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000 FXUS62 KMFL 221421 AFDMFL AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MIAMI FL 1021 AM EDT MON SEP 22 2008 .UPDATE... EAST COAST SEA BREEZE IS ALREADY MOVING THROUGH THE EAST COAST METRO AREAS BASED ON VIS SATELLITE AND SURFACE OBS. THEREFORE HAVE LOWERED POPS ACROSS THESE AREAS TODAY...BUT KEPT 30 PERCENT CHANCE AS SCATTERED SHOWERS AND POSSIBLY A FEW STORMS WILL DEVELOP ALONG IT AS IT MOVES INLAND...WITH ACTIVITY BECOMING MORE ISOLATED BY MID AFTERNOON. THE FOCUS SHOULD SHIFT TO THE INTERIOR AND WEST COAST THIS AFTERNOON AS NEW DEVELOPMENT TAKES PLACE WITH DAYTIME HEATING...AND ALONG SEA BREEZE BOUNDARIES FROM BOTH COASTS. WIND PROFILE FROM THE 12Z MIAMI SOUNDING SUGGESTS STORMS WILL BE SLOW MOVING...SO HEAVY RAINFALL WILL BE THE MAIN THREAT TODAY. FOR MARINE INTERESTS...A HIGHLY UNCERTAIN FORECAST FOR THE MID WEEK PERIOD DEPENDING ON EVOLUTION OF CLOSED UPPER LOW AND ANY ACCOMPANYING SURFACE LOW OFF THE SE CONUS COAST. IF CURRENT GFS/WAVEWATCH ARE CORRECT...WE WOULD GET A MODERATE SWELL DOWN INTO OUR WATERS LATE WEDNESDAY AND THURSDAY. OTHER MODELS ARE A LITTLE FURTHER WEST WITH THE UPPER/SURFACE LOWS...AND THIS WOULD CREATE AN UNFAVORABLE FETCH FOR SWELLS THIS FAR SOUTH. AT THIS TIME I CHOSE TO INCREASE SWELLS AND COMBINED SEAS SOME...BUT STILL REMAIN BELOW WHAT WAVEWATCH SUGGESTS. MARINERS SHOULD KEEP TABS ON THE LATEST WITH THIS DEVELOPING SITUATION THE NEXT FEW DAYS. /STRASSBERG && .PREV DISCUSSION... /ISSUED 730 AM EDT MON SEP 22 2008/ AVIATION...WINDS WILL PREVAIL OUT OF THE EAST NEAR 10 KT TODAY EXCEPT BECOMING W-NW AT KAPF...AND THIS IS WHERE THE BEST CHANCE FOR TSRA WILL BE THIS AFTERNOON...BUT HAVE INCLUDED VCTS AT ALL TERMINALS AS STORMS ARE POSSIBLE IN THE VICINITY OF ANY TERMINAL THIS AFTERNOON. DISCUSSION...A WEAK UPPER LOW OVER THE UPPER MIDWEST MOVES ESE AND DEEPENS OVER THE APPALACHIANS AS A LONG WAVE RIDGE...EXTENDING FROM OL` MEX NNE ACROSS THE GREAT PLAINS INTO THE GREAT LAKES...BUILDS. THE UPPER LOW BECOMES CLOSED AND CUTOFF OVER THE CAROLINAS TUE AND PERSISTS OVER THE ATLC OFF OF THE SE U.S. OR OVER THE SE U.S. INTERIOR THROUGH THE REMAINDER OF THE PERIOD. FOR THE SHORT TERM...TODAY THROUGH WED...AS THE UPPER LOW DEVELOPS NEAR THE CAROLINAS...A SURFACE LOW ALSO DEVELOPS OFFSHORE OF THE CAROLINAS ...WHICH CONNECTS TO A WEAK TROUGH THAT EXTENDS OVER CENTRAL FLA. AS THE SURFACE LOW DEEPENS...THE SURFACE TROUGH EDGES S AND COMBINED WITH GRADUALLY INCREASING DEEP-LAYER MOISTURE...POPS WILL BE HIGHER TODAY AND TUE DUE TO GREATER CONVERGENCE WITH THE TROUGH AND E/W COAST SEA BREEZES. STEERING WINDS FAVOR THE INTERIOR AND W/SW AREAS. TONIGHT...AFTER EVE CONVECTION MAINLY W...NOCTURNAL SHOWERS WILL AFFECT MAINLY THE ATLC/E COAST TONIGHT AND TUE NIGHT. BY WED...CIRCULATION ABOUT THE UPPER LOW TO THE N BRINGS A WESTERLY DRIER AIR MASS ALOFT OVER S FLA AND POPS LOWER. MAX TEMPS MAY SHADE A LITTLE LOWER AS INCREASED CLOUDS AND CHANCES OF PRECIP HAMPER THE CLIMB TOWARDS NEAR NORM TEMPS. EXTENDED PERIOD...THU THROUGH SUN...POSITIONING AND PERMANENCE OF THE UPPER LOW WILL AFFECT THE WEATHER. CURRENTLY MODELS INDICATE DRIER AND MORE STABLE AIR MOVING OVER THE AREA WITH FLOW FROM W TO E WHICH MAY COOL THE W COAST SOME BUT WARM THE INTERIOR AND E. TOWARDS NEXT WEEKEND DEEPER MOISTURE IS PULLED TOWARD S FLA FROM THE SW AND POPS COULD INCREASE. AT THE PRESENT TIME WILL CHANGE CURRENT PACKAGE VERY LITTLE AWAITING DEVELOPMENTS. ONE GOOD THING WITH THE INCREASED WESTERLY FLOW ALOFT OVER THE AREA...IF THE CONVECTION NEAR PUERTO RICO DEVELOPS INTO A DEPRESSION...SYSTEM SHOULD STAY E OF THE FLA PENINSULA. MARINE...EAST WINDS 10 KNOTS OR LESS TODAY THROUGH EARLY TUE. THEN AS THE SURFACE TROUGH SLIDES THROUGH S FLA WITH WINDS BECOMING NE AND GRADUALLY INCREASING TUE AFTERNOON THROUGH THU BEFORE GRADUALLY DECREASING. GULF STREAM SEAS GRADUALLY RISEAS WELL WITH THE NE FLOW AND CAUTION MAY BE REQUIRED TUE AFTERNOON WITH POSSIBLE ADVISORY FOR THE ATLC WATERS WED MORNING THROUGH FRI AS NE SWELLS MAY BEGIN TO ADD TO THE WAVE HEIGHTS WITH LOW PRESS PERSISTENT OFF OF THE CAROLINAS. FIRE WEATHER...NO CONCERNS AS MINIMUM AFTERNOON RH VALUES REMAIN SUFFICIENTLY HIGH. && .PRELIMINARY POINT TEMPS/POPS... WEST PALM BEACH 90 78 86 74 / 30 40 50 30 FORT LAUDERDALE 90 80 86 75 / 30 40 50 30 MIAMI 90 79 87 75 / 30 40 50 30 NAPLES 91 74 89 73 / 50 40 60 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...NONE. GM...NONE. && $$ LONG TERM...15/JR SHORT TERM/AVIATION...04/AT