ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM 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 NNNN