000 WTNT41 KNHC 051439 TCDAT1 TROPICAL STORM FLORENCE DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062012 1100 AM AST SUN AUG 05 2012 VISIBLE IMAGES SUGGEST THAT SOUTHEASTERLY SHEAR HAS TAKEN A TOLL ON THE STRUCTURE OF FLORENCE. THE CENTER APPEARS TO BE ON THE EDGE OF A WEAKENING AREA OF CONVECTION...WITH SOME DEGRADATION NOTED ON MICROWAVE IMAGES. A BLEND OF THE MOST RECENT ESTIMATES STILL GIVES A CURRENT WIND SPEED OF 50 KT...BUT THIS COULD BE GENEROUS. THERE HAS BEEN A CHANGE WITH THE INTENSITY GUIDANCE...WITH NONE OF THE MODELS SHOWING ANY SIGNIFICANT STRENGTHENING. PERHAPS THIS IS BECAUSE OF A SLIGHTLY DRIER AND MORE SHEARED ENVIRONMENT THAN WAS EXPECTED YESTERDAY. IN ANY EVENT...GLOBAL MODELS SHOW FLORENCE MOVING DEEPER INTO THE DRY AIR FOR THE NEXT SEVERAL DAYS. ALTHOUGH SSTS SHOULD GRADUALLY BE RISING...STRONGER SHEAR IS LIKELY WITHIN 48 HOURS DUE TO A LARGE MID-OCEANIC TROUGH. THESE CONDITIONS SHOULD GENERALLY CAUSE WEAKENING OF THE CYCLONE...AND THE OFFICIAL FORECAST IS REDUCED FROM THE PREVIOUS ONE. THE NHC PREDICTION IS PRIMARILY BASED ON A BLEND OF THE PREVIOUS FORECAST AND THE INTENSITY CONSENSUS. I WOULD NOT BE SURPRISED IF THIS SYSTEM BECAME A REMNANT LOW FASTER THAN WHAT WAS INDICATED BELOW GIVEN THE MARGINAL CONDITIONS. MICROWAVE AND CONVENTIONAL IMAGES SHOW THAT FLORENCE HAS TURNED WESTWARD AT ABOUT 12 KT AS PREVIOUSLY FORECAST. A FASTER WESTWARD MOTION OF THE CYCLONE IS EXPECTED FOR THE NEXT COUPLE OF DAYS WHILE A RIDGE BUILDS OVER THE EAST-CENTRAL ATLANTIC. AFTER THAT TIME...A WEAKNESS IN THE RIDGE SHOULD ALLOW A TRACK MORE TO THE WEST- NORTHWEST...WHICH WOULD BRING FLORENCE A FEW HUNDRED MILES TO THE NORTHEAST OF THE LESSER ANTILLES. WHILE THE ECMWF IS A SOUTHERN OUTLIER...THE REST OF THE GUIDANCE HAS COME INTO VERY GOOD AGREEMENT ON THE PATH OF THE STORM. THE LATEST NHC TRACK FORECAST IS SHIFTED TO THE SOUTH AT ALL FORECAST TIMES...BUT REMAINS ON THE NORTHERN SIDE OF THE GUIDANCE ENVELOPE THROUGH DAY 3. FORECAST POSITIONS AND MAX WINDS INIT 05/1500Z 16.5N 35.6W 50 KT 60 MPH 12H 06/0000Z 16.7N 37.5W 50 KT 60 MPH 24H 06/1200Z 16.9N 40.1W 50 KT 60 MPH 36H 07/0000Z 17.4N 43.0W 45 KT 50 MPH 48H 07/1200Z 18.0N 46.2W 45 KT 50 MPH 72H 08/1200Z 19.5N 53.0W 35 KT 40 MPH 96H 09/1200Z 21.5N 59.0W 30 KT 35 MPH 120H 10/1200Z 24.0N 64.0W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ FORECASTER BLAKE