDI NOT CHNG CURRENT FCST TEMPS TOO MUCH...THIS EVENING MAV GUIDANCE APPEAR TOO WARM FOR TUE AND WED. .LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)... NO CHANGES FOR NOW. PREV DISC...COLD FRONTAL PASSAGE EXPECTED TO TAKE PLACE MONDAY NIGHT OR TUESDAY WILL SET UP A COLD AIR ADVECTION PATTERN OVER THE AREA TUESDAY NIGHT. FLOW BECOMES WELL ALIGNED TUESDAY EVENING FROM THE NORTHWEST BUT SHEAR DOES DEVELOP IN THE LOWER LEVELS BASED ON GFS 06Z MODEL RUN. MOISTURE IS PROGGED TO BE LIMITED SYNOPTICALLY BUT I THINK WITH WARM WATERS ON THE LAKES THERE SHOULD BE ENOUGH MOISTURE SUPPLIED LOCALLY TO PRODUCE SOME LAKE EFFECT RAIN SHOWERS TUESDAY NIGHT. MODELS ALWAYS TRY TO END THE THREAT OF LAKE EFFECT PRECIPITATION WELL BEFORE IT ACTUALLY ENDS SO WILL PUT IN A THREAT OF 30 PERCENT CHANCE OF SHOWERS TUESDAY NIGHT. WEATHER SHOULD BE RATHER TRANQUIL WEDNESDAY AFTERNOON AND THURSDAY AS SURFACE HIGH PRESSURE AND BROAD UPPER LEVEL RIDGE DOMINATE THE AREA THROUGH THURSDAY. A COLD FRONT IS PROGGED TO MOVE EAST TOWARD THE AREA BY THURSDAY AFTERNOON AND BECOME QUASI STATIONARY BY SATURDAY ACROSS OHIO AND PENNSYLVANIA. WAVES OF LOW PRESSURE AT THE SURFACE AND WEAK UPPER LEVEL SHORTWAVES WILL MOVE EAST ALONG THE BOUNDARY FRIDAY THROUGH SUNDAY. THIS WILL SET THE STAGE FOR A RATHER WET WEEKEND ACROSS THE FORECAST AREA. I WILL INTRODUCE SHOWERS OVER THE AREA FRIDAY THROUGH SUNDAY AND I DONT ANTICIPATE ANY THUNDER AS BOUNDARY SHOULD REMAIN JUST SOUTH OF THE FORECAST AREA KEEPING OUR AREA IN THE STABLE AIR MASS. MEX GUIDANCE TEMPERATURES APPEAR TO BE ON THE WARM SIDE CONSIDERING COLD AIR ADVECTION EARLY IN THE PERIOD AND ALSO THREAT OF EXPECTED PRECIPITATION. SO WILL LOWER TEMPERATURES A BIT THROUGH THE PERIOD. && .CLE WATCHES/WARNINGS/ADVISORIES... .OH...NONE. .PA...NONE. $$ SHORT TERM...WCR LONG TERM...WCR/LOMBARDY AVIATION...ABE oh AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 850 PM CDT MON SEP 19 2005 WEAK CDFNT CONTINUES TO DRIFT SWD THIS EVENING ACROSS NRN OK. WITH WARM MID LEVEL TEMPS...COOLING BOUNDARY LAYER...AND ONLY WEAK CONVERGENCE ALONG THE BNDRY...WILL DROP POPS FOR TONIGHT. WILL TWEAK THE MIN TEMPS A BIT BASED ON THE EXPECTED MOVEMENT OF THE FRONT...OTRW NOT MUCH ELSE TO CHANGE. II AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 213 PM CDT MON SEP 19 2005 .DISCUSSION... INITIAL IMPRESSIONS ARE THAT THE SHORTWAVE TROUGH OVER NORTHWEST KANSAS IS STRONGER THAN EXPECTED WITH ITS ASSOCIATED FIELD OF ASCENT RESULTING IN CONTINUED SOUTHWESTWARD EXPANSION OF CONVECTION ALONG AN ASSOCIATED COLD FRONT AND MOISTENING OF MID/UPPER LEVEL COLUMN PER WATER VAPOR IMAGERY. POPS THEREFORE APPEAR MORE JUSTIFIED ACROSS NORTHERN OKLAHOMA THIS AFTERNOON/EVENING THAN EVEN A FEW HOURS AGO DESPITE AN IMPRESSIVE CAPPING INVERSION. THIS SCENARIO ALSO HAS SIGNIFICANT IMPLICATIONS ON THE FUTURE FRONTAL POSITION WITH ALL MODELS EXCEPT THE RUC POORLY INITIALIZING ITS DEPTH AND STRUCTURE. GIVEN THIS EARLY ASSESSMENT...IT IS QUITE POSSIBLE THAT ASSOCIATED SUBSIDENCE WILL ALSO BE STRONGER THAN FORECAST RESULTING IN A MORE SOUTHWARD FRONTAL POSITION BY EARLY TUESDAY. HAVE LEANED SLIGHTLY TOWARD THIS SCENARIO IN THE GRIDS ESPECIALLY IN THE WEST...AND TO BE CONSISTENT HAVE ALSO INCORPORATED MORE STRATUS/FOG LATE TONIGHT/ EARLY TUESDAY BASED ON THIS MORNING OBSERVATIONS AND MODEL BIAS. MEANWHILE...MORNING UPPER AIR ANALYSES SHOW THE MID/UPPER RIDGE BUILDING STEADILY NORTHWARD FROM TEXAS WITH THE RIDGE FORECAST TO BUILD EVEN FURTHER ONCE THE ABOVE MENTIONED TROUGH PASSES. THE FRONT SHOULD WEAKEN AND RETREAT NORTHWARD TUESDAY AND WEDNESDAY WITH UNUSUALLY WARM/NEAR HOT TEMPERATURES CONTINUING THROUGH THE END OF THE WEEK. MODELS INDICATE ANOTHER COLD FRONT MAY ATTEMPT TO ENTER NORTHWEST OKLAHOMA FRIDAY. HOWEVER GIVEN CLOSE PROXIMITY OF THE MID/UPPER RIDGE AND HOT TEMPERATURES IN ADVANCE OF THE FRONT AM NOT CONFIDENT THE FRONT WILL EVEN MOVE INTO THE AREA. EVEN IF THE FRONT DOES MOVE INTO THE AREA THE MEDIUM RANGE MODELS ARE CONSISTENT IN WEAKENING THE FRONT AND RETREATING IT NORTHWARD AS A WARM FRONT JUST AS TROPICAL STORM/HURRICANE RITA MAKES LANDFALL. HAVE CLOSELY FOLLOWED GUIDANCE FROM THE HURRICANE CENTER ON THE FUTURE PATH OF RITA WHICH TAKES IT TO NEAR GALVESTON BY 12Z SAT THEN CURVES IT NORTHWARD TOWARD EASTERN OKLAHOMA/ARKANSAS SATURDAY NIGHT INTO SUNDAY NIGHT. GIVEN THE SMALL SPATIAL NATURE OF TROPICAL SYSTEMS COMPARED TO THE SYNOPTIC SCALE AND THAT RITA IS STILL 4 TO 5 DAYS AWAY...HAVE REMAINED CONSERVATIVE IN INTERPRETING MODEL OUTPUT WITH ONLY CHANCE POPS (20-30) AND NO MENTION OF STRONG WINDS AT THIS TIME AS RITA POSSIBLY NEARS THE AREA. .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 71 94 71 97 / 20 0 0 0 HOBART OK 70 95 69 98 / 20 0 0 0 WICHITA FALLS TX 72 98 72 98 / 10 0 0 0 GAGE OK 66 91 65 99 / 10 0 0 0 PONCA CITY OK 68 92 69 95 / 20 0 0 0 DURANT OK 74 98 73 97 / 10 0 0 0 .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. $$ JAMES ok AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 213 PM CDT MON SEP 19 2005 .DISCUSSION... INITIAL IMPRESSIONS ARE THAT THE SHORTWAVE TROUGH OVER NORTHWEST KANSAS IS STRONGER THAN EXPECTED WITH ITS ASSOCIATED FIELD OF ASCENT RESULTING IN CONTINUED SOUTHWESTWARD EXPANSION OF CONVECTION ALONG AN ASSOCIATED COLD FRONT AND MOISTENING OF MID/UPPER LEVEL COLUMN PER WATER VAPOR IMAGERY. POPS THEREFORE APPEAR MORE JUSTIFIED ACROSS NORTHERN OKLAHOMA THIS AFTERNOON/EVENING THAN EVEN A FEW HOURS AGO DESPITE AN IMPRESSIVE CAPPING INVERSION. THIS SCENARIO ALSO HAS SIGNIFICANT IMPLICATIONS ON THE FUTURE FRONTAL POSITION WITH ALL MODELS EXCEPT THE RUC POORLY INITIALIZING ITS DEPTH AND STRUCTURE. GIVEN THIS EARLY ASSESSMENT...IT IS QUITE POSSIBLE THAT ASSOCIATED SUBSIDENCE WILL ALSO BE STRONGER THAN FORECAST RESULTING IN A MORE SOUTHWARD FRONTAL POSITION BY EARLY TUESDAY. HAVE LEANED SLIGHTLY TOWARD THIS SCENARIO IN THE GRIDS ESPECIALLY IN THE WEST...AND TO BE CONSISTENT HAVE ALSO INCORPORATED MORE STRATUS/FOG LATE TONIGHT/ EARLY TUESDAY BASED ON THIS MORNING OBSERVATIONS AND MODEL BIAS. MEANWHILE...MORNING UPPER AIR ANALYSES SHOW THE MID/UPPER RIDGE BUILDING STEADILY NORTHWARD FROM TEXAS WITH THE RIDGE FORECAST TO BUILD EVEN FURTHER ONCE THE ABOVE MENTIONED TROUGH PASSES. THE FRONT SHOULD WEAKEN AND RETREAT NORTHWARD TUESDAY AND WEDNESDAY WITH UNUSUALLY WARM/NEAR HOT TEMPERATURES CONTINUING THROUGH THE END OF THE WEEK. MODELS INDICATE ANOTHER COLD FRONT MAY ATTEMPT TO ENTER NORTHWEST OKLAHOMA FRIDAY. HOWEVER GIVEN CLOSE PROXIMITY OF THE MID/UPPER RIDGE AND HOT TEMPERATURES IN ADVANCE OF THE FRONT AM NOT CONFIDENT THE FRONT WILL EVEN MOVE INTO THE AREA. EVEN IF THE FRONT DOES MOVE INTO THE AREA THE MEDIUM RANGE MODELS ARE CONSISTENT IN WEAKENING THE FRONT AND RETREATING IT NORTHWARD AS A WARM FRONT JUST AS TROPICAL STORM/HURRICANE RITA MAKES LANDFALL. HAVE CLOSELY FOLLOWED GUIDANCE FROM THE HURRICANE CENTER ON THE FUTURE PATH OF RITA WHICH TAKES IT TO NEAR GALVESTON BY 12Z SAT THEN CURVES IT NORTHWARD TOWARD EASTERN OKLAHOMA/ARKANSAS SATURDAY NIGHT INTO SUNDAY NIGHT. GIVEN THE SMALL SPATIAL NATURE OF TROPICAL SYSTEMS COMPARED TO THE SYNOPTIC SCALE AND THAT RITA IS STILL 4 TO 5 DAYS AWAY...HAVE REMAINED CONSERVATIVE IN INTERPRETING MODEL OUTPUT WITH ONLY CHANCE POPS (20-30) AND NO MENTION OF STRONG WINDS AT THIS TIME AS RITA POSSIBLY NEARS THE AREA. .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 71 94 71 97 / 20 0 0 0 HOBART OK 70 95 69 98 / 20 0 0 0 WICHITA FALLS TX 72 98 72 98 / 10 0 0 0 GAGE OK 66 91 65 99 / 10 0 0 0 PONCA CITY OK 68 92 69 95 / 20 0 0 0 DURANT OK 74 98 73 97 / 10 0 0 0 .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. $$ JAMES ok AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BURLINGTON VT 952 AM EDT MON SEP 19 2005 .SHORT TERM (REST OF TODAY)... MINOR CHANGES TO GOING FORECAST THIS MORNING TO ADJUST SKY COVER ONLY. IMPRESSIVE FOG COVERAGE THIS MORNING OVER MUCH OF THE NORTHEAST ESPECIALLY IN CHAMPLAIN...CONNECTICUT...AND MOHAWK RIVER VALLEYS WHICH IS JUST BEGINNING TO BURN OFF. HIGH PRESSURE CENTERED OVER NEW ENGLAND WILL HOLD OFF MAJORITY OF CLOUD COVERAGE CURRENTLY NORTH AND WEST OF FORECAST AREA...SO FEEL AN UPDATE FOR MOSTLY SUNNY SKIES IS JUSTIFIED. GFS AND NAM12 850 TEMPS SUPPORT HIGH TEMPS IN THE MID 70S ACROSS THE AREA TODAY...AND GOING FORECAST HAS THIS COVERED WELL. NO OTHER CHANGES TO FORECAST PLANNED. && .PREVIOUS DISCUSSION... (ISSUED 335 AM EDT MON SEP 19 2005) SYNOPSIS... HI PRESS TO BUILD ACRS THE FA FROM THE WEST TODAY. WK CF TO STAY TO THE NORTH OF THE FA TODAY. STORM SYS TO MOVE ACRS THE GREAT LKS REGION TODAY...THEN ACRS SRN CANADA TONITE. THIS SYSTEM/S ASSOCIATED CF TO MOVE ACRS THE FA ON TUE. WK HI PRESS TO AFFECT THE FA ON TUE NITE AND WED. SHORT TERM (TODAY THROUGH WEDNESDAY)... 00-01Z RUC13 SHOWS TEMPS TO GET UP INTO THE U60S TO NEAR 80F TODAY WITH WESTERLY SFC WINDS AT 5-15 KTS. T1MAX TEMPS ARE IN THE U70S-L80S TODAY. FEW TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON THIS DATA AND MESONET OBS. SOME LOW-LVL MSTR TO AFFECT THE FA TODAY. RUC SHOWS A FEW CLDS ACRS THE FA TODAY WITH SOME -SHRA POSSIBLE ACRS THE NRN TIER ZONES. H85 WAA TO DEVELOP ACRS THE FA FOR TODAY AND TONITE AND AGAIN ON WED...WITH CAA ON TUE/TUE NITE. LOW-LVL MSTR ADVECTION TO TAKE PLACE ACRS THE FA TONITE...EARLY ON TUE...LATE ON TUE NITE...AND FOR MUCH OF WED. SOME LOW-LVL MSTR TO AFFECT THE FA LATER TONITE THRU EARLY ON TUE NITE...AND AGAIN ON WED. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA THIS AFTERNOON AND ON WED AFTERNOON. MID-LVL LAPSE RATES TO BE HI ACRS THE FA THIS AFTERNOON AND TONITE AND AGAIN ON WED AFTERNOON. SOME MID-LVL MSTR TO AFFECT THE FA LATE TONITE AND EARLY ON TUE. PW VALUES ACRS THE FA TO BE 0.5-1.1" TODAY AND ON TUE...1-1.5" TONITE... AND AROUND 0.75" TUE NITE/WED. NAM CAPES ACRS THE FA APPEAR TO BE BLW 400 J/KG TONITE...BLW 1000 J/KG ON TUE...AND BLW 800 J/KG ON WED. IR SAT PIX SHOWS A FEW CLDS MOVING ACRS MUCH OF THE FA ATTM. WILL OPT TO HANDLE ANY LINGERING FG ACRS THE FA THIS MORNING WITH THE STF. LATER SHIFTS WILL NEED TO KEEP AN EYE ON ANY POSSIBLE -SHRA ASSOCIATED WITH THE CF THAT SHOULD STAY TO THE NORTH OF THE FA TODAY. GOING FCST ACRS MUCH OF THE REST OF THE SHORT-TERM PERIOD STILL LOOKS GOOD ATTM. WILL CONT TO GO WITH CHC POPS (HIGHEST ACRS THE WRN ZONES) BY LATER TONITE AND LIKELY POPS ON TUE FOR SHRA/TSRA. SOME PCPN STILL EXPECTED TO LINGER ACRS THE FA EARLY ON TUE NITE AS WELL. T1MAX TEMPS ARE IN THE L-M70S ON TUE. LONG TERM (WEDNESDAY NIGHT THROUGH SUNDAY)... NO CHANGES TO THE GOING FCST FOR NOW. WRK ZONES AND PRELIM ISC GRIDS AVAILABLE. ALL FINAL PRODUCTS BY 4 AM. AVIATION... WK SFC HI PRES ERLY THIS MRNG FM WRN PA WITH A RDG ACRS NRN NEW ENG. THIS HI MOVS OFSHR TNGT WITH S OR SW SFC FLO RETURNING. AN AREA OF LOW PRES WL MOV ACRS THE NRN GRTLKS LATER TDY AND INTO SRN ONT TNGT. CLR SKIES AND LIGHT WINDS ASOCD WITH ABV MENTIONED SFC HI ERLY THIS MRNG HAS RESULTED IN VLY FG AT THE USUAL LOCATIONS...ESPCLY THE KSLK AND KMPV TAF SITES. THIS FG WL RESULT IN LCL IFR CONDS THRU ABT 13Z...AND THEREAFTER MIX OUT UPON HEATING OF THE SUN WITH VFR CONDS THRU 06Z/20TH. BTWN 00Z/20TH AND 06Z/20TH EXPECT SCT-BKN CLDS 6-8K FT DVLPG WITH BKN CI ABV AS MOISTURE FM GRTLKS MOVS E. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SHORT TERM...LAHIFF vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 230 PM CDT MON SEP 19 2005 .DISCUSSION...FORECAST FOCUS IS ON QUIETER PERIOD COMING UP... THEN ON RETURN OF PCPN THREAT ARND MIDWEEK. IN THE SHORT TERM...SFC LOW NOW INTO UPR MI WITH TRAILING CDFNT TO NW IL. CANNOT COMPLETELY RULE OUT PSBLTY OF NEW CNVTV DVLPT UNTIL FNT LEAVES THE STATE THIS EVE. BUT RUC BUFKIT SOUNDING IS STILL SHWG A RATHER STG LOOKING CAP...AND WINDS EVEN AHD OF FNT ARE TURNING MORE WLY. MAY HANG ON TO SLGT CHC ERLY THIS EVE BEFORE FNT LEAVES. NW WINDS BHND IT WL STAY UP FOR AWHILE BEFORE DMSHG LATER TNGT. TMRW AND WED STILL LOOK GOOD AS A RDG OF HI PRES SLIDES ACROSS THE RGN. TMPS SHUD BE ABV SEAS NORMALS FOR THE MOST PART. NAM AND GFS STILL BRING NEXT RN CHC IN WED NGT AND THU AS ANTHR CDFNT SAGS SWD THRU CWA. && .MKX WATCHES/WARNINGS/ADVISORIES...NONE. && $$ wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO CO 343 AM MDT TUE SEP 20 2005 .SHORT TERM... (TODAY AND TONIGHT) SHORT TERM CONCERNS INCLUDE TEMPERATURES AND PRECIP CHANCES ACROSS THE CENTRAL AND SOUTHWEST MTS. CURRENT WATER VAPOR IMAGERY AND RUC UPPER AIR ANALYSIS INDICATING WEAK WEST TO SOUTHWEST FLOW ACROSS THE STATE AS BROAD UPPER LEVEL RIDGE CONTINUES TO BUILD ACROSS TEXAS THROUGH THE DESERT SW AND INTO THE GREAT BASIN REGION ATTM. WATER VAPOR IMAGERY ALSO INDICATING INCREASING MID AND UPPER LEVEL MOISTURE ACROSS THE REGION WITH SUBTROPICAL MOISTURE BECOMING EMBEDDED IN THE FLOW ALOFT. AT THE SFC...LOW LEVEL MOISTURE REMAINS IN PLACE ACROSS EASTERN COLORADO WITH SATELLITE LOOP INDICATING OCCASIONAL BOUTS OF HIGH LEVEL CLOUDS MOVING ACROSS STATE...WHICH HAS KEPT TEMPERATURES ON THE MILD SIDE ACROSS THE REGION AND HAS HAMPERED ANY STRATUS DEVELOPMENT ACROSS THE EASTERN PLAINS ATTM. TODAY AND TONIGHT...UPPER FLOW ALOFT BECOMES SLIGHTLY MORE SW AS UPPER LOW CURRENTLY SPINNING OFF THE SOUTHERN CALIF COAST SLOWLY MOVES ONSHORE. MOISTURE EMBEDDED IN FLOW WILL CONTINUE TO INCREASE ACROSS THE REGION...THOUGH SOUNDINGS INDICATING MAINLY UPPER LEVEL MOISTURE (AOB H3)...WITH BEST MID LEVEL PLUME MOVING ACROSS UTAH. TEMPERATURES ALOFT CONTINUE TO WARM ACROSS THE STATE UNDER BUILDING RIDGE WITH H7 TEMPS INCREASING TO BETWEEN +13C AND +16C...AND WITH WEAK DOWNSLOPE FLOW...SHOULD SEE HIGHS SOME 8-15F ABOVE SEASONAL AVERAGES THIS AFTERNOON...EVEN WITH SOME LOSS OF DIRECT INSOLATION WITH BOUTS OF CIRRUS MOVING ACROSS THE REGION. HAVE KEPT SLIGHT POPS ACROSS THE HIGHER ELEVATIONS OF THE SW AND CENTRAL MTS THIS AFTERNOON AND EVENING...DUE TO STEEP LAPSE RATES AND GRADUAL MOISTENING OF LOWER LEVELS WITH MODELS INDICATING H7-5 SPECIFIC HUMIDITIES INCREASING TO NEAR 4G/KG ACROSS WESTERN COLORADO TONIGHT. H7 THERMAL TROUGH ALSO PROGGED TO MOVE ACROSS THE EASTERN PLAINS TONIGHT...KEEPING WEAK WESTERLY FLOW AND TEMPERATURES UP WITH MILD OVERNIGHT LOWS EXPECTED ONCE AGAIN ACROSS THE REGION. -MW .LONG TERM... (WEDNESDAY THROUGH MONDAY) STILL APPEARS WEDNESDAY WILL BE THE WARMEST DAY OF THE UPCOMING WEEK...WITH LARGE AREA OF 14C TO 16C 700MB TEMPS PROGGED OVER ALL OF SOUTHERN COLORADO. WED MAX TEMPS IN CURRENT SET OF GRIDS WOULD TIE THE RECORD HIGH AT KALS...AND BREAK RECORDS AT BOTH KPUB AND KCOS. TRIED TO KEEP ANY POPS LIMITED TO THE MTS AND WRN VALLEYS...WHERE MID LEVEL MOISTURE WILL BE DEEPER...BEST CHANCES WILL BE ALONG THE CONT DVD AND WWD. FRONT SHOULD SAG SOUTH THROUGH THE PLAINS BY EARLY THURSDAY MORNING...WITH UPSLOPE WINDS ADVECTING LOW LEVEL MOISTURE WESTWARD BY THU AFTERNOON. WOULD EXPECT AN UPTURN IN -TSRA CHANCES OVER THE EAST BY THU EVENING...THOUGH WITH ONLY WEAK DYNAMICS...ISOLATED POPS ARE SUFFICIENT. SHOULD SEE THU MAXES COOL ABOUT 10F MOST OF THE EAST...LESS COOLING OVER THE MTS AND WEST AS 700 MB TEMPS DECREASE ONLY SLIGHTLY. GENERALLY DRY SOUTHWEST FLOW SPREADS ACROSS THE AREA FRI AHEAD OF DIGGING WRN U.S. UPPER TROUGH...WITH POPS LIMITED TO AREAS ALONG THE CONT DVD. SAT THROUGH MON TIME FRAME STILL LOOKING UNSETTLED...AS WRN TROUGH EDGES EASTWARD AND FRONT SAGS INTO THE PLAINS SAT NIGHT. CURRENT GRIDS FIT LATEST MODEL RUNS FAIRLY WELL...ONLY MADE SOME VERY SMALL CHANGES TO POPS AND TEMPS. --ETP && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 338 AM EDT TUE SEP 20 2005 .DISCUSSION... MAIN FORECAST CONCERN ARE TEMPERATURES THROUGH WED AND PRECIPITATION CHANCES WED AFTERNOON THROUGH THU. CURRENT WEATHER...07Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS SHOWED ZONAL FLOW FROM WASHINGTON STATE TO NORTH DAKOTA...THEN NW FLOW INTO A SHRTWV TROUGH OVER GEORGIAN BAY. THIS SHRTWV WAS RESPONSIBLE FOR THE HEAVY RAIN AND WINDS EXPERIENCED ACROSS THE WISCONSIN AND MICHIGAN YESTERDAY. DUE TO THE ZONAL FLOW...THIS SHRTWV CONTINUES TO PUSH OFF TO THE EAST FAIRLY RAPIDLY AND AS A RESULT...A RIDGE OF HIGH PRESSURE HAS BEEN BUILDING IN AT THE SURFACE OVER WESTERN LAKE SUPERIOR. BREEZY CONDITIONS STILL EXIST OVER EASTERN LAKE SUPERIOR CLOSER TO A 1002 MB LOW ASSOCIATED WITH THE SHRTWV. DESPITE THE HIGH BUILDING IN...LOW LEVEL MOISTURE REMAINS TOUGH TO GET RID OF ON THE BACK SIDE OF THIS LOW. CLEARING LINE RIGHT NOW REMAINS FROM THUNDER BAY ONTARIO TO IRONWOOD...THEN EASTWARD ALONG US-2. MUCH OF CLOUD COVER OVER FAR WESTERN UPPER MICHIGAN IS IN THE FORM OF FOG. WHERE IT HAS BEEN CLEAR OUT IN NE MINNESOTA AND NW WISCONSIN...TEMPERATURES HAVE DROPPED THROUGH THE 40S. TO THE WEST...ANOTHER SHRTWV WAS MOVING ACROSS CENTRAL SASKATCHEWAN WITH A WARM FRONT EXTENDING FROM LAKE WINNIPEG SOUTHWARD TOWARDS FARGO. LITTLE IN THE WAY OF CLOUDS EXIST WITH THE FRONT DUE TO A DRY AIR MASS IN PLACE. 00Z BIS SOUNDING HAD A PRECIPITABLE WATER OF 0.46 INCHES AND A K-INDEX OF -7. 00Z INL SOUNDING WAS A BIT MORE MOIST BEING CLOSER TO THE SURFACE LOW...BUT EVEN THERE THE PRECIPITABLE WATER HAS DROPPED TO 0.72 INCHES (A CHANGE OF ALMOST 0.4 SINCE 12Z). TODAY...AFTER A BUSY DAY YESTERDAY...THE COMPLETE OPPOSITE IS EXPECTED FOR TODAY WITH WINDS AND TEMPS THE ONLY CONCERNS. THIS IS DUE TO THE DRY AIR MASS LOCATED OVER BIS PROGGED TO MOVE EASTWARD OVER THE U.P.. ANY FOG/STRATUS THIS MORNING WILL QUICKLY DISSIPATE AS SUNSHINE HELPS MIX OUT THE LOW LEVELS. OTHER THAN THAT...MUCH OF THE DAY SHOULD BE MOSTLY SUNNY EXCEPT FOR SOME HIGH CLOUDS MOVING IN DURING THE AFTERNOON IN THE ZONAL FLOW. WARM FRONT OFF TO THE WEST IS EXPECTED TO CROSS UPPER MICHIGAN LATE THIS AFTERNOON WITH SOME BREEZY CONDITIONS BEHIND IT...PARTICULARLY ACROSS THE NORTHERN PART OF THE CWA CLOSER TO THE SHRTWV TRACK. WITH THE SW TO W WINDS ALONG WITH 850MB TEMPERATURES PROGGED FROM 10C EAST TO 14C WEST AT 18Z...READINGS WILL HAVE NO PROBLEM CLIMBING THROUGH THE 70S. LOCATIONS IN THE FAR WEST AND THOSE THAT DOWNSLOPE WITH THE WINDS DESCRIBED ABOVE MAY TOP OUT AROUND 80. TONIGHT...ZONAL FLOW COMING OFF THE ROCKIES WILL ALLOW FOR ANOTHER FRONT TO DEVELOP OVER THE PLAINS WHICH IS PROGGED TO REACH THE FARGO AREA BY 12Z WEDNESDAY. CLOSER TO HOME...ANOTHER RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD IN BEHIND THE WARM FRONT TODAY...ALLOWING WINDS TO DROP OFF. LITTLE IN THE WAY OF CLOUD COVER ALONG WITH THE CLEAR SKIES WOULD SIGNAL A COOL NIGHT...BUT THE PRECIPITABLE WATER IS ON THE ORDER OF 0.5-0.75 INCHES...SO AM RELUCTANT TO GO TOO COOL ON LOWS. MID 40S DO SEEM POSSIBLE THOUGH IN THE INTERIOR WEST HALF. ALSO THOUGHT ABOUT PATCHY FOG SINCE THE SKIES WILL BE CLEAR...BUT SOUNDINGS LOOK TOO DRY. GROUND SHOULD ALSO DRY OUT QUITE A BIT TODAY FROM THE BREEZY WINDS AND WARM TEMPERATURES. THEREFORE NO PATCHY FOG MENTIONED IN THE FORECAST. WEDNESDAY INTO WEDNESDAY NIGHT...MODEL DIFFERENCES ARISE ON HOW FAST THE FRONT PUSHES EASTWARD. THIS DEPENDS ON A SHRTWV RIGHT NOW JUST OFF THE COAST OF VANCOUVER ISLAND AND HOW FAST IT MOVES THROUGH THE FLOW. GIVEN THE ZONAL NATURE...A FASTER SOLUTION WITH THE TROUGH MAY SEEM IN ORDER. THE NAM IS THE FASTEST PUSHING THE TROUGH INTO THE CENTRAL U.P. BY 21Z WED. UKMET/GFS ARE SLOWER...DELAYING THE FRONT ABOUT 6 HOURS...BUT FASTER THAN PREVIOUS RUNS. FOR NOW HAVE FOLLOWED THE UKMET/GFS BUT COULD SEE THE NEED TO GO WITH THE FASTER NAM. WARM AIR ADVECTION AHEAD OF THE FRONT WILL ALLOW 850MB TEMPERATURES TO CLIMB UP TO 16C BY 18Z WEDNESDAY...SO WEDNESDAY MAY END UP BEING THE WARMEST DAY OF THE WEEK. THERE DOES APPEAR TO BE PLENTY OF HIGH CLOUDS MOVING INTO THE WESTERN U.P. DURING THE AFTERNOON...WHICH MAY RESTRICT SURFACE HEATING SLIGHTLY. UKMET CONTINUES TO SHOW PRECIP IN THE WESTERN U.P. DURING THE AFTERNOON DUE TO ISENTROPIC LIFT AND RIGHT ENTRANCE REGION JET DYNAMICS ASSOCIATED WITH A 140 KT JET MOVING ACROSS ONTARIO. THEREFORE HAVE MAINTAINED A SLIGHT CHANCE. BOTH UKMET AND THE GFS SHOW SOME QPF MOVING ACROSS WEDNESDAY NIGHT AHEAD OF THE FRONT...AGAIN AS A RESULT OF THE ABOVE FACTORS AND THEREFORE CONTINUE THE CHANCE FOR RAIN. THURSDAY...WITH THE FASTER PROGRESSION OF THE FRONT TO THE SOUTHEAST PER THE UKMET/GFS...HAVE ENDED PRECIPITATION A LITTLE QUICKER THAN IN THE PREVIOUS FORECAST. HAVE NOT WENT FULL FLEDGED ON THE ENDING TIME OF THE GFS (NO RAIN FOR THURSDAY) TO TRY TO BLEND WITH CONTINUITY AND THE PAST FLIP-FLOPPING THE MODELS HAVE BEEN GOING THROUGH WITH THE FRONT. TEMPERATURES WILL BE HIGHLY DICTATED ON THE SPEED OF THE FRONT...BUT WITH COLD ADVECTION BEHIND IT...TEMPERATURES SHOULD STAY IN THE 60S. THE WARMEST SPOT WOULD BE IN THE SOUTH CENTRAL WHERE THE NORTHERLY WINDS BEHIND THE FRONT DOWNSLOPE. THURSDAY NIGHT AND FRIDAY...CANADIAN HIGH PRESSURE IS PROGGED BY ALL MODELS TO BUILD SOUTHWARD THURSDAY NIGHT. THE SPEED IT DROPS SOUTH IS CRITICAL TO LOW TEMPERATURES THURSDAY NIGHT AS THE AIRMASS LOOKS BOTH DRY AND CHILLY. RIGHT NOW IT APPEARS THAT THE 975-950MB WINDS WILL STAY UP ENOUGH TO KEEP TEMPERATURES UP. HOWEVER...MAV COOP GUIDANCE IS IN THE LOW 30S FOR SOME OF THE TYPICAL COLD SPOTS IN THE INTERIOR WEST HALF. HAVE DROPPED LOWS A BIT TO ACCOUNT FOR THE POTENTIAL OF A COLD NIGHT...BUT WILL LET FURTHER FORECASTS IRON THIS OUT. FRIDAY SHOULD TURN OUT TO BE A COOL DAY AS 850MB TEMPS ARE PROGGED TO BE AROUND 4C. NE WINDS WILL HELP KEEP TEMPS DOWN SLIGHTLY...BUT WITH LAKE SUPERIOR IN THE LOW 60S...LITTLE EFFECT SHOULD BE SEEN. NO PRECIPITATION EXPECTED WITH THE CANADIAN HIGH NEARBY. ONLY OTHER CHANGE TO THE FORECAST WAS TO DROP TEMPS IN THE INTERIOR EAST HALF FRIDAY NIGHT DUE TO THE PROXIMITY TO THE HIGH PRESSURE AREA. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ AJ mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 414 AM CDT TUE SEP 20 2005 .DISCUSSION...TODAY AND TONIGHT...ANOTHER DAY OF RECORD HEAT EXPECTED TODAY ACROSS MUCH OF OUR AREA WITH THE HIGHEST TEMPERATURES EXPECTED ALONG AND WEST OF THE MISSISSIPPI RIVER. RECORD HIGHS THAT ARE IN DANGER OF BEING EQUALED OR EXCEEDED INCLUDE: GREENVILLE 98 ...GREENWOOD 98...VICKSBURG 96...MERIDIAN 96 AND HATTIESBURG 98. ALTHOUGH IT WILL BE QUITE HOT...THE RECORD HIGH OF 104 AT JACKSON LOOKS SAFE TODAY. IN ADDITION TO THE HEAT...DEW POINTS WILL BE IN THE LOWER 70S IN OUR WESTERN ZONES AND PARISHES LEADING TO HIGH INDEX VALUES NEAR 105 FOR A COUPLE OF HOURS AGAIN THIS AFTERNOON. LATEST SATELLITE IMAGERY/RUC ANALYSIS SHOWS A POTENT SHORTWAVE MOVING EAST ACROSS THE MID MISSISSIPPI VALLEY. THIS SHORTWAVE WILL SCOOT OFF TO THE EAST TODAY LEAVING A WEAK COLD FRONT TO DRIFT SLOWLY SOUTH. THIS BOUNDARY WILL DRIFT INTO NORTHERN MISSISSIPPI TONIGHT. A FEW MID LEVEL CLOUDS ARE EXPECTED IN OUR NORTHERN COUNTIES TONIGHT WITH THIS FEATURE BUT NO PCPN. /22/ QUIET BUT WARM AND VERY DRY FORECAST FOR MUCH OF THE CWA LOOKS TO CONTINUE INTO FRI. THIS IS WHERE THE FORECAST BECOMES PROBLEMATIC AS THE TRACK OF RITA WILL GREATLY WEIGH ON THE FORECAST. BEFORE THAT HIGH PRESSURE WILL CONTINUE TO DOMINATE THE REGION. WED AND THU H5 HEIGHTS WILL FALL AND H85 TEMPS WILL SLIGHTLY COOL DOWN AND THIS WILL ALLOW FOR HIGHS TO BE A FEW DEGREES COOLER BUT TEMPS WILL STILL REMAIN ABV NORMAL WITH HIGHS IN THE LOWER TO MID 90S. THE RIDGE REMAINS IN CONTROL OVER THE AREA AND WITH THE WARM MID LEVELS CAPPING THE ATMOSPHERE CLOUDS WILL BE HARD TO COME BY WED AND OVER MOST OF THE AREA THUR WITH THE EXCEPTION OF THE EXTREME STHRN COUNTIES. THESE COUNTIES MAY BEGIN TO SEE AND OUTER BAND OR TWO FROM RITA. TS RITA STILL A BIG CONCERN WITH MANY UNCERTAINTIES. AS OF 04Z THE PRESSURE WAS DOWN TO 988MB ABOUT A 14MB DROP IN THE PAST 27 HRS. BUT THE GOOD NEWS IS THE WINDS REALLY HAVEN'T RESPONDED AND RITA REMAIN A TS. THERE IS A GROWING SHIFT IN THE MDLS BACK TO THE LEFT AS RITA HAS BEEN MOVING FASTER THAN EXPECTED. KEY FEATURES ARE GOING TO BE THE RIDGE THAT IS CURRENTLY BEGINNING TO RETROGRADE...FWRD SPEED OF RITA...AND THEN THE DEVELOPMENT OF THE RIDGE TO THE NORTH OF RITA LATER IN THE FORECAST. WITH A FASTER FWRD MOTION RITA WILL GET FURTHER WEST AS A RIDGE DEVELOPS TO THE NORTH MAKING THE TURN TO THE NORTH FURTHER WEST...PROBABLY ALONG THE LOWER TO MIDDLE TX COAST. A SLOWER FRWD MOTION WILL ALLOW THE RIDGE TO DEVELOP AND PUSH EAST AND LEAD TO A POSSIBLE LANDFALL ALONG THE NRTHN TX OR EVEN SW LA COAST. CURRENTLY NHC FORECAST BRINGS THE CENTER OF RITA INTO THE MIDDLE TO UPPER TX COAST JUST SOUTH OF GALVESTON. THAT SAID THE OVERALL ERROR STILL STRETCHES FROM JUST SOUTH OF BROWNSVILLE TX TO MORGAN CITY LA. ONCE AGAIN LANDFALL WILL DEPEND ON THE DREADED TURN TO THE NORTH AS HAS BEEN THE CASE THIS YEAR WITH DENNIS AND KATRINA...KATRINA MORE SO THAN DENNIS AS WE WAITED FOR DENNIS TO TURN MORE TWRDS THE N FROM ITS WNW MOTION. WITH LANDFALL BEING WEST OF THE CWA HAVE CONTINUED TO CARRY AND INCREASE POPS FOR LATE SATURDAY BUT ESPECIALLY INTO SUN AND MON AS RITA MOVES N THROUGH EAST TX AND THEN NE INTO AR. WITH THIS TRACK AMPLE GULF MOISTURE WILL PUMP INTO THE REGION AND SHRA AND TSRA WILL DEVELOP ACROSS MOST OF THE CWA WITH HEAVY RAINFALL ACROSS THE LA AND AR COUNTIES AND FIRST TIER OF MS COUNTIES IN THE CWA. ALSO WITH THIS TRACK WE ARE STILL IN A FAVORABLE AREA FOR A FEW SEVERE STORMS CAPABLE OF PRODUCING TORNADOES. AFTER THE REMNANTS OF RITA MOVE THROUGH THERE MAY BE A LINGERING SFC BNDRY DRAPED ACROSS STHRN PORTIONS OF THE CWA. THIS WILL PROVIDE A SFC FOCUS FOR AFTERNOON SHRA AND TSRA DURING THE BEGINNING OF NEXT WEEK. THE ONE GOOD THING WITH ALL THIS IS THE RAIN IS VERY MUCH NEEDED ACROSS NE TX...AR...NRTHN LA...AND MUCH OF MS AND THIS COULD SERIOUSLY ALLEVIATE THE DEVELOPING FIRE WEATHER CONCERNS. /CAB/ && .AVIATION...LIFR CONDITIONS DUE TO FOG CONTINUE TO BE REPORTED AT GTR. OTHERWISE MAINLY MVFR CONDITIONS DUE TO VISIBILITY RESTRICTIONS ARE EXPECTED AGAIN THIS MORNING IN THE EAST AND SOUTH. VFR CONDITIONS ARE EXPECTED TO RESUME AFTER 14Z AND PREVAIL THROUGH THE DAY. /22/ && .PRELIMINARY POINT TEMPS/POPS... JACKSON 97 72 95 71 / 0 0 0 0 MERIDIAN 97 70 95 69 / 0 0 0 0 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...NONE. LA...NONE. AR...NONE. && $$ 22/CAB/22 ms AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPRINGFIELD MO 1232 AM CDT TUE SEP 20 2005 .UPDATE... STRONG CAPPING INVERSION EVIDENT ON SGF 00Z SOUNDING STILL APPEARS TO BE HOLDING STRONG. 04Z ACARS FLIGHT OUT OF TUL SHOWS NO EVIDENCE OF ANY COOLING BETWEEN 800-700MB AND THE AXIS OF THE SHORTWAVE IS CURRENT OVER TUL...SO ANY HOPE OF WEAKENING CAP FROM TROUGH PASSAGE IS FADING FAST. MADE A QUICK UPDATE TO SHORT TERM GRIDS TO CUT BACK ON THE WESTERN EXTENT OF POP/WX IN THE GRIDS FOR OVERNIGHT. ALSO BUMPED LOW TEMPS UP A BIT OVER OUR NORTHERN CWA...LITTLE CHANGE IN THE AIRMASS PRESENT BEHIND THE BOUNDARY WITH DEWPOINTS STILL IN THE 70S TO THE NORTH OF OUR CWA. FINALLY...ONCE PRECIP ENDS COULD SEE SOME FOG DEVELOP LATE TONIGHT OVER MID MISSOURI WHERE RAIN FELL THIS EVENING...CONFIDENCE IS ESPECIALLY HIGH THOUGH SEEING AS THOUGH CLOUDS MAY LINGER INTO THE OVERNIGHT HOURS. IZZI && .AVIATION... FOR THE 06Z TAFS...GENERALLY VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 HOURS. OUTFLOW BOUNDARY CURRENTLY MOVING THROUGH JLN/SGF TERMINALS SHOULD CAUSE A BRIEF GASP OF WIND FROM THE NORTH BEFORE GOING LIGHT/VARIABLE OVERNIGHT. SCT-BKN DECK AT FL040-060 CURRENTLY MOVING THROUGH THE AREA SHOULD CLEAR OUT BY SUNRISE HOWEVER FEW-SCT CUMULUS MAY DEVELOP TOMORROW AFTERNOON AROUND FL040-050. IZZI && .PREV DISCUSSION... THE TWO PRIMARY FORECAST CHALLENGES WITH THIS ISSUANCE ARE THE AREAL COVERAGE AND INTENSITY OF CONVECTION THIS EVENING...AND THE POTENTIAL INFLUENCES OF SOON TO BE HURRICANE RITA LATE THIS WEEKEND INTO MONDAY. IN THE SHORT TERM...18Z SGF SOUNDING SHOWED A 2C CAP IN PLACE BETWEEN 700 AND 750 MB. THIS LAYER WAS ALSO VERY DRY (-17C DP)...BUT LOOKING AT THE 12Z RAOBS...IT APPEARS TO BE VERY LOCALIZED. RUC PROGS WOULD SUPPORT THIS...WITH A NARROW TONGUE OF DRY AIR IN THE 700 TO 750 MB LAYER ADVECTING NEWD INTO SW MO AROUND MIDDAY TODAY. RUC THEN TAKES THE DRY LAYER AND SWEEPS IT EASTWARD AHEAD OF THE FRONT...AND TEMPS COOL BY ABOUT 2C. THIS SHOULD BE ENOUGH TO WEAKEN THE CAP AND ALLOW UPDRAFTS TO PUNCH THROUGH WHATEVER REMAINS OF IT. SLIGHTLY ELEVATED CAPE NEAR 2000 J/KG REMAINS INTO THE EVENING...SO THE POTENTIAL EXISTS FOR CONVECTION TO LAST WELL INTO THE EVENING. A SIGNIFICANT PORTION OF THE CAPE DOES EXTEND ABOVE THE -20C LEVEL...SO LARGE HAIL IS A THREAT. MAY GET SOME MARGINALLY SEVERE WINDS BEFORE THE SURFACE COOLS THIS EVENING...AS WINDEX SHOWS GUSTS TO 59 KNOTS POSSIBLE. COLD FRONT WILL MOVE TO NEAR THE ARKANSAS LINE AFTER MIDNIGHT AS UPPER LEVEL SUPPORT MOVES QUICKLY EASTWARD. TUESDAY MAY SEE THE REMAINS OF THE SURFACE FRONT NEAR THE SOUTHERN CWA...HOWEVER WITH UPPER LEVEL SUPPORT LACKING...DO NOT THINK THAT CONVECTION WILL BE WIDESPREAD ENOUGH TO MENTION. FRONT WASHES OUT OVER THE NEXT 24 HOURS...AND SOUTHERLY FLOW RETURNS BY WEDNESDAY. IN RESPONSE TO THE FORMATION OF AN ANOMALOUSLY DEEP 500 MB TROUGH OVER THE WEST COAST...THE VERY STRONG 500 MB RIDGE OVER TEXAS IS FORECAST TO MOVE EASTWARD INTO ARKANSAS BY 12Z FRIDAY. A SHORTWAVE RIDING OVER THE RIDGE THROUGH THE UPPER MIDWEST WILL NOT LIKELY MAKE MUCH OF A DENT IN THE RIDGE AT OUR LATITUDE...AND THE ASSOCIATED COLD FRONT SHOULD STALL OVER NORTHERN MISSOURI ON FRIDAY. WELL ABOVE NORMAL TEMPS AND DRY WEATHER WILL LIKELY PERSIST THROUGH AT LEAST SATURDAY. THE NEXT BIG FORECAST CHALLENGE COMES ON SUNDAY INTO MONDAY WITH RITA. LATEST TPC LANDFALL NEAR GALVESTON WOULD STILL GIVE SW AND ESPECIALLY SOUTH CENTRAL MO A SHOT AT HEAVY RAIN AS THE REMAINS OF THE SYSTEM PASS BY. ANY FURTHER SHIFTS EASTWARD...LETS NOT EVEN THINK ABOUT THAT!...WOULD LIKELY LEAVE SW MO ON THE DRY SIDE OF THE STORM. WILL EASE INTO THIS...AND JUST GO LOW CHANCE POPS AREAWIDE FOR NOW. BROWNING && SGF WATCHES/WARNINGS/ADVISORIES... .MO...NONE. .KS...NONE. $$ WFO SGF mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 220 AM EDT TUE SEP 20 2005 .SHORT TERM (TODAY THROUGH WEDNESDAY NIGHT)... THROUGH DAYBREAK: SO FAR THE LOWEST VISIBILITIES IN FOG HAVE DEVELOPED OVER THE NORTHWEST PIEDMONT ALTHOUGH THE STRATUS IS QUICKLY CHARGING INTO THE COASTAL PLAIN. WITH VERY LIGHT SE WINDS & HIGH DEWPOINTS... FOG AND STRATUS SHOULD BECOME WIDESPREAD EVERYWHERE. WILL CONSIDER AN EXPANSION OF THE DENSE FOG ADVISORY TO THE NW CWA IF PRESENT TRENDS PERSIST. MID MORNING THROUGH TONIGHT: WIDESPREAD BACKBUILDING CONVECTION CONTINUES PUSHING THROUGH THE OH VALLEY AND KY... OUTPACING GFS/NAM PROJECTIONS & EXCEEDING BOTH MODELS' QPFS. THE EASTERN PORTION OF THIS ACTIVITY SHOULD CONTINUE TO PETER OUT AS IT MOVES AWAY FROM THE LOW LEVEL THETA-E RIDGE AND PRIME INSTABILITY. THE ATTENDANT POSITIVELY TILTED MID LEVEL TROUGH DROPS INTO NC LATE TODAY BRINGING INCREASING MID LEVEL LAPSE RATES... DESTABILIZING LI VALUES TO -2 TO -4... AND CAPES CLIMBING TO NEAR 2000 J/KG. GIVEN THE WEAK SHEAR IN PLACE... EXPECT CONVECTION BE MULTICELLULAR... MOVING INTO THE NW CWA DURING THE AFTERNOON... POSSIBLY INITIATING OVER THE HIGHER TERRAIN RATHER THAN AS A PURE TRANSLATION OF EXISTING CONVECTION... THEN DROPPING SOUTHEASTWARD DURING THE EVENING & OVERNIGHT. THE GFS REMAINS SLIGHTLY SLOWER THAN THE NAM WITH BOTH RAIN ONSET AND WITH THE MID LEVEL TROUGH... AND BASED ON THE RUC AND PRE-ECLIPSE WATER VAPOR IMAGERY THE NAM SPEED MAY BE CLOSER TO REALITY... ALTHOUGH NAM PRECIP AMOUNTS APPEAR UNDERDONE CONSIDERING THAT THE PW IS EXPECTED TO RISE TO 150% OF NORMAL. MOST OF THE CWA WILL HAVE A PERIOD OF CHANCE POPS FROM LATE AFTERNOON THROUGH TONIGHT. TEMPS WILL DEPEND A GREAT DEAL ON THE DEPTH & EXTENT OF STRATUS THIS MORNING AND WILL STICK WITH 88-92 FOR THE TIME BEING. WITH DEWPOINTS LIKELY REMAINING HIGH... FAVOR THE WARM END OF MOS GUIDANCE MIN TEMPS TONIGHT... 65-72. WED THROUGH THU: THE SURFACE FRONT AND MID LEVEL SHEAR AXIS ARE EXPECTED TO HANG UP OVER THE SOUTHEASTERN CWA THROUGH THU AS WEAK HIGH PRESSURE ZIPS BY TO THE NORTH. WILL HOLD ONTO RAIN CHANCES ACROSS THE SOUTHERN CWA WITH WEAK BOUNDARY LAYER CONVERGENCE ACTING ON A GOOD AMOUNT OF RESIDUAL MOISTURE AND A MODERATELY UNSTABLE COLUMN. WILL RAISE HIGHS A DEGREE OR SO ACROSS THE SOUTH HALF WED AND EVERYWHERE THU WITH A NEGLIGIBLE CHANGE IN AIR MASS. && .LONG TERM (FRIDAY THROUGH MONDAY)... NO SIGNIFICANT CHANGES FOR THIS PERIOD WITH THE GFS/ECMWF SHOWING UPPER RIDGING DRIFTING EASTWARD FROM THE OZARKS TO THE CAROLINAS... LIKELY TO YIELD TEMPS ABOUT A CATEGORY OR TWO ABOVE NORMAL. BASED ON THE STRENGTH OF THIS RIDGE... AT THIS TIME DO NOT FAVOR THE BACKDOOR FRONTAL PASSAGE THROUGH THE ENTIRE CWA AS INDICATED BY THE 00Z/20 GFS. IT'S FAR TOO EARLY TO SPECULATE WHERE RITA'S REMNANTS WILL GO DAYS 6/7 AND WILL RETAIN DRY WEATHER. && .AVIATION... CLEAR SKIES AND CALM WINDS AT MOST LOCATIONS ACROSS THE REGION IS RESULTING IN THE DEVELOPMENT OF FOG AND STRATUS. MOSTLY VFR CIGS EXCEPT PATCHY CIGS NEAR 1KFT AND MVFR VSBYS. CIGS/VSBYS WILL BECOME IFR WITH POCKETS OF LIFR CIGS/VSBYS BETWEEN 07Z-09Z. AFTER 09Z THROUGH 14Z WIDESPREAD LIFR CIGS AND VSBYS. STRATUS AND FOG WILL GRADUALLY LIFT AFTER 14Z BCMG SCT-BKN LAYER 3-5KFT. 21Z-03Z...SCT SHOWERS AND TSTMS WITH CIGS 2-3KFT VSBYS 3-5 MILES. && .RAH WATCHES/WARNINGS/ADVISORIES... DENSE FOG ADVISORY FOR NCZ008>011-024>028-040>043-074>078- 083>086-088-089 UNTIL 9 AM TUESDAY. && $$ SHORT TERM...HARTFIELD LONG TERM...HARTFIELD AVIATION...RA nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 300 AM EDT TUE SEP 20 2005 .SHORT TERM (TODAY THROUGH WEDNESDAY)... BASED ON RECENT NAM GFS AND RUC MODEL RUNS...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO EXIT THE UPPER OHIO VALLEY BY EARLY AFTERNOON AS WEAK COLD FRONT MOVES THROUGH THE AREA. HIGH PRESSURE WILL THEN BUILD INTO THE AREA TONIGHT AND WEDNESDAY...BRINGING DRY CONDITIONS. FORECASTED TEMPERATURES CLOSE TO A BLEND OF NAM AND GFS MOS VALUES. && .LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)... GFS MODEL RUNS CONTINUE TO SHOW ZONAL UPPER FLOW ACROSS THE NORTHERN U.S. OCCASIONAL INFLUX OF ENERGY FROM CANADIAN SHORT-WAVE TROUGHS PHASING INTO THIS FLOW WILL RESULT IN FRONTAL PASSAGES ACROSS THE UPPER OHIO VALLEY ACCOMPANIED BY A CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY FRIDAY AND NEXT MONDAY. EXPECT TEMPERATURES TO CONTINUE ABOVE NORMAL. && .AVIATION... TSTMS DEVELOPED NR ERI, MUCH AS MOIST FLUX INDICATED. BASED ON THAT, SRN HALF OF CWA IS IN JEOPARDY OF THUNDER AND RAIN. IT IS EXPECTED TO END IN PIT AT 13Z, FOLLOWED BY A PERIOD OF BKN035, THEN SCT050, AND CLR BY 23Z, AS VIGOROUS H5 TROF PUSHES E. FOG UNLIKELY OVERNIGHT (6-12Z WED). FOR MGW, I PUT RAIN, NOT THUNDER, TIL 17Z, CLR BY 00Z. DUJ HAS THUNDER TIL 08Z, THEN A PD OF RAIN, BKN015 AT 15Z, SCT035 AT 17Z, CLR BY 23Z. WINDS MAY GUST TO 20-23KT IN MID AFTN, ACCORDING TO THE DOWNWARD TRANSPORT OF THE BUFKIT MOMENTUM. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BURLINGTON VT 332 AM EDT TUE SEP 20 2005 .SYNOPSIS... STORM SYS TO MOVE ACRS SRN CANADA TODAY...AS IT/S ASSOCIATED CF MOVES ACRS THE FA FROM THE WEST. WK HI PRESS TO AFFECT THE FA TONITE THRU WED NITE. ANOTHER CF TO MOVE DOWN ACRS THE GREAT LKS REGION AND SRN CANADA ON THU. .SHORT TERM (TODAY THROUGH THURSDAY)... 00-02Z RUC13 SHOWS TEMPS TO GET UP INTO THE M60S-M70S TODAY WITH S-SW SFC WINDS AT 5-15G30 KTS. T1MAX TEMPS ARE IN THE L70S-L80S TODAY. FEW TWEAKS TO FIRST PERIOD TEMPS/WINDS BASED ON THIS DATA AND MESONET OBS. LOW-LVL MSTR TO CONT TO AFFECT THE FA TODAY. RUC SHOWS MOCLDY SKIES ACRS THE FA TODAY. H85 CAA TO TAKE PLACE ACRS THE FA TODAY THRU EARLY ON WED...THEN WAA FOR LATER ON WED THRU THU. LOW-LVL MSTR ADVECTION TO TAKE PLACE ACRS THE FA EARLY TODAY AND AGAIN ON THU. SOME LOW-LVL MSTR TO AFFECT THE FA TONITE AND EARLY ON WED...AND AGAIN ON THU. LOW-LVL LAPSE RATES TO BE HI ACRS THE FA OVER THE NEXT 3 AFTERNOONS. SOME MID-LVL MSTR TO AFFECT THE FA EARLY TODAY AND THE NRN FA ON THU. PW VALUES ACRS THE FA LOOK TO BE 0.5-1.4" TODAY...0.5-0.75" TONITE THRU WED NITE...THEN AROUND AN INCH ON THU. CAPES ACRS THE FA APPEAR TO BE AOB 1100 J/KG TODAY AND BLW 1000 J/KG ON THU. ENVIRONMENT ACRS THE FA APPEARS TO BE MODERATE TO HIGHLY SHEARED WITH WET-BULB ZERO HTS OF 7-10 KFT TODAY. SHEAR APPEARS TO GET WEAKER WITH TIME ACRS THE FA AS THE DAY PROGRESSES TODAY THOUGH. LACK OF STRONG INSTABILITY AND PLENTY OF CLDS ACRS THE FA APPEAR TO BE LIMITING FACTORS FOR ANY SVR WX TODAY. WOULD NOT BE SURPRISED TO SEE ANY +TSRA THAT DO HAPPEN TO FORM ACRS THE FA CAUSING SOME STRONG WIND GUSTS THOUGH. LATER SHIFTS WILL NEED TO KEEP AN EYE ON THIS. FOR NOW...WILL CONT TO MENTION TS POSSIBLE ACRS THE FA TODAY WITH NO ENHANCED WORDING. IR SAT PIX SHOW PLENTY OF CLDS ACRS THE FA ATTM. BUFCAN/88D MOSAIC SHOWS A FEW LT RETURNS MOVING ACRS THE FA FROM THE WEST ATTM. WILL CONT TO HANG ONTO LIKELY POPS ACRS THE FA FOR ANY CONVECTION TODAY. THE REST OF THE GOING FCST FOR THE SHORT-TERM PERIOD LOOKS PRETTY GOOD...WITH THE NEXT SMALL CHC FOR ANY PCPN ACRS THE FA ON THU AFTERNOON. T1MIN TEMPS TONITE AND ON WED NITE APPEAR TO BASICALLY BE 45-55F. T1MAX TEMPS ARE 75-80 ON WED. .LONG TERM (THURSDAY NIGHT THROUGH MONDAY)... NO CHANGES TO THE GOING FCST FOR NOW...EXCEPT TO TRY AND MESH A LIL BETTER WITH SURROUNDING WFOS. WRK ZONES AND PRELIM ISC GRIDS AVAILABLE. ALL FINAL PRODUCTS BY 4 AM. .AVIATION... HV INDCD PTCHY IFR IN ERLY MRMG FG THRU ABT 10Z ACRS CNTRL/ERN VT DUE TO WK WNDS AND SLOWNESS OF MOISTURE TO ADVECT E. OTRW PTCHY FG AT KSLK THRU 08Z WITH UNRESTD VSBY ELSW BEFORE NXT WX SYS IMPACTS AREA. SFC LO OVR SRN ONT ERLY THIS MRNG FCST TO MOV ACRS SRN QUE TDY AND INTO THE GULF OF ST LAW TNGT. ONE WK FNTL BNDRY JUST N OF VT/CANADIAN BORDER WL NOT IMPACT OUR AREA. HOWEVER MAIN CDFNT ASOCD WITH SFC LO WL MOV W TO E ACRS OUR AREA DURG THE LATE MRNG AND ERLY AFTN. NOTED H/3 WND MAX ACRS NRN OH VLY BUT EXPECT FAVORED TSTM AREAS TO BE IN SRN CANADA AND FROM SRN NEW ENG SOUTHWARD. THUS HV JUST INDCD SHWRS AT TAF SITES. FOR TDY SCT-BKN CLDS AFT 12Z 040-060 BKN080 WITH VSBY 5SM AT TIMES IN SCT -SHRA. PCPN SHUD BE ENDG IN NRN NY ARND 16-18Z AND VT BY 20Z. TNGT EXPC SCT CLDS 060-080. HV INDCD S OR SW WND GSTS TO 25 KTS AFTR 12Z BASED ON VAD WND PROFILE AND H/8 DATA FM 00Z/19TH. SFC WND SHFTS TO W BY LATE MRNG AND ERLY AFTN. .BTV WATCHES/WARNINGS/ADVISORIES... VT...NONE. NY...NONE. && $$ SYNOPSIS/SHORT TERM/LONG TERM...MURRAY AVIATION...SFH vt AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SACRAMENTO CA 430 AM PDT SUN MAY 15 2005 .DISCUSSION... FIRST PROBLEM OF THE MORNING...THE 00Z MODEL RUN WAS ALREADY TOO FAST WITH THE MOVEMENT OF THE CLOSED LOW. LOOKING AT THE WATER VAPOR LOOP...THE CENTER CIRCULATION OF THE UPPER LOW HAS JUST STARTED TO LIFT TO THE NORTH-NORTHEAST. THIS WAS WELL BEHIND THE 00Z TIMING AND SLIGHTLY BEHIND THE 06Z RUN OF THE MODEL RUNS. SO HAVE LEAN TOWARDS THE LATEST RUC MODEL RUN WHICH HAS A BETTER HANDLE OF THE SITUATION. SATELLITE LOOP EARLY THIS MORNING INDICATED THAT THE SUBTROPICAL MID TO UPPER LEVEL MOISTURE PLUME WAS RACING NORTH-NORTHEAST AT 55 TO 65 MPH AND HAS ALREADY REACHED OUR SOUTHERN COUNTY WARNING NEAR TURLOCK AT 2 AM. THIS PLUME IS RIDING ALONG AN UPPER JET MAX OF 65 TO 70 KNOT THAT IS ROUNDING THE WEST SIDE OF THE UPPER LOW. MOST OF THE CLOUD TO GROUND STRIKES ARE OVER SOUTHERN CA SINCE LAST EVENING. ONLY A FEW ISOLATED CLOUD TO GROUND STRIKES WERE DETECTED IN THE SAN JOAQUIN VALLEY. HOWEVER THE LIGHTNING DETECTION NETWORK ONLY DETECTS CLOUD TO GROUND. BASED ON PILOT REPORTS...MANY OF THE LIGHTNING HAS BEEN CLOUD TO CLOUD OR CLOUD TO AIR. WITH THE LEADING SECTION OF THE MOISTURE PLUME IN THE MID TO UPPER LEVELS OF THE ATMOSPHERE...EXPECT MOST OF ANY LIGHTNING ACTIVITY TO BE FROM HIGH BASED CLOUDS WITH BASES STARTING ABOVE 12000 FEET. WITH WELL ELEVATED INSTABILITY...ONE INITIAL CONCERN IS THE POSSIBILITY OF DRY LIGHTNING. THIS CONCERN SHOULD DECREASE DURING THE DAY AS THE LOWER AIRMASS MOISTEN UP THROUGH THE LATE MORNING AND AFTERNOON HOURS. THUS EXPECT THE ISOLATED THREAT OF DRY LIGHTNING TO DECREASE AND END IN MOST AREAS BY MID AFTERNOON OR EARLY THIS EVENING. AN AREA OF MODERATE TO STRONG UPPER LEVEL DIVERGENCE IS ASSOCIATED WITH THE NOSE OF THE SPEED MAX AND WILL MOVE THROUGH OUR COUNTY WARNING AREA FROM SOUTH TO NORTH THIS MORNING. THIS IS FOLLOW BY THE SECOND AREA LATE THIS AFTERNOON AND EVENING. THIS SECOND AREA IS ASSOCIATED WITH THE TAIL END OF THIS SPEED MAX. THE DIFFICULT PART OF THIS FORECAST WILL BE FORECASTING THE AMOUNT OF PRECIPITATION POSSIBLE WITH THIS SYSTEM. THREE MAIN FACTORS MAKES THIS DIFFICULT ARE THAT WE ARE DEALING WITH A CLOSED LOW SYSTEM WHICH MODELS TEND TO BE TO PROGRESSIVE...AN TIMING OF THE LOWERING OF THE MOISTURE IN THE AIRMASS...AND THE CONVECTIVE NATURE OF THIS SYSTEM. IN THE HIGHER ELEVATIONS...ESPECIALLY THE NORTHERN SIERRA...THE AMOUNT OF PRECIPITATION WILL ALSO DEPEND ON THE OROGRAPHICS WHICH WILL DEPEND ON WHERE THE LOW DRIFTS AND WHETHER IT WILL OPEN UP INTO A OPEN WAVE. WITH THE SLOWER MOVEMENT OF THIS LOW...WILL NEED TO KEEP AN EYE ON ADDITIONAL MOISTURE THAT MAY GET ENTRAINED AROUND THE UPPER LOW. FOR NOW...WILL LEAN ON THE SLOWEST MODEL AND WILL HANG ON TO THE THREAT OF CONVECTIVE PRECIPITATION A LITTLE LONGER THEN THE PREVIOUS FORECAST PACKAGE. IF THE MODELS ARE CORRECT IN LIFTING THIS LOW AND THEN OPENING IT UP INTO A WAVE TONIGHT...WE SHOULD SEE A SIGNIFICANT DECREASE OF CONVECTIVE PRECIPITATION ON WEDNESDAY. SHORTWAVE RIDGE WILL BUILD IN BEHIND THE EXITING TROUGH. SOME MODELS ARE STILL TRYING TO DEVELOP A BRIEF NORTH WIND PATTERN ON WEDNESDAY BEFORE ANOTHER TROUGH DIGS INTO NORTHERN CA TOWARDS THE WEEKEND. HOWEVER...EACH RUN IS A LITTLE WEAKER WITH BOTH THE SURFACE GRADIENT AND UPPER LEVEL SUPPORT. ANOTHER SYSTEM WILL DIG IN FROM THE NORTH OR NORTHWEST. MODELS HINT THAT THIS MAY BE A SLIDER TYPE SYSTEM...WHICH IS MORE COMMON THIS TIME OF THE YEAR. WILL INTRODUCE A SLIGHT CHANCE FOR THE NORTHERN MOUNTAINS...MAINLY IN THE HIGH ELEVATION AREAS FOR THE EXTENDED PERIOD FOR NOW. LAM && .AVIATION... UPR LOW OVR SRN CA CSTL WTRS MOVG SLOWLY NEWD THRU 00Z. FLOW ALF LIGHT-MDT S-SE. AMS BECMG INCRG MOIST AND UNSTBL THRU 00Z. VFR CNTRL CA SCT050 BKN100 OVC150 TOP FL250 ISOL -SHRA/-TSRA. ALG CSTLN IFR CIG BR -SHRA BKN010 TOPS 020 LCL 3-5SM BR...AFT 17Z VFR BKN050 -SHRA/-TSRA TOP FL250. OVR SIERNV AFT 17Z AREAS -SHRA/-TSRA CIGS BKN040 MTS OBSC TOP FL250. SG .STO WATCHES/WARNINGS/ADVISORIES...NONE. && $$ ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TAUNTON MA 1013 AM EDT TUE SEP 20 2005 ...SVR WX POTENTIAL IN SNE THIS AFTERNOON WITH A WARM WORKWEEK IN PROGRESS... M3: 1009 AM. STILL HOLDING OFF ON GENERAL SPS UNTIL MORE DEFINITIVE SIGNAL. NAM AND NGM VIEWED THRU 00Z/21. M2: 951 AM LATEST RUC IS INTERESTING FOR MID AFTN. SAW SPC UPGRADE. HOLDING OFF ON GENERAL SPS FOR ISO SVR TIL 1015 AM VIEW OF NEW 12 HR NAM AND NGM. STORMS ALREADY TO EL IN E MA. WILL UPDATE THIS AFD ARD 1015 AM. LATE MORING CWF WILL BE DELAYED 30 MIN FOR POSSIBLE SVR INCLUSION. M1 846AM: HAVE BRIEFLY COLLAB WITH SPC. 5% SEE TEXT MATERIAL IN THE 13Z UPDATE. IF ANY MORE HEATING THAN CURRENTLY MODELED THEN BIGGER PROBS ARISE. WIND FIELDS STRONG...JUST BELOW RULE OF THUMB TOR CRITERIA FOR 60KT SHEAR LOWEST 10K (ABT 10KT SHY). SOME MODEL SOUNDING FCSTS OF BRN ARD 25...SUPERCELL POTENTIAL...TT ARD 50... SWEAT 300+...EXCT TIME OF DAY. DIFFLUENT THICKNESS AND SO DESPIUTE CONFUSING RFQ OF 3H JET...SVR WX POTENTIAL EXISTS. SKYWARN HAS BEEN BRIEFED. WE MAY UPDATE THIS FCST AND IF MORE CONFIDENT...SPS AT 10AM. && PRIOR DISCUSSION FM THE MID SHIFT... .SHORT TERM (TODAY THROUGH WEDNESDAY)... A COLD FRONT CROSSING THE GREAT LAKES WILL QUICKLY APPROACH SOUTHERN NEW ENGLAND THIS AFTERNOON THEN PUSH OFFSHORE THIS EVENING. INSTABILITY BURST ASSOCIATED WITH DEVELOPING WARM AIR ADVECTION PATTERN INDICATED AS SCATTERED SHOWERS AND THUNDERSTORMS FROM KBGM RADAR OVER UPSTATE NY AND PENNSYLVANIA. THIS BATCH OF PRECIPITATION SHOULD CROSS THE BERKSHIRES SHORTLY AFTER 12Z AND THROUGH THE REMAINDER OF THE FORECAST AREA DURING THE MIDDAY HOURS. ADDITIONAL SHOWERS AND THUNDERSTORMS WILL FORM LATER THIS AFTERNOON AND EARLY EVENING AS THE COLD FRONT PUSHES THROUGH THE FORECAST AREA. NOTED THE STORMS PREDICTION CENTER DISCUSSION WHICH BRINGS SEVERE THUNDERSTORM POTENTIAL WELL SOUTH OF THE FORECAST AREA TODAY. UPPER LEVEL DYNAMICS APPEAR IMPRESSIVE BUT GRADUALLY WEAKEN WITH TIME THIS AFTERNOON ACROSS THE FORECAST AREA. LOW LEVEL INSTABILITY APPEARS RATHER MARGINAL FOR SEVERE THUNDERSTORMS TODAY WITH SURFACED BASED LIFTED INDICES AROUND MINUS 1 TO MINUS 2 AND CAPE VALUES NEAR 500 J/KG THIS AFTERNOON. THUS INCREASING CLOUD COVER AND THE INITIAL INSTABILITY BURST WILL LIKELY STABILIZE THE LOWER LEVELS TODAY. WIND FIELDS ARE IMPRESSIVE WITH DEEP LAYER SHEAR THROUGH 700 MILLIBARS. PRECIPITABLE WATER VALUES JUMP TO 1.8G/KG IMMEDIATELY AHEAD OF THE COLD FRONT THIS AFTERNOON. WET BULB ZERO VALUES ARE RATHER HIGH TODAY WITH 0C ISOTHERM NEAR 12K FEET AND -20 CELCIUS ISOTHERM NEAR 22.5K. THEREFORE HAVE DECIDED TO ADD THE MENTION OF GUSTY WINDS, FREQUENT LIGHTNING AND HEAVY DOWNPOURS WITH ANY THUNDERSTORMS. DRIER AND SLIGHTLY COOLER AIR WILL PUSH INTO THE REGION TONIGHT AND WEDNESDAY. && .LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)... FAST-LOW AMPLITUDE NORTHERN STREAM FLOW WILL BE FEATURED ACROSS NEW ENGLAND THIS PERIOD...WHICH WILL TRANSLATE TO QUICK WEATHER CHANGES. FIRST...A SEASONABLY COOL AND DRY AIRMASS WILL LINGER OVER THE REGION WEDNESDAY NIGHT...AS HIGH PRES SLIDES ACROSS THE AREA. BY THURSDAY...A WARM SOUTHWEST RETURN FLOW SETS UP ACROSS THE REGION AS THE HIGH MOVES OFFSHORE AND A COLD FRONT APPROACHES FROM THE GREAT LAKES. SO DESPITE AUTUMN ARRIVING THU...EXPECT A SUMMER-LIKE DAY WITH TEMPERATURES CLIMBING INTO THE LOW AND MID 80S (AWAY FROM THE S.CST)...AS BOTH GFS AND UKMET HAVE 850 MB TEMPS RISING TO +14C TO +16C. THE ABOVE NORMAL TEMPS WILL BE SHORT-LIVED AS THE COLD FRONT MOVES THRU THE REGION FRI. 00Z GFS/UKMET AND CAN GLOB ALL IN GOOD AGREEMENT ON PUSHING THE FRONT THRU THE REGION FRI...WITH A DRYING TREND DURING THE AFTERNOON FROM NORTH TO SOUTH. THUS...HIGHEST CHANCE OF SHOWERS SHOULD OCCUR EARLY ON AND DECREASE DURING THE AFTERNOON FROM NORTH TO SOUTH. ALTHOUGH GIVEN TIME RANGE AND SURROUNDING OFFICES NOT AS CONFIDENT ON THIS FASTER SOLUTION...WILL KEEP CURRENT FRI FCST AS IS. NEXT SHIFT WILL HAVE TO EVALUATE FULL 00Z MODEL SUITE AND COLLABORATE FOR A POSSIBLE DRIER FORECAST LATE FRI AND FRI NIGHT. BY SAT MORNING...BOTH 00Z GFS/CAN GLOB AND UKMET HAVE FROPA OFFSHORE FOLLOWED BY A GOOD PUSH OF COOL CANADIAN AIR AS UPPER TROF AMPLIFIES AS IT CROSSES THE MARITIMES. THIS IS QUICKER THAN CURRENT FORECAST...ALTH AS MENTIONED ABOVE...IF TREND CONTINUES DAY-SHIFT MAY HAVE TO TRANSITION TO A DRY FCST FOR SAT. UPPER AIR PATTERN REMAINS PROGRESSIVE WHICH WILL TRANSPORT NEXT SHORT WAVE TROF AND ASSOCIATED FROPA LATE SUNDAY OR SUNDAY NIGHT. && .AVIATION... LOCAL IFR/LIFR CEILINGS/VSBYS IN STRATUS THROUGH 12Z. MVFR/IFR CONDITIONS IN AREAS OF SHOWERS AND SCATTERED THUNDERSTORMS AFTER 12Z. VFR CONDITIONS FROM WEST TO EAST FROM 02-06Z TONIGHT AFTER FRONTAL PASSAGE. FOG PATCHES POSSIBLE WITH MVFR/IFR VSBYS/CEILINGS IN THE SHELTERED VALLEYS BEYOND 06Z. && .MARINE... SHORT RANGE...SMALL CRAFT ADVISORIES HAVE BEEN POSTED TODAY AND THIS EVENING FOR WIDESPREAD WIND GUSTS 25 TO 30 KT AND SEAS APPROACHING 7 FEET ON THE SOUTHERN WATERS. IN THE LONG RANGE...SW WINDS COULD GUSTS TO 20-25 KT THU AHEAD OF THE FRONT. THEN A PERIOD OF GUSTY N TO NE WINDS ARE EXPECTED LATE FRI NIGHT INTO SAT AM BEHIND FROPA. THEREAFTER...LIGHT WINDS AND SEAS EXPECTED (PENDING TRACK OF PHILIPPE) AS HIGH PRES CREST OVER THE REGION LATE SAT INTO SUN. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...NONE. MA...NONE. NH...NONE. RI...NONE. MARINE...SMALL CRAFT ADVISORY NOON THROUGH MIDNIGHT TODAY ALL WATERS. && $$ MESO...DRAG SHORT TERM...STRAUSS/DRAG LONG TERM...NOCERA/KAB AVIATION...STRAUSS/DRAG ma AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE RALEIGH NC 928 AM EDT TUE SEP 20 2005 .SHORT TERM (REST OF TODAY)... FOG AND LOW STRATUS IS BREAKING UP QUICKER THIS MORNING THAN IT DID YESTERDAY. THUS HIGH TEMPS SHOULD REACH NEAR FULL SUN VALUES FROM LOCAL THICKNESS SCHEME...IN THE LOWER 90S. THIS IS IN LINE WITH THE CURRENT FORECAST SO NO CHANGES WILL BE NEEDED. WILL SEND AN UPDATE ONLY TO REMOVE THE MENTION OF MORNING FOG. SEVERE THREAT...A CONVECTIVELY-INDUCED VORTICITY CENTER NOW CROSSING KY WILL LIKELY INITIATE CONVECTION OVER THE MOUNTAINS EARLY THIS AFTERNOON...AND MOVE EAST INTO THE PIEDMONT AFTER 18Z. 12Z GSO SOUNDING MODIFIED TO 90/70 YIELDS A CAPE OVER 3000 J/KG AND A LI OF -7. THE THETA-E DIFFERENCE IN THE LOWEST 300 MB...A GOOD PARAMETER FOR STRAIGHT-LINE WIND POTENTIAL...INDICATES THAT WIND DAMAGE WILL BE THE PRIMARY THREAT. WET BULB ZERO HEIGHTS ARE ON THE LOW SIDE...SO HAIL WILL ALSO BE A POSSIBILITY. LAPSE RATES ARE NOT STEEP IN THE OBSERVED SOUNDING...HOWEVER THE RUC FORECAST SOUNDINGS SHOW COOLING AROUND 500 MB WILL CREATE STEEPER LAPSE RATES THIS AFTERNOON. && .PREVIOUS DISCUSSION... (ISSUED 220 AM EDT TUE SEP 20 2005) SHORT TERM (TODAY THROUGH WEDNESDAY NIGHT)... THROUGH DAYBREAK: SO FAR THE LOWEST VISIBILITIES IN FOG HAVE DEVELOPED OVER THE NORTHWEST PIEDMONT ALTHOUGH THE STRATUS IS QUICKLY CHARGING INTO THE COASTAL PLAIN. WITH VERY LIGHT SE WINDS & HIGH DEWPOINTS... FOG AND STRATUS SHOULD BECOME WIDESPREAD EVERYWHERE. WILL CONSIDER AN EXPANSION OF THE DENSE FOG ADVISORY TO THE NW CWA IF PRESENT TRENDS PERSIST. MID MORNING THROUGH TONIGHT: WIDESPREAD BACKBUILDING CONVECTION CONTINUES PUSHING THROUGH THE OH VALLEY AND KY... OUTPACING GFS/NAM PROJECTIONS & EXCEEDING BOTH MODELS' QPFS. THE EASTERN PORTION OF THIS ACTIVITY SHOULD CONTINUE TO PETER OUT AS IT MOVES AWAY FROM THE LOW LEVEL THETA-E RIDGE AND PRIME INSTABILITY. THE ATTENDANT POSITIVELY TILTED MID LEVEL TROUGH DROPS INTO NC LATE TODAY BRINGING INCREASING MID LEVEL LAPSE RATES... DESTABILIZING LI VALUES TO -2 TO -4... AND CAPES CLIMBING TO NEAR 2000 J/KG. GIVEN THE WEAK SHEAR IN PLACE... EXPECT CONVECTION BE MULTICELLULAR... MOVING INTO THE NW CWA DURING THE AFTERNOON... POSSIBLY INITIATING OVER THE HIGHER TERRAIN RATHER THAN AS A PURE TRANSLATION OF EXISTING CONVECTION... THEN DROPPING SOUTHEASTWARD DURING THE EVENING & OVERNIGHT. THE GFS REMAINS SLIGHTLY SLOWER THAN THE NAM WITH BOTH RAIN ONSET AND WITH THE MID LEVEL TROUGH... AND BASED ON THE RUC AND PRE-ECLIPSE WATER VAPOR IMAGERY THE NAM SPEED MAY BE CLOSER TO REALITY... ALTHOUGH NAM PRECIP AMOUNTS APPEAR UNDERDONE CONSIDERING THAT THE PW IS EXPECTED TO RISE TO 150% OF NORMAL. MOST OF THE CWA WILL HAVE A PERIOD OF CHANCE POPS FROM LATE AFTERNOON THROUGH TONIGHT. TEMPS WILL DEPEND A GREAT DEAL ON THE DEPTH & EXTENT OF STRATUS THIS MORNING AND WILL STICK WITH 88-92 FOR THE TIME BEING. WITH DEWPOINTS LIKELY REMAINING HIGH... FAVOR THE WARM END OF MOS GUIDANCE MIN TEMPS TONIGHT... 65-72. WED THROUGH THU: THE SURFACE FRONT AND MID LEVEL SHEAR AXIS ARE EXPECTED TO HANG UP OVER THE SOUTHEASTERN CWA THROUGH THU AS WEAK HIGH PRESSURE ZIPS BY TO THE NORTH. WILL HOLD ONTO RAIN CHANCES ACROSS THE SOUTHERN CWA WITH WEAK BOUNDARY LAYER CONVERGENCE ACTING ON A GOOD AMOUNT OF RESIDUAL MOISTURE AND A MODERATELY UNSTABLE COLUMN. WILL RAISE HIGHS A DEGREE OR SO ACROSS THE SOUTH HALF WED AND EVERYWHERE THU WITH A NEGLIGIBLE CHANGE IN AIR MASS. LONG TERM (FRIDAY THROUGH MONDAY)... NO SIGNIFICANT CHANGES FOR THIS PERIOD WITH THE GFS/ECMWF SHOWING UPPER RIDGING DRIFTING EASTWARD FROM THE OZARKS TO THE CAROLINAS... LIKELY TO YIELD TEMPS ABOUT A CATEGORY OR TWO ABOVE NORMAL. BASED ON THE STRENGTH OF THIS RIDGE... AT THIS TIME DO NOT FAVOR THE BACKDOOR FRONTAL PASSAGE THROUGH THE ENTIRE CWA AS INDICATED BY THE 00Z/20 GFS. IT'S FAR TOO EARLY TO SPECULATE WHERE RITA'S REMNANTS WILL GO DAYS 6/7 AND WILL RETAIN DRY WEATHER. AVIATION... CLEAR SKIES AND CALM WINDS AT MOST LOCATIONS ACROSS THE REGION IS RESULTING IN THE DEVELOPMENT OF FOG AND STRATUS. MOSTLY VFR CIGS EXCEPT PATCHY CIGS NEAR 1KFT AND MVFR VSBYS. CIGS/VSBYS WILL BECOME IFR WITH POCKETS OF LIFR CIGS/VSBYS BETWEEN 07Z-09Z. AFTER 09Z THROUGH 14Z WIDESPREAD LIFR CIGS AND VSBYS. STRATUS AND FOG WILL GRADUALLY LIFT AFTER 14Z BCMG SCT-BKN LAYER 3-5KFT. 21Z-03Z...SCT SHOWERS AND TSTMS WITH CIGS 2-3KFT VSBYS 3-5 MILES. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...DGS nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 1220 PM EDT TUE SEP 20 2005 .SHORT TERM (REST OF TODAY THROUGH WEDNESDAY)... WILL UPDATE ZONES TO FRESHEN WORDING FOR THIS AFTERNOON. NO CHANGES TO LATER PERIODS. && .PREVIOUS DISCUSSION... (ISSUED 300 AM EDT TUE SEP 20 2005) SHORT TERM (TODAY THROUGH WEDNESDAY)... BASED ON RECENT NAM GFS AND RUC MODEL RUNS...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO EXIT THE UPPER OHIO VALLEY BY EARLY AFTERNOON AS WEAK COLD FRONT MOVES THROUGH THE AREA. HIGH PRESSURE WILL THEN BUILD INTO THE AREA TONIGHT AND WEDNESDAY...BRINGING DRY CONDITIONS. FORECASTED TEMPERATURES CLOSE TO A BLEND OF NAM AND GFS MOS VALUES. LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)... GFS MODEL RUNS CONTINUE TO SHOW ZONAL UPPER FLOW ACROSS THE NORTHERN U.S. OCCASIONAL INFLUX OF ENERGY FROM CANADIAN SHORT-WAVE TROUGHS PHASING INTO THIS FLOW WILL RESULT IN FRONTAL PASSAGES ACROSS THE UPPER OHIO VALLEY ACCOMPANIED BY A CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY FRIDAY AND NEXT MONDAY. EXPECT TEMPERATURES TO CONTINUE ABOVE NORMAL. AVIATION... TSTMS DEVELOPED NR ERI, MUCH AS MOIST FLUX INDICATED. BASED ON THAT, SRN HALF OF CWA IS IN JEOPARDY OF THUNDER AND RAIN. IT IS EXPECTED TO END IN PIT AT 13Z, FOLLOWED BY A PERIOD OF BKN035, THEN SCT050, AND CLR BY 23Z, AS VIGOROUS H5 TROF PUSHES E. FOG UNLIKELY OVERNIGHT (6-12Z WED). FOR MGW, I PUT RAIN, NOT THUNDER, TIL 17Z, CLR BY 00Z. DUJ HAS THUNDER TIL 08Z, THEN A PD OF RAIN, BKN015 AT 15Z, SCT035 AT 17Z, CLR BY 23Z. WINDS MAY GUST TO 20-23KT IN MID AFTN, ACCORDING TO THE DOWNWARD TRANSPORT OF THE BUFKIT MOMENTUM. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 235 PM EDT TUE SEP 20 2005 .SHORT TERM... COLD FRONT COMING THROUGH TO KNOCK TEMPS AND DEWPOINTS DOWN TO MORE REASONABLE LEVELS FOR MID SEPTEMBER...ALTHOUGH STILL ABOVE NORMAL. AVERAGES FOR TOMORROW ARE DCA MAX 78 MIN 60...BWI MAX 77 MIN 55. BEFORE THAT THERE IS THE THREAT OF SOME SHRA AND TSRA...MAINLY SE OF BALT AND DC. IN THAT AREA THERE IS DECENT INSTAB AROUND 1000 J PER KG AND A THETA E RIDGE. HELICITY AROUND 80. SATELLITE REVEALS THE PROBLEMATIC AREA WITH A GOOD CU FIELD OVER SE MD AND SE AND CENTRAL VA. SPC HAS ISSUED A SVR TSTM WATCH JUST S OF OUR AREA THIS AFTERNOON AND EVE. AT 2 PM...WATER VAPOR AND LATEST RUC MODEL SHOW A SHORT WAVE MOVING INTO EASTERN WV. ALL OF THIS SHOULD ALLOW FOR SOME CONVECTION TO BEGIN SE OF DC AND BALT. BY EVENING HOWEVER... THE THREAT WILL BE RAPIDLY DIMINISHING AS DRIER AIR MOVES OVER THE FORECAST AREA. POPS DOWN TO ZERO BY MIDNIGHT FOR THE ENTIRE AREA. THEN PAST THAT AND THROUGH WEDNESDAY... DO NOT SEE ANY REASON FOR ANY SORT OF CLOUDS. FORECAST SOUNDINGS DO NOT SUPPORT ANY CU AND NGM MODEL KEEPS ALL HIGH CLOUDS AWAY. SHOULD BE A GREAT MID SEPTEMBER DAY WITH HIGHS GENERALLY IN THE LOWER 80S. && .AVIATION... SKY COVER WITH FROPA FOR THE TAF SITES WILL BE MAINLY MIDDLE CLOUDS WITH OVC AROUND 080. FOG NOT EXPECTED OVERNIGHT WITH DRIER AIR MOVING IN. && .MARINE... WINDS BELOW SMALL CRAFT CRITERIA. AT 2PM BAY HAS S TO SW WINDS 10 TO 15 KT...EXPECT ABOUT THE SAME AFTER FROPA WITH WINDS BACKING NW... THEN N WED MORNING AND DIMINISHING. && .LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY... AT THE SURFACE...HIGH PRESSURE WILL CONTINUE THROUGH THURSDAY NIGHT. A COLD FRONT IS PROGGED TO SLOWLY MOVE THROUGH THE REGION ON FRIDAY. CANADIAN HIGH PRESSURE WILL FILTER INTO THE MID ATLANTIC ON FRIDAY NIGHT AND HOLD THROUGH THE WEEKEND. ANOTHER COLD FRONT IS EXPECTED MONDAY. ALOFT...A 500 MB TROUGH WILL PUSH OFFSHORE OVERNIGHT WEDNESDAY. THE FORECAST AREA WILL REMAIN BETWEEN ZONAL FLOW TO THE NORTH AND HIGH PRESSURE OVER THE SOUTHWEST THAT SPREADS OVER THE SOUTHEASTERN STATES. ZONAL FLOW WILL SPREAD FURTHER SOUTH BY SATURDAY AS THE SOUTHERN RIDGE BREAKS DOWN. TEMPERATURES WILL BE NEAR TO ABOVE NORMAL THROUGH FRIDAY. SATURDAY WILL BE BETWEEN 7 AND 10 DEGREES COOLER AT MOST LOCATIONS AFTER THE COLD FRONT MOVES THROUGH. SUNDAY AND MONDAY WILL GRADUALLY WARM TO NEAR NORMAL TEMPERATURES AHEAD OF THE NEXT POSSIBLE FRONTAL SYSTEM. WILL CONTINUE TO MONITOR RITA FOR ANY REMNANT EFFECTS. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SHORT/AVIATION/MARINE...STRONG LONG...SEA md AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 325 PM EDT TUE SEP 20 2005 .DISCUSSION... 12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW FAST ZONAL FLOW ALG THE US/CNDN BORDER TO THE N OF PERSISTENT RDG ACRS THE SRN CONUS DOWNWIND OF CUTOFF LO OFF THE CA COAST. FA UNDER INFLUENCE OF WEAK SFC RDG THIS MRNG. 12Z GRB/APX SDNGS ARE DRY AND STABLE (KINX -10 AT GRB/-6 AT APX)...BUT INSOLATION/ISENTROPIC LIFT ON THE 300K SFC HAS COMBINED WITH SOME LLVL MSTR SHOWN ON THESE RAOBS/RECENT TAMDAR SDNG FM SAW TO CAUSE SOME SC/AC BLO SUBSIDENCE INVRN ARND H75. OTRW...FAIRLY STRG SHRTWV NOTED MOVING THRU NW ONTARIO THIS AFTN. ALTHOUGH ATTENDANT COLD FNT/LO PRES TROF APRCHG THE WRN ZNS THIS AFTN...AIRMASS UPSTREAM IN THE NRN PLAINS/MN SO RELATIVELY DRY/STABLE (KINX ARND 15 AT MPX/ INL) AND AREA IN SUBSIDING RIGHT EXIT REGION OF SUPPORTING 120KT H3 JET MAX TRACKING ACRS SCNTRL CAN...THERE IS BARELY A CLD ALG THE BNDRY. AIRMASS UNDER WEAK RDG AXIS IN THE NRN PLAINS BEHIND THE TROF IS EVEN DRIER...12Z PWAT/KINX AT BIS 0.39 INCH/3. NEXT SHRTWV IN THIS ZONAL FLOW IS NOW MOVING INTO BRITISH COLUMBIA. MAIN FCST CONCERNS THIS PACKAGE ARE TEMPS INTO WED...THEN PCPN CHCS LATE WED INTO THU ASSOCIATED WITH SHRTWV NOW MOVING INTO BRITISH COLUMBIA/CUTOFF LO OFF THE CA COAST. FOR TNGT...SHRTWV NOW IN NW ONTARIO PROGGED TO DRIVE QUICKLY EWD INTO QUEBEC BY 12Z WED...WITH ATTENDANT LO PRES TROF CLRG THE ERN FA THIS EVNG AND FLAT SFC HI PRES RDG IN THE PLAINS PUSHING E OF ERY BY DAWN. STRONGEST ISENTROPIC LIFT ON THE 300K SFC AHEAD OF THE SFC TROF SHIFTS E OF ERY BY FCST ISSUANCE. ALTHOUGH RETURN SW FLOW COMMENCES LATE TNGT IN THE WAKE OF THE SFC RDG...UPSTREAM AIRMASS IS SO DRY THERE SHOULD BE LTL IF ANY CLD. SO EXPECT A MOCLR SKY TNGT AS DRY PACIFIC AIR TO THE W FLOODS EWD IN ZONAL FLOW. ALTHOUGH WINDS MAY GO LGT FOR A SHORT TIME AS SFC RDG AXIS PASSES OVHD...THERE SHOULD BE ENUF OF A WIND MOST OF THE TIME TO RESTRICT DIURNAL FALL OF TEMP/PSBL FOG FORMATION. SFC DWPTS UPSTREAM OVER THE NRN PLAINS AS LO AS THE UPR 30S...BUT WIND ABV SHALLOW RADIATION INVRN SHOULD BE ENUF TO KEEP TEMPS EVEN OVER THE COLDER INTERIOR SPOTS FM GOING BLO 45. ON WED...SHRTWV NOW ENTERING BRITISH COLUMBIA PROGGED TO MOVE INTO NW ONTARIO BY LATE IN THE DAY...CAUSING SFC TROF TO DVLP OVER THE UPR GRT LKS LATE IN THE DAY. GFS PERSISTS IN SHOWING H85 DWPT RISING UP 12C LATE IN THE DAY OVER THE W IN RETURN SW FLOW BTWN DVLPG TROF AND DEPARTING RDG TO THE E...BUT 12Z H85 RAOBS SUG THIS MSTR RETURN IS PROBABLY TOO AGGRESSIVE. NAM/UKMET/NGM DO GENERATE PCPN OVER THE ERN ZNS WHERE ISENTROPIC LIFT IS MORE SUSTAINED AND HAS A CHC TO SATURATE VERY DRY AIRMASS (NAM ALSO PUSHES SFC DWPTS IN THIS AREA IN LK MI MODIFIED FLOW TOWARD AN UNREALISTIC 70)...BUT WL KEEP E DRY FOR NOW AND REMOVE PCPN MENTION FM THE W BECAUSE UPSTREAM AIRMASS ACRS THE PLAINS IS SO DRY. OTRW...DAY WL BE A WARM ONE WITH H85 TEMPS FCST TO RISE TO 17-18C NR THE WI BORDER. MIXING TO H8 ON GFS/NAM FCST SDNGS YIELDS TMAX IN THE 80 TO 85 RANGE OVER THE SCNTRL AWAY FM LK MI INFLUENCE IN FCST SW FLOW. FOR WED NGT...FCST WL DEPEND ON COMPLEX INTERACTION BTWN SHRTWV MOVING THRU ONTARIO AND REMNANTS OF CUTOFF UPR LO NOW OFF THE CA COAST THAT IS FCST TO SHEAR ENEWD INTO THE UPR MIDWEST LATE WED NGT. NAM/GFS/UKMET TEND TO FOCUS HIER QPF OVER THE SCNTRL ZNS WHERE BETTER DPVA/H85-3 QVECTOR CNVGC ASSOCIATED WITH SHRTWV REMNANTS INTERACT WITH RRQ OF UPR JET MAX IN SE CAN/ATTENDANT SFC COLD FNT/ FAIRLY SHARP H7-6 FRONTOGENESIS ASSOCIATED WITH ONTARIO SHRTWV. WL BUMP UP POPS TO 50 ACRS THE SCNTRL BUT THEN CUT BACK TO JUST LO CHC OVER THE KEWEENAW. GRDL MOISTURE RETURN/CLDS WL HOLD UP TEMPS MUCH OF THE NGT... BUT READINGS WL FALL LATER FOLLOWING THE COLD FROPA IN THE WAKE OF ONTARIO SHRTWV. LINGERING SHRA WL END THU MRNG AS SFC HI PRES/COOLER AND DRIER AIR UNDER INCRSLY CONFLUENT WLY FLOW BLD INTO THE AREA. H85 TEMPS FCST TO FALL TO ARND 3C BY THE END OF THE DAY OVER THE KEWEENAW. POTENTIAL FOR FROST A REAL ONE OVER THE INTERIOR W/CNTRL FA THU NGT WITH SFC HI PRES CENTER BLDG TOWARD CYQT BY 12Z FRI AND AXIS OF MIN PWAT ARND 0.33 INCH MOVING OVER THE WRN CWA AS LLVL FLOW BCMS DIFFLUENT AND LGT UNDER THE RDG AXIS TOWARD 12Z. AVN MOS WITH COOP SITES SHOWS LO TEMPS AS LO AS 31 NR THE WI BORDER. WL INCLUDE MENTION OF PTCHY FROST IN THESE AREAS...BUT WL NOT FCST TEMPS THAT LO RIGHT NOW. IN THE MEDIUM/EXTENDED RANGE...CANADIAN HIGH PRES PROGGED TO BUILD INTO THE UPR GRT LKS THU NGT WL LINGER INTO SAT...WITH H85 TEMPS AS LO AS 2-4C ON FRI. ALTHOUGH THIS H85 TEMP WOULD BE LO ENUF TO WARRANT CONSIDERATION OF LK EFFECT PCPN... DRY ACYC NATURE OF THE FLOW WOULD MINIMIZE THIS THREAT. THE HI CENTER WL MOVE QUICKLY TO THE E ON SAT UNDER A BLDG UPR RDG DOWNSTREAM OF DEEPENING WRN TROF. ALTHOUGH A RETURN SLY FLOW WL DVLP...DRYNESS OF AIRMASS AND LOCATION OF FNT ON THE SRN EDGE OF DRY AIRMASS WELL TO THE S WL ALLOW FOR ONLY INCRSG HI CLDS AS UPR RDG AXIS PUSHES TO THE E. HAVE MAINTAINED GOING CHC POPS FOR LATER IN THE DAY OVER THE W AND ENTIRE CWA SAT NGT INTO SUN AS INTENSIFYING NRN BRANCH TROF DRIVES COLD FNT TOWARD AND THRU THE FA. THEN COOLER ON MON AS CNDN HI PRES BLDS INTO THE UPR GRT LKS AND H85 TEMPS FALL TOWARD 0C PER THE ECMWF/00Z GFS. PER NCEP MANUAL GUIDANCE...HAVE FOLLOWED THE 00Z ECMWF/GFS TO MAINTAIN DRY FCST THRU TUE. 06Z GFS INDICATED WRN TROF LIFTING OUT TOWARD THE UPR GRT LKS...BUT 00Z GFS/ECMWF MAINTAINED DRY NW NRN BRANCH NW FLOW ALF. COORDINATED WITH APX/GRB/DLH. && .MQT...WATCHES/WARNINGS/ADVISORIES...NONE. && $$ KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ABERDEEN SD 245 PM CDT TUE SEP 20 2005 .SHORT TERM...TODAY THROUGH FRIDAY... HIGH PRESSURE AND NARY A CLOUD IN SIGHT TODAY THROUGH TONIGHT. VERY TIGHT DRYLINE ACROSS CENTRAL SOUTH DAKOTA...AND THIS WILL MAKE FOR A RATHER TRICKY MINIMUM TEMPERATURE FORECAST TONIGHT. BOTH RUC AND ETA SHOW GRADIENT MAINTAINING OVERNIGHT...SO AREAS WEST OF JAMES VALLEY SHOULD RADIATE WELL...AND THUS DROPPED WESTERN CWA TEMPS AROUND 5 DEGREES. FRONTAL PASSAGE STILL ON TRACK FOR LATE TOMORROW...AND STILL A DRY PASSAGE MAINTAINED. PRECIPITATION IS STILL EXPECTED POST FRONTAL WITH SOME MID LEVEL FORCING AT 700MB. CONCERN WITH THIS IS TWOFOLD. FIRST...WITH MOST FORCING WELL ALOFT...AND BOUNDARY LAYERS STAYING QUITE DRY IN ETA BUFR SOUNDINGS...IT WILL TAKE SOME TIME TO MOISTEN UP COLUMN ENOUGH TO RAIN. SECOND...12 UTC ETA BACKED OFF THE PRECIPITATION COVERAGE AND AMOUNTS. MORE CONVECTIVE RELEASE NOTED OVER MINNESOTA AHEAD OF FRONT AND LESS FOR US. TO ACCOUNT FOR THIS...DELAYED ONSET OF PRECIPITATION OUT WEST...AND SHADED POPS LOWER IN NORTH. GFS STILL SHOWING SHOWERS SO DIDN'T REMOVE COMPLETELY...BUT DEFINITELY DOWNPLAYED IT. TEMPERATURES COOL BEHIND FRONT WITH SURFACE HIGH DOMINATING. NEXT PRECIP ON TRACK FOR FRIDAY LATE...BUT ETA IS A BIT SLOWER THAN BEFORE. FIRE WEATHER CONCERNS FOR TOMORROW WESTERN CWA STILL THERE...BUT CURRENT GRIDS LACK BOTH WIND SPEEDS AND LOW HUMIDITIES TO WARRANT RED FLAG WATCH. WITH SLIGHTLY SLOWER FRONTAL PROGRESSION STRONGER POST FRONTAL WINDS DELAYED UNTIL AFTER MAX HEATING. STILL VERY HIGH TO EXTREME FIRE DANGER...BUT NO WATCH ISSUED. .LONG TERM...SATURDAY THROUGH TUESDAY NOT VERY MANY CHANGES WERE MADE TO THE EXTENDED THIS TIME AROUND. MODELS STILL AGREE WITH A TROUGH DIGGING ACROSS THE WESTERN U.S. AND A PIECE OF ENERGY GETTING EJECTED OUT INTO THE NORTHERN PLAINS AT THE START OF THE WEEKEND. GFS AND EC SEEM TO INDICATE THIS WAVE GETTING PICKED UP IN THE NORTHERN BRANCH OF THE JET STREAM AS IT MOVES ACROSS THE DAKOTAS AND MINNESOTA. AS THIS HAPPENS...A CUTOFF LOW FORMS OVER THE CALIFORNIA AREA. DID NOT CHANGE WX/POP GRIDS AND KEPT PRECIP CHANCES THROUGH 12Z SUN. MODELS STILL SHOWING HIGH RH IN THE LOW TO MID LEVELS AND KEPT SKY COVER FAIRLY HIGH FOR SAT INTO SAT NIGHT. GFS AND EC NOW AGREE ON A SURFACE HIGH SETTLING INTO THE REGION ON SUN AND MON BEHIND THE DEPARTING WAVE. GFS MOVES THE HIGH OFF TO THE EAST WHILE THE EC KEEPS IT ANCHORED OVER THE DAKOTAS INTO MONDAY NIGHT. MEX GUIDANCE IS NOW QUITE A BIT COOLER FOR LATE IN THE EXTENDED AND THE TREND WAS TO LOWER TEMPS FURTHER FROM PREVIOUS FORECAST. GFS BRINGS THE MAIN CUTOFF LOW UP INTO THE NORTHERN PLAINS BY TUESDAY WITH WIDESPREAD QPF. THIS WAS ALSO SEEN IN THE 06Z RUN BUT WOULD STILL LIKE TO SEE ANOTHER MODEL RUN OR TWO FROM A FEW DIFFERENT MODELS BEFORE ANY PRECIP IS ADDED. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. && $$ HARDING/TARVER sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 600 PM EDT TUE SEP 20 2005 .SHORT TERM (REST OF TONIGHT)... FEW SMALL SHRA POPPING UP IN NORTHERN CWA...WORKING WITH WHAT LITTLE INSTABILITY THERE IS. DESPITE ADVANCING COLD FRONT...SEE LITTLE TO KEEP ACTIVITY GOING PAST SUNSET. THUS...HAVE REDUCED POPS FOR THE NEXT FEW HOURS...CUTTING OFF PRECIP BY 01Z. STILL APPEARS CLOUDS WILL SUFFICIENTLY CLEAR FOR FOG FORMATION OVERNIGHT...BUT WILL MONITOR OVER THE NEXT FEW HOURS. ADJUSTED SKY GRIDS SOMEWHAT AS WELL BASED ON CURRENT TRENDS. TEMPS ARE ON TRACK FOR NOW. && .PREVIOUS DISCUSSION... (ISSUED 305 PM EDT TUE SEP 20 2005) SHORT TERM (REST OF TONIGHT THROUGH WEDNESDAY)... MESOETA SHOWS A BAND OF MOISTURE AROUND 850MB LAGGING TONIGHT WHILE THE LATEST RUC AND GFS SHOW DRYING AT ALL LEVELS THIS EVENING. HAVE KEPT SHOWERS IN THIS AFTERNOON AS BOTH THE RUC AND ETA SHOW A GOOD SHOT OF COLD AIR MOVING ACROSS WEST VIRGINIA DURING THE AFTERNOON. ASSUMING DRYING TONIGHT FOG WILL SETTLE IN. SEE NO GOOD REASON TO DEVIATE FROM MIN TEMP ON MOS. LONG TERM (WEDNESDAY NIGHT THROUGH TUESDAY)... MODELS AGREE ON HIGH PRESSURE IN CONTROL OF WEATHER CONDITIONS WED NIGHT THRU THU NIGHT. WENT WITH HIGHER POPS THAN GUIDANCE FOR FRIDAY...AS A WEAK COLD FRONT MOVES THROUGH ACROSS THE AREA...AND BECOMES STATIONARY AS IT DISSIPATES ACROSS OUR EXTREME SOUTHERN SECTIONS ON SAT. ANOTHER SHOT OF PRECIP EXPECTED ON MONDAY AS ANOTHER COLD FRONT AFFECTS THE AREA THROUGH EARLY TUESDAY. MEX DEPICTS MID TO HIGH CHANCES OF PRECIP FROM SUN THROUGH TUE...BUT BELIEVE PRECIP WILL START MON AND END EARLY TUE. WINDS BECOME SOUTHEAST BY THURSDAY BRINGING MOISTURE AND WARMER TEMPERATURES TO THE REGION. GFS SHOWS H8 TEMPERATURES INCREASING TO ABOUT 16C WED AND THU....WHILE THE ETA SHOWS TEMPS UP TO 20C BY THU. MAV NUMBERS IN THE MID 80S FOR WEDNESDAY AND INTO UPPER 80S TO AROUND 90 FOR THURSDAY. KEPT THURSDAY IN THE UPPER 80S. MORE SEASONAL TEMPERATURES ARE EXPECTED THROUGH THE WEEKEND. AVIATION... EXPECT CLEARING TONIGHT AFTER 00Z AS DRYING OCCURS AT ALL LEVELS. SO LIFR FOG SHOULD DEVELOP WITH COOL TEMPERATURES AND WARM RIVER WATER IN RIVER VALLEYS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SHORT TERM...CL wv AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON WV 305 PM EDT TUE SEP 20 2005 .SHORT TERM (REST OF TONIGHT THROUGH WEDNESDAY)... MESOETA SHOWS A BAND OF MOISTURE AROUND 850MB LAGGING TONIGHT WHILE THE LATEST RUC AND GFS SHOW DRYING AT ALL LEVELS THIS EVENING. HAVE KEPT SHOWERS IN THIS AFTERNOON AS BOTH THE RUC AND ETA SHOW A GOOD SHOT OF COLD AIR MOVING ACROSS WEST VIRGINIA DURING THE AFTERNOON. ASSUMING DRYING TONIGHT FOG WILL SETTLE IN. SEE NO GOOD REASON TO DEVIATE FROM MIN TEMP ON MOS. && .LONG TERM (WEDNESDAY NIGHT THROUGH TUESDAY)... MODELS AGREE ON HIGH PRESSURE IN CONTROL OF WEATHER CONDITIONS WED NIGHT THRU THU NIGHT. WENT WITH HIGHER POPS THAN GUIDANCE FOR FRIDAY...AS A WEAK COLD FRONT MOVES THROUGH ACROSS THE AREA...AND BECOMES STATIONARY AS IT DISSIPATES ACROSS OUR EXTREME SOUTHERN SECTIONS ON SAT. ANOTHER SHOT OF PRECIP EXPECTED ON MONDAY AS ANOTHER COLD FRONT AFFECTS THE AREA THROUGH EARLY TUESDAY. MEX DEPICTS MID TO HIGH CHANCES OF PRECIP FROM SUN THROUGH TUE...BUT BELIEVE PRECIP WILL START MON AND END EARLY TUE. WINDS BECOME SOUTHEAST BY THURSDAY BRINGING MOISTURE AND WARMER TEMPERATURES TO THE REGION. GFS SHOWS H8 TEMPERATURES INCREASING TO ABOUT 16C WED AND THU....WHILE THE ETA SHOWS TEMPS UP TO 20C BY THU. MAV NUMBERS IN THE MID 80S FOR WEDNESDAY AND INTO UPPER 80S TO AROUND 90 FOR THURSDAY. KEPT THURSDAY IN THE UPPER 80S. MORE SEASONAL TEMPERATURES ARE EXPECTED THROUGH THE WEEKEND. && .AVIATION... EXPECT CLEARING TONIGHT AFTER 00Z AS DRYING OCCURS AT ALL LEVELS. SO LIFR FOG SHOULD DEVELOP WITH COOL TEMPERATURES AND WARM RIVER WATER IN RIVER VALLEYS. && .PREVIOUS DISCUSSION... (ISSUED 711 AM EDT TUE SEP 20 2005) AVIATION (12Z TO 12Z)... FRONT MOVING THROUGH THE AREA TODAY WILL BRING SHOWERS AND POSSIBLY A THUNDERSTORM...BUT CONDITIONS SHOULD NOT GET MUCH WORSE THAN MVFR. TONIGHT...IT APPEARS CLOUDS WILL HANG IN AT LEAST ACROSS SOUTHERN SITES...MOSTLY ABOVE 3KFT. THIS WILL KEEP DENSE FOG FROM FORMING. DENSE FOG IS LIKELY NIGHT TONIGHT ACROSS NORTHERN SITES...WHERE IT DOES CLEAR. PREVIOUS DISCUSSION... (ISSUED 339 AM EDT TUE SEP 20 2005) SHORT TERM (TODAY)... COLD FRONT TRAVERSES AREA FROM NORTHWEST TO SOUTHEAST TODAY. ASSOCIATED RAIN SUPPORTED BY GOOD UPPER DIVERGENCE AND MID LEVEL SPIN...THOUGH LOW LEVEL FORCING WEAK. THEREFORE THIS IS PANNING OUT TO BE MAINLY A MVFR EVENT WITH LOWER CIGS AND VIS ONLY WITH THE HEAVIEST RAINFALL. INSTABILITY MAINLY ON HIGH LOW LEVEL MOISTURE WITH PWS PUSHING 1.75 INCHES FROM THE NAM SUPPORTING ONGOING THUNDERSTORMS AND NO REASON TO BELIEVE THEY WILL NOT CONTINUE UNTIL FRONTAL PASSAGE. WENT WITH HPC QPF VALUES BETWEEN A QUARTER AND ONE HALF INCH WHICH SEEMS REASONABLE ESPECIALLY GIVEN LACK OF LOW LEVEL CONVERGENCE...LOCALLY HIGHER VALUES IN HEAVIER THUNDERSTORMS THOUGH. CLEARING TAKES PLACE FROM THE NORTHWEST THIS AFTERNOON WITH NAM PARTICULARLY DRY LOOKING IN THE LOW LEVELS WITH LOW DEW POINTS COMING IN. IT DOES APPEAR TO SUGGESTS AFTERNOON CUMULUS BEHIND CLEARING LINE OVER NORTHWEST COUNTIES GIVEN ENOUGH HOURS OF SUNSHINE THERE. TEMPERATURES WILL BE VERY MUCH A FUNCTION OF HOW QUICKLY CLEARING TAKES PLACE. MIDDLE GROUND MET APPEARED TO MAKE THE MOST SENSE ESPECIALLY GIVEN FACT THAT IT HAS PERFORMED WELL OVER THE PAST COUPLE OF DAYS EVEN WITH VARYING AMOUNTS OF CLOUDS. LONG TERM (TONIGHT THROUGH MONDAY)... BAROCLINIC ZONE WILL BE OUT OF THE FCST AREA BY THIS EVENING GIVING WAY TO A SFC ANTICYCLONE BUILDING SE FM THE GRTLKS. BENIGN WX THEN ENSUES UNTIL THUR NGT OR FRI. IN THE MEANTIME...MID LVL HGTS BUILD PROVIDING A CLR SKY AND OVRNGT FG DEVELOPMENT IN RVR VLYS TNGT THRU DAY 2 NGT. ANAFRONT DROPS SLOWLY S FM LAKE ERIE THUR NGT INTO FRI. THERE IS STILL SOME QSTN HOW FAR S THE FRONT WL PENETRATE INTO THE UNSEASONABLY STRONG UPR LVL HIGH. FOR THE TIME BEING...INCREASED CLDS AND POPS OVR FAR NWRN SECTIONS AND TRIMMED BACK SRN EXTENT OF SCHC POPS IN THE COAL FIELDS. NAM CONTS TO PLAY UP A LOT OF THERMODYNAMIC INSTABILITY IN THE WARM XCTR AHEAD OF THE FRONT AFT 06Z FRI. MUCAPES STAY ABOVE 2.0KJ/KG AND GOOD BL EQUIV POT TEMP/CONV IS FCST. ANOTHER POINT OF INTEREST IS STG H2 UPR LVL DIV IN THE OH VLY. DISCRETE PROPAGATION COULD BRING A TSTM COMPLEX INTO NRN FA EARLY FRI MRNG...SOMETHING TO WATCH OUT FOR IN FUTURE RUNS. H8 TEMPS AGAIN PUSH 20C LATE IN THE WEEK...WHICH CORRESPONDS TO HIGHS 10 TO 15F ABOVE NORMAL WITH LOW 90S PREDICTED IN THE TRI STATE AREA DAY 3. OVERALL...PLAYED NUMBERS ALONG THE LINES OF THE WARMER MET GVN ITS OUTSTANDING VERIFICATION OF LATE. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...NONE. OH...NONE. KY...NONE. VA...NONE. && $$ SHORT TERM...AAR LONG TERM...ARJ AVIATION...AAR wv