AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 915 AM EDT MON AUG 23 2004 .SHORT TERM...CURRENT SURFACE ANALYSIS SHOWS WIND SHIFT PORTION OF THE SURFACE FRONT HAS SHIFTED SOUTHWARD SLIGHTLY OVER THE LAST FEW HOURS TO RESIDE OVER THE GEORGIA PORTION OF THE FORECAST AREA. NOT MUCH CHANGE IN THE ENVIRONMENT ON EITHER SIDE OF THE FRONT...AND THE ONLY TANGIBLE DIFFERENCES ARE SEEN ALOFT. THIS IS IN THE FORM OF A VORTICITY AXIS DEPICTED BY THE RUC AND HANDLED WELL INITIALLY BY THE MODEL SUITES. THIS PLACES A GOOD PORTION OF THE GEORGIA CWA IN NVA WITH THE PVA AXIS STRETCHING FROM APALACHEE BAY INTO THE SUWANNEE VALLEY AND THROUGH KJAX. THIS AGREES WELL WITH CURRENT POP DISTRIBUTION IN THE GRIDS AND SEE NO MAJOR CHANGES IN STORE. EVEN WITH THE NVA OVER THE GEORGIA PORTION...PRECIPITABLE WATER VALES CONTINUE TO APPROACH 2 INCHES AND CANNOT SEE GOING ANY LOWER THAN 50%. JAX SOUNDING THIS MORNING MOIST AND UNSTABLE LEADING TO FURTHER CONFIDENCE OF DECENT RAIN COVERAGE TODAY. WITH ACTIVITY ALREADY FIRING WEST OF LEVY COUNTY...SEE NO REASON WHY IT WON'T RAIN FAIRLY EARLY TODAY IN MARION...ALACHUA...AND PUTNAM COUNTIES AND MAY INCREASE POPS SLIGHTLY THERE. PRIMARY THREAT FROM AFTERNOON STORMS WILL BE HEAVY RAINFALL...ALTHOUGH UNIFORM WESTERLIES SHOULD SUBDUE THE POTENTIAL SOMEWHAT. && .MARINE...CURRENT FORECAST GENERALLY IN GOOD SHAPE...BUT MAY NEED TO BREAK OUT THE NORTHERN GROUP TO ACCOUNT FOR DEVELOPING NORTHERLY WINDS. && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. && $$ DEESE/ZAPPE/DYKES fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LINCOLN IL 1030 AM CDT MON AUG 23 2004 .DISCUSSION... WILL BE MAKING AN UPDATE SHORTLY TO REMOVE AFTERNOON WORDING. IN ADDITION...WILL BE INCREASING POPS SLIGHTLY IN SRN AND WRN ZNS. LATEST ETA AND RUC CONTINUE TO INDICATE BULK OF PRECIP OVER MISSOURI ATTM WILL DIMINISH AS IT PRESSES INTO ILLINOIS. AREA HAS REMAINED ORGANIZED AND FORECAST SOUNDINGS FROM ETA SUGGEST SUFFICIENT INSTABILITY BE IN PLACE BY LATE AFTERNOON TO RESPOND TO ANY TRIGGERS PRODUCED BY CONVECTIVE AREA. IN ADDITION...AREA OF PRECIP OVER SOUTHERN ILLINOIS IS NOT BEING HANDLED PARTICULARLY WELL AND GIVEN A GENERAL NORTHEAST DRIFT WILL LIKELY IMPACT SOUTHEAST BY LATE AFTERNOON. WILL INCREASE POPS TO TAKE INTO ACCOUNT TRENDS WITH THESE PRECIPITATION AREAS. OTHERWISE...ONGOING FORECAST SEEMS TO BE REASONABLE. && .PREV DISCUSSION... UPPER LEVEL RIDGE BECOMES ESTABLISHED ACROSS THE ATLANTIC STATES THIS WEEK WHILE UPPER LEVEL TROF STAYS OUT WEST OVER THE ROCKIES. IL IN A MORE UNSETTLED SW UPPER LEVEL FLOW AS MORE SUMMERLIKE HEAT AND HUMIDITY LEVELS RETURN WITH HIGHS IN THE MID TO UPPER 80S THRU FRI. NW IL WILL HAVE BEST CHANCE OF CONVECTION OVERALL THIS WEEK CLOSER TO A FRONTAL BOUNDARY THAT MOVES THRU THE STATE THIS WEEKEND. WILL CONTINUE TO BLEND BETWEEN GFS AND ETA THIS PACKAGE SINCE GFS STILL APPEARS TO BE SUFFERING SOME CONVECTIVE FEEDBACK WITH ITS VERY GENEROUS QPF. DECENT SHORT WAVE OVER CENTRAL KANSAS TO EJECT NE ACROSS IL TUE AND ENHANCE CONVECTION CHANCES AND FORECAST CHALLENGE IS HOW HIGH POPS WILL BE NEXT FEW DAYS. SHORT TERM...TODAY THROUGH WEDNESDAY... COLD FRONT PRESSING SLOWLY SOUTH ACROSS CENTRAL LOWER MI AND INTO SOUTHERN WI AND CENTRAL IOWA. 1018 MB HIGH PRESSURE ACROSS THE MID ATLANTIC STATES AND STILL KEEPING IL DRY. MCS AND ASSOCIATED CONVECTION ON NOSE OF LOW LEVEL JET OVER NW IOWA AND SMALLER AREA OF CONVECTION OVER FAR SW MO AHEAD OF SHORT WAVE IN CENTRAL KS. NEARLY CLEAR SKIES ACROSS CENTRAL IL EARLY THIS MORNING WITH PATCHY FOG OVER SE IL WITH DENSE FOG AT ROBINSON WHERE TEMP COOLED TO 55. OTHERWISE TEMPS RANGE FROM 59 TO 67 DEGREES. COLD FRONT TO MOVE SLOWLY SOUTH INTO FAR NORTHERN IL TODAY BEFORE RETURNING BACK NORTH TONIGHT AND ITS CONVECTION TO STAY NORTH OF I-80. HOWEVER...A MORE UNSTABLE AIR MASS THIS AFTERNOON WITH WARMER TEMPS IN THE MID 80S AND DEWPOINTS ELEVATING INTO THE UPPER 60S TO AROUND 70 AND LIFTED INDICES AROUND MINUS 2C. WIDELY SCATTERED TO SCATTERED CONVECTION TO DEVELOP ACROSS CENTRAL IL UNDER PARTLY SUNNY SKIES THIS AFTERNOON WHILE BEST CHANCES REMAIN TO THE NORTH AND WEST. HIGHS YESTERDAY IN THE LOWER 80S SHOULD NUDGE UP INTO THE MID 80S THIS AFTERNOON WITH LAWRENCEVILLE THE WARMEST. BUMPED CONVECTION CHANCES TO 50% FROM I-55 WEST TONIGHT SINCE CLOSER TO APPROACHING SHORT WAVE FROM KANSAS AND LIKELY POPS JUST WEST OF CWA. OVER NW AND WESTCENTRAL IL NEAR THE MS RIVER. BUMPED NW COUNTIES INTO LIKELY CHANCE OF SHOWERS AND THUNDERSTORMS TUE AND MAY NEED TO INCLUDE SPRINGFIELD GROUP IN LIKELY CHANCE TOO WHICH IS CLOSEST TO SHORT WAVE THAT MOVE INTO WESTCENTRAL IL BY DAYBREAK TUE AND INTO WI BY TUE AFTERNOON. SPC KEEPS SLIGHT RISK OF SEVERE THUNDERSTORMS WEST OF IL TUE. MAINTAINED 30% CHANCE OF CONVECTION TUE NIGHT THRU WED NIGHT AND SLIGHT RISK OF CONVECTION THU/FRI. OTHER WEAKER SHORT WAVES COULD MOVE ACROSS IL LATER THIS WEEK... BUT TIMING OF THESE SMALL SCALE FEATURES DIFFICULT THAT FAR OUT. LONG TERM...THURSDAY THROUGH SUNDAY... MAIN COLD FRONT THAT STAYS OUT WEST IN THE PLAINS STATES THIS WORK WEEK TO MOVE THRU IL SAT AFTERNOON AND SAT NIGHT IN RESPONSE TO A VIGOROUS UPPER LEVEL TROF EJECTING OUT OF THE ROCKIES TOWARD THE WESTERN GREAT LAKES THIS WEEKEND. THIS RETURNS A BETTER CHANCE OF CONVECTION TO CENTRAL IL THEN WITH COOLER WEATHER TO FOLLOW SUNDAY. && .ILX WATCHES/WARNINGS/ADVISORIES... IL...NONE. && $$ BARKER/HUETTL il AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 951 AM CDT MON AUG 23 2004 .DISCUSSION... LTL CHG TO GOING FCST TDA...BUT DID EXPAND POPS FA WIDE THIS AFTN. EXPANSIVE MCSS IN PROGRESS ACRS KS/MO WITH OTHER LINGERING TSTMS ACRS PTNS OF NE AND MN. 12Z KOAX SOUNDING AND LATEST RUC SHOW FAIRLY STEEP LAPSE RATES AND DEEP LYR INSTABILTY PUSHING EWD INTO FA. PRIMARY QG FORCING ASSOCD WITH SVRL SHRT WVS FLOATING TWRD MO VLY IN BASE OF TROF SPLITTING FA TO NW AND S ATTM...BUT STILL FEEL IT WL BE ENOUGH TO TRIGGER DVLPMT THIS AFTN. COULD SEE ELEVATED CONVECTION AND SFC BASED LATER. 12Z RUC INDCS DMSHG SFC CIN BY AFTN...AND 14Z SFC ANLYS INDCS WRMFNT AND WEAK CNVGNC ZN ACRS CNTRL NE THRU CNTRL IA TWRD KDBQ WITH DWPNTS APCHG 70F. AS MENTIONED WITH PREVIOUS FCST...FEEL SVR THREAT LTD TO PULSE HAIL WITH WEAK SHEAR IN PLACE. LCLLY HVY RAINS MAY BE A GREATER LIKELIHOOD WITH DEEP WRM CLD LYR AND SLOW STORM MOVMT XPCD. H85/H3 STEERING WNDS ONLY 10-15 KTS. NO CHGS TO TEMPS THIS AFTN. ALTHOUGH WE ARE NOT THAT FAR OFF FM XPCD MAXES...FEEL CU AND PCPN DVLPMT THIS AFTN SHOULD HOLD US IN CHECK. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE && $$ SMALL ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 930 AM CDT MON AUG 23 2004 .DISCUSSION... GOT A THOROUGH LOOK AT 12Z RUC AND FIRST 12 HRS OF ETA12 WHICH BOTH SUPPORT CURRENT FCST GRIDS AND TEXT. TWO S/W'S THIS MORNING...ONE LIFTING THRU ERN ND WITH BATCH OF RA/TSRA...AND ANOTHER STRONGER AND SLOWER ONE MOVING THRU KS FIRING STORMS FM NCNTL NEB INTO KS/MO. ANOTHER BIG COOL CANADIAN HI SITTING OVR LK SUPERIOR W/COOL AND DRY ELY FLOW ONCE AGAIN KEEPING TEMPS DOWN. PLENTY OF RH IN ALL LVLS TODAY...AND JUST DON'T PLAN ON SEEING TOO MUCH SUN. MOST AREAS WILL SEE A FEW PDS FROM TIME TO TIME...BUT WL MAINTAIN MO CLOUDY WORDING MUCH OF CWA. BEST SUN IN FAR EAST THIS MORNING AND FAR WEST THIS AFTN. KS S/W WL SLOWLY MIGRATE NORTHEAST AND SET OFF STORMS ALNG WARM/STATIONARY FRNT DRAPED ACRS IA/NE/SD. SOME OF THIS WL WORK INTO SW MN IN AFTN...BUT BULK OF DAY WL BE DRY...COOL...CLOUDY. MAY NOT MAKE 70F IN SOME SPOTS ONCE AGAIN ON ELY FLOW. MOISTURE/HIGH PW WL CONT TO WORK NWRD INTO SRN MN WITH DWPTS APPROACHING 70 IN FAR SOUTH BY LATE AFTN...WITH PW INTO 1.5" RANGE AS FRONTAL ZONE SLOWLY LIFTS NWRD. PRIMARY ACTION THOUGH WL BE OUT WEST WHERE DEEPER INSTABILITY LIES...CLOSER TO MEAN THICKNESS/THETA-E RIDGE IN CNTL SD INTO CNTL ND. SFC HI WL KEEP WRN WI HI AND DRY THRU MUCH OF TONIGHT...AS ANY ACTION IN SRN/WRN MN WL RAPIDLY WEAKEN AS IT HEADES NORTHEAST INTO MARKEDLY MORE STABLE AIRMASS. WL FRESHEN ZONES CLOSER TO NOON AND REMOVE MORNING WORDING AND TWEAK TEMPS/SKY...BUT EXPECT TO KEEP POPS PRETTY MUCH WHERE THEY ARE. && MPX WATCHES/WARNINGS/ADVISORIES... MN...NONE. WI...NONE. && $$ BINAU mn AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BUFFALO NY 959 AM EDT MON AUG 23 2004 .UPDATE... COLD FRONT ON THE LATEST SURFACE ANALYSIS STRETCHING ACROSS SOUTHWEST QUEBEC TO CENTRAL LAKE HURON AND NORTHERN LOWER MICHIGAN. DEW POINTS WERE IN THE 50S SOUTH OF THE FRONT WITH SOME DEW POINT POOLING ALONG THE FRONT...WITH VALUES IN THE LOWER TO MID 60S. WATER VAPOR SHOWS A STRONG MID-LEVEL SHORTWAVE MOVING INTO QUEBEC WITH DRY MID-LEVEL AIR OVER WESTERN NEW YORK. MORNING KBUF SOUNDING WAS DRY. BOTH THE RUC AND THE MESOETA ARE CONSISTENT WITH ONE ANOTHER PROVIDING FOR A THETA-E RIDGE AT BOTH 850MB AND 700MB OVER THE FORECAST AREA...MAINLY SOUTH OF LAKE ONTARIO...THIS AFTERNOON. WITH THE RIGHT ENTRANCE REGION OF A 500MB 70KT JET PASSING JUST TO THE NORTH DURING THE AFTERNOON...DECENT UVV IS FORECAST AT THE 850MB AND 700MB LEVELS IN WESTERN NEW YORK. ALTHOUGH THE MORNING KBUF SOUNDING IS DRY...AND THE ETA MODEL SOUNDINGS ARE LIKELY OVERDONE IN THE AMOUNT OF SURFACE DEW POINT INCREASE OVER WESTERN NEW YORK THIS AFTERNOON...THERE IS A DEGREE OR TWO COOLING FORECAST AT 700MB AND 500MB. THIS WILL PROVIDE FOR CAPE IN THE HUNDREDS J/KG...WITH LIFTED INDICES JUST BELOW ZERO. THE RUC AND THE MESOETA SUGGEST THE FRONTAL BOUNDARY REACHES AS FAR SOUTH AS THE SOUTHERN TIER THIS AFTERNOON...AND THIS MAY BE A BIT FAST GIVEN SURFACE HIGH PRESSURE OVER WEST VIRGINIA AND THE ZONAL FLOW ALOFT OVER THE NORTHEAST STATES. CONVERGENCE IS FORECAST TO BE WEAK THIS AFTERNOON ALONG THE FRONT AND AT 850MB...AND THE DEVELOPMENT OF ANY SHOWERS WILL BE DEPENDENT ON HOW HIGH THE DEW POINTS RISE...AND WHETHER THE FRONTAL BOUNDARY PROVIDES FOR ENOUGH CONVERGENCE AND LIFT TO OVERCOME LOW LEVEL CIN...WHICH WILL BE HIGHER AS THE DEW POINTS REMAIN LOWER. THINK ENOUGH PARAMETERS ARE IN PLACE TO CONTINUE THE CHANCE POPS AS CURRENTLY FORECAST...WITH POPS CERTAINLY NOT HIGHER THAN CHANCE AT THIS TIME. PLAN TO UPDATE THE FORECAST BETWEEN 11 AND 1130 AM...MAINLY TO REMOVE AFTERNOON WORDING AND TO MASSAGE THE CLOUD COVER AND WIND WHERE NEEDED. MOISTURE BELOW 700MB IS FORECAST TO BE RATHER HIGH THIS AFTERNOON...AND SKIES...EXCEPT IN THE SOUTHERN TIER...MAY SHOW MORE CLOUDS THAN SUN. WILL LOOK AT THE LATEST VISIBLE IMAGES LATE THIS MORNING AND UPDATE THE FORECAST FROM THERE. MARINE FORECAST WILL SHOW WINDS A LITTLE HIGHER BASED ON LATEST OBSERVATIONS FROM BUOYS...AND THIS IS IN CONCERT WITH THE FAIRLY TIGHT GRADIENT JUST AHEAD OF THE COLD FRONT OVER WESTERN NEW YORK. .PREVIOUS DISCUSSION... SHORT TERM (TODAY THROUGH TUESDAY)... FAIRLY VIGOROUS SHORT WAVE TROF WILL SWING NORTH OF THE AREA TODAY. AT THE SURFACE...COLD FRONT DROPS ACROSS THE AREA THIS AFTERNOON AND EVENING. WHILE FRONT CROSSES THE AREA DURING MAX HEATING, MOISTURE IS SOMEWHAT LIMITED WHICH IN TURN SHOULD LIMIT CONVECTION. STILL, ETA BUFKIT DOES SHOW CAPES IN THE 700-900 RANGE THIS AFTERNOON SO MENTION OF THUNDER IS APPROPRIATE. POPS BARELY INTO CHANCE CATEGORY FROM THE NIAGARA FRONTIER ACROSS THE FINGER LAKES AND INTO THE NORTH COUNTRY. LOWEST MODEL POPS ALONG THE SOUTHERN TIER. WILL USE LOW CHANCE POPS (30-40 PCT)THIS AFTERNOON. ANY CONVECTION SHOULD DIE DOWN QUICKLY AFTER SUNSET. FORECAST GRIDS WILL SHOW CHANCE OF EVENING CONVECTION IN THE SOUTHERN TIER. MODELS THEN SHOW FRONT ESSENTIALLY WASHING OUT ALONG NY/PA BORDER LATE TONIGHT AND TUESDAY. LOW LEVEL MOISTURE PERSISTING ALONG DYING BOUNDARY SO DON'T REALLY EXPECT BRIGHT SUNSHINE ON TUESDAY EXCEPT PERHAPS IN THE NORTH COUNTRY. BUT ON THE OTHER HAND, IT WON'T BE A BAD DAY EITHER WITH PARTLY SUNNY SKIES AND FAIRLY WARM TEMPERATURES. && LONG TERM (WEDNESDAY THROUGH SUNDAY)... 06Z GFS TO 120 HOURS REALLY PUMPS UP THE EASTERN RIDGE BEGINNING MIDWEEK AND PERSISTING INTO THE WEEKEND. PATIENT SUMMER WORSHIPPERS CAN FINALLY REJOICE. BOTH GFS AND ETA MOS SHOW A VERY WARM WEDNESDAY, SO WE INCREASED THE MAX TEMPS A FEW DEGREES FROM THE PREVIOUS FORECAST. WILL NOT MAKE ANY OTHER CHANGES AT THIS TIME, BUT IF THE GFS FORECAST HOLDS, SEE ONLY A SMALL CHANCE OF DIURNAL CONVECTION THROUGH SATURDAY. TEMPERATURES SHOULD BE WELL UP INTO THE 80S. PREVIOUS LONG TERM DISCUSSION WITH THE UPPER RIDGE ESTABLISHED ACROSS THE REGION, I HAVE PULLED PRECIPITATION OUT OF WEDNESDAY, MAINLY BECAUSE OF THE POTENTIAL TO DEVELOP A CAP ASSOCIATED WITH THAT RIDGE. AS THE WEEKS PROGRESSES I FEEL THAT THE HUMIDITY ASSOCIATED WITH MOISTURE FROM THE SOUTHEAST WILL CONTINUE TO INCREASE. ALTHOUGH THE TIMING OF SUBTLE WEATHER FEATURES WILL BE DIFFICULT IN THIS PATTERN, I WILL KEEP MENTION OF DIURNAL THUNDERSHOWERS ON THURSDAY AND FRIDAY AND KEEP A CHANCE OF THUNDERSTORMS IN FOR THE WEEKEND. && AVIATION... A COLD FRONT WITH LIMITED MOISTURE IS FORECAST TO CROSS THE REGION DURING THE AFTERNOON. FLYING CONDITIONS SHOULD REMAIN VFR MOST OF THE TIME TODAY BUT AS THE FRONT APPROACHES FROM THE NORTHWEST THIS AFTERNOON THERE IS A 30 PERCENT CHANCE OF A SHOWER OR THUNDERSTORM. CIGS ARE EXPECTED AT THIS TIME TO BECOME MVFR AT TIMES IN THE SHOWERS/TSTMS WITH CIGS BECMG MVFR BEHIND THE FRONT FOR A SHORT TIME LATER THIS AFTERNOON. CONDITIONS ARE EXPECTED TO BECOME VFR AGAIN AROUND 00Z-01Z TIME FRAME. DUE TO THE PRESENCE OF A LOW-LEVEL JET EARLY THIS MORNING AND LIGHTER WINDS AT THE SURFACE HAVE CONTINUED THE MENTION OF LOW LEVEL WIND SHEAR IN THE TAFS IN THE 1500-2000 FT LEVEL WITH WINDS AROUND 35-40 KTS TILL AROUND 11Z. WIND DIRECTION AT THE SURFACE SHOULD BE RUNNING FROM THE SSW WITH WINDS FROM 250 IN THE 1500-2000 FT LYR. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...NONE. MARINE...NONE. $$ UPDATE...DJF PREVIOUS SHORT TERM..SL PREVIOUS LONG TERM...SL/TAN PREVIOUS AVIATION...JJP ny AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORMAN OK 928 PM CDT MON AUG 23 2004 .DISCUSSION... WILL REMOVE EVENING POPS AND DECREASE CLOUD COVER. ALSO WILL ADJUST WIND AND TEMP GRIDS...INCLUDING LOWS TONIGHT...BASED ON MODIFIED RUC FIELDS. 24 && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 72 95 73 94 / 10 10 10 20 HOBART OK 72 97 72 96 / 10 20 20 20 WICHITA FALLS TX 73 97 74 97 / 10 10 10 20 GAGE OK 69 97 69 96 / 10 20 20 20 PONCA CITY OK 74 94 74 94 / 10 10 10 20 DURANT OK 73 93 74 94 / 10 10 10 20 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$ 24 ok AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE PITTSBURGH PA 715 PM EDT MON AUG 23 2004 .SHORT TERM (REST OF TONIGHT)... WILL BE SENDING OUT AN UPDATE SHORTLY TO REMOVE POPS IN MY NORTH. WITH SUN SETTING WOULD EXPECT PRECIP ASSOCIATED WITH WEAK COLD FRONT TO DISSIPATE. SUBSIDENCE OVER AREA IS KEEPING PRECIP FROM MAKING SOUTHWARD PROGRESSION. && .PREVIOUS DISCUSSION... THE FOLLOWING WAS ORIGINALLY ISSUED AT 220 PM EDT MON AUG 23 2004 AVIATION SCT CU SHUD DSIPT WITH LOSS OF HEATING. CLDS MAY HANG ON A BIT LONGER UP N INVOF WKNG FNTL BNDRY PUSHING SWD ACRS NY. WINDS SHUD BE LGT ENUF AGN OVRNGT TO ALLOW PATCHY IFR FOG FORMATION...SPCLY IN VLYS. CHC OF TSTMS ACRS NRN PTN FCST AREA NR CDFNT THIS EVE...BUT ODDS TOO SMALL TO MENTION IN TAFS. SHORT TERM (THRU THU)... RAISED POPS IN NRN 1/3 TO 25-33% FOR EVE HRS. WEAK FRONT PRESSING DOWN. CONVECTIVE TEMP REACHED 4 PM. MID LEVEL CAP ERODES AFTER 4 PM. RUC HAS A LTL MOIST FLUX UP N; 12Z ETA MODEL HAD A LTL MORE. AFTER THAT, ITS BACK TO CLEAR SUMMER NIGHTS AND FOGGY MRNGS, AS H5 RIDGE BUILDS AND BUILDS. LONG TERM (THU NIGHT THRU MON)... PERSISTENCE SEEMS PRUDENT TDA FOR THE LONG TERM PACKAGE WITH GFS INDG RIDGE MAINTENANCE OVR THE E COAST INTO THE WEEKEND. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ SHORT TERM...22 pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 220 PM EDT MON AUG 23 2004 .AVIATION SCT CU SHUD DSIPT WITH LOSS OF HEATING. CLDS MAY HANG ON A BIT LONGER UP N INVOF WKNG FNTL BNDRY PUSHING SWD ACRS NY. WINDS SHUD BE LGT ENUF AGN OVRNGT TO ALLOW PATCHY IFR FOG FORMATION...SPCLY IN VLYS. CHC OF TSTMS ACRS NRN PTN FCST AREA NR CDFNT THIS EVE...BUT ODDS TOO SMALL TO MENTION IN TAFS. && .SHORT TERM (THRU THU)... RAISED POPS IN NRN 1/3 TO 25-33% FOR EVE HRS. WEAK FRONT PRESSING DOWN. CONVECTIVE TEMP REACHED 4 PM. MID LEVEL CAP ERODES AFTER 4 PM. RUC HAS A LTL MOIST FLUX UP N; 12Z ETA MODEL HAD A LTL MORE. AFTER THAT, ITS BACK TO CLEAR SUMMER NIGHTS AND FOGGY MRNGS, AS H5 RIDGE BUILDS AND BUILDS. && .LONG TERM (THU NIGHT THRU MON)... PERSISTANCE SEEMS PRUDENT TDA FOR THE LONG TERM PACKAGE WITH GFS INDG RIDGE MAINTENANCE OVR THE E COAST INTO THE WEEKEND. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ pa AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY NATIONAL WEATHER SERVICE RAPID CITY SD 200 PM MDT MON AUG 23 2004 .DISCUSSION...LATEST SFC ANALYSIS PLACES LOW OVER NR MT WITH FRONT EXTENDING SE THROUGH K2WX AND KPHP IN WRN SD. DRY LINE AS JUST MOVED OUT OF WY INTO WRN SD AND ACROSS BLACK HILLS. TD CHANGE AROUND 20-25 F ACROSS DRY LINE. SATELLITE INDC THIN MID/HIGH STRATUS OVER NE WY/WRN SD...WITH GOOD CU POPPING RAPIDLY OVER SE MT. 12Z MODELS INITIALIZED WELL AND SHOW GOOD AGREEMENT IN EARLY PERIODS...BUT DIVERGE IN LATER PERIODS WITH LONGWAVE TROF OVER WRN U.S. TODAY/THIS EVE WILL ANTICIPATE A TOR WATCH FOR PTNS OF NW/CENT SD. 18Z RUC SOUNDING AND HODOGRAPHS AT KD07 GIVE 01KM SRH AROUND 180 M2/S2 LATER THIS AFTERNOON. THIS IS DOUBLE WHAT THE 12Z RUC INDICATED...BUT LOOKS REASONABLE GIVEN LOW LEVEL WINDS. 0-6 KM TOTAL SHEAR AROUND 32/MS. CAPE AXIS EXIST OVER CENT SD WITH MLCAPE NEAR 2000 J/KG. THETA-E AXIS ACROSS CENT SD WITH VERY IMPRESSIVE ADVECTION IN NW/N CENT SD THROUGH LATE AFTERNOON/EARLY EVE. LCLS SUPPORT TORNADOES AS WELL. VERY POTENT UPPER LEVEL WAVE WILL PROVIDE MORE THAN AMPLE UPPER LEVEL FORCING FOR SEVERE THUNDERSTORMS AND SOME TORNADOS LIKELY. INSTABILITY EXISTS OVER S-CENT SD...BUT LOWER AND UPPER LEVEL FORCING WILL NOT BE PRESENT UNTIL AFTER 00Z...CLOSER TO 03-06Z. WILL ANTICIPATE RAPID CONVECTIVE DEVELOPMENT FAR NW AND CENT SD THIS AFTERNOON AND EVE. DRY LINE PUSHING THROUGH FASTER THAN 18Z RUC SUGGESTS...AND MAY ACTUALLY PUSH WELL AHEAD OF APPROACHING DYNAMICS IN S-CENT SD THIS EVE. HOWEVER SIGNIFICANT MID LEVEL MOISTURE AND INSTABILITY WILL SUPPORT CONVECTION...WITH ADEQUATE SHEAR FOR SUPERCELLS PRODUCING DAMAGING WIND GUSTS UNDER DRY BASES. BEYOND 06-08Z WILL SEE SUBSIDENCE AND DRY AIR ENGULF ALL OF CWFA...EXCEPT ERN MOST ZONES. UPPER LOW AND ASSOCD ENERGY WILL ROTATE N AND E OF CWFA. TUESDAY WILL SEE UPPER FLOW BECOME MORE ZONAL AHEAD OF DEVELOPING W COAST DEEP LOW. THIS WILL RESULT IN WEAK ENERGY IN WRLY FLOW. ADEQUATE MOISTURE AND INSTABILITY WILL BE AROUND WITH GOOD INSOLATION TO SUPPORT DAILY LOW-CHANCE POPS FOR MAINLY DIURNAL CONVECTION THROUGH THE END OF THE WEEK. FRIDAY WILL SEE DEEP UPPER LOW OVER W U.S. MOVE ACROSS CENT/NRN ROCKIES AND ONTO NRN PLAINS. GFS IS MORE CONSISTENT THAN ETA GOING INTO THE EXTENDED PERIODS. && .UNR...WATCHES/WARNINGS/ADVISORIES... .SD...NONE. .WY...NONE. $$ 99 sd AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEMPHIS TN 922 AM CDT MON AUG 23 2004 .UPDATE... WARM AND HUMID AIRMASS COVERING ALL OF THE MID SOUTH AS THE WEAK WARM FRONT HAS MOVED NORTH OF THE REGION THIS MORNING. SFC DEWPOINTS WERE IN THE LOWER 70S WITH PWS OF NEARLY 2 INCHES. THE MAIN SHORTWAVE WAS LOCATED OVER ERN KS AT 14Z AND WILL MOVE ACRS NRN MO THIS AFTN. WEAKER SHORTWAVES TO THE SOUTH ACRS THE RED RIVER VALLEY AND SRN AR WERE EVIDENT IN THE LATEST RUC ANALYSIS. THE COMBINATION OF AFTN HEATING...MOIST AIRMASS AND THESE SHORTWAVES WL LEAD TO SCT THUNDERSTORMS THIS AFTN. CURRENT FORECAST RIGHT ON TRACK WITH NO CHANGES ATTM. .PREV DISCUSSION ISSUED AT 257 AM... ZONAL FLOW WITH A SERIES OF SHORT WAVES AND IMPULSES WILL SHIFT TO SOUTHWESTERLY FLOW FROM THE CALIFORNIA COAST TO THE GREAT LAKES THIS WEEK AS A RIDGE BUILDS ALONG THE EAST COAST AND ACROSS THE DEEP SOUTH. SHORT WAVES WILL CARVE A TROF IN THE WEST THURSDAY AND FRIDAY THAT WILL LIFT OUT NORTHEASTWARD ACROSS THE NORTHERN PLAINS TO THE GREAT LAKES OVER THE WEEKEND. THE RIDGE FLATTENS OUT IN THE EAST OVER THE WEEKEND BUT CONTINUES ACROSS THE SOUTH AS THE FLOW BECOMES MORE ZONAL. AT THE SURFACE A WEAK STATIONARY FRONT ACROSS THE NORTHERN GULF COAST STATES WILL MOVE NORTHWARD ACROSS THE MID SOUTH AS A WARM FRONT THIS MORNING AND DISSIPATE THIS AFTERNOON. A HIGH PRESSURE AREA WILL COVER THE EASTERN STATES INCLUDING THE MID SOUTH THROUGH THIS WEEK AND CAUSE SOUTHERLY WINDS TO BRING IN WARM MOIST GULF AIR. TO THE WEST LOW PRESSURE AREAS WILL SHEAR NORTHEASTWARD FROM THE CENTRAL PLAINS TO THE GREAT LAKES. A COLD FRONT WILL APPROACH THE MID SOUTH FROM THE WEST FRIDAY AND SATURDAY. THE RESULT WILL BE WARMER AND MORE HUMID WEATHER THIS WEEK WITH CHANCES OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS. THE APPROACH OF THE COLD FRONT WILL BRING BETTER CHANCES OF RAIN FRIDAY AND OVER THE WEEKEND. && .MEG...WATCHES/WARNINGS/ADVISORIES... AR...NONE. MS...NONE. MO...NONE. TN...NONE. && $$ SJM/JCL tn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 550 PM CDT MON AUG 23 2004 .UPDATE...THE SEA BREEZE BOUNDARY AND SEVERAL OUTFLOW BOUNDARIES ARE CONVERGING ON RIO GRANDE PLAINS. SUN HAS BROKEN OUT ENOUGH TO PRODUCE TEMPS IN THE 90S TO AROUND 100 DEGREES IN THIS AREA AND LAPS SHOWING STRONG MOISTURE CONVERGENCE ASSOC W/ THE CONVERGING BOUNDARIES W/ CAPES OF 2000-4000 J/KG. GOES SOUNDER STILL SHOWS PWS NEAR 2 INCHES POOLED IN THIS REGION AND CU FIELDS LOOKING BETTER WITH TIME AND RADAR BEGINNING TO SHOW SMALL SHOWERS DEVELOPING SOUTH OF COTULLA. STILL ENOUGH WEAK DYNAMIC FORCING LEFT TO GENERATE SCT CONVECTION ACROSS THE BORDER ATTM AND THIS MAY AID IN CONVECTIVE DEVELOPMENT ACROSS THE RIO GRANDE PLAINS SLIGHTLY AS WELL. RUC IS ALONE IN SHOWING CONVECTIVE DEVELOPMENT ACROSS THE WEST THROUGH 03Z...BUT GIVEN THE ABOVE DISCUSSION...AM INCLINED TO BELIEVE IT. THEREFORE AM RAISING POPS TO 40 PERCENT FOR LASALLE AND WEBB COUNTIES THIS EVENING TAPERING OFF TO 30 FOR MCMULLEN AND DUVAL AND 20 PERCENT OF LESS FURTHER EAST. THINKING (AND HOPING) WE WILL NOT SEE A REPEAT OF LAST NIGHTS EVENT BUT WILL KEEP CLOSE WATCH ON CONVERGING BOUNDARIES. PORT ARANSAS C-MAN...BOB HALL PIER...BAFFIN BAY TCOON AND CRP OBS ALL SHOWING SUSTAINED WINDS AOA 20 KNOTS WITH GUSTS TO 24-27 KNOTS...WITH OTHER SITES BELOW 20 KNOTS SUSTAINED BUT ALSO GUSTING OVER 20 KNOTS. HAVE UPDATED THE CWF TO SHOW SCA FOR BAYS SOUTH OF PORT ARANSAS AND NEARSHORE WATERS SOUTH OF ROCKPORT. .PREVIOUS DISCUSSION... SHORT-TERM (TONIGHT THROUGH TUESDAY NIGHT)...LAST IN A SERIES OF SHORTWAVES NOW MOVING OUT OF THE CWFA...TAKING CHANCES OF PRECIPITATION WITH IT. UPPER RIDGE WILL BUILD INTO THE AREA THROUGH THE REST OF THE SHORT TERM...WITH JUST SMALL CHANCES FOR SEABREEZE CONVECTION...AND WITH DRIER AIR MOVING IN EVEN THOSE CHANCES LOOK SLIM. MOS TEMPS LOOK PRETTY MUCH IN LINE. LONG-TERM (WEDNESDAY THROUGH MONDAY)...GFS/GFS ENSEMBLES INDICATE/SUGGEST THAT THE UPPER RIDGE WL DEVELOP OVR THE REGION WITH THE RIDGE AXIS AROUND THE LATITUDE OF CRP...WEDNESDAY THROUGH SAT. WL CONFINE DIURNAL CONVECTION TO THE ERN CWFA/COASTAL WATERS...WITH A GRADUAL DECREASE IN COVERAGE...CONSISTENT WITH A DECREASE IN PW AS PROGD BY THE GFS. THUS BY FRI/SAT...EXPECT DRY CONDITIONS OVR LAND...EXCEPT OVR THE NERN CWFA AS MSTR CONVERGENCE MAY BE SUFFICIENT. GFS AND CANADIAN DIFFER WITH RESPECT TO THE UPPER PATTERN SUNDAY-MONDAY...WITH AN UPPER DISTURBANCE MOVG/DIMINISHING ACRS THE PLAINS...YET SUFFICIENT TO PUSH THE UPPER RIDGE AXIS SWD. HWR THE CANADIAN MAINTAINS THIS UPPER DISTURBANCE TO THE WEST. WL FAVOR THE GFS GIVEN ITS CONSISTENCY IN THE PAST TWO RUNS. THUS EXPECT UPPER DYNAMICS... ALTHOUGH THE BULK WL REMAIN NORTH...TO AFFECT THE NRN CWFA SUN-MON AND WL INCREASE COVERAGE/CHANCE OF CONVECTION. MARINE...ANTICIPATE DIURNAL WIND DRG THE PERIOD...WITH SCEC/SCA CONDITIONS OVR THE BAYS IN THE AFTN/EVENING HOURS. WL FCST SEAS TO REMAIN IN THE 3-5 FT RANGE DRG THE PERIOD. HWR...IF THE DIURNAL FLUCTUATIONS IN WIND WERE NOT TO OCCUR...THE COMBINATION OF FETCH/FETCH LENGTH COULD CAUSE SEAS TO APPROACH 6 FEET. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 77 94 79 94 / 10 10 10 10 VICTORIA 78 93 77 96 / 20 10 10 20 LAREDO 79 102 80 102 / 40 05 00 00 ALICE 75 99 76 97 / 10 10 00 10 ROCKPORT 79 90 81 90 / 10 10 10 20 COTULLA 76 100 77 100 / 40 05 00 10 && .CRP WATCHES/WARNINGS/ADVISORIES...SCA BAYS SOUTH OF PORT ARANSAS AND NEARSHORE WATERS SOUTH OF ROCKPORT. && $$ MJG...UPDATE 71...SHORT-TERM WC/87...LONG-TERM tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 956 AM CDT MON AUG 23 2004 .DISCUSSION... PLAN ON LEAVING TODAY'S HIGH POP FORECAST UNCHANGED. SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED THIS MORNING ACROSS THE NORTHERN COUNTIES...AROUND GALVESTON ISLAND AND THE EAST SIDE OF GALVESTON COUNTY. THE BIG PLAYER TODAY IN OUR WEATHER MIGHT END UP BEING THE SOUTH TEXAS MCS. WITH THE EASTERN PORTION OF THIS FEATURE WEAKENING AT THIS TIME...THINK SOUTHEAST TEXAS WILL BE ABLE TO DESTABILIZE THIS AFTERNOON AS DAYTIME HEATING KICKS IN. THIS SHOULD RESULT IN ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT. IT IS CONCEIVABLE THAT A THICKER THAN EXPECTED CIRRUS SHIELD COULD KICK OUT OF THE MCS AND HELP TO STABILIZE PORTIONS OF OUR AREA....BUT CURRENT THINKING IS THIS IS THE LESS LIKELY SCENARIO. && AVIATION: WILL KEEP TEMPO GROUPS IN PLACE FOR AFTERNOON CONVECTION BUT THINK TSRA WILL END BY 22Z. LOW CEILINGS ONLY EXPECTED DURING CONVECTION BUT NOTHING BELOW MVFR. CIRRUS CANOPY EXPECTED OVERNIGHT WITH WINDS DECOUPLING INLAND...BUT STAYING UP NEAR THE COAST. 43 .HGX WATCHES/WARNINGS/ADVISORIES...NONE. && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 90 74 93 74 93/ 70 30 40 20 30 HOUSTON (IAH) 90 75 92 75 93/ 70 30 50 20 30 GALVESTON (GLS) 89 79 90 79 90/ 60 30 50 20 30 && .PREVIOUS DISCUSSION (405 AM)... CHALLENGE FOR TODAY IS EVOLUTION OF MCS TO OUR WEST...IMPACT OF CIRRUS SHIELD SPREADING OVER FROM SAID MCS...AND POTENTIAL FORCING FROM WEAK SHORT WAVE CROSSING AREA THIS AFTERNOON. PROPAGATION VECTORS FROM MESOETA...RUC AND GFS SUGGEST MCS WILL DEVELOP MORE INTO SOUTH TEXAS THAN SOUTHEAST. SUSPECT AT LEAST A WEAK BOUNDARY WILL MOVE INTO WESTERN THIRD TO HALF OF AREA THIS MORNING. SHORT WAVE EVIDENT IN WV IMAGE WESTERN HILL COUNTRY DOWN TO SOUTHWEST OF LAREDO PROGRESSING EASTWARD. MESOETA (BOTH 00 AND 06Z) HAS PRETTY DECENT HANDLE ON THIS FEATURE SO FAR. THE MODEL TAKES THE SHORT WAVE ACROSS OUR AREA THIS AFTERNOON. MOISTURE AND INSTABLITY CONTINUE ABOVE NORMAL VALUES FOR AUGUST ON THE UPPER COAST. ALL OF THE ABOVE SUGGEST LIKELY TO CATEGORICAL POPS TODAY. ON THE INHIBITOR SIDE...CLOUD COVER WILL LIKELY HOLD DAYTIME HEATING DOWN A BIT AND OUTFLOW BOUNDARY FROM MCS WILL BE WEAK AND COULD DISSIPATE ENTIRELY BY AFTERNOON THUS REMOVING A KEY FOR FOCUSING. WILL STICK LIKELY WITH LOCALLY HEAVY RAINFALL WORDING OUT THIS PACKAGE. MOST PLACES GET LESS THAN AN INCH BUT AS FOR PAST SEVERAL DAYS WHERE SOME MESOSCALKE ORGANIZATION OR TRAINING TAKE PLACE...LOCALLIZED 3 TO 5 INCH RAINS NOT OUT OF QUESTION. MESOETA AND TO A MUCH LESSER EXTENT GFS MAINTAIN SOME OF WEAK TROF OVER SOUTHEAST TEXAS AN SOUTH TEXAS OVERNIGHT AND WEDNESDAY. IF CONVECTION IS AS WIDESPREAD AS WE THINK TODAY...THEN TONIGHT SHOULD BE MOSTLY QUIET DUE TO STABLIZED AIRMASS FOLLOWED BY GOOD CHANCE AGAIN TOMORROW AS DAYTIME HEATING TAKES HOLD. REST OF FORECAST BECOMES A CRAPSHOOT UNLESS ONE REALLY BELIEVES THE MODEL HAS A GRIP ON SUBTLE FEATURES OCCASIONALLY EDING ALONG THE TOP OF THE RIDGE PARKED OVER THE GULF. NO DOUBT THEY WILL OCCUR..THE WHEN WHERE AND IMPACT WILL AWAIT THE SHORT TERM. WILL KEEP THE CHANCE POPS GOING UFN WITH TEMPS HANGING NEAR NORMAL FOR HIGHS AND LOWS A TAD WARM OWING TO HIGH MOISTURE AND DECENT ONSHORE GRADIENT WINDS. MARINE...ONSHORE FLOW CONTINUES WITH BRIEF FORAYS NEAR CAUTION CRITERIA OVERNIGHT AND THE THREAT OF THUNDERSTORMS ESPECIALLY ON THE BAYS. AVIATION...THUNDERSTORMS WILL BE THE MAIN IMPACT ON AIRPORTS TODAY WITH MOST LIKELY BEING 16Z-23Z TIME FRAME. SHORT WAVE AND OR MCS/SEABREEZE BOUNDARIES COULD FOCUS THUNDERSTORMS INTO LINES OR CLUSTERS. 30/41 && $$ tx AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 1015 AM CDT MON AUG 23 2004 .SHORT-TERM UPDATE...MCS NEARLY STATIONARY OVER NW CWFA PRODUCING CLUSTERS OF THUNDERSTORMS WITH FLOODING RAINFALL OVER NORTHERN LASALLE COUNTY...AND SHOWERS ALONG THE NORTHERN TIER OF COUNTIES IN CRP CWFA. GOES SOUNDER SHOWING AIR WITH VERY HIGH MOISTURE CONTENT CONTINUES TO BE LIFTED INTO THIS COMPLEX. MESOETA AND RUC MODELS WANT TO DIMINISH THIS ACTIVITY RATHER RAPIDLY...BUT THE SHORTWAVE RESPONSIBLE FOR ALL THIS IS MOVING SLOWER THAN EXPECTED...SO WILL BE SLIGHTLY MORE PESSIMISTIC ABOUT ENDING THE HEAVY RAIN. REST OF FORECAST UNCHANGED. ...PREVIOUS DISCUSSIONS... .DISCUSSION...MID LEVEL VORTICITY MAX STILL AROUND COTULLA AT 11Z. WITH SLOWER MOVEMENT...STORMS HAVE LINGERED OVER THE BRUSH COUNTRY THIS MORNING. WILL NEED TO UPDATE TO INCREASE POPS FOR THIS MORNING. WILL GO WITH CATEGORICAL POPS FOR THE NORTH AND PUSH THE POPS TO 60 PERCENT FOR THE SOUTHERN COASTAL BEND. THE WINDS HAVE DECREASED SLIGHTLY FOR THE COASTAL WATERS BUT WITH PRESSURE FALLS IN ADVANCE OF THUNDERSTORM COMPLEX AND LOW LEVEL JET STILL EVIDENT ON THE KCRP VAD WIND PROFILE...WILL WAIT TO LOWER SCA. 89/TMT ...PREVIOUS DISCUSSION... .SHORT-TERM (TODAY THROUGH TUESDAY)...MID LEVEL SHORT WAVE TROUGH IN THE PROCESS OF MOVING ACROSS THE RIO GRANDE PLAINS/BRUSH COUNTRY EARLY THIS MORNING. ETA/GFS/RUC SHOW THIS SHORT WAVE TROUGH SLOWLY MOVING TO THE EAST ACROSS THE FORECAST AREA TODAY. THE LOW LEVEL FLOW CONTINUES TO BE STRONG ALONG THE SOUTH TEXAS COAST WITH KCRP VAD WIND PROFILE INDICATING 25-30 KNOTS SOUTH-SOUTHEAST IN THE 1-3 KM LAYER. LATEST MSAS ANALYSIS SHOWS INCREASING MOISTURE CONVERGENCE OVER THE NORTHERN COASTAL BEND IN ADVANCE OF THIS MID-LEVEL SHORT WAVE TROUGH AND CURRENT AREA OF THUNDERSTORMS JUST EAST OF COTULLA. MOIST AIRMASS WILL BE IN PLACE TODAY WITH HIGH MOISTURE CONTENT OF 2.0 TO 2.2 INCH PWATS AVAILABLE. WITH EXPECTED LOW LEVEL CONVERGENCE STRONGER OVER THE NORTHEAST COUNTIES WILL GO WITH HIGHEST POPS THERE. WILL GO WITH THE WETTER ETA GUIDANCE POPS FOR TODAY. ONCE THIS SHORT WAVE TROUGH MOVES EAST OF THE AREA THIS EVENING...RAIN CHANCES WILL QUICKLY DIMINISH. EXPECT ONLY NOCTURNAL CONVECTION ALONG THE LOW LEVEL JET OVER THE MID-COAST REGION AND ISOLATED AFTERNOON STORMS ON THE SEABREEZE NEAR VICTORIA ON TUESDAY. THE STRONG LOW LEVEL FLOW WILL KEEP SCA CONDITIONS OVER THE SOUTHERN BAYS INTO THE OFFSHORE WATERS FOR TODAY INTO TONIGHT WITH A SLIGHT DECREASE TO SCEC LEVELS BY TUESDAY AFTERNOON. THE UPPER LEVEL RIDGE BUILDS INTO SOUTH TEXAS ON TUESDAY SO WENT WITH HIGHER ETA TEMPS ACROSS THE AREA. && .LONG-TERM (TUESDAY NIGHT THROUGH SUNDAY)...LOOKS LIKE THE H5 RIDGE WILL FINALLY BUILD WEST FROM THE WRN GULF...CENTERING ON S TX WED AND THU...SHOWN BY GFS/ETA/ECMWF AND UKMET. THIS WILL KEEP EMBEDDED SHORT WAVES IN FLOW ALOFT FURTHER NORTH...AS OPPOSED TO WHAT WE HAVE SEEN THE PAST FEW DAYS. THERE IS A WEAK TROPICAL WAVE...CURRENTLY MOVING THRU THE WRN CARIBBEAN...THAT IS SHOWN BY THE ETA AND GFS TO MOVE INTO THE BAY OF CAMPECHE TUE NIGHT AND WED MORNING. THIS IS QUICKER THAN PREVIOUS RUNS...AND APPEARS CORRECT BASED ON CURRENT MOVEMENT. DON'T FEEL THAT THIS WILL BE A PLAYER ON THE FORECAST WED-THU...AS MOST OF THE MOISTURE WILL PASS SOUTH OF US INTO THE COAST OF MEXICO AND MID LEVEL RIDGE WILL BE INFLUENCING THE AREA. WILL ONLY FORECAST ISOL (10-20) POPS OVER THE WATERS AND NORTHERN COASTAL BEND EACH MORNING AND OVER THE VCT GROUPING DURING THE LATE MORNING AND AFTERNOON ON WED AND THU. NOT EXPECTING MUCH COVERAGE WITH THESE SHOWERS AS SUBSIDENCE FROM RIDGE WILL HAVE TO BE OVERCOME. EXPECT WINDS DURING THE MIDDLE PART OF THE WEEK MORE TYPICAL FOR THIS TIME OF YEAR...APPROACHING SCEC RANGE DURING THE AFTERNOON AND EVENINGS OVER THE BAYS AND NEARSHORE WATERS. SOME DIFFERENCE EXIST WITH SPEED AND AMPLITUDE OF TROF DIGGING THRU THE INTERMOUNTAIN WEST AND INTO THE PLAINS THU THRU SAT...WITH ECMWF QUICKEST AND CANADIAN SLOWER AND DEEPER. SOLUTION IS PROBABLY LIES IN BETWEEN WITH THE GFS... PER PMDEPD. AS H5 TROF LIFTS NE OUT OF GREAT BASIN ON FRIDAY EXPECT WINDS TO COME UP OVER THE AREA AS PRESS FALLS OCCUR ACROSS WEST TEXAS. WINDS IN SCEC RANGE...APPROACHING SCA CONDITIONS...POSSIBLE THU EVE AND AGAIN FRI EVE AS LLVL NOCTURNAL JET STRENGTHENS. AS TROF SLIDES NORTHEAST ACROSS THE PLAINS SAT AND SUN RIDGE WILL WEAKEN SLIGHTLY ACROSS S TX AND SHIFT SLIGHTLY SOUTH. COULD ALLOW FOR A FEW MORE SHOWERS DEVELOPING FURTHER INLAND AND WEST ALONG THE SEA-BREEZE OVER THE WEEKEND. COLD FRONT WILL ENTER N-CNTRL TX OVER THE WEEKEND AND STALL. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 93 78 95 79 96 / 40 10 10 05 10 VICTORIA 92 76 94 77 96 / 60 20 20 10 20 LAREDO 100 80 104 81 104 / 30 10 05 05 00 ALICE 96 76 99 76 100 / 40 20 10 05 10 ROCKPORT 90 80 92 81 93 / 60 20 20 20 20 COTULLA 97 77 100 77 101 / 30 10 05 05 05 && .CRP WATCHES/WARNINGS/ADVISORIES...SCA TODAY GMZ 230-250-255-270-275. && $$ tx AREA FORECAST DISCUSSION...UPDATE NATIONAL WEATHER SERVICE CORPUS CHRISTI TX 645 AM CDT MON AUG 23 2004 .DISCUSSION...MID LEVEL VORTICITY MAX STILL AROUND COTULLA AT 11Z. WITH SLOWER MOVEMENT...STORMS HAVE LINGERED OVER THE BRUSH COUNTRY THIS MORNING. WILL NEED TO UPDATE TO INCREASE POPS FOR THIS MORNING. WILL GO WITH CATEGORICAL POPS FOR THE NORTH AND PUSH THE POPS TO 60 PERCENT FOR THE SOUTHERN COASTAL BEND. THE WINDS HAVE DECREASED SLIGHTLY FOR THE COASTAL WATERS BUT WITH PRESSURE FALLS IN ADVANCE OF THUNDERSTORM COMPLEX AND LOW LEVEL JET STILL EVIDENT ON THE KCRP VAD WIND PROFILE...WILL WAIT TO LOWER SCA. 89/TMT ...PREVIOUS DISCUSSION... .SHORT-TERM (TODAY THROUGH TUESDAY)...MID LEVEL SHORT WAVE TROUGH IN THE PROCESS OF MOVING ACROSS THE RIO GRANDE PLAINS/BRUSH COUNTRY EARLY THIS MORNING. ETA/GFS/RUC SHOW THIS SHORT WAVE TROUGH SLOWLY MOVING TO THE EAST ACROSS THE FORECAST AREA TODAY. THE LOW LEVEL FLOW CONTINUES TO BE STRONG ALONG THE SOUTH TEXAS COAST WITH KCRP VAD WIND PROFILE INDICATING 25-30 KNOTS SOUTH-SOUTHEAST IN THE 1-3 KM LAYER. LATEST MSAS ANALYSIS SHOWS INCREASING MOISTURE CONVERGENCE OVER THE NORTHERN COASTAL BEND IN ADVANCE OF THIS MID-LEVEL SHORT WAVE TROUGH AND CURRENT AREA OF THUNDERSTORMS JUST EAST OF COTULLA. MOIST AIRMASS WILL BE IN PLACE TODAY WITH HIGH MOISTURE CONTENT OF 2.0 TO 2.2 INCH PWATS AVAILABLE. WITH EXPECTED LOW LEVEL CONVERGENCE STRONGER OVER THE NORTHEAST COUNTIES WILL GO WITH HIGHEST POPS THERE. WILL GO WITH THE WETTER ETA GUIDANCE POPS FOR TODAY. ONCE THIS SHORT WAVE TROUGH MOVES EAST OF THE AREA THIS EVENING...RAIN CHANCES WILL QUICKLY DIMINISH. EXPECT ONLY NOCTURNAL CONVECTION ALONG THE LOW LEVEL JET OVER THE MID-COAST REGION AND ISOLATED AFTERNOON STORMS ON THE SEABREEZE NEAR VICTORIA ON TUESDAY. THE STRONG LOW LEVEL FLOW WILL KEEP SCA CONDITIONS OVER THE SOUTHERN BAYS INTO THE OFFSHORE WATERS FOR TODAY INTO TONIGHT WITH A SLIGHT DECREASE TO SCEC LEVELS BY TUESDAY AFTERNOON. THE UPPER LEVEL RIDGE BUILDS INTO SOUTH TEXAS ON TUESDAY SO WENT WITH HIGHER ETA TEMPS ACROSS THE AREA. && .LONG-TERM (TUESDAY NIGHT THROUGH SUNDAY)...LOOKS LIKE THE H5 RIDGE WILL FINALLY BUILD WEST FROM THE WRN GULF...CENTERING ON S TX WED AND THU...SHOWN BY GFS/ETA/ECMWF AND UKMET. THIS WILL KEEP EMBEDDED SHORT WAVES IN FLOW ALOFT FURTHER NORTH...AS OPPOSED TO WHAT WE HAVE SEEN THE PAST FEW DAYS. THERE IS A WEAK TROPICAL WAVE...CURRENTLY MOVING THRU THE WRN CARIBBEAN...THAT IS SHOWN BY THE ETA AND GFS TO MOVE INTO THE BAY OF CAMPECHE TUE NIGHT AND WED MORNING. THIS IS QUICKER THAN PREVIOUS RUNS...AND APPEARS CORRECT BASED ON CURRENT MOVEMENT. DON'T FEEL THAT THIS WILL BE A PLAYER ON THE FORECAST WED-THU...AS MOST OF THE MOISTURE WILL PASS SOUTH OF US INTO THE COAST OF MEXICO AND MID LEVEL RIDGE WILL BE INFLUENCING THE AREA. WILL ONLY FORECAST ISOL (10-20) POPS OVER THE WATERS AND NORTHERN COASTAL BEND EACH MORNING AND OVER THE VCT GROUPING DURING THE LATE MORNING AND AFTERNOON ON WED AND THU. NOT EXPECTING MUCH COVERAGE WITH THESE SHOWERS AS SUBSIDENCE FROM RIDGE WILL HAVE TO BE OVERCOME. EXPECT WINDS DURING THE MIDDLE PART OF THE WEEK MORE TYPICAL FOR THIS TIME OF YEAR...APPROACHING SCEC RANGE DURING THE AFTERNOON AND EVENINGS OVER THE BAYS AND NEARSHORE WATERS. SOME DIFFERENCE EXIST WITH SPEED AND AMPLITUDE OF TROF DIGGING THRU THE INTERMOUNTAIN WEST AND INTO THE PLAINS THU THRU SAT...WITH ECMWF QUICKEST AND CANADIAN SLOWER AND DEEPER. SOLUTION IS PROBABLY LIES IN BETWEEN WITH THE GFS... PER PMDEPD. AS H5 TROF LIFTS NE OUT OF GREAT BASIN ON FRIDAY EXPECT WINDS TO COME UP OVER THE AREA AS PRESS FALLS OCCUR ACROSS WEST TEXAS. WINDS IN SCEC RANGE...APPROACHING SCA CONDITIONS...POSSIBLE THU EVE AND AGAIN FRI EVE AS LLVL NOCTURNAL JET STRENGTHENS. AS TROF SLIDES NORTHEAST ACROSS THE PLAINS SAT AND SUN RIDGE WILL WEAKEN SLIGHTLY ACROSS S TX AND SHIFT SLIGHTLY SOUTH. COULD ALLOW FOR A FEW MORE SHOWERS DEVELOPING FURTHER INLAND AND WEST ALONG THE SEA-BREEZE OVER THE WEEKEND. COLD FRONT WILL ENTER N-CNTRL TX OVER THE WEEKEND AND STALL. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 93 78 95 79 96 / 40 10 10 05 10 VICTORIA 92 76 94 77 96 / 60 20 20 10 20 LAREDO 100 80 104 81 104 / 30 10 05 05 00 ALICE 96 76 99 76 100 / 40 20 10 05 10 ROCKPORT 90 80 92 81 93 / 60 20 20 20 20 COTULLA 97 77 100 77 101 / 30 10 05 05 05 && .CRP WATCHES/WARNINGS/ADVISORIES...SCA TODAY GMZ 230-250-255-270-275. && $$ TMT...SHORT-TERM JR....LONG-TERM tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSONVILLE FL 318 AM EDT TUE AUG 24 2004 .CURRENTLY...A SFC TROUGH EXTENDS ACROSS THE JAX CWA (COUNTY WARNING AREA) AND CONNECTS 2 AREAS OF LOW PRESSURE...ONE OFFSHORE OF SOUTH CAROLINA AND THE OTHER LOW ACROSS WEST-CENTRAL FL. A SFC HIGH PRESSURE WEDGE IS NOSING ITS WAY DOWN THE APPALACHIANS FROM A LARGE ANTICYCLONE IN EASTERN CANADA. WATER VAPOR IMAGERY SHOWS A PLUME OF MOISTURE EXTENDING ACROSS THE NORTHERN GOMEX AND DOWN THE FL PENINSULA...PLACING AN UPPER LEVEL RIDGE CENTER OVER THE WESTERN GOMEX/EASTERN MEXICO. MOSAIC RADAR SHOWS ISOLD CONVECTION OVER OUR GA ZONES IN THE VICINITY OF FRONTAL CONVERGENCE AND ENHANCED BY A SHORT WAVE TROUGH/POSITIVE VORTICITY ADVECTION (PVA) NOTED ON THE RUC80 AT 500 MB. LOW CIGS AND PATCHY DENSE FOG ARE DEVELOPING ACROSS THE FORECAST AREA THIS MORNING DUE TO ABUNDANT GROUND MOISTURE FROM YESTERDAY RAINS AND NEAR CALM WINDS. WILL NEED TO KEEP A CLOSE EYE ON FOG DEVELOPMENT THIS MORNING TO SEE IF COVERAGE INCREASES ENOUGH THAT IT NEEDS TO BE MENTIONED IN THE ZONES. .SHORT TERM...TODAY THRU WED NIGHT...THE SFC FRONT WILL SLOWLY SHIFT FURTHER SOUTH TODAY AS THE APPALACHIAN WEDGE DEEPENS. MODELS INDICATE THE AREA OF LOW PRESSURE ACROSS W-CENTRAL FL WILL SHIFT E-SE TODAY ALONG THE FRONT AND BEGIN TO AMPLIFY OFFSHORE OF THE FL EAST COAST TONIGHT. THE PRESSURE GRADIENT BETWEEN THIS LOW AND THE WEDGE TO OUR NORTH WILL GRADUALLY INCREASE LOW LVL NNE FLOW ACROSS THE FORECAST AREA. MODELS ALSO AGREE THAT A WEAKNESS IN THE UPPER LEVEL FLOW WILL PERSIST WHICH WILL ALLOW SHORT WAVE TROUGHS AND THEIR ASSOCIATED PVA TO ENHANCE LOW LVL CONVERGENCE. HOWEVER...MODELS DIVERGE IN THE MOISTURE FIELD AND POPS IN THE SHORT TERM. THE ETA IS DRIER AND PLACES THE JAX CWA ON THE SUBSIDENCE SIDE OF THE 850 MB LOW THAT DEVELOPS OFFSHORE OF THE FL COAST. CONVERSELY THE GFS DEVELOPS THE LOW OVER THE FORECAST AREA AND LINGERS MOISTURE WITH PWATS 2+ INCHES. DECIDED TO USE A MOS CONSENSUS FOR POPS WHICH GIVES A NW-SE 30-50% POP DISTRIBUTION FOR MAINLY AFTN AND EVENING CONVECTION. NOTE THAT THE GFS 6 HR ENSEMBLE POPS MATCH THIS SCENARIO...WHICH INCREASES FORECAST CONFIDENCE. INCLUDED A SLIGHT CHC OF NOCTURNAL SHOWERS FOR ZONES EAST OF HWY 301 DUE TO MOISTURE FLUX CONVERGENCE ALONG THE COAST...AND WITH COOL AND MOIST NE FLOW...ALSO INCLUDED PATCHY FOG AFTER MIDNIGHT. TEMPS IN THE MID 80S NEAR THE COAST LOOK GOOD...THEN INCREASING WESTWARD TO NEAR 90 ALONG AND WEST OF INTERSTATE 75. MINS IN THE LOW 70S ACROSS EASTERN AREAS...DROPPING TO NEAR 70 WEST OF TRAIL RIDGE. .LONG TERM...THURSDAY THE PATTERN BEGINS TO CHANGE AS THE COASTAL TROUGH MOVES INLAND AS A STRONG SFC RIDGE BUILDS OFFSHORE OF NEW ENGLAND. AS THE RIDGE BUILDS SOUTHWARD AND OFFSHORE OF THE ATLANTIC SEABOARD...FLOW VEERS MORE SOUTHERLY THROUGH THE WEEKEND. POPS NEAR CLIMO WITH TEMPS AT OR SLIGHTLY BELOW CLIMO. && .MARINE...BETWEEN THE COASTAL TROUGH AND THE WEDGE ALONG THE EAST COAST NE WINDS WILL SURGE SOUTHWARD ALONG GA COAST AND PROBABLY AS FAR AS ST AUGUSTINE WEDNESDAY AND WEDNESDAY NIGHT. HAVE BLENDED MODELS BUT WITH A HEAVIER LEANING TOWARD THE ETA SINCE IT HAS A BETTER DEPICTION OF 15 KT SURGE. OTHERWISE WINDS WILL BE RATHER LIGHT OFFSHORE AND IN SOUTHERN WATERS WITH BROAD AREA OF LOW PRESSURE OVER WATERS THAT WILL EXPAND IN AREA BY FRIDAY. && .PRELIMINARY POINT TEMPS/POPS... AMG 89 71 89 69 / 40 20 30 20 SSI 84 73 85 73 / 40 30 40 30 JAX 87 72 87 72 / 40 30 40 30 SGJ 85 74 85 73 / 50 30 40 30 GNV 89 71 88 70 / 50 30 40 20 OCF 88 72 89 71 / 50 30 40 30 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...NONE. GA...NONE. && $$ PUBLIC...ENYEDI MARINE/FIRE WX...MKT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 230 AM MDT TUE AUG 24 2004 .DISCUSSION...THE PRIMARY FORECAST CONCERN WILL BE COVERAGE OF THUNDERSTORMS THIS AFTERNOON/EVENING AND TEMPERATURES THROUGH THE REMAINING SHORT TERM PERIODS. THE LATEST WATER VAPOR/RUC ANALYSIS INDICATING A BROAD TROUGH ACROSS THE WEST WITH WEAK RIDGING OVER THE EAST AND SOUTHWESTERLY FLOW ACROSS THE CENTRAL HIGH PLAINS. NUMEROUS BOUNDARIES SHOWING UP ON KGLD WSR-88D EARLY THIS MORNING AND A FEW BOUNDARIES WILL LIKELY LINGER ACROSS THE AREA THIS AFTERNOON. SOME CONCERN ABOUT AVAILABLE MOISTURE THIS AFTERNOON AS SURFACE DEWPOINTS HAVE FALLEN INTO THE LOW/MID 40S BEHIND BOUNDARY PUSHING ACROSS THE AREA FROM NORTHWEST TO SOUTHEAST. ETA STABILITY PARAMETERS SUPPORT AN ISOLATED MENTION THIS AFTERNOON WITH LOSS OF INHIBITION AFTER 18Z...HOWEVER THE SURFACE MOISTURE FEILD LOOKS MUCH TO MOIST. THE PRIMARY CHANGES FROM THE PREVIOUS FORECAST WAS TO EXPAND THE ISOLATED MENTION SLIGHTLY AND START THUNDER BEGINNING AT 18Z (SLIGHTLY EARLIER FROM PREVIOUS FORECAST). SHEAR IS ONLY MARGINAL WITH A 30 KNOT WEST/SOUTHWESTERLY WIND AT 500MB. ETA 850 TEMPERATURES SUPPORT HIGHS A DEGREE OR TWO COOLER ACROSS MOST AREAS WITH THE EXCEPTION OF HILL CITY WHERE TEMPERATURES WILL BE VERY SIMILAR TO YESTERDAY. KEPT A SLIGHT CHANCE MENTION ACROSS THE NORTHERN/EASTERN ZONES THIS EVENING WITH LITTLE CHANGE FROM PREVIOUS FORECAST. EXPECT SIMILAR TEMPERATURES ON WEDNESDAY AS SURFACE LOW MOVES FURTHER EAST WITH WEAK SOUTHWEST DOWNSLOPE WINDS WARMING TEMPERATURES INTO THE LOWER 90S. NO PLAN TO BUMP POPS UP WITH NO SIGNIFICANT FEATURE TO FOCUS DEEP MOIST CONVECTION. FOR THURSDAY...LEE TROUGH REDEVELOPS IN THE VICINITY OF THE KANSAS COLORADO BORDER AHEAD OF THE NEXT SHORT WAVE MOVING INTO THE GREAT BASIN AREA. THE LATEST GFS KEEPS THE SURFACE BOUNDARY NORTH OF THE AREA AND WE SHOULD SEE A WARM DAY...HOWEVER SHAVED A FEW DEGREES OFF OF PREVIOUS FORECAST WITH THE POSSIBILITY OF WEAK UPSLOPE FLOW ACROSS THE AREA. WILL KEEP 20 POP OVERNIGHT AS BOUNDARY MOVES INTO THE AREA. DAYS 4 THROUGH 7...NO CHANGES. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ MWM/LAJ ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU MAINE 302 AM EDT TUE AUG 24 2004 .SYNOPSIS...HIGH PRESSURE WILL BUILD IN TODAY AND REMAIN OVER THE REGION TONIGHT AND WEDNESDAY. THE HIGH WILL SLOWLY SINK TO THE SOUTH THURSDAY AND FRIDAY AND REMAIN SOUTH OF THE AREA ON SATURDAY. && .SHORT TERM ( TODAY THROUGH THU )...COOL DRY AIR IS PUSHING IN BEHIND THE COLD FRONT THAT MOVED THROUGH ON MONDAY. DRY AIR WILL MAINTAIN BRIGHT SUNSHINE TODAY. HOWEVER...A WEAK VORT MAX SWINGING DOWN FROM THE NORTH MAY RESULT IN A FEW CUMULUS CLOUDS OVER THE FAR NORTH DURING THE MIDDAY AND AFTERNOON. HIGH PRESSURE OVER THE AREA WILL MAINTAIN CLEAR SKIES AND CALM AIR TONIGHT. WITH DRY AIR IN PLACE...TEMPS WILL GET RATHER COOL TONIGHT DROPPING INTO THE LOW 40S IN MANY PLACES. SOME UPPER 30S CAN'T BE RULED OUT IN SOME ISOLATED VALLEYS IN THE FAR NORTHWEST. THIS BRINGS A SLIGHT CONCERN FOR PATCHY FROST...BUT BELIEVE GROUND MAY BE WARM AND WET ENOUGH TO PREVENT TEMPS FROM GETTING TOO COLD. BRIGHT SUNSHINE WEDNESDAY WILL ALLOW TEMPS TO RECOVER INTO THE MID 70S OVER MUCH OF THE AREA. A CLEAR AND SLIGHTLY MILDER NIGHT WILL FOLLOW FOR WEDNESDAY NIGHT. HIGH PRESSURE WILL SLIDE SOUTH OF THE REGION THURSDAY ALLOWING A WEST SOUTHWESTERLY BREEZE TO BRING WARMER AIR INTO THE AREA. TEMPS THURSDAY AFTERNOON MAY APPROACH 80 IN SOME SPOTS. && .LONG TERM ( THU NIGHT THROUGH MON )... LONG RANGE GUIDANCE CONTINUES TO SHOW HIGH PRES RIDGE TO BECOME ESTABLISHED OVER THE NORTHEAST U.S. INTO THE WEEKEND W/SOME LATE SUMMERLIKE WX. PER COORD/COLLABORATION W/GYX...BOOSTED FRI/SAT MAXES UP DUE TO 500 MB HEIGHTS SHOWING 588 DM OR SO. WOULD NOT BE SURPRISED TO SEE UPPER 80S OVER THE WEEKEND ESP W/WINDS TURNING MORE SWLY. LATEST GFS WANTS TO SLIDE FRONTAL BOUNDARY INTO NORTHERN MAINE EARLY SAT WHILE ECMWF/UKMET & GEM KEEP THE BOUNDARY TO THE WEST. PREV PACKAGE HAS SLIGHT CHC POPS IN THERE FOR SAT. DID TRIM POP GRIDS BACK SOME W/STG RIDGE REMAINING OVER THE CWFA. ALSO SCALED BACK SKY GRIDS W/THICKER CLOUD COVER TO REMAIN NORTH & WEST OF THE BORDER. && .AVIATION... LOOKING FOR VFR CONDITIONS THROUGH THE NEXT 24 HOURS. NW BREEZE THIS AFTERNOON AS SECOND VORT MAX (PER RUC/ETA) SLIDES ACROSS THE CWFA. 10-15 KT SHOULD WORK. WINDS WILL QUICKLY DIMINISH THIS EVENING AS HIGH PRES SLIDES E. && .MARINE...WINDS NORTHWEST AROUND 10 KT TODAY WITH A FEW GUSTS TO 15 KT. WINDS BECOMING WEST AROUND 5 KT TONIGHT. SEAS WILL AVERAGE AROUND 2 FT TODAY SUBSIDING TO 1 FOOT TONIGHT. HIGH PRESSURE OVER THE WATERS WILL MAINTAIN LIGHT WINDS THROUGH MIDWEEK. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...NONE. && $$ SHORT TERM/MARINE: BLOOMER LONG TERM: HEWITT AVIATION: CALDERON/HEWITT me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 325 AM CDT TUE AUG 24 2004 .DISCUSSION...FORECAST CHALLENGE REMAINS ON TIMING OF PRECIPITATION CHANCES THRU THE WEEK. CONVECTION ASSOC WITH SHRT WV THAT RUC ANALYSIS PLACES IN S CNTRL IA TRYING TO MAKE HEADWAY FM NE IA/NW IL INTO RELATIVELY STABLE AIR OVER WI. ERLY SFC FLOW IS ADVECTING STRATUS INTO WRN CWA ATTM WHICH WILL LIMIT TEMPS AND LOW LVL INSTABILITY THIS AM. LATEST ETA RUN PICKING UP ON THIS DELAY AND WILL TREND PCPN TIMING ACCORDINGLY. SCT ELEVATED SHRA/STORMS HAVE POPPED UP OVER CNTRL LK MI EARLY THIS MORNING ON STRENGTHENING 850 MB FLOW...WITH MORE WIDESPREAD TSRA THIS AFTERNOON WITH DIFFLUENT UPR FLOW AND CVA FROM SHRT WV AS IT CROSSES WI. PCPN TAPERS TO SCT SHRA THIS EVE AS WV LIFTS NE TWD LK HURON...BUT NEXT WAVE IN SWLY FLOW APPCHS FOR WED...WITH BETTER CHCS AGAIN DURING THE AFTERNOON AS SHRT WAVE STRENGTHENS UNDER STRONG UPR LVL DIVERGENCE FROM RRQ OF UPR LVL JET...WITH POSSIBLE COUPLED JETS ALOFT FCST BY THE ETA. IN THE LONG TERM...ETA/GFS KEEP DEEP WARM MOIST SOUTHWEST FLOW OVER CWA THROUGH AT LEAST SATURDAY AS A COLD FRONT SLOWLY DROPS SEWD THRU THE STATE. TIMING OF UPPER LEVEL TRIGGERS BEYOND WED DIFFICULT AT BEST...SO WILL KEEP PREV CHANCY MENTION OF CONVECTION THROUGH THIS FORECAST PERIOD..THO THERE WILL BE DRY PERIODS. AFTN CLOUDS AND PCPN WILL HOLD TEMPS DOWN FROM EARLIER FCSTS AND HAVE TRIMMED HI/S FOR TODAY AND WED CLOSER TO MOS GUIDANCE. KEPT LO-MID 80S FOR THURSDAY AS MODELS INDICATE BETTER CHC FOR HEATING BEFORE PCPN DEVELOPS. && .MKX...WATCHES/WARNINGS/ADVISORIES...NONE $$ REM wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SHREVEPORT LA 1025 AM CDT TUE AUG 24 2004 .DISCUSSION... SOMEWHAT MORE STABLE THIS MORNING...AS EVIDENT BY LACK OF SIGNIFICANT CONVECTION. THE MOISTURE IS STILL PRESENT WITH NEARLY 2 INCH PRECIP WATER. SHORT TERM RUC SHOWS CAPE WILL BE HIGHEST ACROSS EASTERN HALF OF FCST AREA NEXT COUPLE HOURS...SO SHOULD SEE CONVECTIVE DEVELOPMENT BEGINNING AROUND MIDDAY. BY MID AFTERNOON... CAPES ACROSS EAST TEXAS INCREASE TO NEARLY 3500...WHICH SHOULD BE HIGH ENOUGH FOR SCATTERED CONVECTION. HOWEVER...THIS IS LOWER THAN SOME AREAS EXPERIENCED MONDAY. SO LOOK FOR STORMS TO REMAIN BELOW SEVERE LIMITS. NO CHANGES TO FORECAST AT THIS TIME. && .POINT TEMPS/POPS... SHV 92 75 93 74 / 50 20 30 20 MLU 90 73 92 74 / 50 20 30 20 TXK 92 74 93 73 / 30 20 30 20 TYR 93 76 94 75 / 30 20 30 20 LFK 93 75 94 75 / 50 20 30 20 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...NONE. LA...NONE. OK...NONE. TX...NONE. && $$ 14 la AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 1135 AM EDT TUE AUG 24 2004 .UPDATE... MAIN FCST CONCERNS THIS AFTERNOON ARE PCPN TRENDS ALONG WITH CLOUDS/TEMPS. WV IMAGERY AND RUC ANALYSIS INDICATED SW MID/UPR LVL FLOW INTO UPR MI BTWN RDG FROM THE SE CONUS AND CNTRL LAKES AND BROAD TROF OVER THE WEST. A VERY WEAK SHRTWV AND ASSOCIATED 300K-305K ISENTROPIC LIFT SUPPORTED SOME ISOLD -SHRA OVER CNTRL UPR MI THAT HAVE BEEN SLOWLY WEAKENING AS THEY MOVE TO THE NORTH. 12Z KGRB INDICATED WEAK ELEVATED CAPE OF NEAR 400 J/KG (FROM 900 MB). A MORE SIGNIFICANT UPSTREAM SHRTWV WAS LOCATED OVER IA WHICH WAS BRINGING SHRA INTO SRN WI. A LINE OF SHRA/TSRA OVER ERN MN WERE LIFTING NNE AND SHOULD REMAIN W OF UPR MI THIS AFTERNOON. SFC OBS AND VIS LOOP SHOWED EXTENSIVE LOW CLOUD COVER OVER MOST OF UPR MI WITH SOME BREAKS IN DOWNSLOPE AREAS ALONG THE NORTH AND OVER THE WHERE DRIER ACYC ESE FLOW CONTINUED TO DOMINATE. EXPECT LOW CLOUDS TO PERSIST THIS AFTERNOON GIVEN SRLY 925-850 MB FLOW WITH ABUNDANT MOISTURE TO THE SOUTH. WITH LACK OF SFC HEATING OR MID/UPR LVL SUPPORT...ANY LINGERING -SHRA/SPRINKLES SHOULD DIMINISH EARLY THIS AFTERNOON. GIVEN RADAR/SATELLITE TRENDS...EXPECT NEXT BATCH OF SCT/NMRS SHRA WITH IA/WI SHRTWV TO ARRIVE MAINLY OVER THE SE LATE THIS AFTERNOON AND EXPAND NE DURING THE EVENING. ALTHROUGH 900 MB TEMPS AROUND 17C WOULD SUGGEST A QUICK WARMUP WITH ANY THIN SPOTS IN THE CLOUDS...EXPECT LOW CLOUDS WILL BE THICK ENOUGH TO KEEP TEMPS DOWN AT OR SLIGHTLY BLO GUIDANCE. && .PREV DISCUSSION...FOR LATER PERIODS ISSUED 420 AM EDT TUE AUG 24. BY TONIGHT...UPPER GREAT LAKES BECOMES SITUATED IN SOUTHWEST FLOW ALOFT ALLOWING FOR SERIES OF UPPER LEVEL DISTURBANCES TO MOVE THROUGH THE AREA OVER THE NEXT FEW DAYS. BETTER SHOWER/THUNDERSTORM ACTIVITY WILL BE ON WED AS FRONT PUSHES ACROSS CWA IN THE MORNING AND EARLY AFTERNOON. ETA/GFS/UKMET DEPICT THE CENTRAL AND EASTERN CWA WILL SEE THE GREATEST AMOUNTS OF PRECIP UNDER BETTER UPPER LEVEL FORCING. THERE WILL UNDOUBTEDLY BE SOME CLEARING ON WED AFTERNOON AND EVENING...BUT IT WILL BE SHORT-LIVED AS NEXT SHORTWAVE DEPICTED BY ETA/GFS/UKMET APPROACHES WED NIGHT. SOME CLEARING IS EXPECTED ONCE AGAIN FOR THU...BUT INCREASING ISENTROPIC LIFT WITH APPROACHING WARM FRONT IS PROGGED TO MOVE THROUGH BY THU AFTERNOON AND EVENING...AND STILL HAVE UNCERTAINTY WITH THE EXACT TIMING SO WILL ONLY TREND DOWN POPS AT THIS TIME. MODELS INDICATE A WARM DAY WITH 850MB TEMPS RISING TO AROUND 18C. HIGHS ON THU SHOULD BE CLOSE OR SLIGHTLY ABOVE ETA GUIDANCE OF AROUND 80F FOR MOST OF CWA. STILL SOME UNCERTAINTY WITH TIMING OF UPPER DISTURBANCE FOR THU NIGHT INTO FRI. ETA/GFS HINT AT A MORE PRONOUNCED BUT SLOW MOVING FRONTAL PASSAGE ON FRI...BUT WITH UPPER GREAT LAKES STILL UNDER SOUTHWESTERLY FLOW WILL CONTINUE CHANCES FOR SHOWER AND THUNDERSTORM ACTIVITY. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && JLB(UPDATE) LAROSA(PREV DISCUSSION) mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 258 PM EST TUE AUG 24 2004 .SHORT TERM... TONIGHT AND WEDNESDAY... KLOT RADAR SHOWING LINE OF TS/SHRA OVER NE IL. CURRENT NE MOVEMENT SHOULD GET THIS INTO OUR NW CWA IN THE NEXT HOUR OR TWO. UPPER LEVEL SHORT WAVE CURRENTLY OVER EASTERN IOWA WILL TRACK NE INTO GREAT LAKES REGION TONIGHT AND WILL BE THE MAIN TRIGGER FOR PRECIP DEVELOPMENT. THIS DISTURBANCE WILL INTERACT WITH DECENT INSTABILITY AS LATEST LAPS DATA SHOWING LI AROUND -4 AND CAPES 1200-2000J/KG. BEST FORCING EXPECTED MAINLY OVER OUR NORTHERN CWA AND WILL ADJUST POPS UP TO LIKELY IN THIS AREA FOR TONIGHT. WILL CONTINUE WITH CHANCE POPS THROUGH WEDNESDAY ALTHOUGH SHOULD SEE SOMEWHAT OF A LULL IN ACTIVITY DURING THE MORNING AS FIRST SHORT WAVE EXITS THE REGION AND NEXT ONE EJECTS OUT OF THE MISSOURI VALLEY. DEWPOINTS OVER THE AREA IN U60S TO AROUND 70. THIS ALONG WITH SUBSTANTIAL CLOUD COVER SHOULD KEEP LOWS TONIGHT IN 65 TO 70 RANGE...CLOSE TO MAV GUIDANCE. WITH A FEW BREAKS IN THE CLOUDS TOMORROW SHOULD BE ABLE TO GET BACK CLOSE TO MID 80S FOR HIGHS ALTHOUGH A DEGREE OR TWO BELOW MAV NUMBERS. && .LONG TERM... THURSDAY THROUGH TUESDAY... A WARM AND WET PATTERN IS EXPECTED TO CONTINUE THROUGH AT LEAST THIS COMING SUNDAY ACROSS THE WESTERN LOWER GREAT LAKES REGION. A WEAK FRONTAL BOUNDARY AND A SERIES OF SHORT WAVE TROFS EMBEDDED IN THE SOUTHWEST FLOW MOVING NORTHEAST ACROSS THE WESTERN GREAT LAKES REGION WILL INTERACT WITH A WARM MOIST TROPICAL AIRMASS IN PLACE ACROSS THE AREA PRODUCING BOUTS OF SHOWERS AND THUNDERSTORMS. GEM/ECMWF/GFS/ETA ARE CONVERGING ON A SOLUTION WHICH WILL FINALLY PUSH THE COLD FRONT SOUTH OF THE FORECAST AREA ON SATURDAY. ECMWF/GFS BOTH DEVELOP A SHORT WAVE ALONG THE FRONT AND MOVE IT NORTHEAST THIS SEEMS REASONABLE WITH LONG WAVE TROF STILL REMAKING TO OUR WEST. THIS WILL PROLONG THE PRECIPITATION THROUGH SUNDAY. GFS SURFACE LOW POSITION SEEMS TO BE TOO FAR NORTH...SO THE ECMWF POSITION IS PREFERRED. CURRENT FORECAST HANDLING THE SITUATION WELL SO FEW CHANGES WERE MADE. MADE MINOR ADJUSTMENTS TO PRECIPITATION PROBABILITY GRIDS KEEPING CHANCE TO HIGH CHANCE POPS CURRENTLY FORECAST. VERY HEAVY RAIN IN THUNDERSTORMS THAT DEVELOP WITH PRECIPITABLE WATER IN THE 1.8 INCH RANGE. STRONGER THUNDERSTORMS ARE CAPABLE OF PRODUCING 1 TO 2 INCHES OF RAIN IN A VERY SHORT TIME WHICH CAN LEAD TO SOME QUICK FLOODING. CONTINUED THUNDERSTORM DEVELOPMENT OVER THE SAME AREA WOULD INCREASE THE FLOOD POTENTIAL. HOWEVER WITH THE SCATTERED NATURE OF THE PRECIPITATION...AREAS AND AMOUNTS ARE TOO DIFFICULT TO PIN DOWN AT THIS TIME. MINOR CHANGES WERE MADE TO THE TEMPERATURE FORECAST. 850MB TEMPS OF +18 TO +19 ARE FORECAST FOR BOTH THURSDAY AND FRIDAY WHICH WITH FULL SUN WOULD GIVE HIGH TEMPERATURES IN THE LOWER 90S. HOWEVER WITH DEBRIS CLOUDINESS EXPECTED AND BOUTS OF SHOWERS AND THUNDERSTORMS ONLY RAISED MAXIMUM TEMPS A DEGREE. ALSO MADE MINOR ADJUSTMENT TO SUNDAY AND MONDAY TEMPERATURE FORECASTS...LOWERING HIGHS A DEGREE OR MORE IN LINE WITH COOLER FORECAST 850MB TEMPS. && .AVIATION... LOW CLOUDS AND FOG HAVE MIXED OUT THIS MORNING LEAVING BOTH FWA AND SBN IN VFR CONDITIONS TO BEGIN FCST PERIOD. KIWX RADAR SHOWING A FEW WEAK ECHOES NEAR SBN AND JUST SW OF FWA BUT TREND HAS BEEN FOR THESE SHRA TO WEAKEN SO WILL BEGIN BOTH TAFS AS DRY. WATER VAPOR LOOP AND LATEST RUC DATA SHOWS SHORT WAVE OVER EASTERN IOWA. KLOT RADAR SHOWING LINE OF TS/SHRA DEVELOPING OVER NE IL AHEAD OF THIS DISTURBANCE. EXPECT SCT TS/SHRA TO REDEVELOP AND MOVE INTO BOTH SITES LATER THIS AFTERNOON AS SHORT WAVE MOVES NE TOWARD LAKE MICHIGAN AND WILL COVER WITH TEMPO GROUPS ACCORDINGLY. PLENTY OF LOW LEVEL MOISTURE OVERNIGHT SHOULD ALLOW FOR FOG TO DEVELOP AGAIN BUT FOR NOW WILL LEAVE AS MVFR VSBYS. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. && $$ SHORT TERM/AVIATION...JAL LONG TERM...GLL in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE INDIANAPOLIS IN 200 PM EST TUE AUG 24 2004 .DISCUSSION...FORECAST FOCUS WILL AGAIN BE ON PRECIP CHANCES THROUGH 48 HOURS. WILL USE A BLEND THIS AFTERNOON AS GFS STILL SEEMS TO BE WRANGLING WITH FEEDBACK ISSUES AND THE ETA COULD USE SOME TWEEKING AS WELL. AT 17Z WMFNT APPEARS TO BE SOMEWHERE BETWEEN KIND AND KLAF. SOME TSRA HAVE SPRUNG UP IN ILLINOIS AND ARE ON THEIR WAY TO WESTERN INDIANA. LATEST RUC SHOWS SOME SUBSIDENCE OVER CENTRAL INDIANA AND H7 TEMPS REVEAL A SLIGHT CAP WHICH IS EVIDENT IN THE LACK OF SIGNIFICANT CU DEVELOPMENT. RUC SHOWS SOME WEAKENING OF THE ALREADY WEAK CAP WHICH WILL KEEP THE ILLINOIS STORMS ALIVE THROUGH PORTIONS OF THE CWA. HOWEVER LOSS OF SOLAR INSULATION WILL ARREST FURTHER DEVELOPMENT LATER THIS EVENING. BEST DYNAMICS FOR TONIGHT STAY TO OUR WEST SO WILL GO WITH SCT THIS EVENING THEN DROP TO 20 OVERNIGHT. FOR THE REMAINDER OF THE WEEK HIGH PRESSURE PARKED OVER THE EASTERN SEABOARD WILL KEEP INDIANA IN WARM SOUTHERLY FLOW. VARIOUS IMPULSES WILL PASS THROUGH THE UPPER FLOW BASICALLY KEEPING A CHANCE OF THUNDER ADNAUSEUM SINCE TIMING AND INTENSITY IS DIFFICULT TO PREDICT FARTHER OUT. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && $$ SALLY in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTHERN INDIANA 1240 PM EST TUE AUG 24 2004 .AVIATION... LOW CLOUDS AND FOG HAVE MIXED OUT THIS MORNING LEAVING BOTH FWA AND SBN IN VFR CONDITIONS TO BEGIN FCST PERIOD. KIWX RADAR SHOWING A FEW WEAK ECHOES NEAR SBN AND JUST SW OF FWA BUT TREND HAS BEEN FOR THESE SHRA TO WEAKEN SO WILL BEGIN BOTH TAFS AS DRY. WATER VAPOR LOOP AND LATEST RUC DATA SHOWS SHORT WAVE OVER EASTERN IOWA. KLOT RADAR SHOWING LINE OF TS/SHRA DEVELOPING OVER NE IL AHEAD OF THIS DISTURBANCE. EXPECT SCT TS/SHRA TO REDEVELOP AND MOVE INTO BOTH SITES LATER THIS AFTERNOON AS SHORT WAVE MOVES NE TOWARD LAKE MICHIGAN AND WILL COVER WITH TEMPO GROUPS ACCORDINGLY. PLENTY OF LOW LEVEL MOISTURE OVERNIGHT SHOULD ALLOW FOR FOG TO DEVELOP AGAIN BUT FOR NOW WILL LEAVE AS MVFR VSBYS. && .SHORT TERM... DEEPER MOISTURE CONTINUES TO ADVECT IN WITH PWAT NEAR 1.8 INCHES BY EVENING. NEGATIVE TILT UPPER LEVEL TROF AXIS WITH A COUPLE OF EMBEDDED SHORTWAVES ROTATING THROUGH WITH ONE LOBE FROM SERN IA TO CENTRAL ILLINOIS. STORMS ACROSS CENT/SRN IL INCREASING COVERAGE WITH AID OF NOCTURNAL JET. THIS FEATURE SHOULD DIE AS IT MOVES UP JUST TO OUR WEST LATER THIS MORNING. INCREASED CHANCES OF TSRA AS NEXT SHORTWAVE KICKS OUT LATE EVENING/TONIHGT INTO WRN GREAT LAKES...TEMPTED TO GO LIKELY POPS HOWEVER WITH CONVECTIVE NATURE AND BETTER FORCING TO NORTHWEST WILL COVER FOR NOW WITH SCATTERED WORDING. LACK OF SIGNIFICANT INSTABILITY WILL PRECLUDE SEVERE CHANCES. && .LONG TERM... WEDNESDAY THROUGH MONDAY...STILL LOOKS LIKE WARM...WET AND HUMID CONDITIONS INTO THE WEEKEND...THEN COOLER AND DRIER BY MONDAY. GFS AND ETA GENERALLY TRENDING HIGHER WITH POPS WEDNESDAY AND WEDNESDAY NIGHT...AND APPEAR TO BE ON TRACK AS DEEP MOISTURE BECOMES ESTABLISHED OVER THE AREA BY WEDNESDAY AFTERNOON. GFS CAPES MAY BE OVERDONE...BUT CERTAINLY IMPRESSIVE AND NOTEWORTHY WITH VALUES RUNNING 2800 J/KG TO 5400 J/KG FROM WEDNESDAY AFTERNOON TO EARLY SUNDAY AFTERNOON. FEEL GFS CAPTURES THIS TROPICAL TYPE PATTERN BETTER THEN THE ETA...NGM OR CANADIAN WITH THE MAIN TROF OUT WEST AND SIGNIFICANT SHORTWAVES EJECTING EAST...EACH OF WHICH WOULD BE CAPABLE OF PRODUCING A ROUND OF STORMS. ALTHOUGH TIMING OF INDIVIDUAL SHORTWAVES UNCERTAIN...BOTH ECMWF AND GFS WERE SLOWER AND HAVE COME INTO BETTER AGREEMENT WITH EACH OTHER WITH THE MOVEMENT OF THE LARGER UPPER TROF THIS WEEKEND. THEREFORE...HAVE RAISED POPS WEDNESDAY AND WEDNESDAY NIGHT...AND HAVE KEPT POPS IN THROUGH SUNDAY...EXCEPT FOR THURSDAY NIGHT. WILL LEAVE POPS IN CHANCE CATEGORY UNTIL BETTER RESOLUTION OF TIMING OF NEXT SHORT WAVE. HAVE RAISED LOW TEMPS UP THURSDAY MORNING THROUGH SATURDAY MORNING AS TROPICAL AIRMASS SHOULD BE OVER THE AREA. ETA HAS RAISED MOS HIGHS FOR WEDNESDAY ABOUT 3 DEGREES...BUT STILL SEVERAL DEGREES COOLER THAN THE GFS. VERY WARM 850 MB TEMPS...+18C TO +19C YIELDS HIGHS AROUND 90 IF MIXED DRY ADIABATICALLY...SO WILL KEEP ONGOING FORECAST WITH HIGHS AROUND 85 NEAR GFS MOS HIGH TEMPS...ALTHOUGH ANY PERSISTENT MCS COULD HOLD TEMPS DOWN AT LEAST INTO THE UPPER 70S. LATEST ECMWF AND GFS SUGGEST FROPA LATER THAN EARLIER MODEL RUNS. DID NOT WANT TO JUMP TOO HARD ON THESE LATEST RUNS...AS STILL TOO FAR OUT AND TOO MANY MODEL INCONSISTENCIES TO MAKE BIG CHANGES SUNDAY/MONDAY. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. && $$ in AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE QUAD CITIES IA IL 340 PM CDT TUE AUG 24 2004 .SYNOPSIS... LATEST SFC AND MSAS ANALYSIS INDICATING MAIN COLD FRONT PUSHING ACRS FAR WESTERN MN...DOWN INTO CENTRAL NE...WITH MAIN WARM FRONT LIFTING UP THRU THE NORTHERN CWA ATTM. SECONDARY FRONT ACRS SOUTHERN/ CENTRAL MO ATTM GETTING OUTFLOW-COLD POOL ENHANCED BY MCS(THAT MODELS SAY ISN'T THERE) NOW PUSHING ACRS THE SOUTHEAST QUARTER OF THE STATE. TWO AREAS OF PRESSURE FALLS OF NOTE...ONE ACRS WEST CENTRAL IL AND EXTENDING NORTH INTO SOUTHWEST WI...AND THE OTHER ACRS FAR NORTH CENTRAL KS AND INTO SOUTHEAST NE. WV IMAGERY IS INDICATING LARGE VORT OVERHEAD ACRS IA IS STARTING TO PULL NORTHEAST TOWARD WI. .SHORT TERM...(TONIGHT AND WEDNESDAY) MAIN CONCERN IN THE NEAR TERM IS WHERE NEXT CONVECTIVE SYSTEM DEVELOPS AND PROPAGATES. WITH LARGE VORT EXITING THE AREA FOR A TEMPORARY BREAK FOR THE 1ST HALF OF THE NIGHT(AFTER THIS EVENINGS WIDELY SCATTERED SHOWER THREAT MAINLY ACRS THE NORTHEAST HALF)...THINGS GET UNCERTAIN FOR LATE TONIGHT AND INTO WED MORNING. WITH NOWCAST TOOLS INDICATING CONVECTIVE SYSTEM SPAWN PARAMETERS COMING TOGETHER AT EDGE OF CAP IN CURRENT SFC PRESSURE FALL FIELD OVER NORTH CENTRAL KS INTO FAR SOUTHEAST KS/NORTHWEST MO ...EXPECT DEVELOPMENT HERE LATER THIS EVENING. LATEST ETA AND UKMET SFC-H85 MB THTA-E ADVECTION AND CONVERGENCE ON BEST THTA-E GRADIENT WOULD ALLOW MCS TO PROPAGATE ALONG THE IA/MO BORDER...WITH RESULTANT SYSTEM AFFECTING MAINLY THE SOUTHERN THIRD OF THE DVN CWA LATE TONIGHT AND INTO WED MORNING. PROGGED UPPER DIVERGENCE OFF LEFT EXIT REGION OF 90 KT SOUTHERN PLAINS H25 MB JET MAX AND APPROACHING VORT IN BROAD SOUTHWEST FLOW OUT OF THE PLAINS WILL ADD PLENTY OF UPPER SUPPORT FOR FAR SOUTHERN IOWA TRACK. THIS GOES AGAINST LATEST RUC AND GFS WHICH TARGETS MAIN SYSTEM TRACK FURTHER SOUTH ACRS NORTHERN AND CENTRAL MO...WITH LINGERING BOUNDARY DOWN THERE(MO) PLAYING A LARGE ROLE IN FURTHER SOUTH FOCUS. HAVE DECIDED TO GO WITH 1ST LINE OF THOUGHT MAINLY WITH THE ETA AND UKMET...BUT CONCERNS FOR AIRMASS RECOVERY ACRS NORTHEAST MO BEHIND DEPARTING MCS MAY HAVE TO BE TAKEN INTO ACCOUNT. FCST SOUNDINGS AND EXTENT OF INSTABILITY SUGGEST SOME DAMAGING WINDS AND HEAVY RAIN A THREAT LATE TONIGHT AND WED MORNING. LARGE SCALE WAA ENGULFS THE CWA ON WED...BUT CONVECTIVE DEBRIS AND HOW FAST IT ERODES WILL TEMPER WARM UP POTENTIAL AT THE SFC FOR WED. THERMAL PROFILES BY LATE AFTERNOON SUPPORT 90 DEGREE TEMPS ACRS THE SOUTH...BUT LINGERING CLOUDS/DEBRIS AND HIGH SFC DPTS MAY KEEP TEMPS IN THE MID 80S. ..12.. && .LONG TERM...(WEDNESDAY THROUGH NEXT TUESDAY)... OMINOUS WEATHER EXPECTED NEXT THREE DAYS WITH STRONG ZONAL FLOW CAUSING FAVORABLE SETUP FOR A SERIES OF MODERATE TO STRONG CONVECTIVE SYSTEMS TO ERUPT OVER CENTRAL PLAINS MOVING ACROSS MIDWEST MAINLY AT NIGHT. STRONG WIND SHEAR AND INSTABILITY SUPPORT ORGANIZED CONVECTIVE SYSTEM WITH SEVERE WEATHER IN FORM OF STRONG WINDS WITH ALSO LARGE HAIL. THURSDAY CAN/T RULE OUT IF CONVECTION ERUPTS IN EVENING FOR ISOLATED TORNADO. THIS ALL CAUSED BY A 90-110 KTS JET THAT IMPINGES INTO AREA...MORE COMMON IN MAY VERSUS AUGUST. HEAVY RAIN ALSO A RISK AND HAVE UPDATED HAZARDOUS WEATHER OUTLOOK AS NOT A QUESTION OF IF WE GET SEVERE WEATHER...BUT WHEN AND HOW OFTEN AND INTENSITY. CONSERVATIVE CALCULATIONS OF UPPER 80S AND NEAR 70 DEWPOINTS SUPPORT 70+ KTS WINDS AND HAIL UP TO GOLF BALLS BUT COULD BE HIGHER IF HEATING AND TIMING OCCURS...MAINLY LATE DAY INTO MID EVENING HOURS. NEEDS TO BE CLOSELY MONITORED NEXT FEW DAYS WITH EACH EVENT. TEMPS WILL BE GREATLY IMPACTED BY CONVECTIVE SYSTEMS AND CLOUDS. HAVE GONE BREEZY THURSDAY WITH LOW 90S FOR HIGHS. THEN FRIDAY NEXT FRONT APPEARS MORE PROGRESSIVE WITH STORMS WHICH WILL KEEP NW SECTIONS SLIGHTLY COOLER. WEEKEND TO BE COOLER AND STILL WOULD NOT BE SURPRISED IF CURRENT TEMPS NEED TO BE LOWERED BASED ON LOWER LEVEL THERMAL FIELDS. THEN QUIET AND TRENDED BACK TO NORMAL TEMPS BY TUESDAY...EVIDENCE OF CHANCE POPS DAY 7 BUT LEFT OUT FOR NOW. ..NICHOLS.. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ 12/NICHOLS ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 314 PM CDT TUE AUG 24 2004 .SHORT TERM...TNGT THRU THU NGT TSTM TRENDS RMN PRIMARY FCST CONCERN FOR NEXT SVRL DAYS WITH RELATIVELY LOW CONFIDENCE. MDLS HAVING DIFFICULT TIME RESOLVING MCS ACTIVITY INCLUDING LONG LIVED COMPLEX OVR MO ATTM. HAVE LEANED TWRD ETA SOLUTION WHICH SEEMS TO BE HANDLING CURRENT WX BETTER ATTM AND DOES NOT SUFFER FM FEEDBACK LIKE GFS BUT STILL NOT GREAT. SHRT WV FM DAKOTAS INTO CANADA LIFTING NEWD...WHILE SPEED MAX LIFTING NEWD AHD OF AZ SHRT WV. LATER WL AID UVM ACRS MO RVR VLY TNGT...BUT HAVE SOME CONCERNS ABT LOW LVL SUPPORT. STRONGEST CNVGNC APPRS TO BE ASSOCD WITH MCS FM KS INTO MO. STLT AND MSAS TRENDS INDC DVRGNC ACRS NERN KS/SERN NE ATTM...BUT THERE ARE SOME SIGNS OF INCRG CNVGNC ALG SIOUXLAND CDFNT AND TROF ENTERING IA PER 19Z SFC ANLYS. THERE IS SOME WEAKNESS IN MLCIN NWRN IA...BUT DO NOT FEEL CVNGNC IS STG ENOUGH TO TRIGGER ANYTHING FOR AWHILE BUT WL LEAVE IN CHC POPS. FOR NOCTURNAL DVLPMT...18Z RUC FOCUSES LLJ AND 1000/850MB CNVGNC INTO MO AND IL...AND THAT IS WITH A LACK OF EMPHASIS ON CURRENT MCS. COULD SEE SOME ELEVATED DVLPMT UPSTREAM OVNGT ON WRN EDGE OF MCS OUTFLOW AS SWRN FEATURES EJECT. MEAN WND SUGGESTS THAT WOULD JUST CLIP SRN ZNS...SO HAVE KEPT LIKELY POPS BUT SCALED DOWNWARD SOMEWHAT. IN LATER PDS HAVE JUST BROAD-BRUSHED POPS WITH CONTD LOW CONFIDENCE. FEEL WED AND THU WL SEE REPEATS OF PEAK HEATING DVLPMT FOLLOWED BY OVRNGT MCS...BUT REALLY CANNOT TELL WHERE FAVORED AREAS WL BE ATTM SO NO FLOOD HEADLINES QUITE YET. TEMPS WL BE PROBLEMATIC TOO DEPENDING ON PCPN TRENDS...BUT DID NOT CHG GOING FCST MUCH WHICH STAYED FAIRLY CLOSE TO GUIDANCE COMPROMISE. .LONG TERM...FRI THRU TUE WE HEAD INTO THE WEEKEND WITH MDLS IN FAIR AGREEMENT WITH REGARD TO RCKYS SHRT WV AND ASSOCD SRN PLAINS SFC FEATURES...BUT DISAGREE WITH MAGNITUDE AND SPEED OF ONTARIO SYS. CANADIAN AND EURO MDLS APPR FASTER WITH ECMWF STGR OUTLIER. FARTHER INTO THE WEEKEND TIMING EVEN MORE PROBLEMATIC WITH WHAT BCMS MO VLY SHRT WV. GFS ENSEMBLES AND DGEX WOULD APPR TO SUPPORT SFC SOLUTION IN GFS BALLPARK SO AM LEANING IN THAT DIRECTION. THIS WOULD KEEP POPS GOING FRI NR FROPA...AND HOLDING INTO SAT ASSOCD WITH LARGER SCALE POST FNTL QG FORCING AIDED BY RIGHT ENTRANCE REGION OF DEPARTING JET SEGMENT. RMNDR OF PD INTO TUE LOOKS DRY WITH BROAD RIDGING ACRS CONUS AND WLYS PUSHED NWD TWRD CANADIAN BORDER. TEMPS QUESTIONABLE THRU WEEKEND WITH DECENT SPREAD IN ENSEMBLE MEMBERS. WITH THIS IN MIND HAVE NOT MADE TOO MANY CHGS FOR START OF PD OUTSIDE OF COOLING THINGS BACK CLOSER TO GUIDANCE WHICH MAKES SENSE CONSIDERING XPCD PCPN AND CFP. DID RAISE ABV GUIDANCE TUE HWVR WHICH MAY BE GOOD REBOUND DAY. && .DMX WATCHES/WARNINGS/ADVISORIES...NONE && $$ SMALL ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GOODLAND KS 221 PM MDT TUE AUG 24 2004 .DISCUSSION...FORECAST CONCERNS WILL BE CHANCE OF PRECIPITATION TONIGHT...HOW WARM IT GETS NEXT TWO DAYS...AND THE BEGINNING OF THE 4 TO 7 DAY PERIOD. SATELLITE SHOWING ACTIVE AND PROGRESSIVE FLOW FROM THE PACIFIC INTO NORTH AMERICA. DEFINITELY IS THE MOST ZONAL IT HAS BEEN IN A WHILE. UNORGANIZED/LINGERING TROUGHINESS OVER THE WESTERN PORTION OF THE COUNTRY WITH NUMEROUS SHORTWAVES IN IT. AT JET LEVEL...MODELS DID WELL OVER THE COUNTRY BUT WERE LOW ON THE SPEEDS BEHIND WESTERN UPPER TROUGH. AT MID LEVELS...MODELS LOOK TO BE UNDERDOING STRENGTH OF SYSTEM OVER ARIZONA. RUC HAS THE BEST HANDLE WITH THE GFS SECOND BEST. WITH THE EXCEPTION OF THE RUC... MODELS ARE TOO FAST. ALSO MODELS NOT LOW ENOUGH ON HEIGHTS AND SATELLITE INDICATING A DECENT SPIN TO THE SYSTEM. AT LOW LEVELS...RUC/ETA LOOK TO BE DOING BETTER AT LOW LEVELS WITH AN EDGE TO THE RUC ON WIND/MOISTURE FIELD. ETA DOING A LITTLE BETTER ON TEMPERATURES. WILL BE BLENDING RUC/ETA/GFS FOR THE EARLY PART OF THE FORECAST THEN GO MORE ETA AT THE SURFACE AND GFS ALOFT FOR THE REMAINDER OF THE FORECAST. FOR TONIGHT/WEDNESDAY...INTERESTING FORECAST FOR TONIGHT. AIR MASS HAS BEEN STABILIZED SOMEWHAT BY OVERNIGHT ACTIVITY. THAT AND CIRRUS SHIELD HAVE SLOWED DOWN HEATING AND DESTABILIZATION. BOTH THE ETA AND GFS SHOW A COUPLED JET STRUCTURE OVERNIGHT WITH THE ETA A LITTLE MORE FAVORABLE. ALSO HAVE INCOMING SHORTWAVE FROM THE SOUTHWEST. THAT S YSTEM ALREADY PRODUCING LIGHTING OVER EASTERN ARIZONA. RUC/GFS TAKE BRUNT OF SHORTWAVE ALONG SOUTHERN PORTION OF THE FORECAST AREA. THEN A ANOTHER SHORTWAVE FOLLOWS CLOSE BEHIND LATE IN THE NIGHT. LOW BOUNDARY MOVES NORTH AND EAST DURING THE NIGHT WITH MOISTURE POOLING TO THE NORTH. THE NORTHEAST HALF OF THE FORECAST AREA LOOKS TO HAVE THE BEST SHOT AND WILL GO 30 TO 40 PERCENT IN THIS AREA WITH 20 PERCENTS ELSEWHERE. WILL HAVE SOME CLOUDS DURING THE DAY WITH AN UNFAVORABLE SURFACE WIND FIELD. TEND TO THINK WILL BE NEAR TO SLIGHTLY WARMER THAN THE MAV AND COOLER THAN THE MET...AND WILL FOLLOW THAT. FOR WEDNESDAY NIGHT/THURSDAY...ABOVE MENTIONED SHORTWAVE MOVES OVER EARLY IN THE DAY. MAY BE SOME LINGER PRECIPITATION IN THE NORTH EARLY. AFTER THAT HAVE LITTLE TO NO DYNAMICS. MAIN JET TO REMAIN NORTH OF AREA. HAVE SOME SORT OF BOUNDARY MOVE THROUGH IN THE MORNING WITH A SHIFT TO THE EAST. ETA STILL RAISE TEMPERATURES SOME EVEN AFTER THE BOUNDARY PASSAGE. HAVE WEST TO SOUTHWEST FLOW ALOFT WHICH TO ME WOULD MEAN THAT THIS BOUNDARY WILL NOT HAVE MUCH OF A PUNCH INITIALLY. WILL AGAIN DO A COMPROMISE. FOR THURSDAY NIGHT/FRIDAY...NEGATIVELY TILTED 700 TO 500 MB SHORTWAVE IN SOUTHWEST FLOW ALOFT MOVES IN DURING THE NIGHT. WILL KEEP/HAVE CHANCE POPS. THEN THINGS SHOULD QUIET DOWN FOR MOST OF THE DAY UNTIL NEXT SHORTWAVE STARTS GETTING CLOSE LATE IN THE DAY. STIFF EAST TO NORTHEAST WINDS DURING THE DAY. WILL TRY TO GO AS FAR BELOW GUIDANCE AS POSSIBLE CONSIDERING WHAT OFFICES AROUND ME DO. FOR THE 4 TO 7 DAY PERIOD...FRONT REMAINS TO SOUTH AND KEEPS US IN POST FRONTAL UPSLOPE THROUGH SAT/SATURDAY NIGHT. SEVERAL SHORTWAVES TO MOVE THROUGH DURING THIS TIME ACCORDING TO ALL MODELS. BEST CHANCE OF PRECIPITATION WILL BE FRIDAY NIGHT INTO SATURDAY. PLAN ON GOING 50 TO 60 PERCENT FRIDAY NIGHT AND 30-40 PERCENT SATURDAY WITH A LINGERING 20 PERCENT SATURDAY NIGHT. LAST 2 TO 3 RUNS HAVE SHOWN MAX TEMPERATURES GETTING COOLER IN THE FRIDAY TO SUNDAY TIME FRAME... ESPECIALLY ON SATURDAY. MEX MOS IS CLOSE TO THE ENSEMBLE MEAN MOS AND PLAN ON GOING NEAR TO. DRIER AND WARMER WEATHER LOOKS TO BE IN PLACE FROM SUNDAY INTO TUESDAY AND TEND TO STAY CLOSE TO MAYBE SLIGHTLY ABOVE GUIDANCE. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. NE...NONE. CO...NONE. && $$ BULLER ks AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 355 PM EDT TUE AUG 24 2004 .DISCUSSION... WV IMAGERY SHOWS A LONGWAVE TROUGH OVER THE NORTHERN ROCKIES...AND RIDGE ALONG THE EASTERN GREAT LAKES...AND THUS SWLY FLOW OVER UPPER MICHIGAN. AN APPROACHING SHORTWAVE IS MOVING INTO SOUTHERN WI... PRODUCING SHOWERS IN WI ASSOCIATED WITH AN AREA OF THETA-E ADVECTION SHOWN WELL BY THE RUC...AND NORTH OF A WARM FRONT WHICH IS LIFTING INTO SOUTHERN WI. SO FAR THE U P HAS REMAINED MOSTLY DRY TODAY. MAIN FORECAST CONCERNS ARE PCPN CHANCES FROM TONIGHT THRU THE REMAINDER OF THE WEEK. AS WAVE AND ASSOCIATED FRONT LIFT THROUGH THE AREA TONIGHT WOULD EXPECT SHOWERS TO SPREAD NORTHWARD...AS RADAR TRENDS WOULD SUGGEST. ELEVATED INSTABILITY IS SOMEWHAT LACKING (SHOWALTERS ONLY AROUND ZERO)...BUT THERE MAY BE ENOUGH FOR SOME EMBEDDED LTG...SO WILL KEEP WITH MENTION OF ISOLD TS. RUC/ETA AGREE IN ENDING THE BETTER DYNAMICS (IE Q-VECTOR DIVERGENCE) OVERNIGHT FROM W TO E...SO WILL TAPER POPS OVERNIGHT ACCORDINGLY...AND END PCPN IN THE EAST EARLY WED. IT THEN APPEARS WE WILL HAVE A DRY PERIOD AT LEAST FOR THE WED MORNING HOURS WITH WEAK CONVERGENCE ALOFT AND ANTICYCLONIC BLYR FLOW. NEXT SHORTWAVE APPROACHES LATE IN THE DAY...BUT SOME SUN AND LAKE BREEZE HELP (950MB WINDS OF 5-15KT)...WITH A SFC BOUNDARY IN THE VCNTY...MAY TRIGGER SOME DIURNAL TS DURING THE AFTN...AHEAD OF THE NEXT WAVE. ETA CAPES SHOW OVER 1000 J/KG OF CAPE AND NO CIN IF TEMPS RISE TO AROUND 80F. THIS SHOULDN'T BE A PROBLEM WITH AT LEAST A FEW SUNNY BREAKS AS H8 TEMPS WILL BE IN THE MID TEENS. NEXT SHORTWAVE COMES THROUGH WED NIGHT...AND WITH PLENTY OF MOISTURE AROUND (PWATS GREATER THAN 1.5 IN)...CHANCES OF ANOTHER ROUND OF PCPN ARE VERY GOOD. SHOWALTERS AT OR A LITTLE BELOW ZERO SUPPORT TS...THOUGH GREATEST INSTABILITY WILL REMAIN TO OUR SW. THERE MAY BE A BREAK AGAIN EARLY THU AS THIS WAVE DEPARTS...THEN A STRONGER TROF MOVES THRU THE NORTHERN PLAINS THU AFTN/EVNG. MODELS SHOW A PERIOD OF STRONG UPPER DIVERGENCE AS A 100+ KT H3 JET APPROACHES ACROSS THE CENTRAL PLAINS. CONSIDERING HIGH SHEAR AND CAPE VALUES (2500-3500 J/KG PER THE ETA) AND A COOL FROPA...THU AFTN/EVNG WILL OFFER THE GREATEST THREAT OF SEVERE WX FOR US. WET BULB ZERO HEIGHTS OF 10-11KFT AND 75+ KT H5 SPEED MAX SUGGEST A POSSIBILITY OF BOTH SVR WINDS AND HAIL. OVERALL...WILL SUSTAIN LIKELY POPS ACROSS THE CWA WED NIGHT AND THU...AND WILL UPDATE THE HWO FOR A SVR POTENTIAL THU AFTN AND EVENING. IT NOW APPEARS (BY ALL MODEL SOLUTIONS)...THAT SFC FRONT WILL PUSH THROUGH AND MOVE EAST OF THE U P BY FRIDAY MORNING. AS THE MAIN UPPER TROUGH PUSHES ACROSS THE UPPER LAKES...A PERIOD OF CONFLUENCE ALOFT WILL SET UP FOR FRI...WITH AN UNPHASED TROUGH LAGGING IN THE GREAT BASIN. CONSIDERING DRYING AND SFC RIDGING EXPECTED...WILL REMOVE ANY MENTION OF PCPN FOR FRI. THOUGH WE WILL BE IN CAA...DRY WESTERLY FLOW COUPLED WITH H8 TEMPS LINGERING IN THE LOWER TEENS SHOULD RESULT IN ANOTHER WARM DAY WITH HIGHS IN THE 70S TO LOWER 80S. OF COURSE IT WILL NOT FEEL NEARLY AS HUMID AS WED/THU. IN THE EXTENDED (SAT-TUE)...THOUGH NO MODELS NOW SUPPORT IT...WILL SUSTAIN LOW CHANCE SHOWERS FOR SAT AS ROCKIES TROUGH WILL COME OUT INTO THE PLAINS AND INTERACT WITH THE FRONT TO OUR EAST. PREVIOUS MODEL RUNS HAD THIS SFC BOUNDARY JUST TO OUR EAST...SO WILL NOT DISCOUNT THIS IDEA ENTIRELY YET. SUN LOOKS DRY AS THIS WAVE PASSES. THEN...ANOTHER CLIPPER WILL MOVE ACROSS THE UPPER LAKES MON. GIVEN THE NICE H3 PV MAX WITH THIS FEATURE...AT A DIURNALLY FAVORABLE TIME...WILL GO AHEAD AND MENTION TS FOR MON. TUE SHOULD BE DRY/ COOLER WITH RIDGING SETTING UP. AGAIN...CONFIDENCE IN THE EXTENDED IS LOW AT THIS POINT AS WE WILL HAVE TO SEE WHERE THE SFC FRONT ENDS UP THIS WEEKEND. && .MQT WATCHES/WARNINGS/ADVISORIES...NONE. && JKL mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ST LOUIS MO 355 PM CDT TUE AUG 24 2004 .DISCUSSION... ACTIVE WX PTRN SHUD CONT ACR AREA FOR THE NXT FEW DAYS...AS UNSEASONABLY STG WESTERLIES INTERACT WITH TYPICAL UNSTBL AMS OF SUMMER. PINNING DOWN THE SPECIFIC CNVTV TRENDS IS THE MAIN FCST PROBLEM FOR THIS PKG. FOR TNGT...BLV ONGOING MCS SHUD CONT TO TRACK ESE THIS EVE...GRDLY ENDING PCPN OVR S AREAS OF CWA. AFT A FEW QUIET HRS...EXPECT RPD INTENSIFICATION OF ELEVATED CNVTN AND THE GENESIS OF THE NXT MCS... IN THE 06-09Z TIME FRAME SOMEWHERE OVR EAX CWA. THIS CLUSTER SHUD THEN TRACK E-SE LT TNGT AND INTO WED MRNG. WHILE MDLS ARE ALL FOCUSING ON N MO AS AREA WITH MAX QPF...THEY DO DIFFER ON TIMING...WITH ONSET OF STG CNVTN DLAD UNTIL WED MRNG BY THE GFS SOLN. MASS FIELDS OF BOTH ETA AND RUC SUPPORT PREVIOUSLY MENTIONED NOCTURNAL PCPN TRENDS...WITH 85H LO LVL JET RAMPING UP TO 35KTS AS ERY AS 06Z...AS DOES LONG TERM CLIMATOLOGICAL TRENDS OF MCS DVLPMT. DUE TO XTRM AMT OF INSTABILITY THAT WL BE FUELING ELEVATED CNVTN...AS WELL AS PWAT FCST OF WELL OVR 2 INCHES...WL BE ISSUING AN FFA FOR W AREAS FOR LT TNGT AND WED...MNLY ALG-W OF A VIH-UIN LN. IF MDLS NAIL THE AXIS OF HVIEST PCPN MID MO MAY NOT HV MUCH AS MUCH OF A THRT...BUT THIS AREA IS ALSO THE MOST SATURATED SO LESSER RAINS HERE WILL STILL MEAN A FLASH FLOOD THRT. AM ALSO A BIT CONCERNED THAT ONGOING ACTIVITY MAY BE PUSHING THERMAL BNDRY A BIT FURTHER S THAN FCST BY MDLS...WHICH IS WHAT OCRD LAST NGT AND THIS MRNG. THIS WULD SHIFT THE HVIEST RAIN INTO THE MOST SATURATED AREA AND CAUSE SERIOUS FLOODING PROBLEMS. BLV TNGTS MCS SHUD FOLLOW TRENDS OF THE PAST FEW DAYS...AND TRACK ESE DURING THE DAY ON WED...WITH ANOTHER ROUND OF NOCTURNAL DVLPMT IN THE OFFING WED NGT. NWD SHIFT OF DYNAMICS AND FORCING SHUD MEAN A RELATIVE PCPN MINIMA OVR AREA FOR THU...BUT PCPN CHCS SHUD GRDLY RETURN THU NGT...FRI...AND FRI NGT AS CDFNT OOZES INTO REGION. IT NOW APRS THIS THRT WL CONT INTO MUCH OF THE WEEKEND. RAIN COOLED AMS SHUD KP MANY AREA AOB GUID THRU WED NGT...BUT JUDGING BY TEMPS IN THE WRM SECTOR TDA TEMPS WL EASILY CLIMB TO MOS GUID ON BOTH THU AND FRI IF CNVTN IS SUPPRESSED. && .LSX WATCHES/WARNINGS/ADVISORIES... MO...FLASH FLOOD WATCH LT TNGT-WED ALG-E OF VIH-UIN LN. IL...FLASH FLOOD WATCH LT TNGT-WED UIN AREA. && $$ TRUETT mo AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI 325 PM CDT TUE AUG 24 2004 .DISCUSSION...FORECAST FOCUS REMAINS ON TIMING OF PRECIPITATION CHANCES AND AREAL COVERAGE THROUGH WEEK. IN THE SHORT TERM...CURRENT REGIONAL 88D DEPICTION SHOWS CONVECTION MORE OF A SCATTERED NATURE THAN INDICATED BY ETA/GFS/NGM PRECIPITATION PROGS. FEEL THAT PART OF THE REASON IS DUE TO THUNDERSTORM COMPLEX OVER SOUTHERN MISSOURI AND SOUTHERN ILLINOIS. AIRMASS CONTINUES TO DESTABILIZE AS SATELLITE LOOP SHOWS HOLES OPENING UP IN CLOUD COVER. IN ADDITION GOOD CIRCULATION OF 19 UNIT VORTICITY CENTER IN UPPER LEVEL SHORT WAVE TO PROVIDE ENOUGH LIFT TO GENERATE MORE CONVECTION INTO THE EVENING AND NIGHTTIME HOURS ACROSS CWA. BUT HAVE DECIDED TO GO WITH SCATTERED THUNDERSTORMS FOR EARLY TONIGHT IN FORECAST AS EFFECT OF MAXIMUM DAYTIME HEATING NOT HELPING ENOUGH TO PRODUCE WIDESPREAD ACTIVITY. PROGS...WITH EXCEPTION OF RUC TAKE BULK OF CONVECTION OUT OF CWA AFTER 06Z. RUC GENERATES ANOTHER COMPLEX OVER NORTHERN ILLINOIS AROUND 06Z. SO WILL KEEP SCATTERED CONVECTION MENTIONED FOR LATE TONIGHT. WILL ALSO PUT PATCHY FOG FOR LATE TONIGHT AS MOIST AIRMASS FROM RAIN WOULD PRODUCE FOG IF THERE ARE HOLES IN CLOUD COVER. IN THE LONG TERM...ALTHOUGH GFS CONTINUES TO OVERDO WEDNESDAY SYSTEM AND ASSOCIATED PRECIPITATION...POSITION AND TIMING OF NEXT WAVE IN SOUTHWEST FLOW IN CLOSE AGREEMENT WITH ETA/NGM. BEST CHANCES FOR RAIN REMAIN IN THE AFTERNOON AND EVENING HOURS. ON THURSDAY AIRMASS OVER CWA BECOMES WARM AND VERY UNSTABLE...BUT PROGS DOWNPLAY RAIN CHANCES. ONLY ETA SHOWS ANY HINT OF A MID LEVEL CAP FORMING DURING THE AFTERNOON HOURS. WILL KEEP DECENT RAIN CHANCES GOING BUT AGAIN EMPHASIZE AFTERNOON AND EVENING FOR BEST RAIN CHANCES. IN THE LONG LONG TERM...12Z GFS SUGGEST SUBTLE PATTERN CHANGE FOR THE WEEKEND. THE SOLUTION WOULD AFFECT CURRENT PRECIPITATION FORECAST. FOR NOW HAVE DECIDED TO WAIT FOR FURTHER PROG RUNS BEFORE CHANGING CURRENT FORECAST. && .MKX...WATCHES/WARNINGS/ADVISORIES...NONE $$ ZAJDEL wi