AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 952 AM EDT TUE SEP 18 2001 CURRENTLY...MSAS ANALYSES SHOWING AREA OF HIGH PRES DOMINATING THE SOUTHEAST WITH TEMPS A FEW DEGREES HIGHER TODAY THAN YESTERDAY. NEAR ZONAL FLOW ALOFT CONTINUED. MORNING SOUNDING INDICATED STRONG SUBSIDENCE INVERSION ABOVE 800 MB WITH SOME MOISTURE TRAPPED BELOW. PW WAS UP TO 1.37. FORECAST...CLOUDS ALREADING BEGINNING TO BREAK...AS HEATING CONTINUES... AND EXPECT A PARTLY CLOUDY AFTERNOON. WITH WEAK GRADIENT...SEABREEZES WILL FORM ALONG BOTH GULF AND ATLANTIC AND CONVERGE INLAND NEAR I-75 LATE THIS AFTERNOON (AS PER MESO-ETA MODEL). MODELS ALSO INDICATE VORT MAX MOVING THROUGH LATE THIS AFTERNOON. THE RUC IS MUCH STRONGER WITH THIS FEATURE...WHEREAS THE OTHER MODELS MUCH WEAKER. HAVE OPTED FOR THE WEAKER SOLUTION AND WILL LEAVE OUT MENTION OF POPS. IN OTHER WORDS...PREVIOUS FCST LOOKS GOOD. MARINE...CURRENT OBS SHOWING 3 FOOT SWELL AT GRAYS REEF AND 4 FEET AT SABSOON TOWER. 20NM EAST OF CAPE CANAVERAL SHOWING 6 FOOT SWELLS. EXPECTING A GRADUAL DECREASE THIS AFTERNOON SO PREVIOUS FCST LOOKS GOOD. .JAX... .GA...NONE. .FL...NONE. EIGHT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 900 PM CDT TUE SEP 18 2001 LINE OF SHOWERS AND THUNDERSTORMS MOVING EAST ALONG A LINE AT 830 PM FROM MENA TO DEQUEEN ARKANSAS TO SULPHUR SPRINGS TO NEAR TERRELL TEXAS. THE STRONGEST STORMS ARE AT THE SOUTHWEST END OF THE LINE AND WILL BE MOVING INTO WOOD COUNTY SHORTLY. THE MAIN THREAT WILL BE DAMAGING WIND BUT BELIEVE STORMS WILL DECREASE BY MIDNIGHT. WILL CLEAN UP SKY CONDITION WORDING. WILL MENTION HEAVY RAIN THREAT ACROSS THE NORTHERN SECTIONS AND CHANCE OF SEVERE WEST AND NORTHWEST FOR THE REMAINDER OF THE NIGHT. RUC INDICATES LIFTED INDEX VALUES FROM -4 TO -7 WITH CAPES OF 1000 TO 2000 J/KG FOR THE NEXT FEW HOURS. 09 .SHV...NONE. la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1010 PM EDT TUE SEP 18 2001 00Z RAOBS/WV LOOP AND RUC ANAL SHOW MAIN BELT OF WESTERLIES WELL TO N ACRS CNTRL CAN. BUT SEPARATE STREAM NOTED ACRS CONUS WITH TROF OVR THE CNTRL STATES. TWO OUT-OF-PHASE SHRTWVS APPEAR TO BE MOVG THRU THIS TROF...SUPPORTING A DEEPENING 1005MB LO PRES OVR NE MO AT 00Z. WHOLE TROF APPEARS TO BE DVLPG A NEGATIVE TILT AS SECOND SHRTWV DIGGING INTO BASE OF LARGER SCALE TROF AND AXIS OF HIER UPR LVL WNDS SHIFT TO E SIDE OF TROF. SFC OBS/88D COMPOSITE SHOW RA AHD OF LO MOVG INTO SRN WI AT 01Z. A SFC HI PRES RDG IN CONFLUENT ZN BTWN TWO BRANCES OF UPR FLOW STRETCHES FM HI CENTER IN QUEBEC INTO SW ONTARIO. 00Z APX/GRB SDNGS SHOW HI RH BLO ABOUT H7...WITH DRIER AIR/INVRN ABV THIS MSTR. SFC DWPTS WELL INTO THE 50S ACRS CWA AND REST OF GREAT LKS UNDER CLDY SKIES N OF TROF TO THE W. TEMPS MAINLY 55 TO 60. ISOLD -SHRA THAT DVLPD THIS AFTN HAVE COMPLETELY DSPTD WITH LOSS OF INSOLATION. MAIN FCST CONCERNS TNGT ARE POTENTIAL FOR PCPN AHD OF LO PRES TO THE S AND MIN TEMPS. 18Z AVN AND 00Z RUC APPEAR TO HAVE VERY GOOD HANDLE ON PLACEMENT AND INTENSITY OF SFC LO AND MOVE THIS SYS TO NR CHI BY 12Z WED. ALTHOUGH AXIS OF HIEST H3 WNDS REMAIN WELL TO S...BOTH MODELS INDICATE H4-2 DVGC INCRSG AFTR 09Z OVR ERN CWA AS FIRST SHRTWV ROTATING ARND TROF CONTS N AHD OF MORE NEGATIVELY TILTED UPR SYS. H85-5 QVECTOR CNVGC LESS IMPRESSIVE WITH LGT LLVL WNDS LIMITING ISENTROPIC LIFT. BUT SINCE LLVLS ALREADY MOIST...THINK INCRSG UPR DYNAMICS WL MOISTEN PROHIBITIVELY DRY HIER LVL LYRS APRNT ON 00Z SDNGS ENUF TO INCRS THE CHC OF RA ACRS THE SE. HAVE INCRSD POPS TO LIKELY OVR MNM COUNTY AND WENT CHCY FOR ESC-ISQ LATE. UPSTREAM MIN TEMPS WERE IN THE 50S TUE MRNG. SINCE SKIES WL REMAIN CLDY AND DWPTS ARE WELL INTO THE 50S...BUMPED UP MIN TEMPS A FEW DEGREES ALL ZNS WITH LTL DIURNAL FALL OFF ON TEMP UNDER THE CLDS AND WITH NO DRY ADVCTN. COORDINATED WITH GRB. AFDMQT FM DAYSHIFT FOR LATER PDS: MAIN FORECAST CONCERN BEGINS WEDNESDAY AS 300-310K ISENTROPIC LIFT OVERSPREADS THE CWA. SIMILAR TO FORECAST TRACKS FOR THE SYSTEM...AVN IS QUICKER AT BRINGING LIFT AND PRECIP INTO UPPER MICHIGAN. 12Z CANADIAN APPEARS THE FASTEST STILL. WITH CONSISTENCY OF THE AVN AND THE NORTHWARD TREND WITH THE ETA WILL LEAN TOWARD THE FASTER SOLUTION. WILL CONTINUE LIKELY POPS ACROSS THE EASTERN CWA...MAINLY IN THE AFTERNOON. CHANCE POPS ACROSS THE WEST AND CENTRAL CWA... WORDED CHANCE WEST AND SCATTERED CENTRAL WHERE PRECIP IS MORE LIKELY. SYSTEM MOVES THROUGH NORTHERN LOWER AND INTO LAKE HURON WEDNESDAY NIGHT. LIKELY POPS ACROSS THE EAST FOR WEDNESDAY NIGHT AS WELL...A GREATER CHANCE THAN DURING THE DAY WITH GREATER MOISTURE NEARBY. WINDS PICK UP AS THE GRADIENT TIGHTENS WEDNESDAY AFTERNOON INTO THE NIGHT...STRONGEST ACROSS THE SOUTHEAST CWA. WEAK RIDGING/DRYING WORKS ACROSS THE CWA LATE WEDNESDAY NIGHT AND THURSDAY. WITH UNCERTAINTY AS TO NORTHWEST EXTENT OF THE SYSTEM WILL LEAVE CHANCE POPS ACROSS THE WEST WITH NO TIMING...ALTHOUGH BETTER WEDNESDAY NIGHT WILL BE IN THE EVENING. AS SW FLOW SFC LOW LIFTS TO THE NE OF THE GRTLKS THURS NGT... MRF/ECMWF/UKMET/CANADIAN ALL SIMILAR IN SLIDING A SECONDARY CDFNT EAST ACROSS UPR MI ON FRI. ECMWF DEEPENS LOW MOVG AWAY FM GRTLKS SIGNIFICANTLY BY 12Z FRI WHILE MRF WEAKEST AND UKMET/CANADIAN A COMPROMISE. UPR RIDGING FOLLOWS IN THE WAKE OF LOW FRI NGT/SAT AHEAD OF NEXT SHRTWV PROGGED TO MOVE ACROSS THE UPR GRTLKS SAT NGT/SUN. MRF HINTING AT THE COOLEST AIRMASS OF THE SEASON TO BE DRAWN DOWN ACROSS THE UPPER MIDWEST/GRTLKS AS DEEP UPR LVL TROF IS CARVED OUT OVR THE AREA IN RESPONSE TO STRONG RIDGING OVER THE PLAINS. THANKS FOR COORD WITH APX. .MQT...NONE. KC mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1123 AM EDT TUE SEP 18 2001 500 SHORTWAVE EXITING LOWER MICHIGAN WITH NEXT SHORTWAVE ACROSS CENTRAL AND NORTHERN PLAINS AS INDICATED BY PLENTY OF MOISTURE AND CONVECTION ON WATER VAPOR OVER MN/IA/MO/OK. THIS SHORTWAVE WILL CONTINUE TO HEAD EAST TODAY AND BRING A VORT LOBE INTO WISCONSIN BY THIS EVENING. THIS VORT LOBE WILL QUICKLY MOVE NORTHEAST INTO THE U.P. LATE TONIGHT AND 500 TROUGH BEGINS TO BECOME NEGATIVELY TILTED LATE WEDNESDAY INTO EARLY THURSDAY ACROSS WESTERN GREAT LAKES WHICH WOULD SLOW DOWN PROGRESS EASTWARD SOME. 00Z ETA SHOWING WEAK ISENTROPIC LIFT TODAY ON I295K SURFACE WITH PLENTY OF MOISTURE AND THIS LIFT STRENGTH. 06Z MESOETA ALSO SUPPORTS THIS SCENARIO WITH WEAK ISENTROPIC LIFT TODAY. 13Z RUC SHOWING WEAK ISENTROPIC LIFT ON I295 SFC OVER CENTRAL U.P. LATE THIS MORNING INTO THIS AFTERNOON WITH THE ISENTROPIC LIFT GETTING STRONGER WITH TIME. I295 SFC AROUND 850-800 MB ACROSS U.P. KMQT RADAR THOUGH SHOWED PCPN HAS DRIED UP FOR THE MOST PART. WITH THE WEAK ISENTROPIC LIFT ACROSS THE AREA...CANNOT COMPLETELY RULE OUT AT LEAST SOME SPRINKLES AND WILL WORD FORECAST AS FEW SPRINKLES POSSIBLE THIS AFTERNOON. CLOUDS WILL BE STUBBORN TO LEAVE WITH PLENTY OF LOW LEVEL MOISTURE IN PLACE AND WILL NOT TAKE MUCH TO PRODUCE A FEW SPRINKLES. ALSO WITH CLOUDS AROUND...WILL LIMIT SFC HEATING. BASICALLY...UPDATED FORECAST TO ADD POSSIBILITY OF SPRINKLES ACROSS CWA THIS AFTERNOON. TEMPS LOOKED GOOD. .MQT...NONE. MICHELS mi SOUTHEAST MICHIGAN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 1038 AM EDT TUE SEP 18 2001 THE LATEST WATER VAPOR LOOP SHOWS A SHORT WAVE TROUGH ACROSS EASTERN OHIO WITH A DEEPER UPPER LEVEL TROUGH ACROSS THE CENTRAL PLAINS. MEANWHILE...SHORT WAVE RIDGING ALOFT IS BUILDING ACROSS THE WESTERN GREAT LAKES REGION. DNVA FROM APPROACHING SHORT WAVE RIDGE HAS SCOURED OUT MUCH OF THE CLOUD COVER ACROSS SOUTHERN LOWER MICHIGAN. THE LATEST MESO-ETA AND RUC SOLUTIONS BRING THIS SHORT WAVE RIDGE ACROSS THE FORECAST AREA THIS AFTERNOON AND KEEP DEEP LAYER MOISTURE ACROSS ILLINOIS AND SOUTHERN INDIANA UNTIL THIS EVENING. BASED ON THE LATEST SATELLITE LOOPS...MID AND UPPER LEVEL MOISTURE HAS PUSHED FURTHER TO THE EAST THAN MODELS WOULD SUGGEST. HOWEVER...LATEST IR IMAGERY IS SHOWING A GENERAL WARMING TREND IN CLOUD TOPS UPSTREAM. SINCE ETA CU SCHEME IS ONLY SUGGESTIVE OF SCT CU THIS AFTERNOON...I WILL GO PARTLY SUNNY IN THE FORECAST...THINKING THAT THE HIGHER MID/HIGH LEVEL MOISTURE WILL HOLD OFF UNTIL THIS EVENING. BASED ON 12Z SOUNDINGS AND MESO-ETA MODEL SOUNDINGS...AFTERNOON HIGHS IN THE LOWER 70S STILL LOOK REASONABLE. .DTX...NONE. CONSIDINE mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON MS 940 PM CDT TUE SEP 18 2001 UPDATED ZONES TO TAKE OUT POPS FROM SOUTHEASTERN ZONES. ALSO REDUCED POPS IN REMAINDER OF ZONES AND USED MAINLY "AFTER MIDNIGHT WORDING". LATEST MESO ETA AND RUC MODELS HOLD BACK THE PRECIPITATION TO LATER TONIGHT. PREVIOUS RUNS OF MESO ETA AND RUC SHOWED WIDESPREAD PRECIPITATION IN WESTERN AND NORTHERN PORTIONS OF THE FORECAST AREA BY NOW, BUT THAT PROVED TO BE TO QUICK. NO OTHER CHANGES NECESSARY AT THIS TIME. .JAN... .MS...NONE .LA...NONE .AR...NONE. 15 ms AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST SOUTH DAKOTA AND WEST CENTRAL MINNESOTA NATIONAL WEATHER SERVICE ABERDEEN SD 1030 AM CDT TUE SEP 18 2001 GOING FCST PCKG HAD THINGS WELL IN HAND...WITH ONLY A FEW TWEAKS NEEDED. TEMPS BUMPED DOWN JUST A HAIR...AS PERSISTENCE WITH Y'DAYS HIGHS AND EXTENSIVE STRATUS DECK TO KEEP THINGS COOL TDY. WINDS WERE FINE...AND ONLY TWEAK TO POPS WERE TO INTRODUCE 20 POP KMBG AREA...AND MOVE REST OF CWA TO ISOLD POP. MORNING UA/ACARS ANALYSIS SHOWS MDLS HANDLING SITN A LITTLE BETTER THAN Y'DAY. NMRS SMALL SCALE CIRCULATIONS EVIDENT IN W/V PICS...WITH MAIN PLAYER FOR MY CWA STILL SPINNING IN MT. SHRA/-TSRA IN WRN SD ASSCD WITH THIS FEATURE WEAKENING AS THEY MOVE SLOWLY E. ONCE AGAIN...JET ENERGY WAY TO SOUTH...WITH ONLY MODEST MID LEVEL INSTABILITY KEEPING SHRA GOING. WIND FIELDS ARE NEAR NIL PER 12Z KABR SOUNDING. SO SHRA WILL BE ISOLD/SCT AND MAINLY LIGHT AS THIS FEATURE MOVES ACROSS CWA PER 12Z RUC LAYER VORTICITY FIELDS. XPCT LOW CLOUDS TO HANG TOUGH THRU DAY WITH ONLY BREAKS WAY OUT WEST. UPDATES ALREADY OUT. .ABR...NONE. BINAU sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 845 PM CDT TUE SEP 18 2001 CURRENT FORECAST FINE AND NO UPDATES NEEDED. LATEST SURFACE ANALYSIS SHOWS COLD FRONT EXTENDS FROM NORTHEASTERN MO TO EASTERN OK. 00Z DATA SHOWS H5 TROUGH MOVING THROUGH CENTRAL PLAINS. A FEW THUNDERSTORMS ARE SHOWN BY 88D NQA NEAR THE TN RIVER ASSOCIATED WITH LEAD UPPER SHORT WAVE. SATELLITE AND RADAR INDICATE ADDITIONAL THUNDERSTORMS ARE INCREASING AHEAD OF THE FRONT AND MAIN UPPER LEVEL TROUGH FROM NORTH CENTRAL AR INTO WESTERN AR. THINK THESE STORMS WILL CONTINUE TO DEVELOP AND MOVE INTO OUR CWFA DURING THE NIGHT AS THE FRONT MOVES EASTWARD. LATEST RUC MODEL RUN SHOWS UPPER LEVEL DIFFLUENCE INCREASING ACROSS THE MIDSOUTH. FORECAST LOWS FOR TONIGHT LOOK OK WITH SOUTH WINDS PUSHING DEWPOINTS IN THE 60S AND 70S INTO OUR AREA. .MEG...NONE. tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LOUISVILLE KY 150 AM EDT WED SEP 19 2001 4Z MSAS AND RUC40 DATA SHOWING DEVELOPING SURFACE CYCLONE OVER WRN IL IN ASSOCIATION WITH MID-LEVEL TROUGH OVER MN/IA. MOST OF THE CONVECTIVE ACTIVITY LOCATED OVER IL NEAR THE LOW CENTER...WITH SCATTERED STORMS ALONG THE 850MB THETA-E RIDGE/30-40KT SW FLOW FROM WRN IN BACK INTO NERN TX. PRESSURE FALLS INDICATING SFC LOW WILL MOVE INTO NRN IL BY DAYBREAK. NATIONAL RADAR MOSAIC SHOWING ADDITIONAL CONVECTION DEVELOPING OVER NRN AR/SRN MO MOVING NORTHEAST...AND 00Z RUC40 DATA INDICATING THAT SHOWERS WILL MOVE ALONG 850MB THETA-E AXIS INTO THE CWA TOWARDS DAYBREAK. OVERALL THE DIFFERENCES BETWEEN THE 00Z ETA/AVN ARE SMALL FOR THE INITIALIZATIONS AND THE FIRST 6 HOURS. BOTH HAVE A GOOD HANDLE ON THE STRUCTURE OF THE MID-LEVEL WAVE OVER MN...AND THE 6 HOUR QPF FORECASTS ARE SIMILAR...HANDLING THE DEVELOPING CONVECTION OVER AR/MO FINE. THE AVN ONCE AGAIN SEEMS TO HAVE A CONVECTIVE FEEDBACK SITUATION OVER MI TODAY...WHICH THROUGH DIABATIC EFFECTS DEEPENS THE MID-LEVEL WAVE 20DM MORE THAN THE ETA. THEREFORE I WILL LEAN TOWARDS THE ETA...BUT THE OVERALL SOLUTIONS AFFECTING THE CWA ARE SIMILAR. BASED ON CURRENT RADAR TRENDS AND ETA/AVN DATA...I THINK TODAY WILL BE WET ACROSS THE CWA. ETA SHOWING 850MB THETA-E RIDGE...300MB DIVERGENCE AXIS...LOW LEVEL MOISTURE CONVERGENCE...AND 850-500MB RH VALUES IN EXCESS OF 80% MOVING THROUGH THE CWA BY 18Z AHEAD OF MID-LEVEL WAVE OVER WI. AFTER 18Z...THE AXIS OF BEST MOISTURE AND DYNAMICS MOVES EAST...HOWEVER WITH 850-500MB RH VALUES ABOVE 65% AND MULI'S AT OR BELOW -2C...I THINK THAT SH/TS WILL CONTINUE THROUGH THE AFTERNOON HOURS. I WILL GO WITH 70-80% POPS TODAY...UNDER MOSTLY CLOUDY SKIES. TEMPERATURES WILL GET INTO THE UPPER 70S AS WE MAY SEE SOME SUNSHINE AFTER THE MAIN AXIS OF CLOUDS/PRECIP MOVES THROUGH BY EARLY AFTERNOON. TONIGHT...THE BEST MOISTURE/DYNAMICS MIGRATE TOWARDS THE EAST COAST AS MID-LEVEL LOW DEEPENS OVER NRN MI. ETA SHOWING ANOTHER WAVE WITH ASSOCIATED 300MB DIVERGENCE ROTATING THROUGH THE CWA BETWEEN 00-09Z. WITH ENOUGH COLUMN MOISTURE AND SOME INSTABILITY (MULI'S<0) THERE WILL LIKELY BE SOME SHOWER ACTIVITY THIS EVENING...ENDING FROM WEST TO EAST AS DRIER AIR WORKS IN FROM THE WEST. I WILL GO WITH 30% POPS AREAWIDE...ENDING AROUND MIDNIGHT. LOWS WILL BE A FEW DEGREES COOLER THAN THIS MORNING WITH DRIER AIR ARRIVING...FROM 60 TO 63 IN GENERAL. LOWER THETA-E AIR AND SUBSIDENCE MOVES INTO THE CWA FOR THURSDAY IN ASSOCIATION WITH WEAK SURFACE HIGH...SO I WILL GO PARTLY CLOUDY WITH HIGHS IN THE MID TO UPPER 70S. SURFACE DEWPOINTS WILL ONLY DROP TOWARDS THE LOWER 60S...SO SOME CLOUDS ARE STILL POSSIBLE DURING THE DAY. NOTHING OF REAL NOTE FOR THURSDAY NIGHT WITH SURFACE HIGH MOVING THROUGH THE AREA. SHOULD SEE MOSTLY CLEAR SKIES AND LIGHT WINDS...SO SOME PATCHY FOG MAY FORM BUT I WILL NOT MENTION IN THE ZONES RIGHT NOW. LOWS WILL BE AROUND THE 60 DEGREE MARK. FRIDAY...BOTH THE ETA AND AVN SHOW ANOTHER WAVE ROTATING AROUND THE DEEP WRN ONTARIO LOW BRINGING A SURFACE TROUGH AND HIGHER 850-500MB RH VALUES INTO THE WESTERN SECTIONS OF THE CWA. MAV POP VALUES COMING IN FOR FRIDAY SHOWING 30-40%. THIS IS HARD TO DISCOUNT SO I WILL GO AHEAD AND ADD 30% CHANCE POPS FOR FRIDAY WITH PARTLY CLOUDY SKIES. HIGHS SHOULD BE A BIT WARMER THAN THURSDAY...CLOSER TO 80. INTO THE EXTENDED...SATURDAY SHOULD SEE PARTLY CLOUDY SKIES AS WAVE MOVES OFF TO THE EAST AND NORTHERLY FLOW PUSHES INTO THE CWA. FRONTAL ZONE WILL BE IN THE AREA ON SUNDAY...SO WILL LEAVE SH/TS IN THE FORECAST. ANOTHER WAVE MOVES INTO THE AREA ON MONDAY...SO GOING PARTLY CLOUDY WITH A CHANCE FOR SH/TS SEEMS WISE. .SDF...NONE. SMALLCOMB ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 440 AM EDT WED SEP 19 2001 WRN EXTENT OF RAIN SHIELD WITH ADVANCING PLAINS SYSTEM IS MAIN FOCUS FOR TODAY...WITH ATTN THEN TURNING TO NEXT CHANCE OF RAIN LATE THU. 00Z RAOB MAPS SHOW SHRTWV TROUGH OVR CNTRL CONUS WITH WV LOOP INDICATING TWO MAIN SHRTWVS OVR QUAD CITIES AREA ON IA/IL BORDER AND SECONDARY WAVE OVR WRN KS. ANOTHER SUBTLE SHRTWV NEAR JOPLIN MO ALSO. ON FRONT SIDE OF TROUGH...08Z SFC ANALYSIS FINDS MAIN SFC LOW PRES NEAR CHICAGO CHECKING IN AT 1002MB...WHICH IS CONSISTANT WITH 18Z/00Z AVN. ETA AND NGM WERE TOO WEAK WITH SFC LOW BY 3-4MB. IR SAT DEPICTS COOLING CLOUDS IMMEDIATELY NE OF SFC LOW WITH ANOTHER BAND OF ENHANCEMENT OVR CNTRL WI...WHICH COULD BE BEGINNING OF FORMATION OF CCB. REGIONAL RADAR MOSAIC AND SFC OBS SHOW LEADING EDGE OF RAIN REACHING FM LSE TO MSN TO OSH. FOR TODAY...3HR MSAS PRESSURE FALL BULLSEYE POINTS TO SFC LOW EASING INTO SRN LK MI BY 12Z THEN INTO WRN LWR MI THIS AFTN. LATEST RUC HAS SHOWN THIS TREND ALSO. AS A RESULT MOST CONCENTRATED H85 CONVERGENCE REMAINS SE OF UPR MI...AND THIS SHOULD HELP TO LIMIT INTENSITY OF RAINFALL OVR ERN ZONES. STILL LOOK FOR PRECIP TO AFFECT ERN 2/3 FA AS COMBINATION OF H85-H5 Q-VECTOR CONVERGENCE/H7 UVM FM CCB SLIDE NE ACROSS AREA. WITH MAIN DYNAMIC FORCING FOCUSED SE MOISTURE AVAILABILITY WILL BE A KEY FACTOR. 00Z RAOBS AT GRB AND APX INDICATE MOIST PROFILES BLO H7 WITH VRY DRY AIR ABOVE. ARRIVAL OF MOISTURE AROUND H6 SHOULD SIGNIFY ONSET OF MORE STEADY RAINFALL...AND AVN/ETA SHOWS THIS OCCURRING ONLY AFT 12Z FOR MNM AND THRU 18Z FOR SERN UPR MI. CUTOFF TO WRN EXTENT OF PRECIP WILL LIKELY BE SHARP AS VRY DRY AIR AT H7 OVR OT THIS MORNING (00Z RAOB H7 DWPT DPRESSION OF 29C AT CWPL) IS GRADUALLY WRAPPED INTO WRN UPR MI WITH DEVELOPING NE FLW. OVERALL FOR POPS WILL TAPER SHARPLY FM LIKELY SE TO CHANCE CNTRL...WITH ONLY A LGT SHRA/SPRINKLES OVR WRN ZONES AS STILL PLENTY OF SUB H7 MOISTURE FOR WEAK DYNAMICS TO ACT UPON. PRIMARY UPR MOTION SHIFTS TO THE EAST OVR SWRN OT AND NRN LK HURON TNGT WITH AREA OF PRIMARY DIFFLUENT FLW AND UPR DIVERGENCE. ETA MODEL IS LESS PROGRESSIVE THAN OTHER SHORT RANGE AND MEDIUM MODELS WITH UPR LOW...KEEPING IT CLOSED TIL THU EVENING. EVEN SO... H85-H5/H7-H3 Q-VECTOR CONVERGENCE AND DEEPER MOISTURE LINGER OVR ERN ZONES INTO FIRST HALF OF THU (AT LEAST...LONGER WITH ETA)...SO WILL CONTINUE SMALL POPS FOR SHRA THERE. OTHERWISE...WILL ONLY CARRY A SMALL CHANCE OF RAIN FOR NCNTRL ZONES FOR TONIGHT. DRY FCST LOOKS GOOD ELSEWHERE. HAVE ADDED FOG TONIGHT FOR NCNTRL ZONES AS DEEP NERLY FLW WITH ANY PRECIP THAT OCCURS TODAY WILL COMBINE WITH DEVELOPING SUBSIDENCE INVERSION OVERNIGHT TO PRODUCE AREAS OF FOG AND DZ OVR THE HIGHER TERRAIN AS SUBSTANTIAL OROGRAPHIC LIFT FM UPSLOPE DEVELOPS. TEMPS BOTH TODAY AND TNGT WILL EXHIBIT VERY LITTLE CHANGE AS CLOUDS REMAIN LOCKED INTO FA. FWC/MAV LOOK GOOD TDY BUT TOO COOL TONIGHT SO HAVE WENT A SHADE ABOVE BOTH FOR MINS. EXCEPTION IS OVR SWRN ZONES WHERE FCST SOUNDINGS SHOWING DRY AIR WORKING COMPLETELY TO SFC WHICH COULD POKE SOME HOLES IN CLOUDS...LEADING TO COOLER OVERNIGHT TEMPS. A BRIEF BREAK UNTIL NEXT RAIN CHANCE WHICH ARRIVES THU NIGHT THANKS TO PAC NW SHRTWV (CURRENTLY SLICING INTO AB/ID). THIS SHRTWV IS FCST TO SLIDE INTO RATHER BROAD TROUGH OVR GREAT LAKES REGION. ALTHOUGH MAIN SHRTWV PASSES WELL TO SOUTH OF UPR MI INTO IA/IL BY FRI MORNING...RIBBON OF H85-H5 QVECTOR CONVERGENCE AND DEEPER MOISTURE SCRAPE UPR MI TO SOUTH. WL LEAVE CHANCE POPS ACROSS SRN ZONES BUT WILL REMOVE FM NRN ZONES WITH BETTER SUPPORT TO SOUTH. COORD WITH APX/GRB/DLH...THANKS. .MQT...NONE. JLA mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 400 AM CDT WED SEP 19 2001 FORECAST CONCERNS FOCUS ON CLOUD AND LGT PRECIP TDY AND CONVECTION THREAT LATE TNGT INTO THU NGT. WV IMAGERY REVEALS VIGOROUS S/W PUSHING THRU NRN IL...SLIGHTLY FARTHER WEST OF ETA PLACEMENT...BUT MORE IN LN WITH LATEST RUC AND AVN GUIDANCE. LATEST RADAR MOSAIC SHOWS LARGE AREA OF RAIN OVR CENTRAL/SRN WI...SHOWING LITTLE WWD DRIFT...HOWEVER PATCHY -RA HAS EXPANDED A BIT OVER WEST CENTRAL WI INTO ERN MN AS WEAKER 5H CIRCULATION PASSES THRU ERN MN. WL NEED TO CONT MENTION OF PATCHY -RA/-DZ OVER MSP/STC AREAS THIS MRNG WITH UNCATEGORICAL IN WI. ETA 300 THETA SFC SHOWS CONDENSATION PRESSURE DEFICITS LESS THAN 20MB WITH WK UPGLIDE INTO ERN MN THIS MRNG...DMSHS IN THE AFTN LENDING CREDENCE TO PATCHY -RA/-DZ AFT 12Z. BINOVC HAVE DVLPD IN PARTS OF SRN MN WITH VSBYS DOWN TO 1/4SM IN FRM BUT LATEST 11-3.9 MICRON IMAGERY SHOWING FOG/LOW CLDS FILLING IN THE HOLES. HENCE WL HOLD OFF ON ADVY FOR NOW BUT MENTION PATCHY DENSE FOG IN ZONE. BOTH ETA AND AVN SHOW SHARPER 5H RDG OVR ERN DAKOTAS/WRN MN AT 00Z WITH LINGERING CYCLONIC CURVATURE IN EAST. CONSIDERING LACK OF STRONG DRY PUNCH AND DEEPER GREAT LAKES SYSTEM...WL CONT WITH CLDS LINGERING OVER ERN AREAS THRU DAY BUT TRY TO BRING IN SOME PARTIAL CLEARING IN WEST. BEST CHANCE MAY BE IN FAR WEST AND SOUTHWEST WHERE TERRAIN EFFECTS NOT AS PRONOUNCED. WL BACK OFF ON PRECIP TNGT...EXCEPT IN FAR WEST AS UPSTREAM S/W TROUGH A BIT SLOWER THAN EARLIER GUIDANCE DUE TO SHARPER FEATURES. ETA/AVN IN GOOD AGREEMENT ON BRINGING LEFT EXIT REGION OF 3H JET ACRS MN CWA ON THU AND ACRS WI THU NGT. PWAT INCREASES TO OVR 1.0. INSTABILITY HOWEVER REMAINS MINIMAL AS DEEPER MOISTURE BOTTLED UP FARTHER SOUTH ALONG WARM FRONT AND VICINITY OF SFC LOW PRES. BEST THREAT FOR -TSRA WL BE EARLY THU IN WRN AREAS FM WEAKENING DAKOTAS CONVECTION AND IN SOUTH DURING THE AFTN ON NRN EDGE OF BETTER BAROCLINICITY. HENCE WL UP POPS TO LKLY CATEGORY IN WEST AND SOUTH ON THU AND INTO ERN MN THU EVE. DIFFICULT TO MAKE POINTS ON GUIDANCE THIS PD. WL UPDATE EFP TO ADD PRECIP IN FOR SAT NGT AND SUN AS SOME CONSISTENCY TO S/W TROUGH PUSHING THRU OVR WEEKEND. .MSP...NONE. KAVINSKY mn EASTERN WASHINGTON AND NORTH IDAHO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WASHINGTON 230 AM PDT WED SEP 19 2001 THRU FRI...A SERIES OF TRANSIENT SHORT WAVELENGTH TROFS WILL MOVE THRU THE PAC NW...ONE THIS MORNING AND ANOTHER FRI MORNING. TODAY...IMPRESSIVE LOOKING SHORT WAVE NOW MOVING EWD ALONG WA/BC BORDER THIS MORNING...WITH DRY SLOT AND DARKENING PER VAPOR LOOP MAKING ITS WAY THRU ERN WA. AVN AND RUC HANDLING PLACEMENT OF MID TROP VORT CENTER...AND WILL FOLLOW THEIR TIMING AS THIS FEATURE MOVES RAPIDLY THRU ERN WA/N ID TODAY. MUCH OF THE CWA WILL REMAIN WITHIN LARGE-SCALE SUBSIDENCE/DRY SLOT TODAY FOR PTLY-SUNNY SKIES. SOME Ac MAY AFFECT THE BC/WA BORDER CLOSER TO VORT MAX AND FORCING FOR ASCENT. INITIAL CONCERN IS WIND THIS MORNING...WITH CROSS-CASCADE PRESSURE GRADS INCREASING AND QG/OMEGA SHOWING A WHOLE LOT OF SUBSIDENCE (AS DOES WATER VAPOR LOOP). THIS WILL BE THE ISSUE THIS MORNING...HOWEVER PRESSURE GRADS/850 WINDS WEAKEN DURING THE DAY. WITH 12Z PDX-FCA GRADIENT OF 9 MB AND 850 NW WINDS OF 15-20 KTS...MAY KEEP MENTION OF BREEZY THIS MORNING E SLOPES/WATERVILLE PLATEAU. LOW LEVEL CAA WILL NOT ONLY HELP TO STABILIZE TROP BUT ALSO COOL TEMPS VS TUE. TONIGHT/THURS...LOW AMP RIDGE AND SUBSIDENCE WITH WEAK SFC PRESSURE GRADIENT SHOULD ALLOW DECENT COOING POTENTIAL TONIGHT. BACKED LOW LEVEL FLOW AND WEAK WAA BEGIN TO DEVELOP AS NEXT WAVE MOVES INSIDE 140W BY 12Z. THIS WILL ALLOW FOR WARMING TREND THURS...AS MUCH OF CWA WILL BE WITHIN THE WARM SECTOR OF THE APPROACHING TROF. THURS NIGHT/FRI...FILLING SHORT WAVE TROF TO MOVE ACROSS SRN BC...AS TAIL END OF FRONTAL BAND MOVES THRU N CASCADES BY 12Z. DEEP LG-SCALE ASCENT REMAINS N INTO BC IN THE MORNING...THEN SUBSIDENCE OVERTAKES MUCH OF THE REGION BY MIDDAY AS THIS FEATURE MOVES E. BEST CHANCE PRECIP WILL BE N CREST CASCADES AND OKANOGAN VLY/NE WA MTNS IN THE MORNING. HOWEVER WL NOT INTRODUCE PRECIP ATTM DUE TO LACK OF SIGNIFICANT FORCING AND SPEED OF WAVE. SAT-TUE...NO CHANGES. LONGWAVE PATTERN KEEPS TROF PAST 140W AND RIDGE OVER ROCKIES. SAT RIDGE AND DRY WX WILL GIVE WAY TO APPROACHING TROF SUN FOR SLT-CHC PRECIP. THIS FEATURE MOVES THRU MON...AND BY TUE HTS BUILD ONCE MORE FOR DRY WX. ...THE INFORMATION IN THIS PRODUCT CONCERNING WARNINGS AND FORECASTS IS VALID ONLY AT THE TIME OF ISSUANCE. THE LATEST WARNING AND FORECAST INFORMATION WILL BE FOUND IN THE APPROPRIATE PRODUCTS... GEG 071/043/074/049/074 00000 COE 071/041/074/045/074 00000 PUW 071/040/074/044/075 00000 LWS 077/046/082/053/081 00000 CQV 079/040/082/045/081 -000- SPT 071/040/073/043/074 -000- WWP 070/038/072/041/074 00000 EAT 075/050/077/055/077 00000 MWH 077/044/079/049/078 00000 .OTX...NONE. wa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 330 AM CDT WED SEP 19 2001 FORECAST FOCUS ON APPROACHING DRY SLOT AFFECTING THE END OF RAIN LATER TODAY AND NEXT SYSTEM FOR LATE THURSDAY. IN THE SHORT TERM...AVN/RUC PROGS BETTER THAN ETA/NGM WITH CURRENT SURFACE LOW STRENGTH AND LOCATION. CURRENT 3 HOURLY RISE/FALL PRESSURE COUPLET POINTS TO LOW MOVING OVER NORTHEAST ILLINOIS AND INTO WESTERN LOWER MICHIGAN WITH TIME..WITH ALL PROGS IN CLOSE AGREEMENT. RUC SFC PROG DEEPENS LOW THE MOST..TO 999 MB BY 18Z AS WELL AS RETARDING ITS MOVEMENT TO THE NORTHEAST. TIME CROSS SECTIONS ALLOW FOR ENDING OF PRECIPITATION FROM WEST TO EAST DURING THE COURSE OF THE DAY. ALTHOUGH...CURRENT IR/WV SATELLITE/500 MILLIBAR RUC COMBINATION LOOP SHOWING DRY SLOT PUSHING NORTHWARD INTO CENTRAL ILLINOIS. SOME CONCERN THAT THIS COULD MAKE ITS WAY INTO CWA AND CUT OFF PRECIPITATION EARLIER THAN EXPECTED...OR RESULT IN SCATTERED PRECIPITATION. BUT CURRENT TREND OF RADAR LOOPS AND CONSISTENT PROG FORECAST OF LOW TRACK SHOULD RESULT IN PRECIPITATION PIVOTING...THEN WRAPPING AROUND CWA WITH LITTLE IF ANY DISRUPTION. WILL CONTINUE TO WATCH THIS TREND WITH EYE TO ADJUSTING DESCRIPTIVE WORDING OF RAIN IN ZONES AT LAST MINUTE. IN THE FAR TERM...WEAK HIGH PRESSURE AT SURFACE AND ALOFT TO OCCUR LATER TONIGHT AND THURSDAY. PROGS BRING SLUG OF ENERGY IN NORTHWEST FLOW ACROSS CWA THURSDAY NIGHT AND FRIDAY...ACCOMPANIED BY WARM AIR ADVECTION IN THE LOW LEVELS. BUT REFLECTION OF ENERGY AT THE SURFACE IS VAGUE. SO WILL KEEP CHANCY SHOWERS IN FORECAST FOR THE MOMENT AND ALLOW LATER MODEL RUNS TO RESOLVE TIMING AND EXTENT OF PRECIPITATION. GUIDANCE TEMPERATURES CONSISTENT FOR TODAY WITH LITTLE CHANGE EXPECTED...AND LOOK TO BE IN BALL PARK FOR LATER PERIODS. .MKX...NONE. $$ ZAJDEL wi FLORIDA KEYS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KEY WEST FL 1000 AM EDT WED SEP 19 2001 CURRENTLY... SIGNIFICANT EARLY MORNING SHOWER/TSTM CLUSTERS THAT WERE OVER ATLANTIC NEAR SHORE WATERS AND ALSO AFFECTING PARTS OF MID AND LOWER KEYS...HAVE MOVED FARTHER SOUTH THE PAST COUPLE OF HOURS. HOWEVER... A NEW SMALLER AREA OF SHOWERS/TSTMS HAS FORMED OVER A SMALL PART OF THE UPPER KEYS EXTENDING INTO FLORIDA BAY (THIS MAY BE ON AN OUTFLOW FROM THE EARLIER STORMS). SATELLITE SHOWS CIRRUS AND MID CLOUD DEBRIS FROM CONVECTION MOSTLY BLOWLY SE AWAY FROM THE KEYS... ALTHOUGH THE FLORIDA BAY TSTMS MAY SOON SEND CIRRUS OVER THE UPPER KEYS. WATER VAPOR IMAGERY SHOWS SIGNIFICANT DRY AIR ALOFT HAVING MOVED SE OVER THE SOUTHERN PENINSULA AND PAST THE LOWER KEYS AS OF 8 AM. HOWEVER...KEY WEST PRECIPITABLE WATER AS OF SOUNDING TIME WAS ONLY DOWN SLIGHTLY TO 1.97 INCHES...AND THIS SEEMS TO BE FOR LEVELS AROUND 500 MB. FARTHER NORTH THE AIR IS DRIER...WITH TAMPA SOUNDING SHOWING DRY AIR 800 MB AND UP. KEY WEST SOUNDING WINDS AT 700-500 MB HAD SHIFTED TO DUE NORTH SINCE 00Z LAST EVENING WHEN THEY WERE WSW. THIS INDICATES THE MID LEVEL TROUGH AXIS IS RATHER SHARP AND HAD MOVED TO KEY WEST BY 12Z...WHICH NONE OF THE MODELS WAS INDICATING. ALL MODELS HAD THE TROUGH AXIS 700-500 MB STILL NW OF THE KEYS. WINDS ARE RUNNING E OR ENE CLOSE TO 10 KT AT C-MAN SITES. THIS AFTERNOON... THE DRY AIR ALOFT HAS GIVEN A LOT OF SUN TO THE LOWER KEYS THIS MORNING...WITH PARTLY CLOUDY CONDITIONS OVER MID AND UPPER KEYS. WHILE MODELS WERE SLOW TO PUSH THE MID LEVEL TROUGH PAST THE AREA... THEY DO SHOW DRYING ALOFT HAVING WORKED SE OVER THE KEYS BY END OF TODAY. BUT...IF LATEST 06Z MESOETA IS CORRECT...MOST DRYING WILL BE AT AND ABOVE 700 MB WITH RH VALUES REMAINING HIGH AT LEVELS BELOW 700 MB. EARLIER ETA AND CURRENT MESOETA AND RUC HINT AT SURFACE WINDS ENE FOR A WHILE THIS AFTERNOON. SO...CONVECTION MAY FLARE WITH TCU/CB LINES NEAR THE KEYS AS WELL AS OVER MAINLAND THIS AFTERNOON. DRIER AIR ALOFT COULD ENHANCE OUTFLOW BOUNDARIES FROM MAINLAND CONVECTION AS WELL. SO, CURRENT 50 PCT POPS WILL BE MAINTAINED BUT MAY BE MAINLY FROM AFTERNOON ACTIVITY. 1030 AM COASTAL WATERS FORECAST CONTAINS NO CHANGES WITH WIND TRENDS AS EXPECTED. .EYW...NONE. CLB fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 925 AM CDT WED SEP 19 2001 LIGHT RAIN HAS PUSHED WESTWARD SOME INTO CENTRAL MN AND PRECIP TRENDS THEN MAIN FORECAST CONCERN. 12Z RUC 300 K ISENTROPIC SURFACE SEEMS TO HAVE CAPTURED THIS WITH LOW PRESSURE DEFICITS OVER CENTRAL INTO SOUTHERN MN. LITTLE OR NO ISENTROPIC OMEGA GOING INTO AFTERNOON SO EXPECT A DIMINISHING TREND. STILL LOOKS LIKE A DRYING TREND IN WESTERN MN ASSUMING FOG DISSIPATES. AFTERNOON TEMPS GENERALLY OK. .MSP...NONE. RICHARDSON mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BUFFALO NY 950 AM EDT WED SEP 19 2001 SURFACE LOW NEAR CHICAGO THIS MORNING WILL DRIFT NORTH NORTHEAST INTO WESTERN LOWER MICHIGAN BY THIS EVENING. BAND OF SHOWERS/STORMS ASSOCIATED WITH SYSTEM MOVING MORE NORTH THAN EAST THIS MORNING. 06Z ETA AND 12Z RUC 40 SUGGESTING THIS GENERAL NORTHERLY MOVEMENT WILL CONTINUE THIS AFTERNOON. THIS WOULD SUGGEST A DELAYED ONSET FOR PRECIPITATION ACROSS THE AREA. A FEW LIGHT SHOWERS TRYING TO WORK INTO THE SOUTHERN TIER FROM NORTHEAST PENNSYLVANIA WILL HAVE A HARD TIME HOLDING TOGETHER AS THEY FALL INTO DRY AIR AT LOW LEVELS. COULD STILL SEE SCATTERED LIGHT SHOWERS WET THE GROUND ALONG THE SOUTHERN TIER...BUT MAIN PRECIPITATION ACTIVITY WILL NOT AFFECT THE AREA UNTIL VERY LATE THIS AFTERNOON OR THIS EVENING. PLENTY OF SUNSHINE FOR EASTERN SECTIONS THROUGH AT LEAST MID AFTERNOON BEFORE CLOUDS THICKEN FROM THE WEST. TEMPERATURES...EVEN WITH THICKENING CLOUD COVER SHOULD REACH INTO THE 70S FOR WESTERN SECTIONS AND MAY APPROACH 80 DEGREES FOR EASTERN SECTIONS. .BUF...NONE. ny AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE WILMINGTON, NC 1015 AM EDT WED SEP 19 2001 ...WILL UPDATE ZONE FCST...AS SHOWERS ARE MOVING TOO CLOSE TO THE CAPE FEAR COAST TO NOT MENTION SHOWERS IN FCST. WILL GO CHC POPS. PREV DISCUSSION... CLOUDS AND ISOLATED SHOWERS AT 20 NM EDGE COASTAL WATERS FROM CAPE FEAR N...ASSOCIATED WITH A WEAK SFC TROUGH. RUC MODEL SHOWS A WEAK 500 MB WAVE OVER WRN SC THIS MORNING...APPARENT IN CLOUD ELEMENTS ON WV SATPIX...WILL MOVE OFF COAST EARLY THIS AFTERNOON AND HELP THE TROUGH TO DEVELOP BRIEFLY INTO MAYBE A WEAK CLOSED LOW...1017 MB ABOUT 70 MILES E OF GEORGETOWN...BEFORE THE UPPER LEVEL SUPPORT CONTINUES MOVING OFFSHORE LATER TODAY AND SFC LOW WEAKENS...BUT THE RUC PAINTS A LITTLE RAIN ON THE SE NC COAST BY LATE TODAY. META DOESN'T GO FOR RAIN. SINCE JUST ABOUT ALL OF THIS IS OFF THE COAST...CURRENT PARTLY SUNNY ZONE FORECAST LOOKS OK WITH NO MENTION OF RAIN TODAY. WIND FORECAST LOOKS OK...SO NO ZONE FCST UPDATE. UPPER LEVEL TROUGHING CROSSING MISSISSIPPI IS SPREADING CI CLDS ACROSS THE AREA FOR TODAYS PTLY SUNNY. APPROACHING TROUGH CAUSES BETTER LIFT ON THU...AT THIS POINT LOOKS LIKE MORE THU DAYTIME SHOWER EVENT IN THIS AREA. CWF: LIGHT WINDS...WILL ADJUST DIRECTION FOR TROUGH IN THE AREA AND ADD SHOWERS. FCSTID = 19 ILM 82 64 83 67 / 10 20 30 30 LBT 84 60 84 63 / 0 10 40 40 FLO 85 62 85 64 / 0 10 40 40 MYR 79 64 81 68 / 10 20 30 30 .ILM... NC...NONE. SC...NONE. MATHESON nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON, NC 955 AM EDT WED SEP 19 2001 CLOUDS AND ISOLATED SHOWERS AT 20 NM EDGE COASTAL WATERS FROM CAPE FEAR N...ASSOCIATED WITH A WEAK SFC TROUGH. RUC MODEL SHOWS A WEAK 500 MB WAVE OVER WRN SC THIS MORNING...APPARENT IN CLOUD ELEMENTS ON WV SATPIX...WILL MOVE OFF COAST EARLY THIS AFTERNOON AND HELP THE TROUGH TO DEVELOP BRIEFLY INTO MAYBE A WEAK CLOSED LOW...1017 MB ABOUT 70 MILES E OF GEORGETOWN...BEFORE THE UPPER LEVEL SUPPORT CONTINUES MOVING OFFSHORE LATER TODAY AND SFC LOW WEAKENS...BUT THE RUC PAINTS A LITTLE RAIN ON THE SE NC COAST BY LATE TODAY. META DOESN'T GO FOR RAIN. SINCE JUST ABOUT ALL OF THIS IS OFF THE COAST...CURRENT PARTLY SUNNY ZONE FORECAST LOOKS OK WITH NO MENTION OF RAIN TODAY. WIND FORECAST LOOKS OK...SO NO ZONE FCST UPDATE. UPPER LEVEL TROUGHING CROSSING MISSISSIPPI IS SPREADING CI CLDS ACROSS THE AREA FOR TODAYS PTLY SUNNY. APPROACHING TROUGH CAUSES BETTER LIFT ON THU...AT THIS POINT LOOKS LIKE MORE THU DAYTIME SHOWER EVENT IN THIS AREA. CWF: LIGHT WINDS...WILL ADJUST DIRECTION FOR TROUGH IN THE AREA AND ADD SHOWERS. FCSTID = 19 ILM 82 64 83 67 / 10 20 30 30 LBT 84 60 84 63 / 0 10 40 40 FLO 85 62 85 64 / 0 10 40 40 MYR 79 64 81 68 / 10 20 30 30 .ILM... NC...NONE. SC...NONE. MATHESON nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1040 AM EDT WED SEP 19 2001 ...WILL UPDATE TO FRESHEN UP WORDING... SURFACE ANALYSIS SHOWS THAT THE WARM/STATIONARY FRONT IS HAVING A TOUGH TIME ENTERING WESTERN PENNSYLVANIA. THE SURFACE LOW IS CENTERED NEAR CHICAGO WITH THE COLD FRONT TRAILING SOUTHWEST. SEVERAL PREFRONTAL CONVERGENCE ZONES WERE NOTED AS WELL. WATER VAPOR IMAGERY SHOWS THAT THE SYSTEM IS STARTING TO OCCLUDE AS DRY AIR IS WRAPPING AROUND THE CIRCULATION CENTER. VAD WIND PROFILE REVEALS 20 TO 30 KNOT SOUTHERLY WINDS IN THE 3-4 KFT LAYER WITH WEAK WINDS IN THE MIDLEVELS. THIS AGREES WITH THE MODEL GUIDANCE. 12Z RUC SOUNDINGS FOR THIS AFTERNOON SHOW WESTERN SITES CLOUDING OVER AS HIGH CLOUDS INVADE THE EASTERN AREAS OF MY CWA. THIS AGREES WITH THE CURRENT VISIBLE SATELLITE TRENDS. ALSO NOTED MIDLEVEL FLOW INCREASES FROM THE SOUTH DURING THE AFTERNOON WITH THE APPROACH OF THE NEXT SYSTEM. THE ETA/AVN SHORT RANGE ENSEMBLES SHOW THAT THERE IS A HIGH CONFIDENCE LEVEL THAT IT WILL RAIN WITH THE FRONTAL PASSAGE. OUT OF THE TEN MEMBERS...AT LEAST 9 HAD WIDESPREAD QUARTER OF AN INCH AMOUNTS VALID LATE TONIGHT INTO TOMORROW AFTERNOON. EARLY MORNING GUIDANCE SUGGESTS A SLOWING OF THE SYSTEM. THIS IS NOT SURPRISING GIVEN THE STRENGTHENING/OCCLUDING NATURE AT THIS TIME. GIVEN EARLY ANALYSIS BELIEVE AS THE WIND FILED AND PRECIPITABLE WATER VALUES INCREASE THIS EVENING...A PREFRONTAL CONVERGENCE TROUGH WILL TRIGGER SHOWERS...WITH POSSIBLE EMBEDDED THUNDER FROM WEST TO EAST. AS THE FRONT PASSES DURING THE THURSDAY AFTERNOON HOURS...BELIEVE THAT THERE IS A LIKELIHOOD FOR CONVECTION. PROJECTED STRONG AND VEERING WIND FIELDS...FORCING AND MARGINAL INSTABILITY INDICATE SOME CONVECTION MAY BECOME STRONG IN THE EAST TOMORROW AFTERNOON. WORK ZONES OUT...REAL ZONES ON THE STREETS IN A FEW... .CTP...NONE. ROGOWSKI/GARTNER pa AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE GOODLAND KS 1105 AM MDT WED SEP 19 2001 LATEST RUC PICKING UP ON MY (AND SPC) EARLIER INKLINGS THAT SOME TRW MAY DEVELOP OVER MY FAR SOUTHEAST CWA WHERE COMBINATION OF SLOW MOISTURE RETURN...PSEUDO DRYLINE/WIND SHIFT LINE ACROSS FAR WESTERN KANSAS...AND FULL SUN EXIST. LATEST RUC GENERATES SOME PRECIP WHICH BACKS WHAT I WAS THINKING AND STATED IN THE HAZARDOUS WEATHER OUTLOOK. HOWEVER...LATEST ETA WASNT PICKING UP THESE FEATURES TIL 00Z-03Z TIME FRAME SO THATS WHY IT WASNT MENTIONED IN THE ZONE UPDATE. WILL NEED TO KEEP WATCH AND ANOTHER UPDATE MAY BE REQUIRED. OTHERWISE...ADJUSTED WINDS A BIT AND MADE SKY CONDITIONS SUNNY. .GLD...NONE. THEDE ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 430 PM EDT WED SEP 20 2001 MAIN FCST CONCERNS THIS PACKAGE INCLUDE RAIN COVERAGE/POPS INTO FRIDAY. WV IMAGERY AND RUC ANALYSIS DEPCIT CLASSIC COLD SEASON CYCLONE WITH VIGOROUS SLIGHTLY NEG TILTED SHRTWV TROF INTO LK MI AND LWR MI WITH DRY SLOT WRAPPED INTO WRN LWR MI. BACK EDGE OF WCB PCPN BAND WAS JUST INTO ERN UPR MI WHILE LARGE AREA OF CCB RAIN HAD CREPT NORTHWESTWARD TO COVER SE 2/3 OF UPR MI. UPWARD MOTION SUPPORTED BY STRONG UPR LVL DIV WITH COUPLING FROM LFQ OF 70 KT H25 JET INTO LWR MI AND 80 KT MAX OVER NE ONTARIO INTO QUEBEC. AT THE SFC...999 MB LOW WAS LOCATED OVER SRN LK MI WITH MAX 3-HR PRES FALLS OF AROUND 4 MB OVER NRN LWR MI AND NRN LK MI. MDLS WERE IN REASONABLE AGREEMENT TO 24 HRS WITH SLIGHTLY STRONGER AND MORE WESTWARD PLACEMENT OF THE SFC LO MOST REASONABLE IN LIGHT OF MDL TRENDS WITH THE SYSTEM. ETA WOULD ALSO HAVE BETTER HANDLE ON LLVL EFFECTS FROM THE GRT LAKES. BY 36-60 HRS MORE CONSISTENT AVN SOLN WITH NEXT SHRTWV IS BETTER BET. HOWEVER...MDL DIFFERENCES HAVE MINIMAL EFFECT ON WX FCST FOR UPR MI. TONIGHT...CCB PCPN BAND SHOULD CONTINUE ACRS ERN 3/4 OF UPR MI WITH DEEP LYR QCONV OVER THE AREA. RADAR TRENDS SUGGEST RELATIVELY SHARP CUTOFF IN PCPN ON THE WRN EDGE SHOULD SET UP OVER WRN CWA. DRY SLOT ALSO SHOULD REMAIN JUST TO THE SOUTH AND EAST. PROXIMITY OF RELATIVELY DEEP LO WITH TIGHTENING GRADIENT WL ALSO BRING INCREASING NRLY WINDS TO 15 TO 25 MPH. THURSDAY...STACKED LO ONLY SLOWLY DRIFTS CCB PCPN LINGERS OVER ERN HLF OF CWA. LAKE ENHANCED PCPN WITH CONDITIONALLY UNSTABLE SFC-900 LYR (LK-900 MB DLT/T NEAR 10C ALONG SOUTH SHORE) ALONG WITH CONVERGENT CYCLONIC FLOW INTO NORTH CNTRL UPR MI SUGGESTS POPS/QPF WELL ABV THAT ADVERTISED BY GUIDANCE. OTHERWISE...CAT WORDING WAS RETAINED OVER THE EAST WITH CHANCE POPS FOR THE WEST. THURSDAY NIGHT INTO FRIDAY...NEXT SHRTWV AND BATCH OF JET ENERGY PLUNGE FROM THE NRN PLAINS TOWARD THE SRN GRT LAKES LEAVING UPR MI IN BTWN THE INCOMING SYSTEM AND REMNANTS OF THE DEPARTING LO. AVN SHOWS ENOUGH DEEP MOISTURE AND CYCLONIC FLOW OVER THE ERN CWA FOR CONTINUED CHANCE OF PCPN EVEN WITH WEAK MID LVL QCONV. EXTENDED...ECMWF/UKMET/MRF ALL DEPICT AMPLIFICATION OF LONG-WAVE PATTERN WITH DEEP GLF AK LOW...DOWNSTREAM RDG INTO THE ROCKIES AND TROF PROGRESSING INTO THE WRN LAKES TOWARD SUNDAY. WL NOT ALTER DRY SAT FCST...DESPITE MINOR QPF DEPICTED BY AVN/MRF WITH LITTLE IN THE WAY OF SHRTWV ENERGY OR FORCING BEFORE TROF MOVES INTO THE AREA WITH GOOD QCONV LATER SAT NIGHT AND SUNDAY. PROGRESSIVE SOLN ADOPTED IN LINE WITH ECMWF AND MRF ENSEMBLE MEAN. 12Z AVN ALSO A BIT QUICKER IN MOVING THE MID LVL TROF THROUGH AND BUILDS SFC HI PRES IN ON MONDAY. .MQT...NONE. JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DULUTH MN ISSUED BY TWIN CITIES/CHANHASSEN, MN 300 PM CDT WED SEP 19 2001 FIRST CONCERN IS SKY CONDITION FOR TONIGHT. LOW LEVEL DIVERGENCE FIELD EXPECTED TO SCOUR MUCH OF THE CLOUDINESS OUT OF THE AREA THIS EVENING. HOWEVER...LOTS OF LOW LEVEL MOISTURE...CLEARING SKIES...AND PRESENCE OF SURFACE RIDGE SHOULD FAVOR DEVELOPMENT OF FOG LATE TONIGHT. THIS IS SIMILAR SCENARIO AS TO WHAT TRANSPIRED OVER THE EASTERN DAKOTAS LAST NIGHT. NEXT CONCERN IS IMPACT ON INCOMING SHORT WAVE. 19Z RUC 300 MB WIND ANALYSIS SHOWS IMPRESSIVE JET FROM SOUTHWESTERN BRITISH COLUMBIA TO MISSOULA MT. 12Z ETA AND 12Z AVN SIMILAR IN MOVING ASSOCIATED JET MAX TO NORTHWESTERN IA BY 00Z FRI. HOWEVER...AVN KEEPS MOST OF THE QPF CLOSE TO THE JET MAX...WHILE THE ETA GENERATES RAINFALL FARTHER NORTH. TRENDED TOWARD AVN AND AWAY FROM ETA QPF (SIMILAR TO NGM MOS POPS)...IN KEEPING POPS LOW ACROSS FORECAST AREA THURSDAY AND THURSDAY. A COUPLE OF MORE SHORT WAVES ARE ASSOCIATED WITH OUT CHANCE OF SHOWERS FRIDAY...SATURDAY...AND FOR THE WI PORTION OF THE CWA ON SUNDAY. FROM SUNDAY ON...WENT WITH MRF ENSEMBLE POPS FOR PRECIPITATION CHANCES. BLENDED MEX AND FMR GUIDANCE TEMPERATURES. POSITIVE 500 MB HEIGHT ANOMALIES WERE USED TO MOVE MORE TOWARD THE WARMER MEX TUESDAY AND WEDNESDAY. .DLH...NONE. RJN mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 300 PM EDT WED SEP 19 2001 NO CHANGES TO PVS THINKING. SHOWERS AHEAD OF COLD FRONT WILL OVERSPREAD WRN PA LATE THIS EVENING INTO OVERNIGHT. SHOWERS WILL LINGER MOST OF THE DAY THUR. TSTM WILL POTENTIAL WILL BE LIMITED ABUT WILL INCLUDE CHANCE OVER ERN PARTS OF CWA WHERE TIMING WILL BE BEST. ANOTHER SHORTWAVE SWINGS THROUGH THE FLOW FRI NIGHT PRODUCING MORE SHOWERS. SAT AND SUN LOOK FAIRLY DRY BEFORE ANOTHER WAVE BRINGS MORE SHOWERS FOR LATE SUN AND MON. HPC MDM RANGE GRAPHICS SHOWING SFC SYSTEM MVNG N ALONG THE SE COAST INTO THE MID ATLC NEXT WED SO INCLUDED CHANCE OF SHOWERS FOR ERN CWA. ....PVS AFD BELOW.... SURFACE ANALYSIS SHOWS THAT THE WARM/STATIONARY FRONT IS HAVING A TOUGH TIME ENTERING WESTERN PENNSYLVANIA. THE SURFACE LOW IS CENTERED NEAR CHICAGO WITH THE COLD FRONT TRAILING SOUTHWEST. SEVERAL PREFRONTAL CONVERGENCE ZONES WERE NOTED AS WELL. WATER VAPOR IMAGERY SHOWS THAT THE SYSTEM IS STARTING TO OCCLUDE AS DRY AIR IS WRAPPING AROUND THE CIRCULATION CENTER. SECOND MORE SOUTHER SHORTWAVE EVIDENT OVER KY/TN. 12Z RUC SOUNDINGS FOR THIS AFTERNOON SHOW WESTERN SITES CLOUDING OVER AS HIGH CLOUDS INVADE THE EASTERN AREAS OF MY CWA. THIS AGREES WITH THE CURRENT VISIBLE SATELLITE TRENDS. ALSO NOTED MIDLEVEL FLOW INCREASES FROM THE SOUTH DURING THE AFTERNOON WITH THE APPROACH OF THE NEXT SYSTEM. THE ETA/AVN SHORT RANGE ENSEMBLES SHOW THAT THERE IS A HIGH CONFIDENCE LEVEL THAT IT WILL RAIN WITH THE FRONTAL PASSAGE. OUT OF THE TEN MEMBERS...AT LEAST 9 HAD WIDESPREAD QUARTER OF AN INCH AMOUNTS VALID LATE TONIGHT INTO TOMORROW AFTERNOON. EARLY MORNING GUIDANCE SUGGESTS A SLOWING OF THE SYSTEM. THIS IS NOT SURPRISING GIVEN THE STRENGTHENING/OCCLUDING NATURE AT THIS TIME. GIVEN EARLY ANALYSIS BELIEVE AS THE WIND FILED AND PRECIPITABLE WATER VALUES INCREASE THIS EVENING...A PREFRONTAL CONVERGENCE TROUGH WILL TRIGGER SHOWERS...WITH POSSIBLE EMBEDDED THUNDER FROM WEST TO EAST. AS THE FRONT PASSES DURING THE THURSDAY AFTERNOON HOURS...BELIEVE THAT THERE IS A LIKELIHOOD FOR CONVECTION. PROJECTED STRONG AND VEERING WIND FIELDS...FORCING AND MARGINAL INSTABILITY INDICATE SOME CONVECTION MAY BECOME STRONG IN THE EAST TOMORROW AFTERNOON. WORK ZONES OUT. .CTP...NONE. GARTNER/ROGOWSKI pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 230 PM CDT WED SEP 19 2001 FORECAST FOCUS ON WHEN PRECIPITATION WILL END TONIGHT OR EARLY THURSDAY...AMOUNT OF CLOUDS ON THURSDAY...AND CHANCES OF RAIN THURSDAY NIGHT. WINTER-LIKE SYSTEM WITH LARGE CIRCULATION WITH SEVERAL VORTICITY CENTERS ROTATING AROUND IT PER THE RUC ANALYSIS AND RELATIVELY SLOW MOVEMENT OF SYSTEM INDICATES A SLOWER THAN EXPECTED END TO THE RAINFALL TONIGHT. AVIATION MODEL LOOKS BEST WITH TIMING FOR ENDING OF SHOWERS LATER TONIGHT OR EARLY THURSDAY MORNING. WITH LOW LEVEL MOISTURE REMAINING ACROSS SOUTHERN WISCONSIN DUE TO WET GROUND AND RELATIVELY HIGH DEWPOINTS...WILL KEEP A SOME CLOUDS IN FORECAST FOR THURSDAY AS HIGH PRESSURE WILL BE RATHER WEAK BEHIND THIS FIRST SYSTEM. THE NEXT SYSTEM LOOKS A BIT WEAKER ON ETA/NGM BUT AVN MORE AGGRESSIVE WITH AMOUNTS WITH NORTHERN EDGE OF RAIN INTO SOUTHERN WISCONSIN. WILL CARRY LOW POPS FOR NOW ON THURSDAY NIGHT BUT DRY THINGS OUT ON FRIDAY. .MKX...NONE. $$ EISE wi