000 WTPZ44 KNHC 100837 TCDEP4 TROPICAL STORM FLOSSIE DISCUSSION NUMBER 7 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092007 200 AM PDT FRI AUG 10 2007 BOTH CONVENTIONAL AND MICROWAVE SATELLITE IMAGERY SUGGEST THAT THE OVERALL STRUCTURE OF FLOSSIE HAS REMAINED ALMOST THE SAME. FLOSSIE SHOWS GOOD CIRRUS OUTFLOW...WITH AN IMPROVEMENT EAST OF THE CENTER WHERE THE OUTFLOW WAS PREVIOUSLY RESTRICTED. DVORAK SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB HAVE HELD AT 55 KT...AND THIS CORRESPONDS TO THE INITIAL ADVISORY INTENSITY AS WELL. THE TROPICAL STORM CONTINUES TO BE STEERED TOWARD THE WEST... 270/12...IN RESPONSE TO A STRONG RIDGE TO THE NORTH. THIS PATTERN IS EXPECTED TO PERSIST THROUGH MUCH OF THE FORECAST...WITH A SLIGHT WEAKNESS IN THE RIDGE DEVELOPING AROUND 140W IN A DAY OR TWO. THE DYNAMICAL MODEL GUIDANCE IS IN GOOD AGREEMENT THAT FLOSSIE WILL REMAIN SOUTH ENOUGH TO CONTINUE ON A GENERAL WESTWARD TRACK THROUGH FIVE DAYS. THE OFFICIAL TRACK FORECAST IS SIMILAR TO THE PREVIOUS... EXCEPT SLIGHTLY TO THE SOUTH AND CLOSE TO THE DYNAMICAL MODEL CONSENSUS. FLOSSIE IS EXPECTED TO REMAIN OVER WATERS BETWEEN 26C-27C AND UNDER MODERATE VERTICAL SHEAR FOR AT LEAST THE NEXT COUPLE OF DAYS. THE SHIPS... HWRF...AND SUPER-ENSEMBLE HAVE BACKED OFF ON INTENSIFYING FLOSSIE TO A HURRICANE...AND THE GFDL INTENSITY GUIDANCE BARELY REACHES HURRICANE STRENGTH. THE OFFICIAL INTENSITY FORECAST IS ESSENTIALLY AN UPDATE OF THE PREVIOUS AND ALLOWS FOR ONLY SLIGHT STRENGTHENING. BY DAYS 4 AND 5...THE CYCLONE IS EXPECTED TO BE OVER COOLER WATERS AND IN A MORE SHEARED ENVIRONMENT RESULTING IN FLOSSIE TO WEAKEN A BIT. IT SHOULD BE NOTED HOWEVER...THAT THE POSSIBILITY REMAINS FOR FLOSSIE TO STILL BECOME A HURRICANE. FORECAST POSITIONS AND MAX WINDS INITIAL 10/0900Z 12.6N 134.9W 55 KT 12HR VT 10/1800Z 12.7N 136.6W 60 KT 24HR VT 11/0600Z 13.0N 139.1W 60 KT 36HR VT 11/1800Z 13.4N 141.3W 60 KT 48HR VT 12/0600Z 13.7N 143.4W 55 KT 72HR VT 13/0600Z 14.5N 147.5W 55 KT 96HR VT 14/0600Z 15.5N 152.5W 50 KT 120HR VT 15/0600Z 17.0N 157.0W 40 KT $$ FORECASTER MAINELLI