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TROPICAL STORM ISIDORE DISCUSSION NUMBER  34
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT TUE SEP 24 2002

MORNING SATELLITE IMAGERY INDICATES THAT ISIDORE IS COMPRISED
OF A VERY LARGE SWIRL OF LOW/MID-LEVEL CLOUDS...WITH THE NEAREST
CONVECTIVE BANDS WELL-REMOVED TO THE SOUTHWEST AND NORTHEAST OF
THE CENTER.  THE EARLIER RECONNAISSANCE MISSION INDICATED THE 
RADIUS OF MAXIMUM WINDS WAS NEAR 100-125 N MI...CONFIRMING THE
OBSERVATIONS FROM YESTERDAY ABOUT THE COLLAPSE OF THE INNER CORE.
RE-EXAMINATION OF THE FLIGHT-LEVEL WIND DATA SUGGESTS THAT THE
MAXIMUM WINDS ARE 50 KT...AND THAT IS IN GOOD AGREEMENT WITH THE
55 KT...55 KT...AND 45 KT SATELLITE ESTIMATES FROM SAB...AFWA...
AND TAFB.
 
THE INITIAL MOTION IS 335/7.  WATER VAPOR IMAGERY AND MORNING
RAWINSONDES INDICATE BROAD MID/UPPER-LEVEL TROUGHING OVER THE
CENTRAL UNITED STATES AND WESTERN GULF COAST...AND A DEVELOPING
RIDGE EXTENDING FROM THE NORTHWESTERN CARIBBEAN TO FLORIDA.  THIS
PATTER SHOULD MOVE ISIDORE NORTH-NORTHWESTWARD TO NORTHWARD...WITH
THE STORM EVENTUALLY RECURVING NORTHEASTWARD IN FRONT OF AN
AMPLIFYING SHORTWAVE TROUGH.  TRACK GUIDANCE GENERALLY AGREES WITH
THIS SCENARIO SAVE FOR THE NHC98UK...WHICH STRANGELY MOVES THE
SYSTEM SLOWLY NORTHWEST.  THE OFFICIAL FORECAST IS AN UPDATE OF THE
PREVIOUS PACKAGE...CALLING FOR LANDFALL IN SOUTHEASTERN LOUISIANA
IN ABOUT 48 HR FOLLOWED BY ACCELERATION TO THE NORTHEAST.
 
THE INTENSITY FORECAST IS MORE PROBLEMATIC THAN THE TRACK.  WITH
THE BROAD CENTER AND CURRENT LACK OF CENTRAL CONVECTION...ISIDORE
WILL STRENGTHEN SLOWLY EVEN THOUGH CONDITIONS ARE FAVORABLE.
A FASTER RATE OF INTENSIFICATION IS LIKELY ONCE SOMETHING RESEMBLING
A CENTRAL CORE REFORMS.  THE INTENSITY FORECAST WILL CALL FOR SLOW
STRENGTHENING FOR THE FIRST 12 HR...FOLLOWED BY A MORE NORMAL
RATE UNTIL LANDFALL.  IT SHOULD BE NOTED THAT THE STORM MAY NOT
BEGIN RE-INTENSIFICATION UNTIL THE MAIN CONVECTIVE BAND TO THE
SOUTHWEST MOVES OVER WATER LATER TODAY OR TONIGHT.

THE COMBINATION OF THE FORECAST TRACK AND THE LARGE SIZE OF THE
CIRCULATION MAKES IT NECESSARY TO ISSUE WATCHES AND WARNINGS AT
THIS TIME.  ADDITIONAL WATCHES AND WARNINGS MAY BE REQUIRED...
ESPECIALLY IF THE THE WIND RADII EXPAND MORE THAN CURRENTLY
FORECAST.
 
FORECASTER BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     24/1500Z 22.1N  90.0W    50 KTS
12HR VT     25/0000Z 23.3N  90.5W    55 KTS
24HR VT     25/1200Z 25.1N  91.0W    65 KTS
36HR VT     26/0000Z 27.3N  91.2W    75 KTS
48HR VT     26/1200Z 29.8N  91.0W    75 KTS...INLAND
72HR VT     27/1200Z 34.5N  87.5W    30 KTS...INLAND
 
 
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