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#533421 (Received by flhurricane at: 10:35 PM 10.Aug.2012) TCDAT2 TROPICAL DEPRESSION SEVEN DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072012 1100 PM AST FRI AUG 10 2012 WHILE THERE HAS BEEN SOME INCREASE IN DEEP CONVECTION NEAR THE CENTER OVER THE PAST FEW HOURS...THE OVERALL CLOUD PATTERN REMAINS RATHER SHAPELESS WITH LITTLE EVIDENCE OF BANDING. SATELLITE ESTIMATES ARE STILL T1.5 FROM TAFB AND SAB...AND THE INITIAL INTENSITY OF 30 KT IS BASED ON A 1-MINUTE WIND OBSERVATION AT NOAA BUOY 41040 OF 31 KNOTS AT 2246Z. THE ENVIRONMENT IS CURRENTLY MARGINAL FOR INTENSIFICATION...AND THE SHIPS MODEL SHOWS THE SHEAR INCREASING ABOVE 20 KT IN THE NEXT DAY OR SO AS AN UPPER-LEVEL TROUGH AMPLIFIES TO THE NORTHWEST OF THE CYCLONE. THE NEW NHC FORECAST SHOWS THE DEPRESSION BECOMING A TROPICAL STORM IN 12 HOURS WITH LITTLE CHANGE AFTER THAT TIME UNTIL DISSIPATION IN 72 HOURS. THIS SCENARIO IS SUPPORTED BY THE GFS AND ECMWF GLOBAL MODELS... WHICH CONTINUE TO SHOW THE CYCLONE DEGENERATING INTO A TROUGH OVER THE EASTERN OR CENTRAL CARIBBEAN SEA IN 2 TO 3 DAYS. THE DEPRESSION CONTINUES TO MOVE RAPIDLY WESTWARD WITH AN INITIAL MOTION OF 275/21. THIS MOTION IS EXPECTED TO CONTINUE THROUGH DISSIPATION AS THE TROPICAL CYCLONE IS STEERED BY THE ATLANTIC SUBTROPICAL RIDGE TO THE NORTH. THE NEW NHC FORECAST IS AN UPDATE OF THE PREVIOUS ONE AND IS CLOSE TO A CONSENSUS OF THE GFS AND ECMWF MODELS. GIVEN THE CONTINUING UNCERTAINTY AS TO WHETHER THE DEPRESSION WILL BECOME A TROPICAL STORM...TROPICAL STORM WATCHES CONTINUE FOR PART OF THE LESSER ANTILLES...EVEN THOUGH TROPICAL STORM CONDITIONS WOULD REACH THOSE LOCATIONS WITHIN THE NEXT 24 TO 36 HOURS. FORECAST POSITIONS AND MAX WINDS INIT 11/0300Z 13.9N 54.1W 30 KT 35 MPH 12H 11/1200Z 14.1N 57.0W 35 KT 40 MPH 24H 12/0000Z 14.3N 60.8W 35 KT 40 MPH 36H 12/1200Z 14.6N 64.7W 35 KT 40 MPH 48H 13/0000Z 14.8N 68.7W 35 KT 40 MPH 72H 14/0000Z...DISSIPATED $$ FORECASTER BRENNAN |