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TROPICAL STORM GABRIELLE DISCUSSION NUMBER  28
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT TUE SEP 18 2001

DEEP CONVECTION HAS PERSISTED NEAR THE LOW-LEVEL CIRCULATION 
CENTER...MAINLY TO THE WEST AND NORTH. HOWEVER...THE OVERALL CLOUD 
PATTERN IS MORE INDICATIVE OF AN EVOLVING EXTRATROPICAL LOW PRESSURE 
SYSTEM.  THE CURRENT INTENSITY OF 55 KT IS BASED ON TROPICAL AND 
EXTRATROPICAL SATELLITE INTENSITY ESTIMATES OF 50 AND 55 KTS FROM 
TAFB AND AFWA...RESPECTIVELY.  THE OUTFLOW REMAINS GOOD IN THE 
NORTHERN SEMICIRCLE AND IS NON-EXISTENT ELSEWHERE. 
 
INITIAL MOTION ESTIMATE IS 050/16. THERE IS NO CHANGE TO THE 
PREVIOUS FORECAST TRACK OR REASONING.  GABRIELLE REMAINS EMBEDDED 
IN THE SOUTHERN BRANCH OF THE MID-LATITUDE WESTERLIES AND SATELLITE 
IMAGERY AND 12Z UPPER-AIR OBSERVATIONS INDICATE A LONG FETCH OF 
STRONGER UPPER-LEVEL WINDS APPROACHING THE CYCLONE FROM THE WEST.  
THESE WINDS SHOULD ACCELERATE THE SYSTEM MORE RAPIDLY TO THE 
NORTHEAST DURING THE NEXT 12-24 HOURS. THIS SCENARIO IS SUPPORTED 
BY ALL OF THE GLOBAL MODELS...WHICH ARE IN EXCELLENT AGREEMENT ON 
KEEPING THE CENTER OF GABRIELLE AWAY FROM NEWFOUNDLAND.

LITTLE CHANGE IN INTENSITY IS EXPECTED DURING THE NEXT 24-36 HOURS 
DUE TO INCREASING BAROCLINIC EFFECTS.  IN FACT...GABRIELLE COULD 
EVEN STRENGTHEN SLIGHTLY AND THIS MAY BE INDICATED IN THE NEXT 
ADVISORY.

34-KT AND THE 12-FT SEAS RADII WERE INCREASED BASED ON 12Z SHIP 
REPORTS. 
 
FORECASTER STEWART/MAINELLI
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     18/1500Z 39.5N  59.6W    55 KTS...BECOMING EXTRATROPICAL
12HR VT     19/0000Z 41.2N  57.1W    50 KTS...EXTRATROPICAL
24HR VT     19/1200Z 43.4N  53.3W    45 KTS...EXTRATROPICAL
36HR VT     20/0000Z 45.7N  49.4W    40 KTS...EXTRATROPICAL
48HR VT     20/1200Z 47.9N  44.9W    40 KTS...EXTRATROPICAL
72HR VT     21/1200Z 50.0N  35.0W    40 KTS...EXTRATROPICAL
 
 
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