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TROPICAL STORM ISIDORE DISCUSSION NUMBER  31
NATIONAL WEATHER SERVICE MIAMI FL
5 PM EDT MON SEP 23 2002

ISIDORE HAS CHANGED LITTLE IN STRUCTURE DURING THE PAST 6 HR...
WITH WIDELY SCATTERED DISORGANIZED CONVECTION OCCURRING NEAR THE
CIRCULATION CENTER AND MORE SUBSTANTIAL CONVECTION OCCURRING IN
BANDS WELL REMOVED FROM THE CENTER OVER THE SOUTH SEMICIRCLE.  THE
EXACT INTENSITY AND CENTRAL PRESSURE ARE A LITTLE IFFY AS THERE ARE
CURRENTLY NO OBSERVATIONS NEAR THE CENTRAL CORE OR IN THE OFFSHORE
BANDS.  THE MAXIMUM INTENSITY IS REDUCED TO 45 KT FOR THIS ADVISORY
BASED ON CONTINUED STEADY WEAKENING OVER LAND.
 
ISIDORE IS LIKELY IN THE PROCESS OF MAKING A LOOP...AS THE STORM
HAS NUDGED NORTHEASTWARD DURING THE PAST 6 HR.  THERE IS NO CHANGE
TO THE SYNOPTIC REASONING FROM THE PREVIOUS PACKAGE...AS DEVELOPING
UPPER-LEVEL TROUGHING TO THE NORTHWEST AND DEVELOPING RIDGING
TO THE EAST SHOULD STEER THE STORM NORTHWESTWARD AND EVENTUALLY
NORTHWARD.  NHC TRACK GUIDANCE HAS SHIFTED A BIT TO THE EAST AND
IS FASTER THAN THE PREVIOUS RUNS...WITH THE GLOBAL MODELS NOW
FORECASTING ISIDORE TO BE JUST SOUTH OF THE LOUISIANA COAST AT 72 HR
AND THE GFDL MOVING IT ONSHORE IN ABOUT 60 HR.  AS NOTED 6 HR AGO...
THE GFDL IS LIKELY TOO FAST.  THE FORECAST TRACK IS MUCH FASTER
THAN THE PREVIOUS RUN AND IN GOOD AGREEMENT SPEEDWISE WITH THE
GLOBAL MODELS.  HOWEVER...IT IS DOWN THE LEFT SIDE OF THE
GUIDANCE...AND THE TRACK MAY NEED TO BE SHIFTED EASTWARD IN
SUBSEQUENT FORECASTS.
 
ISIDORE SHOULD CONTINUE TO WEAKEN WHILE OVER LAND.  AFTER THAT...
UPPER-LEVEL AND SEA SURFACE CONDITIONS APPEAR FAVORABLE FOR
RE-INTENSIFICATION.  THE BIGGEST NEGATIVE FACTOR IS THE INTERNAL
DISORGANIZATION OF THE STORM...AS IT WILL LIKELY TAKE SOME TIME
FOR ISIDORE TO RE-FORM A TIGHT CENTRAL CORE.  THE INTENSITY
FORECAST IS REDUCED A LITTLE FROM THE PREVIOUS PACKAGE...CALLING
FOR SLOW RE-INTENSIFICATION UNTIL ISIDORE REGAINS HURRICANE
STATUS AND FASTER STRENGTHENING THEREAFTER.

LOOKING A LITTLE INTO THE MEDIUM RANGE...ISIDORE COULD MAKE LANDFALL
ALONG THE NORTHERN GULF COAST JUST AFTER THE END OF THE FORECAST 
PERIOD.  INTERESTS IN THAT REGION SHOULD CLOSELY MONITOR THE
PROGRESS OF THE STORM.
 
FORECASTER BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     23/2100Z 20.3N  89.4W    45 KTS...INLAND
12HR VT     24/0600Z 21.1N  90.1W    35 KTS...INLAND
24HR VT     24/1800Z 22.3N  90.8W    40 KTS...OVER WATER
36HR VT     25/0600Z 23.6N  91.3W    50 KTS
48HR VT     25/1800Z 25.1N  91.8W    60 KTS
72HR VT     26/1800Z 28.5N  92.5W    85 KTS
 
 
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