SOUTH CENTRAL AND SOUTHEAST COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PUEBLO COLORADO 215 PM MDT SUN AUG 25 2002 FORECAST CHALLENGE WILL BE COVERAGE OF THUNDERSTORMS ACROSS EAST PLAINS NEXT COUPLE DAYS...AND ONSET OF PCPN CHANCES IN THE WESTERN MTN AREAS... LOW CLOUDS ACROSS SOUTHEAST PLAINS HAVE SLOWLY DISSIPATED. A BOUNDARY HAS PUSHED INTO EASTERN KIOWA AND PROWERS COUNTY WITH MARKED CLEARING EAST OF THIS LINE...AND SHALLOW CU DEVELOPING ACROSS CROWLEY/OTERO/BENT/BACA COUNTIES. WV/RUC ANALYSIS SHOWING A WEAK SHORTWAVE FEATURE ACROSS UT...WITH A STRING OF WEAKER VORTS EXTENDING BACK ACROSS CENTRAL CA. ALL THESE FEATURES WILL BE MOVING ACROSS AREA IN WESTERLY FLOW NEXT 24-48 HRS. MAIN CHALLENGE THIS EVENING WILL BE CONVECTIVE POTENTIAL ACROSS SE PLAINS. 12Z MESO-ETA STILL HOLDING ON TO IDEA OF LOWER TROP MIXING OUT WITH DRY LINE SHIFTING EASTWARD ACROSS THE SE BORDER COUNTIES BY THIS EVENING. PLENTY OF 0-6KM SHEAR WITH 50KTS ACROSS THE SOUTHEAST PLAINS TO SUPPORT ISOLATED SVR CONVECTION. BUT...ONCE AGAIN...WE HAVE TO OVERCOME THE CAP AROUND 600 MB. PREFER THE RUC SOLUTION OF KEEPING LOW LEVEL MOISTURE FURTHER WEST TO AROUND PUB. HOWEVER CAP IS ALSO STRONGEST FOR POINTS FURTHER WEST AND SOUTH. DYNAMICS WILL BE WEAK AGAIN TODAY WITH WHATEVER LIFT MAY BE ASSOCIATED WITH SHORTWAVE MOVING IN FROM UT. WILL MONITOR LATEST SAT/RADAR TRENDS...BUT IF I DO HAVE TO INCREASE POP AREAL COVERAGE ACROSS THE SOUTHEAST PLAINS/ADJACENT MTNS...WOULD PROBABLY BE ISOLATED AT BEST. MAIN UPPER DYNAMICS ASSOC WITH UPPER JET APPEAR TOO FAR NORTH TODAY TO BE MUCH OF A PLAYER FOR OUR AREA. MCS WILL LIKELY DEVELOP ACROSS NE CO/SW NE OVERNIGHT AS LOW LEVEL JET INCREASES ACROSS SOUTHEAST PLAINS. STRATUS MAY REDEVELOP ACROSS SE PLAINS AGAIN TONIGHT KEEP MIN TEMPS WARM. ACROSS MTNS AND WEST... VERY LOW DEW POINTS WILL REMAIN OVER THE AREA...ALLOWING EFFICIENT RADIATIONAL COOLING. KALS BRIEFLY HIT 30 DEGREES THIS MORNING. THINK THAT TEMPS COULD DO SOMETHING SIMILAR TONIGHT ALTHOUGH IT MAY JUST ABOVE FREEZING. DUE TO BREVITY (30 MIN OR LESS OF NEAR FREEZING TEMPS) FREEZE ADVISORIES DO NOT SEEM WARRANTED. ANOTHER TROUGH ENTERS THE WESTERN US ON MONDAY WITH CONTINUED WRLY FLOW OVER THE AREA. AS TROUGH APPROACHES...LOW LVL WINDS ENHANCE FROM THE SE ACROSS PLAINS IN RESPONSE TO FALLING PRESSURES TO THE SOUTH. SO LOW LEVEL MOISTURE IN UPSLOPE WILL LINGER AGAIN THROUGH THE AFTERNOON. 12Z MESO ETA SOUNDINGS SHOW LITTLE/NO CAP WITH CONVECTIVE TEMPS IN THE UPPER 80S/LOWER 90S. COMBINED WITH A BIT BETTER DYNAMICS AND UPPER JET APPROACHING AREA LATE IN THE AFTN...SEEMS BETTER POTENTIAL FOR PCPN ACROSS EAST PLAINS. MAY BUMP UP POPS ALONG THE BORDER AREAS...AND MAY PULL WRN EDGE BACK TOWARDS THE I-25 CORRIDOR. STILL SOME UNCERTAINTY IN POSITION OF DRY LINE THOUGH. AGAIN WITH SUFFICIENT SHEAR...AND CAPES AROUND 1500-2000 J/KG...THERE WILL BE A THREAT FOR SVR. OUT WEST...CONTINUED DRY WITH MOISTURE CONFINED TO AROUND 400 MB AND ABOVE. STRATUS MAY DEVELOP ONCE AGAIN FOR MON NIGHT ACROSS SE PLAINS. UPPER TROUGH DEVELOPS ACROSS WRN US WITH UPPER JET NOW ACROSS NRN AZ/NM IN SPLIT FLOW FOR TUES. ANOTHER SHORTWAVE PASSES JUST TO THE NORTH OF THE FORECAST AREA...AND RATHER EARLY IN THE DAY. BUT WITH RESIDUAL LOW LEVEL MOISTURE ACROSS THE SOUTHEAST PLAINS...COMBINED WITH CLOSE PROXIMITY TO LF QUAD OF UPPER JET...WILL KEEP SLIGHT CHANCE POPS EVERYWHERE. ONCE AGAIN...PLAYING WITH THE CAP ISSUE THE FARTHER EAST ON THE PLAINS ONE GOES. IF CONVECTION CAN BE REALIZED... THEN POTENTIAL FOR SVR EXISTS ONCE MORE. PROBABLY LIKELY TO BREAK OUT SOME CONVECTION ALONG THE EAST SLOPES OF THE SOUTHEAST MOUNTAINS WHERE COMBINATION OF UPSLOPE/SUFF HEATING CAN OCCUR...WHICH WILL MOVE OFF INTO THE PLAINS THROUGH LATE AFTN. ACROSS THE WESTERN MTN AREAS...SOME INCREASE IN MID AND HIGH LEVEL MOISTURE WITH APPROACHING SHORTWAVE...SO WILL KEEP ISOLATED TYPE POPS GOING...ALTHOUGH MSTR WILL BE HIGH BASED WITH WIND THE PRIMARY THREAT. COULD BE SOME SORT OF MCS DEVELOPMENT ACROSS ERN CO/WRN KS OVERNIGHT. WILL BUMP UP POPS ACROSS THIS AREA FOR LATE TUES NIGHT. THROUGH THE REMAINDER OF EXTENDED...UPPER TROUGH HANGS OUT ACROSS THE WRN US WITH A CHUNK OF ENERGY SHEARING OFF ACROSS NRN US ROCKIES ON THURS. LITTLE CHANGES IN SENSIBLE WEATHER ACROSS SOUTHEAST COLORADO. ACROSS THE WEST GFS BRINGS BEST INFLUX OF MOISTURE AROUND THE FRI/SAT TIME FRAME. ACROSS THE EAST PLAINS...A WEAK FRONT MAY MOVE IN ON SAT TO HELP ENHANCE CONVECTION. BOTTOM LINE...SLIGHT CHANCE POPS THROUGH EXTENDED STILL LOOK ON TARGET FOR NOW. ALTHOUGH FOR WED/THURS TIME FRAME...TSTORMS IN WRN MTN AREAS WILL STILL BE HIGH BASED/LITTLE-TO-NO RAIN PRODUCERS. .PUB...NONE. KT co AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TALLAHASSEE FL 850 PM EDT SUN AUG 25 2002 IN SPITE OF 70+ VILS ESTIMTATED OVER TALLAHASSEE BY LOCAL RADARS EARLIER THIS EVENING...WE DID NOT OBSERVE...OR RECEIVE REPORTS OF... ANY SEVERE WEATHER. HIGH LFCS AND WET BULB ZERO HEIGHTS MAY HAVE RESULTED IN OVERLY AGGRESSIVE RADAR ESTIMATES. WE UPDATED THE ZONES TO REFLECT CURRENT PRECIPITATION TRENDS. WE ARE SEEING SOME THUNDERSTORM RE-DEVELOPMENT OVER THE EASTERN FL BIG BEND IN RESPONSE TO A SURFACE OUTFLOW BOUNDARY FROM THE LARGE MCS W OF OUR FORECAST AREA...AND ALSO FROM A WEAK SHORTWAVE TROUGH ALOFT THAT HAS BEEN ADVERTISED BY RUC. STILL EXPECT CONVECTION TO BE MOSTLY OVER BY MIDNIGHT...AND HAVE WORDED ZONES ACCORDINGLY. AT THIS TIME...NO CHANGES ARE PLANNED FOR THE COASTAL WATERS FORECAST. .TLH... .AL...NONE. .GA...NONE. .FL...NONE. TJT fl AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 219 PM EDT SUN AUG 25 2002 HATE TO FLIP FLOP ON A FORECAST...BUT BASED ON RADAR TRENDS WILL NEED TO REINTSTATE A POSSIBILITY OF SHOWERS/STORMS INTO ALL OF THE NORTHERN COUNTIES. SHOULD NOT HAVE CHANGED PRECIP PORTION OF ORIGINAL MORNING PACKAGE. .JKL...NONE. HAL --------------------------------------------------------------------- PREVIOUS DISCUSSIONS FOLLOW --------------------------------------------------------------------- 1105 AM EDT SUN AUG 25 2002 MID/HIGH LEVEL CLOUDS ARE MORE PROMINENT THAN FORECAST IN THE NORTH...AND LATEST INFORMATION SUGGESTS THAT WILL NOT CHANGE. HOWEVER...DRIER LOW LEVEL AIR AND SLIGHTLY WARMER TEMPS SEVERAL THOUSAND FEET UP ON THE MESOETA ALSO MEAN IT WILL BE DIFFICULT FOR CONVECTION TO FIRE IN THE FAR NORTH. MEANWHILE...IN THE SOUTHERN PART OF THE AREA...EXTENSIVE CLOUDS WILL HINDER TEMPS FROM WARMING AS MUCH AS WAS FORECAST. WILL SPLIT OFF A FAR NORTHERN GROUP FROM MONTGOMERY COUNTY EAST TO MARTIN COUNTY AND REMOVE AFTERNOON PRECIP. WILL GO WITH 1ST PERIOD CONSIDERABLE CLOUDS IN ALL BUT THE SOUTHERN PART OF THE AREA...WHERE MOSTLY CLOUDY WORDING WILL BE LEFT AS IS. IN THE SOUTH...WILL DROP 1ST PERIOD TEMPS SLIGHTLY TO 80 TO 85. HAL --------------------------------------------------------------------- 300 AM EDT SUN AUG 25 2002 NUMEROUS CHALLENGES THRU THE FCST PACKAGE...MAINLY EVOLVING AROUND PCPN CHANCES AND SKY COVER AND TO A LESSER EXTENT HIGH TEMPERATURES. SFC CHART EARLY THIS MORNING SHOWING WEAK COLD FRONT/BNDRY SLIDING THRU THE CWA WITH A WEAK LOW NEAR HTS AND BTWN BWG AND PAH. HIGH PRESSURE OVER N IN AND W IA. SAT PICS SHOWING COPIOUS CI BLOW OFF ACROSS THE ENTIRE AREA AND SFC OBS ALSO SHOWING SOME MID LVL CLOUDINESS. RADAR SHOWED SOME ISOLATED RENEGADE SHOWERS OVER THE CWA EARLIER...SCT SHOWERS STILL OVER WV MOVING SE THIS MORNING AND INCREASING SHRA/TSRA OVER TN MOVING E-NE. SKY FCST TUFF THE NEXT FEW DAYS AS CONDITIONS WILL PROBABLY RANGE FROM PC TO MCLOUDY AT TIMES. JUST HOW DENSE WILL THE CI BE AND HOW MUCH WILL IT HOLD DOWN INSOLATION IS A TUFF CALL. ETA/M-ETA MODEL THIS MORNING IS WAY TOO WET RIGHT OFF THE BAT BUT THEY SEEM TO REGROUP SOMEWHAT AS THE DAY WEARS ON. THINKING BEST CHC OF POPS TODAY ALONG THE SOUTHERN ZONES AND NEAR THE TN BORDER...LOWER POPS (SLGHT CHC) ACROSS THE NORTH. HIGHS IN THE LOWER 80S NORTH AND MID 80S SOUTH. WILL CONTINUE WITH A SLIGHT CHC NORTH AND 30% SOUTH FOR TONIGHT. MODELS ALL STILL ADVERTISING SOMEWHAT UNUSUAL 5H CUT OFF LOW TO SET UP FOR THE NEXT SEVERAL DAYS OVER W-CNTRL TN/KY AND THEN THE 5H AND SFC LOWS WOBBLE AROUND THE AREA. SOME DIFFERENCES IN PLACEMENT AND STRENGTH BUT THEY AGREE OVERALL IN AN INCRLY WET LOOKING SCENARIO. BASICALLY WENT WITH A SLOWLY INCREASING SKY COVER AND POPS RIGHT ON INTO NEXT WEEK. PREV FCST PACKAGE WAS LEANING THIS WAY AND I AM TO. I INCREASED THE SKY COVER A TAD FOR MON AND TUE AND ALSO RAISED THE THE POPS ANOTHER 10 PERCENT. LOWERED THE MAX TEMPS JUST A LITTLE ALSO FOR MON-TUE TO AROUND/NEAR 80. HAVE SOME CONCERN THAT IT COULD BE EVEN A LITTLE COOLER THAN THAT IN THE FAR E-NE ZONES AND AGREE WITH CRW IN NDFD CHAT ROOM DISC FOR TEMPS. NOTED HPC DAY 3 (TUE) MAX TEMP PROG WITH HIGHS ONLY MID 70S ACROSS THE BOARD. I KEPT EITHER 40 OR 50 POPS IN THE DATABASE FOR WED AND THUR AND CHC POPS AGAIN FOR FRI AND SAT. FIGURE WE WILL BE REFINING POPS ON A DAILY BASIS AS THE EVENT UNFOLDS. GFE/IFPS...DATA BASE LOOKS PRETTY GOOD. ONLY MINOR CHANGES MADE HERE AND THERE AS NOTED ABOVE. DIDNT ADD ANY NEW MODEL DATA. MOS...ETA MOS HITTING THE POPS TOO HARD AND WILL LEAN MORE TOWARD THE MAV AND NGM. ETA TEMPS ALSO A TOUCH TOO COOL. THE META'S UPPER 50S MON NIGHT ALSO SEEMS TOO COOL. THANKS TO CRW AND MRX FOR CHAT ROOM COORDINATION THIS MORNING AND TO SDF FOR LAND LINE COORDINATION. WORK ZONES OUT BEFORE TOO LONG UNDER SDFOZFJKL. HALL --------------------------------------------------------------------- 915 PM EDT SAT AUG 24 2002 QUESTION FOR THIS EVENING IS CHANCE OF OVERNIGHT CONVECTION. CONTINUE TO MONITOR ISOLATED CONVECTION TO THE N AND S OF CWFA...BUT MAIN AREA OF CONVECTION HAS BEEN OVER W TN. CONVECTION TO OUR N CORRESPONDS WITH RIGHT REAR ENTRANCE REGION OF JET FM OH INTO PA. WHILE CONVECTION OVER TN AND AR CORRESPONDS WITH LEFT FRONT EXIT REGION OF THE JET EXTENDING FROM CENTRAL ROCKIES SOUTHEAST TO LOWER MS VALLEY. AT THE SURFACE THE WEAK FRONTAL BOUNDARY IS NOW OVER KY. SOME WEAK LOW LEVEL CONVERGENCE NEAR THE TN KY STATE LINE WITH SOME ISOLATED CONVECTION OVER NORTHEAST TN. CURRENT INDICATIONS ARE THAT MAIN CONVECTION TO REMAIN TO OUR SOUTHWEST OVERNIGHT. CANNOT SEE MUCH TO SUPPORT CONVECTION IN THE CWFA OVERNIGHT WITH MAIN SUPPORT TO OUR SW AND NE. 18Z MESOETA...18Z AVN OR 21Z RUC ARE NOT HANDLING THE CONVECTION VERY WELL...WITH 18Z MESOETA ESPECIALLY OVERDONE IN KY. WILL FOLLOW IDEA OF OUR AFTERNOON FORECAST...AND THE AUG 25 06Z-AUG 25 12Z QPF ISSUED BY HPC AT 22Z. THUS WILL HOLD ONTO SLIGHT CHANCE IN OUR SOUTHWEST ZONES OVERNIGHT. DO NOT EXPECT CONVECTION TO HOLD TOGETHER OVER SRN OH...BUT IF IT DOES MAY NEED TO UPDATE NORTHERN COUNTIES TO INTRODUCE SLIGHT CHANCE POPS THERE OVERNIGHT AS WELL. TEMPERATURES OVERNIGHT LOOK OK. AT THIS TIME NO PLANNED CHANGES TO OVERNIGHT FORECAST. SBH --------------------------------------------------------------------- 241 PM EDT SAT AUG 24 2002 ...FORECAST ISSUES... FORECAST CONCERNS CONTINUE TO REVOLVE AROUND PRECIP CHANCES IN THE SHORT AND IN LONG TERM. TEMPERATURES MAY BE PROBLEMATIC IN THE EXTENDED AS WELL. ...MODELS/ZFP... MODELS IN GENERAL AGREEMENT CONTINUING TO BRING FRONTAL BOUNDARY THROUGH THE AREA TONIGHT. THE MESO ETA/ETA ARE NOW ADVERTISING SOME CONVECTION FIRING TONIGHT ACROSS CENTRAL AND SOUTH CENTRAL KY. THIS APPEARS TO BE ALONG THE FRONT. ALSO AIDING IN THIS IS SOME MID LEVEL COOLING THAT COULD ELIMINATE THE WEAK CAP IN PLACE. I'M HESITANT AT THIS POINT TO DISCOUNT THE SOLUTION ALL TOGETHER GIVEN THE FACT THAT THE ETA/MESO ETA SOMETIMES GO OVERBOARD WITH FIRING CONVECTION. HOWEVER...GIVEN THESE FACTS AND THE FRONT STILL HANGING AROUND...CAN'T RULE OUT SOMETHING POPPING UP. THUS WILL CARRY SLIGHT CHANCE POPS ACROSS THE SOUTHWEST PART OF THE CWA. FWC/MAV/MET NUMBERS IN CLOSE AGREEMENT AND WILL USE A BLEND. FOR SUNDAY THROUGH TUESDAY...MODELS COMING INTO BETTER AGREEMENT WITH THE DEVELOPMENT OF AN UPPER LEVEL CUT OFF AND ASSOCIATED SURFACE LOW OVER THE SOUTHEAST U.S. MESO ETA AND THE ETA PAINT SOME LIGHT QPF AMOUNTS ACROSS THE AREA. PLAN ON GOING WITH PARTLY CLOUDY WORDING FOR SUNDAY AND MONDAY. WILL KEEP SLIGHT CHANCE POPS ACROSS NORTHERN/CENTRAL PARTS OF THE CWA FOR SUNDAY AND CHANCE POPS FURTHER SOUTH. ON MONDAY...PLAN ON JUST RUNNING LOW CHANCE POPS ACROSS THE ENTIRE AREA. BY TUESDAY UPPER LEVEL LOW JUST WEST OF U.S. WITH SURFACE LOW TO OUR SOUTH. LOTS OF MOISTURE AND CLOUDS AROUND...SO PLAN ON GOING WITH CHANCE POPS IN THIS PERIOD. MAV/FWC/MET NUMBERS IN CLOSE AGREEMENT AND PLAN ON USING A BLEND. BASICALLY LOOKING AT HIGH TEMPS IN THE LOWER 80S AND OVERNIGHT LOWS IN THE LOWER 60S. ...EXTENDED... EXTENDED MODELS CONTINUE TO BE IN AGREEMENT WITH THE DEVELOPMENT OF A UPPER LEVEL CLOSED LOW AND ASSOCIATED SURFACE LOW OVER THE SOUTHEAST BY EARLY NEXT WEEK. MODELS IN DISAGREEMENT WITH THE STRENGTH OF THE SYSTEM. THE 00Z GFS RUN IS SIMILAR TO THE ECMWF AND CANADIAN MODEL RUNS...HOLDING A STRONG SYSTEM JUST TO THE WEST OF US. ON THE OTHER HAND...THE UKMET HAS A STRONGER UPPER TROF COMING ACROSS CENTRAL CANADA AND IS FORECASTING THIS TROF TO LIFT THE CUT OFF LOW UP AND OVER THE WESTERN ATLANTIC RIDGE. WE AGREE WITH THIS MORNINGS PREEPD AND HAVE FOLLOWED THE 00Z GFS RUN EVENTHOUGH ITS CONSISTENCY HAS NOT BEEN ALL THAT GREAT. WITH THIS SOLUTION IN HAND...EXPECT UPPER LOW TO LIFT OUT TOWARDS THE END OF NEXT WEEK. AS FOR SENSIBLE WEATHER...LOOKS TO BE A MOSTLY CLOUDY WEEK WITH A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS. RIGHT NOW THE LOOKS LIKE THE BEST CHANCE OF RAIN WILL BE IN THE TUE/WED TIME FRAME. WITH ALL THE CLOUDS AND RAIN AROUND...TEMPS WILL BE COOLER THAN PREVIOUSLY FORECAST. PLAN ON STICKING CLOSE TO THE MEX NUMBERS FOR THIS CYCLE. LOOKING AT AFTERNOON HIGHS IN THE LOW 80S AND OVERNIGHT LOWS IN THE MID 60S. ...GRIDS... FORECAST DATABASE IN GOOD SHAPE. MADE SOME TWEAKS IN ALL THE SHORT TERM ELEMENTS TO REFLECT UPCOMING FORECAST. DID RELOAD WINDS IN THE FIRST 60 HOURS. IN THE EXTENDED...RAISED POPS AND CLOUD COVER...LOWERED AFTERNOON TEMPS. LOADED IN NEW DATA FOR DAY SEVEN. ...PRELIM NUMBERS... LOZ 66/84 65/82 2323 JKL 65/83 63/82 1213 JARVIS ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE JACKSON KY 1105 AM EDT SUN AUG 25 2002 MID/HIGH LEVEL CLOUDS ARE MORE PROMINENT THAN FORECAST IN THE NORTH...AND LATEST INFORMATION SUGGESTS THAT WILL NOT CHANGE. HOWEVER...DRIER LOW LEVEL AIR AND SLIGHTLY WARMER TEMPS SEVERAL THOUSAND FEET UP ON THE MESOETA ALSO MEAN IT WILL BE DIFFICULT FOR CONVECTION TO FIRE IN THE FAR NORTH. MEANWHILE...IN THE SOUTHERN PART OF THE AREA...EXTENSIVE CLOUDS WILL HINDER TEMPS FROM WARMING AS MUCH AS WAS FORECAST. WILL SPLIT OFF A FAR NORTHERN GROUP FROM MONTGOMERY COUNTY EAST TO MARTIN COUNTY AND REMOVE AFTERNOON PRECIP. WILL GO WITH 1ST PERIOD CONSIDERABLE CLOUDS IN ALL BUT THE SOUTHERN PART OF THE AREA...WHERE MOSTLY CLOUDY WORDING WILL BE LEFT AS IS. IN THE SOUTH...WILL DROP 1ST PERIOD TEMPS SLIGHTLY TO 80 TO 85. .JKL...NONE. HAL --------------------------------------------------------------------- PREVIOUS DISCUSSIONS FOLLOW --------------------------------------------------------------------- 300 AM EDT SUN AUG 25 2002 NUMEROUS CHALLENGES THRU THE FCST PACKAGE...MAINLY EVOLVING AROUND PCPN CHANCES AND SKY COVER AND TO A LESSER EXTENT HIGH TEMPERATURES. SFC CHART EARLY THIS MORNING SHOWING WEAK COLD FRONT/BNDRY SLIDING THRU THE CWA WITH A WEAK LOW NEAR HTS AND BTWN BWG AND PAH. HIGH PRESSURE OVER N IN AND W IA. SAT PICS SHOWING COPIOUS CI BLOW OFF ACROSS THE ENTIRE AREA AND SFC OBS ALSO SHOWING SOME MID LVL CLOUDINESS. RADAR SHOWED SOME ISOLATED RENEGADE SHOWERS OVER THE CWA EARLIER...SCT SHOWERS STILL OVER WV MOVING SE THIS MORNING AND INCREASING SHRA/TSRA OVER TN MOVING E-NE. SKY FCST TUFF THE NEXT FEW DAYS AS CONDITIONS WILL PROBABLY RANGE FROM PC TO MCLOUDY AT TIMES. JUST HOW DENSE WILL THE CI BE AND HOW MUCH WILL IT HOLD DOWN INSOLATION IS A TUFF CALL. ETA/M-ETA MODEL THIS MORNING IS WAY TOO WET RIGHT OFF THE BAT BUT THEY SEEM TO REGROUP SOMEWHAT AS THE DAY WEARS ON. THINKING BEST CHC OF POPS TODAY ALONG THE SOUTHERN ZONES AND NEAR THE TN BORDER...LOWER POPS (SLGHT CHC) ACROSS THE NORTH. HIGHS IN THE LOWER 80S NORTH AND MID 80S SOUTH. WILL CONTINUE WITH A SLIGHT CHC NORTH AND 30% SOUTH FOR TONIGHT. MODELS ALL STILL ADVERTISING SOMEWHAT UNUSUAL 5H CUT OFF LOW TO SET UP FOR THE NEXT SEVERAL DAYS OVER W-CNTRL TN/KY AND THEN THE 5H AND SFC LOWS WOBBLE AROUND THE AREA. SOME DIFFERENCES IN PLACEMENT AND STRENGTH BUT THEY AGREE OVERALL IN AN INCRLY WET LOOKING SCENARIO. BASICALLY WENT WITH A SLOWLY INCREASING SKY COVER AND POPS RIGHT ON INTO NEXT WEEK. PREV FCST PACKAGE WAS LEANING THIS WAY AND I AM TO. I INCREASED THE SKY COVER A TAD FOR MON AND TUE AND ALSO RAISED THE THE POPS ANOTHER 10 PERCENT. LOWERED THE MAX TEMPS JUST A LITTLE ALSO FOR MON-TUE TO AROUND/NEAR 80. HAVE SOME CONCERN THAT IT COULD BE EVEN A LITTLE COOLER THAN THAT IN THE FAR E-NE ZONES AND AGREE WITH CRW IN NDFD CHAT ROOM DISC FOR TEMPS. NOTED HPC DAY 3 (TUE) MAX TEMP PROG WITH HIGHS ONLY MID 70S ACROSS THE BOARD. I KEPT EITHER 40 OR 50 POPS IN THE DATABASE FOR WED AND THUR AND CHC POPS AGAIN FOR FRI AND SAT. FIGURE WE WILL BE REFINING POPS ON A DAILY BASIS AS THE EVENT UNFOLDS. GFE/IFPS...DATA BASE LOOKS PRETTY GOOD. ONLY MINOR CHANGES MADE HERE AND THERE AS NOTED ABOVE. DIDNT ADD ANY NEW MODEL DATA. MOS...ETA MOS HITTING THE POPS TOO HARD AND WILL LEAN MORE TOWARD THE MAV AND NGM. ETA TEMPS ALSO A TOUCH TOO COOL. THE META'S UPPER 50S MON NIGHT ALSO SEEMS TOO COOL. THANKS TO CRW AND MRX FOR CHAT ROOM COORDINATION THIS MORNING AND TO SDF FOR LAND LINE COORDINATION. WORK ZONES OUT BEFORE TOO LONG UNDER SDFOZFJKL. HALL --------------------------------------------------------------------- 915 PM EDT SAT AUG 24 2002 QUESTION FOR THIS EVENING IS CHANCE OF OVERNIGHT CONVECTION. CONTINUE TO MONITOR ISOLATED CONVECTION TO THE N AND S OF CWFA...BUT MAIN AREA OF CONVECTION HAS BEEN OVER W TN. CONVECTION TO OUR N CORRESPONDS WITH RIGHT REAR ENTRANCE REGION OF JET FM OH INTO PA. WHILE CONVECTION OVER TN AND AR CORRESPONDS WITH LEFT FRONT EXIT REGION OF THE JET EXTENDING FROM CENTRAL ROCKIES SOUTHEAST TO LOWER MS VALLEY. AT THE SURFACE THE WEAK FRONTAL BOUNDARY IS NOW OVER KY. SOME WEAK LOW LEVEL CONVERGENCE NEAR THE TN KY STATE LINE WITH SOME ISOLATED CONVECTION OVER NORTHEAST TN. CURRENT INDICATIONS ARE THAT MAIN CONVECTION TO REMAIN TO OUR SOUTHWEST OVERNIGHT. CANNOT SEE MUCH TO SUPPORT CONVECTION IN THE CWFA OVERNIGHT WITH MAIN SUPPORT TO OUR SW AND NE. 18Z MESOETA...18Z AVN OR 21Z RUC ARE NOT HANDLING THE CONVECTION VERY WELL...WITH 18Z MESOETA ESPECIALLY OVERDONE IN KY. WILL FOLLOW IDEA OF OUR AFTERNOON FORECAST...AND THE AUG 25 06Z-AUG 25 12Z QPF ISSUED BY HPC AT 22Z. THUS WILL HOLD ONTO SLIGHT CHANCE IN OUR SOUTHWEST ZONES OVERNIGHT. DO NOT EXPECT CONVECTION TO HOLD TOGETHER OVER SRN OH...BUT IF IT DOES MAY NEED TO UPDATE NORTHERN COUNTIES TO INTRODUCE SLIGHT CHANCE POPS THERE OVERNIGHT AS WELL. TEMPERATURES OVERNIGHT LOOK OK. AT THIS TIME NO PLANNED CHANGES TO OVERNIGHT FORECAST. SBH --------------------------------------------------------------------- 241 PM EDT SAT AUG 24 2002 ...FORECAST ISSUES... FORECAST CONCERNS CONTINUE TO REVOLVE AROUND PRECIP CHANCES IN THE SHORT AND IN LONG TERM. TEMPERATURES MAY BE PROBLEMATIC IN THE EXTENDED AS WELL. ...MODELS/ZFP... MODELS IN GENERAL AGREEMENT CONTINUING TO BRING FRONTAL BOUNDARY THROUGH THE AREA TONIGHT. THE MESO ETA/ETA ARE NOW ADVERTISING SOME CONVECTION FIRING TONIGHT ACROSS CENTRAL AND SOUTH CENTRAL KY. THIS APPEARS TO BE ALONG THE FRONT. ALSO AIDING IN THIS IS SOME MID LEVEL COOLING THAT COULD ELIMINATE THE WEAK CAP IN PLACE. I'M HESITANT AT THIS POINT TO DISCOUNT THE SOLUTION ALL TOGETHER GIVEN THE FACT THAT THE ETA/MESO ETA SOMETIMES GO OVERBOARD WITH FIRING CONVECTION. HOWEVER...GIVEN THESE FACTS AND THE FRONT STILL HANGING AROUND...CAN'T RULE OUT SOMETHING POPPING UP. THUS WILL CARRY SLIGHT CHANCE POPS ACROSS THE SOUTHWEST PART OF THE CWA. FWC/MAV/MET NUMBERS IN CLOSE AGREEMENT AND WILL USE A BLEND. FOR SUNDAY THROUGH TUESDAY...MODELS COMING INTO BETTER AGREEMENT WITH THE DEVELOPMENT OF AN UPPER LEVEL CUT OFF AND ASSOCIATED SURFACE LOW OVER THE SOUTHEAST U.S. MESO ETA AND THE ETA PAINT SOME LIGHT QPF AMOUNTS ACROSS THE AREA. PLAN ON GOING WITH PARTLY CLOUDY WORDING FOR SUNDAY AND MONDAY. WILL KEEP SLIGHT CHANCE POPS ACROSS NORTHERN/CENTRAL PARTS OF THE CWA FOR SUNDAY AND CHANCE POPS FURTHER SOUTH. ON MONDAY...PLAN ON JUST RUNNING LOW CHANCE POPS ACROSS THE ENTIRE AREA. BY TUESDAY UPPER LEVEL LOW JUST WEST OF U.S. WITH SURFACE LOW TO OUR SOUTH. LOTS OF MOISTURE AND CLOUDS AROUND...SO PLAN ON GOING WITH CHANCE POPS IN THIS PERIOD. MAV/FWC/MET NUMBERS IN CLOSE AGREEMENT AND PLAN ON USING A BLEND. BASICALLY LOOKING AT HIGH TEMPS IN THE LOWER 80S AND OVERNIGHT LOWS IN THE LOWER 60S. ...EXTENDED... EXTENDED MODELS CONTINUE TO BE IN AGREEMENT WITH THE DEVELOPMENT OF A UPPER LEVEL CLOSED LOW AND ASSOCIATED SURFACE LOW OVER THE SOUTHEAST BY EARLY NEXT WEEK. MODELS IN DISAGREEMENT WITH THE STRENGTH OF THE SYSTEM. THE 00Z GFS RUN IS SIMILAR TO THE ECMWF AND CANADIAN MODEL RUNS...HOLDING A STRONG SYSTEM JUST TO THE WEST OF US. ON THE OTHER HAND...THE UKMET HAS A STRONGER UPPER TROF COMING ACROSS CENTRAL CANADA AND IS FORECASTING THIS TROF TO LIFT THE CUT OFF LOW UP AND OVER THE WESTERN ATLANTIC RIDGE. WE AGREE WITH THIS MORNINGS PREEPD AND HAVE FOLLOWED THE 00Z GFS RUN EVENTHOUGH ITS CONSISTENCY HAS NOT BEEN ALL THAT GREAT. WITH THIS SOLUTION IN HAND...EXPECT UPPER LOW TO LIFT OUT TOWARDS THE END OF NEXT WEEK. AS FOR SENSIBLE WEATHER...LOOKS TO BE A MOSTLY CLOUDY WEEK WITH A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS. RIGHT NOW THE LOOKS LIKE THE BEST CHANCE OF RAIN WILL BE IN THE TUE/WED TIME FRAME. WITH ALL THE CLOUDS AND RAIN AROUND...TEMPS WILL BE COOLER THAN PREVIOUSLY FORECAST. PLAN ON STICKING CLOSE TO THE MEX NUMBERS FOR THIS CYCLE. LOOKING AT AFTERNOON HIGHS IN THE LOW 80S AND OVERNIGHT LOWS IN THE MID 60S. ...GRIDS... FORECAST DATABASE IN GOOD SHAPE. MADE SOME TWEAKS IN ALL THE SHORT TERM ELEMENTS TO REFLECT UPCOMING FORECAST. DID RELOAD WINDS IN THE FIRST 60 HOURS. IN THE EXTENDED...RAISED POPS AND CLOUD COVER...LOWERED AFTERNOON TEMPS. LOADED IN NEW DATA FOR DAY SEVEN. ...PRELIM NUMBERS... LOZ 66/84 65/82 2323 JKL 65/83 63/82 1213 JARVIS ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 210 PM EDT SUN AUG 25 2002 .UPDATED... UPDATED TO ADD CHANCE OF ISOLATED THUNDERSTORM ALL AREAS...OTHERWISE...NO CHANGES. .SYNOPSIS... LOW PRESSURE WILL TRACK EAST OF NOVA THIS AFTERNOON WHILE A COLD FRONT CROSSES THE REGION FROM THE WEST. HIGH PRESSURE WILL BUILD ACROSS THE AREA TONIGHT AND MONDAY. ANOTHER COLD FRONT WILL PASS THROUGH THE AREA LATE MONDAY AFTERNOON. HIGH PRESSURE WILL BUILD INTO THE REGION FROM CANADA ON TUESDAY AND MOVE INTO THE CANADIAN MARITIMES ON WEDNESDAY. .DISCUSSION... WILL CONTINUE W/CONSISTENCY & CONTINUITY. ETA HAS COME ARND BUT STILL HIGHLY OVERDONE ON ITS PRECIP FIELDS AS WELL STATED BY DAYCREW. FOR THE 1ST 12-24 HRS...I WILL USE THE RUC/MAPS AS IT IS MATCHING WELL W/CRNT SITUATION. OTRW...AVN/GEM/UKMET SOLN USED. FOR TDA: WILL LEAN W/LIKELY POPS (-RA) FOR BGR TO BHB-EPO AREAS THRU 18Z & THEN I BELIEVE RA SHOULD END W/MO CLDY CONDS. OVER NRN/CNTL AREAS...WILL CARRY 40% POPS FOR SCTD SHRA/TSRA W/COLD FROPA THIS AFTN. MDL SNDGS SHOW CAPES APCHG 500 J/KG W/LIS NR -2. TTS NEARING 50. SO...I BELIEVE THUNDER A GOOD BET.SOME LTG STRIKE WERE SHOWING UP OVER ONTARIO THE LAST FEW SCANS. DOWNEAST/CST MORE STABLE W/MARINE INFLUENCE & LAGGING CLD COVER. TEMPS WILL BE ABV GUID. TNGT: FRONT CLRS THE CST & BUBBLE OF HIGH PRES MOVES IN TO ALLOW FOR CLRG TREND. DECIDED TO STAY W/PC OVER THE N WHILE DOWNEAST AREAS SHOULD GO CLR. BELIEVE MINS WILL BE HELD UP A BIT OVER THE N W/CONTD GRDNT. OVER DOWNEAST/CSTL AREAS...WILL USE MAV FOR MINS. FOR MON: A SECOND COLD FRONT W/REINFORCING SHOT DECENT LLVL CAA TO SUPPORT SCU DEVELOPMENT MAINLY ACROSS THE N. POTENT VORT MAX TO RIDE ACROSS SOUTHERN QUEBEC MON AFTN JUST CLIPPING FAR N. ATTM...WILL LEAVE ANY MENTION PRECIP OUT AS BEST FORCING WELL N OF THE ME BORDER. WLY WIND W/CAA WILL KEEP TEMPS DOWN SOME ON MON. MAV MIGHT BE A TAD TOO COOL. DECIDED TO AVG THE GUID ON MAXES. LOOKING FURTHER OUT: NO CHGS MADE AS STRONG HIGH PRESSURE WILL BUILD INTO THE CWFA FROM CAN ON TUE & REMAIN ACROSS THE REGION THRU WED. DESPITE HGTS CLIMBING TO 588DM...BELIEVE TEMPS SHOULD FAVOR WHERE DAYCREW HAS THEM W/DRAINAGE FROM CANADIAN MARITIMES. LONG RANGE GUID SHOWS NEXT CHANCE FOR SHRA ACTIVITY WILL BE LATER THU INTO EARLY FRI AS THE NEXT FRONT CROSSES THE CWFA. DRIER WX BACK IN FOR THE WEEKEND. .COASTAL WATERS... NO FLAGS THIS GO ARND. N WINDS BECMG W W/SPDS ON THE AVG OF 10 KTS. .CAR...NONE. BT/CN me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CARIBOU ME 1249 PM EDT SUN AUG 25 2002 .UPDATED... UPDATED TO LOWER TEMPS SLIGHTLY OVER ALL AREAS AND TO CONTINUE A CHANCE OF SCATTERED SHOWERS THROUGH THE AFTERNOON. SLIGHT CHANCE OF THUNDERSTORM OVER NORTHERN AREAS. .SYNOPSIS... LOW PRESSURE WILL TRACK EAST OF NOVA THIS AFTERNOON WHILE A COLD FRONT CROSSES THE REGION FROM THE WEST. HIGH PRESSURE WILL BUILD ACROSS THE AREA TONIGHT AND MONDAY. ANOTHER COLD FRONT WILL PASS THROUGH THE AREA LATE MONDAY AFTERNOON. HIGH PRESSURE WILL BUILD INTO THE REGION FROM CANADA ON TUESDAY AND MOVE INTO THE CANADIAN MARITIMES ON WEDNESDAY. .DISCUSSION... WILL CONTINUE W/CONSISTENCY & CONTINUITY. ETA HAS COME ARND BUT STILL HIGHLY OVERDONE ON ITS PRECIP FIELDS AS WELL STATED BY DAYCREW. FOR THE 1ST 12-24 HRS...I WILL USE THE RUC/MAPS AS IT IS MATCHING WELL W/CRNT SITUATION. OTRW...AVN/GEM/UKMET SOLN USED. FOR TDA: WILL LEAN W/LIKELY POPS (-RA) FOR BGR TO BHB-EPO AREAS THRU 18Z & THEN I BELIEVE RA SHOULD END W/MO CLDY CONDS. OVER NRN/CNTL AREAS...WILL CARRY 40% POPS FOR SCTD SHRA/TSRA W/COLD FROPA THIS AFTN. MDL SNDGS SHOW CAPES APCHG 500 J/KG W/LIS NR -2. TTS NEARING 50. SO...I BELIEVE THUNDER A GOOD BET.SOME LTG STRIKE WERE SHOWING UP OVER ONTARIO THE LAST FEW SCANS. DOWNEAST/CST MORE STABLE W/MARINE INFLUENCE & LAGGING CLD COVER. TEMPS WILL BE ABV GUID. TNGT: FRONT CLRS THE CST & BUBBLE OF HIGH PRES MOVES IN TO ALLOW FOR CLRG TREND. DECIDED TO STAY W/PC OVER THE N WHILE DOWNEAST AREAS SHOULD GO CLR. BELIEVE MINS WILL BE HELD UP A BIT OVER THE N W/CONTD GRDNT. OVER DOWNEAST/CSTL AREAS...WILL USE MAV FOR MINS. FOR MON: A SECOND COLD FRONT W/REINFORCING SHOT DECENT LLVL CAA TO SUPPORT SCU DEVELOPMENT MAINLY ACROSS THE N. POTENT VORT MAX TO RIDE ACROSS SOUTHERN QUEBEC MON AFTN JUST CLIPPING FAR N. ATTM...WILL LEAVE ANY MENTION PRECIP OUT AS BEST FORCING WELL N OF THE ME BORDER. WLY WIND W/CAA WILL KEEP TEMPS DOWN SOME ON MON. MAV MIGHT BE A TAD TOO COOL. DECIDED TO AVG THE GUID ON MAXES. LOOKING FURTHER OUT: NO CHGS MADE AS STRONG HIGH PRESSURE WILL BUILD INTO THE CWFA FROM CAN ON TUE & REMAIN ACROSS THE REGION THRU WED. DESPITE HGTS CLIMBING TO 588DM...BELIEVE TEMPS SHOULD FAVOR WHERE DAYCREW HAS THEM W/DRAINAGE FROM CANADIAN MARITIMES. LONG RANGE GUID SHOWS NEXT CHANCE FOR SHRA ACTIVITY WILL BE LATER THU INTO EARLY FRI AS THE NEXT FRONT CROSSES THE CWFA. DRIER WX BACK IN FOR THE WEEKEND. .COASTAL WATERS... NO FLAGS THIS GO ARND. N WINDS BECMG W W/SPDS ON THE AVG OF 10 KTS. .CAR...NONE. BT/CN me AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MARQUETTE MI 430 PM EDT SUN AUG 25 2002 SHORT TERM FCST CONCERNS INCLUDE FOG POTENTIAL TONIGHT ALONG WITH TEMPS. LONGER TERM...FOCUS SHIFTS TO PCPN POTENTIAL FROM WED-SUN. WV IMAGERY AND RUC ANALYSIS INDICATED SPLIT FLOW ACRS NOAM WITH MID/UPR LVL RDG AND BLOCKING OVER THE UPR MS VALLEY SEPARATING NRN STREAM OVER NRN MANITOBA/ONTARIO AND SRN STREAM FROM THE CNTRL/SRN PLAINS INTO THE SE CONUS. WEAK NRN STREAM SHRTWV AND ASSOCIATED FRONT/TROF SUPPORTED BAND OF SCT-BKN CU AND MID CLOUDS NE OF LK SUPERIOR. OTHERWISE...WRN LAKES WERE DOMINATED BY SUBSIDENCE AND DRY AIR ABV MIXED LYR BENEATH MID LVL RDG LEAVING ONLY SCT DIURNAL CU OVER INLAND PORTIONS OF UPR MI. SFC DEWPOINTS LINGERED IN THE UPPER 50S F TO AROUND 60. MDLS WERE IN REASONABLE AGREEMENT WITH REGARD TO FEATURES AFFECTING UPR MI THROUGH TUESDAY. SO...HAVE LEANED TOWARD ETA FOR DETAILS WITH WINDS/TEMPS. TONIGHT...CU WILL FADE THIS EVENING LEAVING MOSTLY CLEAR SKIES. WITH DIMINISHING WINDS...FAVORABLE RADIATIONAL COOLING CONDITIONS SHOULD ALLOW TEMPS TO FALL TOWARD AOB SFC DEWPOINTS LEADING TO SOME FOG FORMATION. LIMITING FACTOR WILL BE VERY SHALLOW MOISTURE PROFILE. SO...BEST FOG POTENTIAL SHOULD BE IN RIVER VALLEYS AND OTHER LOW-LYING AREAS. MONDAY...SFC HI BUILDS INTO UPR MI FROM NRN MANITOBA AND NW ONTARIO BRINGING VEERING WINDS TO NE. H8 TEMPS NEAR 15C SUGGEST MAX TEMPS INTO THE UPPER 70S TO NEAR 80 INLAND WITH COOLER READINGS NEAR LK SUPERIOR WHERE NEARSHORE WATER TEMPS WERE IN THE MID 60S. MONDAY NIGHT INTO TUESDAY...DRY ADVECTION AND MIXING WITH STRENGTHENING ACYC NERLY FLOW FROM NRN ONTARIO SHOULD MINIMIZE ANY FOG POTENTIAL. STRONGER ENE GRADIENT FLOW ACRS LK SUPERIOR WILL AGAIN KEEP TEMPS SIGNIFICANTLY LOWER OVER NORTH CNTRL UPR MI. SO...GUIDANCE TEMP VALUES LOOK REASONABLE. TUESDAY NIGHT AND WEDNESDAY...AXIS OF DEEPER MOISTURE GRADUALLY APPROACHES UPR MI FROM THE UPR MS VALLEY AS BLOCKING PATTERN KEEPS INFLUENCE FROM WEAK MID LVL TROF (INSTABILITY AND MOISTURE INFLOW) MAINLY WEST OF UPR MI. HAVE SCALED BACK PCPN FCST TO INCLUDE POPS ONLY FOR THE WRN 1/3 OF UPR MI. THURSDAY THROUGH SUNDAY...PLENTY OF UNCERTAINTY WITH MID/UPR LVL PATTERN GIVEN WEAK FLOW REGIME. MDLS (12Z AVN/UKMET/ECMWF) TREND HAS BEEN TO KEEP UPR MI UNDER INFLUENCE OF DRIER ACYC FLOW FROM HIGH RDG EXTENDING INTO THE WRN GRT LAKES FROM HI PRES TO THE NE MINIMIZING PCPN POTENTIAL. BY SUNDAY...00Z/12Z AVN SUGGEST STRONG ENOUGH SHRTWV AND SFC TROF MAY PROGRESS INTO THE AREA TO BRING CHANCE FOR SHRA/TSRA. .MQT...NONE. JLB mi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 250 PM CDT SUN AUG 25 2002 A SLIGHT CHANCE OF CONVECTION EXPECTED ACROSS THE SOUTH THIS EVENING. CURRENT SURFACE DEW POINT TEMPERATURES ARE PUSHING 70 ALONG AND SOUTH OF THE MINNESOTA RIVER VALLEY. ALSO...THE RUC MODEL... THROUGH BUFKIT...SHOWS LITTLE IF ANY MID LEVEL CAP BY LATE AFTERNOON AROUND WOODLAKE/REDWOOD FALLS. A BROAD AREA OF HIGH THETA E AIR IS FORECAST OVER OUR COUNTY WARNING AREA BUT MODELS INDICATE ONLY WEAK VERTICAL FORCING ESPECIALLY TONIGHT TROUGH MONDAY. MODELS ALSO INDICATE EASTERLY SURFACE FLOW WILL HAVE A STABILIZING EFFECT THROUGH MONDAY NIGHT. THE PASSAGE OF A MIDDLE LEVEL RIDGE ALONG WITH LOW LEVEL WARM ADVECTION ARE FORECAST TO MOVE FROM WEST CENTRAL MINNESOTA MONDAY INTO WEST CENTRAL WISCONSIN LATE MONDAY NIGHT. THESE FEATURES SHOULD ENHANCE OF THE CHANCE OF SHOWERS AND THUNDERSTORMS BUT WEAK WIND PROFILES AND LACK OF SURFACE BOUNDARIES SHOULD TRANSLATE TO SCATTERED AIR MASS CONVECTION DRIVEN MAINLY BY DIURNAL HEATING. .MSP...NONE. WH mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 1030 AM EDT SUN AUG 25 2002 SFC TROUGH NEARLY SPLITS OUR CWA FROM NE TO SW AT 12Z AND FRONTAL BOUNDARY (WEAK AS IT MAY BE) STRETCHES FROM NEAR ORF W TO NEAR DAN THEN SW TO BETWEEN AVL AND GSP. NO REAL TRIGGER FOR SHRA/TSTMS UPSTAIRS SO AGREE WITH MID-SHIFT THAT THERE IS A SLIGHT CHANCE ALONG AND S OF TROUGH. WINDS REALLY NOT MUCH OF AN ISSUE TODAY BUT WILL UPDATE TO ACCOUNT FOR CHANGES THAT HAVE OCCURRED SINCE ZFP WAS ISSUED. A DECENT AMOUNT OF SUNSHINE OVER OUR CWA CURRENTLY BUT VIS AND IR SAT LOOPS SHOW CLOUDS TO OUR W MOVING PRETTY SWIFTLY E PLUS CU/SC TO OUR N-NE WILL BE MOVING S SO SEE NO REASON TO CHANGE MIX OF CLOUDS AND SUNSHINE FCST. 12Z MHX SOUNDING SHOWING PW OF 2.04 WITH A K INDEX OF 36 AND LI OF -4 WHICH BACKS UP KEEPING SLIGHT CHANCE POPS. MARINE...FNT RMNS W OF WTRS THIS AM. LTST RUC80 SHOWG ITS GOING TO HV A HARD TM DROPPG S OF HAT TDY...EVEN THO RUC10 BRINGS IT S OF MHX WTRS BY 0Z. MESOETA SHOWS IT DROPPG S OF WTRS LTR TNGT. WL PROB GO WI A HAT-OCRACOKE AREA FOR WND SHIFT THIS PD. RMN IN SUBSIDENCE AREA AND CNVCTV INDICES SHOWG BEST INSTBLTY S OF AREA AS S/WV MVS E S OF CWA. WI THAT TO OUR S AND FROPA IN NRN SXNS CANT RULE OUT PCPN OVR WTRS TDY. WNDS AND SEAS RMN BLO HDLN CRIT. IF NECESSASRY WL TWEAK PCPN WORDING AND TIMING OF WND. WILL GO LOW ON RIP THREAT TODAY DESPITE SLGTLY ABV NORMAL ASTRO TIDES. OVERALL ENERGY MAKING TO THE BEACHES WEAK AND WINDS NOT FAVORABLE TODAY FOR ADDING TURBULENCE TO THE SURF ZONE. .MHX...NONE WS/CGG-G nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 10 AM EDT SUN AUG 25 2002 MSAS ANALYSIS SHOWING BEST DEFINED FEATURE IS SURFACE TROUGH WHICH HAS PUSHED JUST S OF CWA AND EXTENDS SW INTO E CNTRL GA. FRONTAL BOUNDARY TO THE N GETTING MORE DIFFUSE BUT LOOKS BE STILL NEAR THE VA/NC BOARDER. SKIES CLEARING NICELY IN WAKE OF CONVECTIVE CLUSTER PUSHING WELL S OF CWA. MHX SOUNDING STILL SHOWING PW GREATER THAN 2 INCHES AND MODERATE INSTABILITY BY AFTN HEATING. NEXT UPSTREAM SHRTWV/VORT LOBE EVIDENT IN IMAGERY AND MODELS IS SPREADING CLOUDS AND ASSOCIATED SHWRS/CNVTN INTO WESTERN CAROLINAS. BY 21Z RUC DEPICTING IMPRESSIVE UVVS AND POTENTIAL CNVTN WHILE META DEPICTING FEATURE SLOWER AND UPSTREAM THIS EVENING. SOME POTENTIAL FOR MORE STRONG STORMS THIS EVENING. WILL CONSIDER NUDGING 30% POPS UP SLIGHTLY FOR EVENING. EXPECT MOSTLY SUNNY THROUGH EARLY AFTERNOON THEN INCREASING CLOUDINESS WITH BETTER POTENTIAL FOR SHWRS/TSTMS DEVELOPING THIS AFTERNOON AND EVENING SO MAY TRY TO TWEAK SKY CONDITIONS ALSO. MARINE: WITH FRONT NEAR THE NORTH CAROLINA AND VIRGINIA BORDER WINDS NORTH OF WRIGHTSVILLE BEACH ARE BECOMING MORE NORTHWEST WITH TIME. THIS SHOULD BE RATHER SHORT LIVED. THE LATEST RUC IS A LITTLE TO AGGRESSIVE ON SHIFTING THE WINDS TO THE NORTHWEST TO FAR SOUTH. LATEST BEACH CAMS SHOWING FAIRLY FLAT CONDITIONS WITH OFFSHORE WIND WITH A PERIODIC 2 TO 3 FOOT WAVE. SO FOR UPDATE WILL SPLIT AREA NORTH OF CAPE FEAR FOR WINDS SHIFTING TO THE NORTHWEST THROUGH EARLY AFTERNOON AND WILL PLACE RANGE OF SEA HEIGHTS FOR THE INITIAL OFFSHORE WIND. FCSTID = 01 PRELIMINARY NUMBERS KILM 93 75 87 73 / 30 30 50 50 KLBT 93 73 87 70 / 30 30 50 50 KFLO 94 73 88 71 / 30 30 50 50 KMYR 90 75 85 73 / 30 30 50 50 .ILM... NC...NONE. SC...NONE. RWA/DRH nc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON OH 930 PM EDT SUN AUG 25 2002 00Z SFC ANALYSIS SHOWED A VERY WEAK WIND FLOW PATTERN ACRS THE ERN TWO THIRDS OF THE UNITED STATES. SEVERAL AREAS OF WEAK CONVERGENCE WERE NOTED. A WEAK SFC LOW WAS LOCATED BETWEEN KSDF...KLEX AND KBWG. THE WEAK SFC LOW WAS ALSO BEING SUPPORTED BY A DEVELOPING H5 LOW PRESSURE AREA OVER THE MIDDLE OHIO VLY. A WEAK S/WV WAS ALSO NOTED ON WATER VAPOR AND RUC/ETA MODEL OVER CNTRL KY. KILN RADAR WAS SHOWING A CLUSTER OF THUNDERSTORMS JUST SOUTH...BUT EVER SO CLOSE...TO THE CWFA. AT THIS POINT...WILL BANK ON PIVOT POINT OF S/WV VORTICITY AT H5 TO STAY NEAR IN THE SAME LOCATION...AND WITH THE LOSS OF DAYTIME HEATING...THUNDERSTORMS WILL EVENTUALLY WEAKEN AND DISSIPATE OVER TIME. HOWEVER...BEING THAT THEY ARE SO CLOSE...WILL HAVE TO KEEP A CLOSE EYE ON THEM SHOULD THEY CROSS OVER THE KILN CWFA LINE. FOR THE REMAINDER OF THE CWFA....UPR LVL DEFORMATION AXIS DUE TO DEVELOPING H5 LOW WAS CREATING A CIRRUS SHIELD OVER THE NRN CWFA. WITH THIS NOTED...WILL CHANGE MOSTLY CLEAR IN THE NORTH TO MOSTLY CLOUDY...THINKING THAT SKIES SHOULD REMAIN THIS WAY AT LEAST FOR THE GOOD PORTION OF THE NIGHT. PARTLY CLOUDY SOUTH LOOKS OK AT THIS POINT. TEMPS ALSO LOOK OK WITH LOWER 60S NORTH TO MID 60S SOUTH. .ILN...NONE. HICKMAN oh SOUTHWEST OREGON/NORTHERN CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 830 AM PDT SUN AUG 25 2002 A FEW ISSUES ON THE TABLE FOR THE MORNING UPDATE. NORTH BEND FINALLY HAD THE MEASUREABLE DRIZZLE END SHORTLY AFTER 8 AM. CLOUDS BEGINNING TO BREAK UP TO SOME DEGREE IN THIS AREA AND ANY LOCAL DRIZZLE LEFT SHOULD END BY LATE MORNING. LOW CLOUDS ARE WELL INLAND WITH TOPS NEAR 4000 FEET IN THE EASTERN DOUGLAS COUNTY FOOTHILLS. CLOUDS WILL GRADUALLY BREAK UP THIS AFTERNOON. BIGGER QUESTION IS POSSIBILITY OF AFTERNOON CONVECTION. 12Z MESO-ETA FOCUSES 00Z MONDAY INSTABILITY NORTH OF DIAMOND LAKE AREA WITH A -4 SHOWALTER INDEX. THE INSTABILITY EXTENDED ACROSS NORTHERN KLAMATH AND LAKE COUNTIES AS A WEAK SHORT WAVE JUST OFFSHORE MOVES INLAND. WE ALREADY SAW NOCTURNAL CONVECTION THIS MORNING JUST NORTH OF OUR CWA. RUC MODEL FOCUSED MAXIMUM INSTABILITY A LITTLE EAST OF THE MESOETA... ACROSS NORTHERN KLAMATH AND LAKE COUNTIES. WILL LEAVE 20% POPS FOR THIS REGION TODAY. LOW CLOUDS SHOULD BE DEEP AGAIN TONIGHT AND WOULD EXPECT MORE DRIZZLE AT THE COAST FROM CAPE BLANCO NORTHWARD. WILL LOOK AT THIS FURTHER THIS AFTERNOON. WILL LOWER BROOKINGS HIGH TODAY BASED ON LAST COUPLE OF DAYS AND LOW CLOUDS THERE THIS MORNING. WILL RAISE HOWARD PRAIRIE INTO THE MID 70S TODAY. SANDLER .MFR...NONE. or AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHARLESTON SC 945 PM EDT SUN AUG 25 2002 RUC SHOWS H5 VORT MOVG OFF CST ATTM. DOESN'T APR TO BE MUCH IN THE WAY OF UPR DYNAMICS UNTIL MON WHEN NXT VORT SWINGS THRU THE AREA. AMS RMNS MST AND UNSTBL...AND MSAS SHOWS SFC LOW ACRS CNTRL GA WITH SFC TROF EXTENDING NEWD OFF THE NC CST. MSTR CONVERGENCE CONTG W OF FA HELPING TO INITIATE TSRA DVLPMT ACRS GA CNTYS THIS EVE. WILL CONT WITH CHC POPS OVERNIGHT FOR ENTIRE AREA WITH HIGHEST POPS ACRS GA CNTYS. MOCLDY SKIES...LGT WINDS...AND TEMPS HOLDING IN THE MID 70S FOR RMNDR OF TNGT. MARINE...MINOR CHGS ON UPDATE MAINLY FOR INITIAL CONDS. WINDS SHUD BECOME SW-W LTR TNGT 10-15 KT AND SEAS 2-4 FT. .CHS... GA...NONE. SC...NONE. JAC sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 940 PM EDT SUN AUG 25 2002 FAIRLY SIG VORT OVER NE AL AND CENTRAL TN SHOWS UP WELL ON THE WATER VAPOR ATTM. IT ALSO SHOWS UP VERY WELL AS AN AREA OF LOWERED TROP ON THE RUC. IN RESPONSE TO THIS...THE ETA/AVN/RUC ALL DEVELOP DEFORMATION ZONE PCPN OVER THE NRN CWA BEGINNING AFTER 6 UTC. THE EXACT LOCATION AND TIMING ARE ALL A LITTLE DIFFERENT. HOWEVER...LOOKING AT THE 00 UTC GSO SOUNDING...WHICH IS SATURATED WITH A MOIST ADIABATIC LAPSE RATE...VERY LITTLE FORCING WL BE NEEDED TO GENERATE WIDESPREAD PCPN. SO...IT SHOULD RAIN. HOWEVER...THE AIRMASS HAS BEEN WORKED OVER PRETTY GOOD TDA...AND H8 ANALYSIS SHOWS ONLY A WEAK H8 COLD POOL. THUS...UPGLIDE PCPN WL HAVE ITS WORK CUT OUT FOR IT. WL UP POPS TO 70 PERCENT IN THE NE HALF ON THE CWA TNGT AND MON. WL ALSO ADD "NUMEROUS" WORDING AND POSSIBLE HEAVY RAIN TO THESE ZONES FOR LATE TNGT AND MON. WOULD GO CAT POP (PROBABLY SHOULD) BUT I DO HAVE SOME DOUBTS ABOUT HOW FAR S THE PCPN WL DEVELOP W/THE LACK OF A STRONG SFC BNDRY/COLD POOL. FCSTID = 14 GSP 69 82 67 81 / 60 60 50 50 AND 69 83 67 83 / 60 60 50 50 CLT 69 80 67 81 / 70 70 50 50 HKY 67 79 65 77 / 70 70 50 50 AVL 65 77 62 76 / 70 70 50 50 .GSP... GA...NONE. NC...NONE. SC...NONE. MCAVOY sc AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE COLUMBIA SC 908 PM EDT SUN AUG 25 2002 SOME SHOWER AND THUNDERSTORM ACTIVITY CONTINUES IN THE CSRA BUT MAINLY CONFINED TO NORTHERN PART. ACTIVITY CONTINUES TO MOVE SOUTH THOUGH. RUC AND MESOETA SHOW NVA REPLACING VORT LOBE OVER ALL OF THE CAE CWA BY MIDNIGHT. WILL DO QUICK UPDATE TO TAKE LIKELY POPS OUT OF ENTIRE AREA. WILL LEAVE IN CHANCE POPS CSRA UNTIL MIDNIGHT. NVA CONTINUES MONDAY MORNING...SO WILL SAY AFTERNOON ACTIVITY LIKELY ON MONDAY. TEMPERATURES STILL SOUND OK. OTHERWISE...NO MORE CHANGES. FCSTID = 7 CAE 74 89 72 87 / 10 60 50 60 AGS 71 89 70 88 / 30 60 50 60 SSC 73 88 72 88 / 10 60 50 60 OGB 74 88 71 88 / 10 60 50 60 .CAE... GA...NONE. SC...NONE. TTH sc AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY...UPDATED NATIONAL WEATHER SERVICE RAPID CITY SD 320 PM MDT SUN AUG 25 2002 WATER VAPOR DEPICTS UPR LOW OVR MT...WITH WEAK RIDGING EXTENDING NORTH THROUGH THE CNTRL ROCKIES. SFC TROF DVLPG IN THE LEE OF ROCKIES...WITH HIGH PRESSURE OVR CNTRL PLAINS RESULTING IN RETURN FLOW ACRS CWFA. STRONG CONVECTION STARTING TO FIRE OVR ERN MT AND WRN ND. WILL CONT TO SEE ISOLD PULSE TSTMS OVR BLKHLS INTO THIS EVE AS CAP HAS ERODED. AMS HAS DRIED AND MID-LVL FLOW PICKED UP...THEREFORE THREAT OF HEAVY RAINS AND SLOW MOVG TSTMS IS MINIMAL THIS EVE. TSTM ACTIVITY WILL LIKELY CONT TO DVLP ACRS ERN MT AND WRN ND. 18Z ETA/RUC BEGINNING TO PICK UP ON THIS ACTIVITY AND SPRDG IT E/SE TNGT. CORFIDI VECTORS SUGGEST IF THIS ACTIVITY EVOLVES INTO MCS IT WILL TRAVEL ESE...AFFECTING NWRN ZONES. ADDITIONALLY...LO LVL JET INCREASES LATER TONIGHT ACRS SRN ZONES WITH MUCAPE VALUES OF 1000-1500J/KG ALG WITH GOOD THETA-E ADVECTION. THEREFORE IF AN MCS DVLPS IT WILL HAVE THE POTENTIAL TO DVLP SWD ACRS ERN HALF OF ZONES. HOWEVER...IF MCS REMAINS TOO FAR NORTH...THERE WILL STILL BE DECENT SHOT OF SEEING ISOLD CONVECTION ACRS SRN/ERN ZONES AS ENOUGH UVV WILL BE IN PLACE. UPR LVL TROFING REMAINS THE DOMINANT FEATURE FROM THE PAC NW TO NRN ROCKIES THRU MID WEEK. IT WILL BE QUITE DIFFICULT TO TIME/POSITION SHORT WAVES EMBEDDED IN UNSTABLE SW FLOW...THEREFORE CHC OF POP WARRANTED THROUGH ENTIRE 1-3 DAY FCST. TEMPS WILL REMAIN FAIRLY CONSISTENT DURING THIS PD AS WELL. EXTENDED...CONTD TROFING WITH UNSETTLED WX PATTER EXPECTED THROUGH FRI...WITH LONGER RANGE GUIDANCE SHOWING SOME HINT OF SHORT WAVE RIDGING ON SAT. A MORE PROGRESSIVE TROF SWINGS THRU NRN PLAINS DAY 7 FOR RETURN TO UNSETTLED WX AND SLIGHT COOL DOWN. .UNR...NONE JOHNSON sd WEST CENTRAL TEXAS FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN ANGELO TX 300 PM CDT SUN AUG 25 2002 CURRENT...LAMP SURFACE WIND STREAMLINE ANALYSIS PLACES FRONT JUST SOUTH OF THE RED RIVER. SATELLITE IMAGERY SHOWS SUNNY SKIES CONTINUE TO DOMINATE WEST CENTRAL TEXAS. DAYS 1-4...LATEST RUC SUGGESTS SURFACE FRONT WILL STALL ACROSS THE NORTHERN BIG COUNTRY TONIGHT BEFORE RETREATING NORTH AGAIN TOMORROW. WILL GROUP OUR NORTHERN TWO COUNTIES SEPARATE FROM THE REMAINDER OF THE BIG COUNTRY TO ACCOUNT FOR SLIGHTLY COOLER TEMPERATURES AND INCREASED CLOUD COVER THERE TONIGHT AND TOMORROW. OTHERWISE...SUNNY DAYS...CLEAR NIGHTS...AND NIL POPS WILL CONTINUE THROUGH THE MIDDLE OF NEXT WEEK AS HIGH PRESSURE REMAINS IN CONTROL. THE MET MOS NUMBERS LOOK WAY TOO HIGH FOR AFTERNOON HIGHS. MAV NUMBERS LOOK BETTER...BUT TEMPERATURES CLOSE TO PERSISTENCE LOOK BEST WITH LITTLE CHANGE IN THE UPPER RIDGE. DAYS 5-7...SEE LITTLE CHANGE FOR WEST CENTRAL TEXAS THROUGH NEXT WEEKEND. CCF PRELIMS... ABI 075/099/075/098 0000 SJT 075/100/075/099 0000 JCT 074/098/074/098 0000 .SJT...NONE. 23/HUBER tx AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 330 PM CDT SUN AUG 25 2002 PRIMARY CONCERNS REMAIN FOCUSED ON FOG POTENTIAL TONIGHT...THEN TIMING AND EXTENT OF NEXT RAIN CHANCES. AT LATE AFTERNOON...VISIBLE SATELLITE IMAGERY SHOWED LINE OF TOWERING CUMULUS HAD DEVELOPED ALONG WEAK CONVERGENCE ZONE FROM NEAR KAEL TO KOLZ. RADAR INDICATED ISOLATED SHRA/TSRA HAD FORMED ALONG THIS LINE AS WELL. RUC MODEL DEPICTED THIS WEAK BOUNDARY AND ALSO SHOWED THE CONVECTION. IN THE UPPER ATMOSPHERE...WEAK WINDS ALOFT OVER THE UPPER MIDWEST BETWEEN TROUGH OVER THE NORTHEAST U.S. AND THE NORTHERN PLAINS. THE NORTHERN ROCKIES CIRCULATION SEEN WELL IN WATER VAPOR IMAGERY NEAR THE NORTH DAKOTA/MONTANA BORDER. THE AVN AND ETA MODELS FROM THE AUGUST 25TH 12Z DATA SET WERE IN OVERALL AGREEMENT ON FORECAST SCENARIO. HOWEVER...AVN GENERATED QPF ACROSS SOUTHEAST MN AND NORTHEAST IOWA MONDAY EVENING...WHILE ETA DID NOT. OTHERWISE...THE ETA AND AVN ADVERTISED KEEPING QPF NORTH AND WEST OF THE FORECAST AREA MONDAY INTO TUESDAY FOR THE MOST PART. THIS APPEARS DUE TO LARGE SURFACE HIGH RIDGING OUT OF SOUTHEAST CANADA NEXT COUPLE DAYS...WHILE MONTANA/NORTH DAKOTA SHORT WAVE LIFTS ONLY VERY SLOWLY TOWARD LAKE WINNIPEG. NCEP SHORT RANGE ENSEMBLE CONTINUES TO INDICATE HIGHEST PROBABILITIES OF RAIN MONDAY THROUGH TUESDAY WEST OF THE MISSISSIPPI RIVER AS WELL. ISOLATED CONVECTION OVER SOUTHEAST MN AND NORTHEAST IOWA EXPECTED TO END THIS EVENING AS WEAK CONVERGENCE PUSHES SOUTHWARD. CONFIDENCE WAS HIGH THERE WILL BE AREAS OF DENSE FOG AGAIN TONIGHT DUE TO GOOD RADIATIONAL COOLING AND LIGHT WINDS. WE BELIEVE THE DENSE FOG SHOULD NOT BE WIDESPREAD ENOUGH TO WARRANT AN ADVISORY. AFTER THE FOG DISSIPATES MID-MORNING MONDAY...INSTABILITY INCREASES WITH SURFACE BASED CAPE BUILDING TO 2000-3000 J/KG ALONG AND WEST OF THE MISSISSIPPI RIVER. THUS OPTED TO MAINTAIN RAIN CHANCES MONDAY NIGHT ACROSS SOUTHEAST MN AND NORTHEAST IOWA...BUT KEPT MISSISSIPPI RIVER ZONES EASTWARD INTO CENTRAL WI DRY. THIS DUE DRYING/SUBSIDENCE ASSOCIATED WITH SURFACE HIGH BUILDING IN ACROSS THE GREAT LAKES. TUESDAY STILL PROBLEMATIC WITH RESPECT TO RAIN CHANCES...ESPECIALLY ACROSS WI ZONES WHERE INFLUENCE OF SURFACE HIGH CONTINUES. CONFIDENCE WAS NOT HIGH ENOUGH TO PULL RAIN CHANCES...SO MAINTAINED PROBABILITIES IN THE CHANCE CATEGORY AREAWIDE FOR TUESDAY. NORTHERN PLAINS UPPER TROUGH CONTINUES TO BE A PLAYER THROUGH MIDWEEK. FLOW ALOFT REMAINS WEAK...BUT DECENT INSTABILITY PERSISTING...SO APPEARS RAIN CHANCES WILL BE WARRANTED THROUGH THURSDAY AS ANY SORT OF MESOSCALE BOUNDARIES SHOULD TRIGGER CONVECTION. PERSISTENCE AND CONTINUITY APPEARS THE WAY TO GO WITH TEMPERATURE FORECAST. HIGHS IN THE UPPER 70S TO LOWER 80S...WITH LOWS IN THE UPPER 50S TO LOWER 60S LOOK REASONABLE. AVN...NGM...ETA MOS GUIDANCE IN OVERALL SUPPORT OF THESE VALUES. .LSE...NONE. THOMPSON wi AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 225 AM CDT MON AUG 26 2002 MAIN FORECAST CONCERNS THIS PACKAGE INCLUDE NEAR TERM DENSE FOG POTENTIAL...PRECIP CHCS IN NORTH TODAY AND TEMPERATURES. LESS CI ACROSS FA TONIGHT THAN LAST NIGHT...WHEN WIDESPREAD DENSE FOG DID NOT DEVELOP. SO FAR MASON CITY...WATERLOO...AND FORT DODGE HAVE DROPPED DOWN BELOW ONE MILE AT TIMES. AREAS FROM MASON CITY TO AROUND WATERLOO...AND SOUTH TO AROUND OTTUMWA RECEIVED SOME DECENT RAIN SUNDAY AFTERNOON...AND ARE MOST FAVORED FOR DENSE FOG OVER THE NEXT FEW HOURS. WL MONITOR TRENDS TOWARDS FOR POSSIBILITY OF LAST-MINUTE ADVISORY BEFORE ISSUANCE. SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND EVENING VERY MUCH IN QUESTION. AVN AND EXTENDED RUC SUGGEST SCATTERED PRECIP...WHILE ETA/NGM REMAIN DRY. THERE WILL BE SOME FAVORABLE CAPE AND WEAK SHORTWAVE MOVING THROUGH...SO HESITANT TO PULL LOW POPS IN NORTH COMPLETELY. WL SCALE BACK WORDING TO ISOLATED. EASTERLY FLOW FAVORABLE FOR FOG LATE TONIGHT...ALTHOUGH WIND SPEED PROGGED TO BE UP SLIGHTLY. WL MENTION PATCHY FOG LATE TONIGHT/EARLY TUESDAY. TUESDAY AND MUCH OF WEDNESDAY LOOK DRY. RAIN CHC WEDNESDAY NIGHT ALSO QUESTIONABLE PER AVN/EXTENDED ETA....BUT WITH LOW CONFIDENCE...WL LEAVE MENTION IN FOR CENTRAL AND NORTHERN FA. FOR TEMPERATURES...COOLER MAV GUIDANCE TURNED OUT TO BE A BIT TOO COOL FOR SUNDAY AFTERNOON. I'LL GO WITH A BLEND FOR MAXES...AND STAY TOWARDS THE WARM END FOR MINS. IN THE EXTENDED (THU-SUN) RAIN CHC STILL LOOKS TO BE NORTH AND WEST OF FA ON THURS AND FRI...WITH THE NEXT CHC OF PRECIP LATE SAT INTO SUNDAY WITH FROPA. TEMPS WL REMAIN JUST ABOVE NORMAL. NO CHANGES PLANNED TO EXTENDED GRIDS. .DSM...NONE. KINNEY ia AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 1030 AM EDT MON AUG 26 2002 FRONTAL BOUNDARY TO OUR S AND WAVES OF LOW PRES EXPECTED TO RIDE ALONG THE FRONT. ONE VORT HAS JUST ABOUT MOVED THROUGH OUR CWA THIS MORNING AND DUMPED OVER AN INCH OF RAIN IN A FEW SPOTS (HERE AT MHX WE RECEIVED 1.37 AND NCA 1.64). ANOTHER VORT SHOULD MOVE THROUGH THIS AFTERNOON SPAWNING ANOTHER ROUND OF SHRA/TSTMS. WILL BACK OFF POPS A LITTLE FOR THIS AFTERNOON BECAUSE IT WILL NOT RAIN ALL AFTERNOON. WILL GO WITH 80%. WILL ALSO MAKE SOME MINOR TWEAKS TO WINDS. NC WILL BE IN THE FAVORED RRQ OF UPPER JET THIS AFTERNOON BUT SOUNDING FROM MHX AND GSO DO NOT FAVOR SEVERE TSTMS. 12Z MHX SOUNDING REAL JUICY WITH PW OF 2.19. CAPE IS DOWN A BIT FROM YESTERDAY'S 1936 J/KG TO 1351 J/KG TODAY. LI THIS MORNING WAS -3 COMPARED TO -4 YESTERDAY. FCST MAX TEMP FROM SOUNDING IS 82 BUT ALL IT WILL TAKE IS FOR SOME PEAKS OF SUNSHINE WHICH WILL ALLOW FOR FCST VALUES OF MID 80S TO BE ATTAINABLE. MARINE...CRNT SFC ANAL SHOWG FRNT RUNNG ALNG THE CST. LTST RUC KPG FRNT S OF WTRS TDY WHILE 6Z ETA BRINGS IT N AND HAS IT NR OREGON INLET ARND 0Z AND AVN BRINGS IT N OF WTRS BY 0Z. NONE OF THE MDLS INITIALIZED VERY WL ON PSN OF FNT. WL LEAN TWRDS 6Z ETA AND MODIFY WI CRRNT CONDS. OTRWS NO MJR CHGS PLANNED IN CWF. .MHX...NONE WS/CGG-G nc UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 1025 AM MDT MON AUG 26 2002 .SYNOPSIS...AN UPPER LEVEL TROUGH WILL DEVELOP OVER THE WESTERN STATES TODAY AND REMAIN OVER THE REGION THROUGH WEDNESDAY. .DISCUSSION...UPPER FLOW PATTER SHOWS A BROAD LONGWAVE RIDGE EXTENDING ACROSS CANADA WITH SEVERAL WEAKNESSES IN THE WEST UNDERNEATH THIS RIDGE. ONE SUCH TROUGH CURRENTLY MOVING THROUGH EASTERN OREGON. THIS SYSTEM IS STILL MODELED TO MOVE INTO THE FORECAST AREA LATE THIS AFTERNOON AND TONIGHT...THEN STICKS AROUND IN WEAK UPPER FLOW THROUGH AT LEAST WEDNESDAY. GOOD DYNAMICS SHOULD MOVE THROUGH THE NORTH LATE THIS AFTERNOON...BUT WITH LITTLE MOISTURE TO WORK WITH. ENOUGH FOR HIGH BASED CONVECTION OVER HIGHER TERRAIN...WHICH IS COVERED IN CURRENT FORECAST. MORE WIDESPREAD CONVECTION SHOULD BE NORTH OF THE AREA. COLD FRONT ASSOCIATED WITH UPPER TROUGH LOOKS TO BE MOVING THROUGH CENTRAL NEVADA AT THIS TIME. LIKELY JUST MOVED THROUGH WINNEMUCCA PAST HOUR WITH A SLIGHT JUMP IN THEIR NORTHWEST WIND AND A PRESSURE RISE. NOT A SHARP BOUNDARY HOWEVER. THIS FITS WITH LATEST RUC ANALYSIS. RUC AND MESOETA PUSH THE FRONT THROUGH THE NORTHWEST THIRD OF THE AREA AS EARLY AS LATE THIS AFTERNOON. INITIAL WIND SHIFT WILL BE FAIRLY MINOR...NOT TO BE CONFUSED WITH ANY LAKE BREEZE SOUTH OF THE LAKE...THEN FOLLOWED BY STRONGER NORTHWEST WINDS THIS EVENING THAT WILL DIMINISH THROUGH THE NIGHT. FORECAST LOOKS GOOD AT THIS TIME SO NO ADJUSTMENTS NEEDED. SLC 243 CDC 011 JACKSON .SLC...RFW...FIRE WEATHER WATCH FOR DRY LIGHTNING NORTHERN AND CENTRAL UTAH FOR LATE THIS AFTERNOON AND TONIGHT. ut INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA 300 PM PDT MON AUG 26 2002 WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUES TO SHOW A SHORTWAVE TROUGH PUSHING THROUGH THE PACIFIC NORTHWEST THIS AFTERNOON. SATELLITE IMAGERY DOES SHOW SOME HIGH LEVEL CLOUDS HEADING TOWARDS THE NORTHERN EDGE OF THE CWFA...HOWEVER...WILL EXPECT MUCH OF IT TO DISSIPATE BEFORE REACHING THE DISTRICT. HIGH CENTERED OVER THE SOUTHWEST REMAINS FLAT AND ELONGATED AS THE FLOW ALOFT REMAINS WESTERLY TO NORTHWESTERLY. THEREFORE...WILL EXPECT NO NORTHWARD TRANSPORT OF MONSOONAL MOISTURE INTO THE SIERRA NEVADA. MODELS HAVE SHOWN GOOD RUN TO RUN AGREEMENTS IN DROPPING THE UPPER LOW IN A RETROGRADE FASHION FROM EASTERN OREGON. THIS WILL PROVIDE FOR A MORE NORTHERLY TO ALMOST NORTHEASTERLY FLOW ALOFT. THE MAIN CONCERN FOR THE SHORT TERM WILL BE THE BEHAVIOR OF TEMPERATURES WITH THE INTRODUCTION OF THE TROUGH. WILL CONTINUE TO UNDERCUT GUIDANCE AS IT SHOWS FORECASTED MAX TEMP/S FROM THE UPPER-MID 90S TO ALMOST 100 DEGREES ON TUESDAY. FEEL THAT AS THE TROUGH DROPS HEIGHTS ON TUESDAY...TEMPERATURES WILL RESPOND WITH A FEW DEGREES OF COOLING. WILL INCREASE WINDS ON TUESDAY AS A VORT MAX SWINGS THROUGH THE DISTRICT. YET...WILL EXPECT THE WIND INCREASE TO REACH BREEZY LEVELS AND LOCALLY WINDY OVER THE HIGHER ELEVATIONS IN THE AFTERNOON. WILL SEE FURTHER COOLING ON WEDNESDAY BEFORE THE TROUGH LIFTS OUT ON THURSDAY. WILL SEE SLIGHT WARMING ON THURSDAY...BUT... WILL EXPECT IT TO REMAIN WEAK AS ANOTHER TROUGH ENTERS TO REGION ON FRIDAY. THE FLOW PATTERN CURRENTLY OVER THE DISTRICT AND THE ONE EXPECTED ON THURSDAY WILL NOT LAST LONG ENOUGH TO ALLOW MOIST MONSOONAL AIR TO PUSH NORTHWARD. THEREFORE...WILL EXPECT SEVEN DAYS OF DRY CONDITIONS. AFTER A BRIEF WARM-UP THURSDAY OF A DEGREE OR TWO...HEIGHTS BEGIN FALLING ON FRIDAY TO FURTHER THE COOL DOWN OVER THE DISTRICT. EVEN WITH ALL OF THE SHORT AND LONGER RANGE MODELS SHOWING AGREEMENT WITH THIS EVENT...GUIDANCE REMAINS VERY WARM THROUGH THE PERIOD. WILL CONTINUE TO GO BELOW TO WELL BELOW GUIDANCE THIS FORECAST PACKAGE AS THE TWO TROUGHS PROVIDE FOR STABLE COOL AIR TO SETTLE OVER THE REGION FOR SEVEN DAYS. .HNX...NONE. MOLINA ca INTERIOR CENTRAL CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD CA 945 AM PDT MON AUG 26 2002 WATER VAPOR IMAGERY AND RUC ANALYSIS IS SHOWING A SHORTWAVE PUSHING THROUGH THE PACIFIC NORTHWEST INTO THE INTER-MOUNTAIN REGION. THIS SHORTWAVE HELPED KICK OUT THE CUT OFF UPPER LOW THAT SPUN AROUND EASTERN OREGON/WESTERN IDAHO OVER THE WEEKEND. THE SHORTWAVE REMAINED TOO FAR NORTH TO INFLUENCE THE DISTRICT/S WEATHER OTHER THAN INCREASE SOME OF THE UPPER LEVELS WINDS. UPPER AIR OBSERVATIONS FROM OAKLAND AND VANDENBERG WERE SHOWING GOOD NORTHERLY FLOW OF 10 TO 20 KNOTS ABOVE 2500 FEET THIS MORNING. YET...BOTH LOCATIONS ALSO SHOWED WARMING IN THE LOWER LEVELS ON THE 24 HOUR TREND. THEREFORE... FEEL THAT POSSIBLE DOWNSLOPE WINDS FROM THE NORTHERLY FLOW MAY BE RESPONSIBLE FOR THE WARMING IN THE LOWEST LAYERS. HOWEVER...THE FLOW ALOFT BECOMES MORE WESTERLY TO NORTHWESTERLY WITH HEIGHT...SO WILL NOT EXPECT ANY MOISTURE TO TRANSPORT NORTHWARD IN THE NEAR FUTURE. CURRENT TRENDS STILL LOOK REASONABLE WITH FORECASTED CONDITIONS... SO NO UPDATED NEEDED AT THIS TIME. .HNX...NONE. MOLINA ca AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DES MOINES IA 312 PM CDT MON AUG 26 2002 SYNOP...CNTRL U.S. RDG XPNDG WITH TROFING OVR THE WRN U.S./ROCKIES. BEST LOW LVL MOISTURE TRANSPORT...INSTABILITY...ETC W OF FA. E/SE LOW LVL FLOW WITH LWR H8 THETAE AIR PUSHING OVR MOST OF FA. SHORT TERM...WK LOW LVL CONVERGENCE AIDING IN ISOLD TRW DVLPMT IN SRN MN...MAY BUILD INTO N CNTRL IA THIS EVEN. 18Z RUC LENDS SOME SUPPORT TO THIS. PREV FCST HAD MENTIONED AND WL LET IT RIDE. OTRW AMS HAS NOT CHGD SO XPCG MORE FOG OVRNGT. NICE DAY TMR WITH TOLERABLE DEWPTS AND HIGHS IN THE L-M80S. LONGER TERM...CUR FCST HAS TSTM MENTION WED NGT AND THU MRNG NRN HALF AS S/W TOPS THE RDG. H8 BNDRY SINKS INTO NRN IA TO ACT AS A FOCUS WITH SOME RETURN FLOW. DRY FCST TIL LATE SAT INTO SUN UNTIL NXT XPCD WAVE. HIGHS THRU THE PD IN THE 80S WITH LOWS IN THE 60S. .DSM...NONE MYERS ia AREA FORECAST DISCUSSION...MORNING ZONE UPDATE NATIONAL WEATHER SERVICE PADUCAH KY 1207 PM CDT MON AUG 26 2002 MAIN ADJUSTMENT TO ZONE PACKAGE JUST ISSUED WAS POP/TEMPERATURE FORECAST FOR EAST OF A KMVN-KPAH LINE AND CLOUD FORECAST WEST OF THAT LINE. AVN MOS TEMPS PRETTY CLOSE...SO ONLY MADE MINOR TEMPERATURE RANGE TWEAKS FOR REVISED DIGITAL FORECAST. ALSO MADE ADJUSTMENTS TO THU-SAT TIME PERIOD PCPN/CLOUD FORECAST. MAIN VORT CENTER ASSOCIATED WITH THE RECENTLY DEVELOPED CLOSED LOW WAS CENTERED APPROXIMATELY 25 NM SE OF KOWB /OWENSBORO KY/ AT 26/15Z...WITH BEST GUESS LOCATION OF CENTER OF 50H LOW NEAR KFFT /FRANKFORT KY/. THE LOW CENTER IS CLOSE TO THE 12Z UPPER MANUAL ANALYSIS AND THE 26/00Z MRF AND 26/12Z AVN PROGGED LOCATION. THE ETA AND NGM MODELS SEEMED TO INITIALIZE THE LOW TOO FAR INTO ERN KY. QPF FIELDS FOR PCPN THIS AFTN APPEARED TO BE 70NM TOO FAR NORTHEAST FOR THE 15Z RUN OF THE 40 KM RUC MODEL...AND 140-150 NM SW FOR THE 12Z AVN MODEL. WITH MINOR ADJUSTMENTS FOR DIFFERENCES IN MASS AND TEMPERATURE FIELDS...BELIEVE THE BEST CHANCES OF FOR MEASURABLE RAIN SHOULD BE EAST OF A FAIRFIELD IL...PRINCETON TO MURRAY KY LINE THIS AFTN. I AM CONCERNED THAT SOME CONVECTION MAY DEVELOP AND DRIFT OFF THE FOOTHILLS IN SERN MO INTO SWRN IL...BUT CONSIDERED THAT COVERAGE MAY BE TO SMALL TO WARRANT MENTION IN CURRENT ZONE PACKAGE. .PAH...NONE. SMITH ky AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 315 PM CDT MON AUG 26 2002 A LINE OF THUNDERSTORMS HAVE DEVELOPED ALONG A WEAK SURFACE BOUNDARY IN CENTRAL AND SOUTH CENTRAL MN. SOME POTENTIAL FOR HEAVY RAIN AS THE STORMS HAVE VERY LITTLE SHEAR. STORMS ARE EXPECTED TO DIURNAL. THE OTHER CONCERN IS POSSIBLE DEVELOPMENT OVER WEST CENTRAL MN WITH LOW-MID LEVEL THETA-E ADVECTION AND A MODERATE LOW LEVEL JET. THE MODELS DIVERGE ON THIS DEVELOPMENT WITH THE ETA DRIER AND FURTHER WEST. THE LATEST RUC MODEL ALSO SHOWS WEAK FORCING AND DEVELOPMENT. THE FORECAST WILL CONTINUE A SMALL CHANCE IN W CENTRAL ZONES. THE AVN AND ETA MODELS ARE CONSIDERABLY DIFFERENT IN THE DEVELOPMENT OF THE WEATHER TUESDAY AND WEDNESDAY. THE AVN IS MORE AGGRESSIVE AND ADVECTS INSTABILITY ACROSS MUCH OF MN...WHILE THE ETA MAINTAINS A STRONG HIGH TO THE EAST AND KEEPS ERLY FLOW OVER THE ERN ZONES AND THE STRONGER INSTABILITY TO THE WEST. BOTH MODELS HAVE TRENDED A SLOWER AND FURTHER WEST DEVELOPMENT FROM PREVIOUS RUNS. THE CUTOFF LOW FORECAST FOR THE GREAT BASIN IS FORECAST TO PUSH OUT AS A WAVE THURSDAY...STRONGER SWRLY FLOW IS EXPECTED INTO THE WEEKEND STRONGER FLOW INTO MN AND A CHANCE OF THUNDERSTORMS FOR LABOR DAY WEEKEND. .MSP...NONE. SCOTT mn AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE ST LOUIS MO 200 PM CDT MON AUG 26 2002 MAIN CONCERNS THIS PKG TO BE CLD CVR AND TEMPS IN NR TERM AND CHCS FOR PCPN OVR WKEND IN XTNDD. VSBL SAT PIX SHWG VORT CTR NOW OVR CTRL KY AT 18Z. RUC AND AVN HV BEST PLACEMENT WITH ETA ABOUT 75NMI TOO FAR E. MDLS KEEP THIS LO QSTNRY THRU 72H AND THEN FILL AS 50H CTRS STRENGTHEN OVR SW AND WRN ATLC. L/WV TROF MVS INTO NW US BY 120HR WITH A S/WV MOVG ACRS NRN PLNS AT SAME TIME. SFC HI FM GT LKS INTO NE US SHUD KEEP NE-ELY SFC WNDS ACRS FA THRU NR TERM WITH AT OR SLGTLY BLO NRML TEMPS. LOTS OF CU AND A FEW SHWRS DVLPG THIS AFTN OVR NE MO IN LO LVL CNVRNGC. XPCT THIS ACTVTY TO WKN AND DISPT THIS EVE. MAY INCLD A THIS EVE PD IN CTRL AND ERN ZNS THO TO ACCT FOR PCPN PSBLTY. MDLS INDCTG VERY LO POPS UNTIL WELL INTO XTNDD AND WL KP ZNS DRY PER GOING FCSTS. XPCT SUM SMALL VORT MAXES TO ROTATE ARND 50H LO WHICH COULD TRIGGER SUM WDLY SCTD SHWRS...MAINLY AFTN...BUT TRICKY TO IDENTIFY VERY FAR IN ADVANCE. MRF INCRSNG POPS LT IN XTNDD BUT RELUCTANT TO INTRO POPS THIS FAR IN ADVANCE FOR MAJ HOLIDAY WKEND WITHOUT MORE CONFIRMATION. TEMPS TO CONT NR NRML. .STL...NONE WDB mo AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 250 PM EDT MON AUG 26 2002 CLOSED 500MB LOW NOW OVER KENTUCKY THE PROBLEM FOR THE WEEK. LATEST RUC ANALYSIS ALSO SHOWING CLOSED 850MB LOW OVER NC/SC BORDER. SFC WIND FIELD SHOWS AN INVERTED TROUGH TO AROUND HATTERAS. NORTH OF THAT INVERTED TROUGH/WIND SHIFT...DEW POINTS HAVE FALLEN TODAY AS DRIER AIR ADVECTS IN FROM THE NORTH. ETA/AVN HAVE CAUGHT ON TO THIS DRYING TREND AND ARE TRENDING DRIER WITH QPF. AVN GUIDANCE LOOKED GOOD TO ME AS NGM WAS WETTER THIS RUN WHICH SEEMS INCONSISTENT WITH OBSERVATIONS. KEPT CWA DRY THROUGH TOMORROW. A STRAY SHRA/TSRA MAY MOVE IN FROM SOUTH INTO SOUTHERN BORDER COUNTIES TOMORROW EVENING. MAIN RAIN LOOKS TO HOLD OFF UNTIL WEDNESDAY FOR SOUTHERN AREAS AND WEDNESDAY NIGHT FOR NORTHERN AREAS. EXTENDED...BEST CHANCE AT RAIN SEEMS TO BE THU BUT AVN NOW MORE AGGRESSIVE WITH BACKDOOR FRONT WHICH PUSHES INTO NE PA. WITH SOUTHERLY MOIST FLOW AROUND BUILDING RIDGE FROM WESTERN ATLANTIC A NICE CONVERGENCE ZONE SEEMS TO SET UP ACROSS PA FRI-SAT. LEFT CHANCE POPS FOR SHRA/TSRA IN FCST THROUGH SUNDAY...ALTHOUGH SUNDAY LOOKS MAINLY DRY. HOPEFULLY ENTIRE HOLIDAY WEEKEND WON'T BE A WASHOUT. WORK ZONES ALREADY SENT AS PHLWRKMIS. .CTP... PA...NONE. DIRIENZO pa AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LA CROSSE WI 250 PM CDT MON AUG 26 2002 PRIMARY FOCUS OF THE FORECAST WILL BE CENTERED ON SURFACE HIGH PRESSURE BUILDING ACROSS THE GREAT LAKES AND ITS EFFECTS ON RAIN CHANCES THAT ARE CURRENTLY IN OUR FORECAST. AFTERNOON SURFACE ANALYSIS INDICATED HIGH PRESSURE CENTERED NEAR HUDSON BAY...ASSOCIATED WITH COOLER/DRIER AIR ACROSS SOUTHEAST CANADA. OVER THE UPPER MISSISSIPPI VALLEY...SUBTLE BOUNDARY DETECTED FROM NEAR KMKT TO KMCW...TRIGGERING ISOLATED CONVECTION AS HAS BEEN THE CASE LAST COUPLE OF DAYS. IN ADDITION...OUTFLOW BOUNDARY PUSHING OFF LAKE SUPERIOR INTO NORTHERN WI...WHICH COULD ALSO TRIGGER CONVECTION. FURTHER WEST...SOUTHERLY FLOW CONTINUES ACROSS THE PLAINS...FUELING CLUSTERS OF TSRA. WATER VAPOR IMAGERY SHOWED MAIN CIRCULATION CENTERED IN SOUTHEAST SASKATCHEWAN...WHILE ANOTHER WAVE LOCATED OVER THE PACIFIC NORTHWEST. AUGUST 26TH 12Z MODELS INITIALIZED WELL AND THERE WERE NO MAJOR DIFFERENCES NOTED IN THE FORECAST UPPER AIR OR SURFACE FEATURES. IN THE 60HR-84HR TIME FRAME...THE ETA DEPICTED QPF MAINLY OVER NORTH AND WEST PORTIONS OF THE FORECAST AREA AS COMPARED TO THE AVN. DECIDED TO USE A COMPROMISE APPROACH...WITH RAIN CHANCES WEDNESDAY NIGHT FROM SOUTHEAST MN INTO NORTH CENTRAL WI...THEN RAIN CHANCES AREAWIDE ON THURSDAY. RUC MODEL INDICATED POTENTIAL FOR EVENING CONVECTION IN NORTH CENTRAL WI ASSOCIATED WITH SOUTHWARD MOVING LAKE BOUNDARY...SO INCLUDED MENTION OF ISOLATED SHRA/TSRA THERE. RUC ALSO SHOWED POTENTIAL FOR EVENING CONVECTION IN SOUTHEAST MN. CURRENT CONVECTION ALONG BOUNDARY IN SOUTH CENTRAL MN ANTICIPATED TO DRIFT SOUTHWARD...TAKING IT INTO NORTH CENTRAL IOWA...SO PLAN TO KEEP NORTHEAST IOWA/SOUTHEAST MN ZONES DRY. OTHERWISE...ANOTHER CLEAR TO PARTLY CLOUDY NIGHT EXPECTED...WITH PATCHY VALLEY FOG ALONG MISSISSIPPI AND WISCONSIN RIVER VALLEYS. ALL OF THE MODELS TRANSIT THE SURFACE HIGH ACROSS SOUTHEAST CANADA THROUGH MIDWEEK...WITH ASSOCIATED RIDGE BUILDING INTO THE GREAT LAKES. THE COMBINATION OF DRIER EASTERLY FLOW AND LOW LEVEL MOISTURE TRANSPORT REMAINING WEST SHOULD KEEP CONVECTION TO THE NORTH AND WEST. AS A RESULT...HAVE OPTED FOR A DRY FORECAST THROUGH WEDNESDAY. SCATTERED CONVECTION POSSIBILITY STILL APPEARS VIABLE WEDNESDAY NIGHT INTO THURSDAY. MODELS INDICATED WEAK REFLECTION OF A SURFACE TROUGH...ALONG WITH LOW LEVEL THETA-E CONVERGENCE...CROSSING THE FORECAST AREA. AS MENTIONED IN PREVIOUS ARX FORECAST DISCUSSIONS...PERSISTENCE STILL LOOKS GOOD WITH RESPECT TO TEMPERATURES. AS A RESULT...NEXT FEW DAYS SHOULD HAVE DAYTIME HIGHS FROM NEAR 80 TO THE MID 80S...WITH NIGHTTIME LOWS IN THE MID 50S TO NEAR 60. PREFERRED THE ETA MOS GUIDANCE AND ETA 2M TEMPERATURES DUE TO GOOD TRACK RECORD OF LATE. IN THE MEDIUM RANGE...SURFACE RIDGING FROM HIGH PRESSURE OVER SOUTHEAST CANADA CONTINUES TO INFLUENCE THE WEATHER THROUGH THE END OF THE WEEK. THUS...PLAN TO MAINTAIN DRY CONDITIONS INTO THE FIRST HALF OF THE WEEKEND IN SPITE OF QPF DEPICTED BY AVN. WE RETAINED CONTINUITY OF NEXT CHANCE FOR RAIN ON SUNDAY...BUT LOW CONFIDENCE IN THIS DUE TO MAIN STORM TRACK REMAINING IN CANADA. .LSE...NONE. THOMPSON wi