000 WTNT42 KNHC 080840 TCDAT2 SUBTROPICAL STORM GABRIELLE DISCUSSION NUMBER 2 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072007 500 AM EDT SAT SEP 08 2007 THE SATELLITE PRESENTATION OF GABRIELLE HAS IMPROVED EARLY THIS MORNING. A CURVED CONVECTIVE BAND IS NOW LOCATED CLOSER TO THE CENTER OF CIRCULATION OVER THE NORTHERN AND WESTERN QUADRANTS... WHICH COULD BE AN INDICATION THAT GABRIELLE IS GRADUALLY ACQUIRING TROPICAL CHARACTERISTICS. DVORAK INTENSITY CLASSIFICATIONS ARE T 2.5/35 KT FROM SAB AND ST 2.5/35-40 KT FROM TAFB. BASED ON THIS... GABRIELLE WILL REMAIN A SUBTROPICAL 40 KT STORM FOR THIS ADVISORY. WHILE THE CYCLONE IS CURRENTLY OVER WARM WATERS...THE UPPER LEVEL ENVIRONMENT IS NOT FAVORABLE FOR SIGNIFICANT STRENGTHENING. THEREFORE...ONLY SLIGHT STRENGTHENING IS INDICATED AS GABRIELLE APPROACHES THE COAST. THIS IS CONSISTENT WITH A BLEND OF THE SHIPS...GFDL...AND HWRF INTENSITY GUIDANCE. THE INITIAL MOTION IS 300/10. GABRIELLE IS SITUATED BETWEEN AN UPPER-LEVEL LOW TO ITS SOUTHWEST AND A DEEP-LAYER RIDGE OVER THE NORTHWESTERN ATLANTIC. AS THE UPPER-LEVEL LOW MOVES WESTWARD AND WEAKENS...GABRIELLE WILL BE STEERED AROUND THE WESTERN PERIPHERY OF THE RIDGE TOWARD THE COAST OF NORTH AND SOUTH CAROLINA IN THE NEXT DAY OR TWO. THEREAFTER...GABRIELLE IS EXPECTED TO BE EMBEDDED WITHIN THE MID-LATITUDE SOUTHWESTERLY FLOW RESULTING IN AN ACCELERATION TOWARD THE NORTHEAST. BY DAYS 4 AND 5 GABRIELLE SHOULD BE AN EXTRATROPICAL CYCLONE...MOVING AWAY FROM THE UNITED STATES. THE OFFICIAL TRACK FORECAST IS CLOSE TO THE DYNAMICAL MODEL CONSENSUS AND IS NOT SIGNIFICANTLY DIFFERENT FROM THE PREVIOUS ADVISORY. TROPICAL STORM WARNINGS WILL LIKELY BE REQUIRED LATER TODAY FOR A PORTION OF THE TROPICAL STORM WATCH AREA. FORECAST POSITIONS AND MAX WINDS INITIAL 08/0900Z 30.9N 73.5W 40 KT 12HR VT 08/1800Z 31.8N 74.9W 45 KT 24HR VT 09/0600Z 33.1N 76.2W 50 KT...TROPICAL 36HR VT 09/1800Z 34.5N 76.6W 55 KT 48HR VT 10/0600Z 36.0N 75.5W 55 KT 72HR VT 11/0600Z 38.5N 71.0W 50 KT 96HR VT 12/0600Z 41.0N 62.0W 45 KT...EXTRATROPICAL 120HR VT 13/0600Z 45.0N 50.0W 45 KT...EXTRATROPICAL $$ FORECASTER MAINELLI/AVILA