000 FXUS64 KBMX 110833 CCA AFDBHM AREA FORECAST DISCUSSION...CORRECTED FOR PUNCTUATION NATIONAL WEATHER SERVICE BIRMINGHAM, AL 300 AM CDT WED SEP 11 2002 FORECAST QUANDARIES...FRONTAL MOVEMENT S...CONDITIONS APPROACHING/AT RED FLAG WARNING CRITERIA CNTRL AND S....AND TEMPS. OK...MOCLR SKIES ACROSS CWA. MSAS/HAND SFC ANALYSES SHOWING DRY COLD FRONT APPROACHING MO BOOTHEEL...STRETCHING FROM TX PANHANDLE W TO E LAKE ERIE E. GUSTAV MOVING TO NE...OFF CAROLINA/S COAST. TEMPS MID 60S TO LOW 70S... DEWPOINT DEPRESSIONS 5 TO 10...CALM WINDS...UNDER STABLE ATM CONDITIONS. BROAD RIDGING ACROSS W U.S...WITH NWLY FLOW DEVELOPING ACROSS REGION... AS TROUGHING ACROSS E GREAT LAKES DEVELOPS. 00Z WED REGIONAL MODEL EVOLUTIONS THRU 12Z FRI IN GOOD AGREEMENT. AGREE WITH CURRENT MODEL DIAGNOSTIC DISCUSSION REASONING THAT AVN HAS HAD GOOD RUN TO RUN CONSISTENCIES. TUE WEATHER HANDLED WELL BY AVN...ESPECIALLY TEMPS. AVN ALSO INITIALIZED WELL WITH CURRENT FRONTAL BOUNDARY POSITION. THUS...WILL LEAN TOWARD SOLUTION. MODELS CONTINUE TO SHOW COLD FRONT PUSHING INTO N AL BY 12Z TODAY. QUESTION WHETHER THIS MOVEMENT IS TOO FAST...AND LOOK FOR MORE OF A LATE MORNING/ EARLY AFTERNOON CROSS OVER OF THE AL/TN BORDER. THUS...FRONT MAY NOT PUSH AS FAR S AS PREVIOUSLY EXPECTED...BUT DO EXPECT IT TO HAVE PUSHED TO NEAR BHM BY 00Z THU. FRONTAL PASSAGE WILL BE DRY....WITH MIDWEST HIGH PRESSURE SYSTEM BUILDING IN BEHIND. FRONT WILL EVENTUALLY HANG UP ACROSS S AL THRU LATE THU. NWLY UPPER LEVEL FLOW WILL CONTINUE THRU PERIOD. ENOUGH MOISTURE WILL BE AHEAD OF FRONT...AND REMAIN BEHIND...TO SUPPORT PTCLDY SKIES TODAY AND CLR SKIES TONIGHT. BELIEVE MOISTURE WILL HAVE DECREASED ENOUGH ON THU TO SUPPORT MOSUNNY SKIES N...BUT PTCLDY SKIES S. WILL GO PTCLDY THU NIGHT... AS AVN ADVECTS MOISTURE NW FROM DEVELOPING E GULF LOW. RED FLAG WARNING DISCUSSION...LOCAL CRITERIA STATES...RED FLAG WARNING IS ISSUED FOR AREA WHEN FOLLOWING CONDITIONS OCCUR CONCORRENTLY: RH EQUAL TO OR LESS THAN 30%...SUSTAINED SFC WIND SPEEDS EQUAL TO OR GREATER THAN 10 MPH ...AND KBDI EQUAL TO OR GREATER THAN 600. WITH FRONTAL TIMING PASSAGE LATER THAN PREVIOUSLY EXPECTED...DO NOT BELIEVE RH VALUES WILL GET BELOW 30% FOR A SIGNIFICANT AMOUNT OF TIME THIS AFTERNOON. RH VALUES MUCH MORE CONDUCIVE OVER GA. SUSTAINED WINDS FORECASTED GENERALLY LESS THAN 10 MPH...LESS THAN PREVIOUSLY EXPECTED 10 TO 15 MPH. KBDI VALUES GREATER THAN OR EQUAL TO 600 ACROSS CNTRL ZONES...WHERE RH VALUE THRESHOLDS QUESTIONABLE. ALL IN ALL... WILL GET CLOSE...BUT DO NOT THINK...OVER A SIGNIFICANT PERIOD OF TIME THIS AFTERNOON...WE WILL REACH LOCAL CRITERIA. REASONING ALSO BACKED UP BY SPC FIRE WEATHER OUTLOOK GRAPHIC. WILL MENTION NEAR RED FLAG CONDITIONS THIS AFTERNOON IN FIRE WEATHER FORECAST. REST OF WEEK...SWLY UPPER LEVEL FLOW WILL DEVELOP ON FRI...WITH BROAD UPPER LEVEL TROUGH PASSAGE ACROSS STATE BY TUE MORNING. LOOK FOR SFC FRONT TO ALSO PUSH ACROSS AREA ON SUN. RIDGING INFLUENCES SHOULD BUILD INTO STATE AS TUE PROGRESSES. CURRENT FORECAST HANDLES SITUATION WELL...AND WILL MAKE ONLY MINOR TEMPS CHANGES IF ANY. TEMPS...TRICKY TEMP FORECAST FOR TODAY...EXACT TIMING OF FRONTAL PASSAGE CRITICAL. BELIEVE NW CORNER WILL STILL BE COOLEST SPOT...AND FRONT SHOULD PASS BEFORE MAX HEATING. WILL CONTINUE WITH 85 TO 90 WORDING HERE. WILL CONTINUE WITH LOWS 90S...BELOW RECORD VALUES...OTHER E LOCATIONS AS FRONTAL PASSAGE INFLUENCES ON HIGHS STILL QUESTIONABLE. WITH FRONT BEING IN GENERAL VICINITY OF BHM BY 00Z THU...DO NOT BELIEVE IT WILL RETARD MAX HEATING INFLUENCES. THUS...RECORD VALUE OF 98 FOR BHM PROBABLY SAFE...BUT RECORDS OF 96 FOR TCL AND ANB COULD BE REACHED. WILL MENTION NEAR RECORD HIGHS IN ZONES THESE LOCATIONS. RECORD HIGH OF 98 AT MGM IN JEOPARDY...AND WILL MENTION NEAR RECORD TEMPERATURES HERE ALSO. EXPECT ALL AREAS COOLER ON THU...AND WILL GO CLOSE TO AVN MOS NUMBERS. THANKS FOR COORDINATION BNA AND MOB PRELIMINARY NUMBERS FOR COORDINATION PURPOSES ONLY... HSV 092/062/086/060 0000 BHM 096/064/088/062 0000 MGM 099/068/091/065 0000 .BHM...NONE. 89 JBW