000 WTPZ45 KNHC 310852 TCDEP5 TROPICAL STORM GIL DISCUSSION NUMBER 8 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP102007 200 AM PDT FRI AUG 31 2007 ENHANCED INFRARED IMAGERY INDICATES THAT THE ONCE DEEP CONVECTION ASSOCIATED WITH GIL HAS WEAKENED CONSIDERABLY OVER THE LAST FEW HOURS. RECENT MICROWAVE PASSES FROM SSMI-S AND AMSU-B DEPICTED AN EXPOSED LOW-LEVEL CENTER JUST TO THE EAST OF THE REMAINING CONVECTION...RESULTING FROM THE 20 KT OF EASTERLY SHEAR THE CYCLONE IS STILL EXPERIENCING. BASED ON THE ABOVE AS WELL AS 35 KT DVORAK INTENSITY ESTIMATES FROM BOTH TAFB AND SAB...THE INITIAL INTENSITY HAS BEEN LOWERED TO 35 KT. THE SHEAR IS FORECAST TO DECREASE OVER THE NEXT 12 TO 18 HOURS AND THE SEA SURFACE TEMPERATURES SHOULD REMAIN ABOVE 26C FOR THE NEXT 36 HOURS OR SO. WHILE THESE CONDITIONS WOULD PROMOTE STRENGTHENING IN THE NEAR TERM...GIL IS MOVING INTO A RATHER STABLE ENVIRONMENT. HOW MUCH THE CURRENT EASTERLY SHEAR SEPARATES THE LOW-LEVEL CIRCULATION FROM THE PRIMARY CONVECTION WILL DETERMINE HOW LONG GIL WILL TAKE TO SPIN DOWN TO A REMNANT LOW. BOTH SHIPS AND FSSE MAINTAIN GIL AS A MINIMAL TROPICAL STORM THROUGH 4 OR 5 DAYS... WHILE THE GFDL TAKES GIL CLOSE TO HURRICANE STRENGTH IN 2 TO 3 DAYS. BASED ON THE CURRENT APPEARANCE OF THE CYCLONE THE GFDL SOLUTION APPEARS UNLIKELY AT THIS TIME. THE OFFICIAL INTENSITY FORECAST IS SLIGHTLY LOWER THAN SHIPS AND IS CONSISTENT WITH THE PREVIOUS ADVISORY. THE INITIAL MOTION...265/9...IS UNCHANGED FROM THE PREVIOUS ADVISORY...AS IS THE TRACK FORECAST PHILOSOPHY. GIL SHOULD CONTINUE A GENERAL WESTWARD MOTION FOR THE NEXT 36 HOURS FOLLOWED BY A TURN TO THE WEST-NORTHWEST AROUND THE WESTERN PERIPHERY OF THE RIDGE TO ITS NORTHEAST. ONCE GIL WEAKENS TO A REMNANT LOW OVER COOLER WATERS...IT WILL LIKELY BE STEERED BACK TOWARD THE WEST IN RESPONSE TO THE LOW-LEVEL EASTERLY FLOW. FORECAST POSITIONS AND MAX WINDS INITIAL 31/0900Z 19.0N 116.5W 35 KT 12HR VT 31/1800Z 18.9N 117.9W 35 KT 24HR VT 01/0600Z 19.0N 120.0W 35 KT 36HR VT 01/1800Z 19.2N 122.2W 35 KT 48HR VT 02/0600Z 19.7N 124.3W 35 KT 72HR VT 03/0600Z 20.5N 128.5W 30 KT 96HR VT 04/0600Z 20.5N 132.5W 25 KT...REMNANT LOW 120HR VT 05/0600Z 20.5N 136.5W 25 KT...REMNANT LOW $$ FORECASTER MAINELLI