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TROPICAL STORM ISIDORE DISCUSSION NUMBER  42
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT THU SEP 26 2002

ISIDORE HAS MOVED ERRATICALLY NORTH-NORTHEASTWARD ACROSS
SOUTHEASTERN LOUISIANA DURING THE PAST 6 HR...WITH RADAR FIXES
SUGGESTING A LOOP OCCURRED RIGHT AFTER LANDFALL.  THE CENTRAL
PRESSURE IS 985 MB BASED ON OBSERVATIONS FROM STATIONS IN THE NEW
ORLEANS AREA.  BUOY 42007 AND THE DAUPHIN ISLAND C-MAN STATION
CONTINUE TO REPORT 40 KT SUSTAINED WINDS.  BASED ON THE AVAILABLE
DATA...THE WINDS ARE DECREASED TO 50 KT.

THE BEST ESTIMATE OF THE INITIAL MOTION IS 020/12.  ISIDORE IS
BETWEEN A MID/UPPER-LEVEL RIDGE OVER FLORIDA AND THE WESTERLIES
OVER THE CENTRAL UNITED STATES.  LARGE-SCALE GUIDANCE INDICATES
THAT THE STORM SHOULD GRADUALLY TURN NORTHEASTWARD AND ACCELERATE
DURING THE NEXT 48 HR AS IT ENTERS THE WESTERLIES...AND THERE IS NO
OBVIOUS REASON TO DISAGREE WITH THESE FORECASTS.  THE OFFICIAL
FORECAST CALLS FOR JUST THAT SCENARIO...WITH SOME NUDGING TO THE
EAST OF THE PREVIOUS TRACK BASED ON THE INITIAL POSITION.
 
THE CENTER AND THE CORE CONVECTION ARE NOW INLAND...SO ISIDORE
SHOULD STEADILY WEAKEN FOR THE NEXT 24-36 HR.  LARGE-SCALE
GUIDANCE INDICATES THAT THE CYCLONE SHOULD MERGE WITH A FRONTAL
SYSTEM BY 36 HR AND THEN INTENSIFY AS A NON-TROPICAL SYSTEM...WHICH
IS REFLECTED IN THE INTENSITY FORECAST.  BY 72 HR...ISIDORE IS
EXPECTED TO LOSE ITS IDENTITY IN A LARGE NON-TROPICAL STORM SYSTEM
OVER THE NORTHWEST ATLANTIC AND CANADIAN ATLANTIC PROVINCES.

TROPICAL STORM WARNINGS HAVE BEEN DISCONTINUED WEST OF MORGAN CITY
AS WINDS HAVE DECREASED IN THE WESTERN SEMICIRCLE.  THE REMAINING 
WARNINGS MAY BE LOWERED LATER TODAY.

FORECASTER BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     26/1500Z 30.7N  89.7W    50 KTS...INLAND
12HR VT     27/0000Z 32.5N  89.1W    30 KTS...INLAND
24HR VT     27/1200Z 35.6N  86.6W    25 KTS...INLAND
36HR VT     28/0000Z 40.0N  80.6W    25 KTS...INLAND EXTRATROPICAL
48HR VT     28/1200Z 45.0N  70.0W    35 KTS...INLAND EXTRATROPICAL
72HR VT     29/1200Z...ABSORBED BY LARGER EXTRATROPICAL LOW
 
 
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