000 WTNT44 KNHC 092042 TCDAT4 TROPICAL STORM SEAN DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL192011 400 PM EST WED NOV 09 2011 SATELLITE IMAGERY INDICATES THAT SEAN IS STRENGTHENING. THE CLOUD PATTERN CONSISTS OF A LARGE COILED BAND...WHICH APPEARS TO BE WRAPPING UP INTO A BANDING EYE FEATURE. DVORAK ESTIMATES ARE 55 KT FROM BOTH TAFB/SAB...SO THIS WILL BE THE INITIAL WIND SPEED. WITH THE DEVELOPMENT OF THE CENTRAL CORE AND ABOUT A DAY OF LIGHT SHEAR CONDITIONS REMAINING...FURTHER INTENSIFICATION SEEMS PROBABLE. IT IS A LITTLE PUZZLING WHY NONE OF THE MODELS MAKE THIS A HURRICANE... ALTHOUGH THE INTENSITY GUIDANCE HAS GENERALLY HAD A LOW BIAS WITH THIS SYSTEM. GIVEN THE DEVELOPING EYE FEATURE...THE NEW NHC FORECAST SHOWS SEAN REACHING HURRICANE STRENGTH...WHICH IS A BIT HIGHER THAN THE SHIPS/LGEM MODELS. THE STORM HAS TURNED TOWARD THE NORTH AT ABOUT 5 KT...A LITTLE FASTER THAN EARLIER. A GRADUAL TURN TOWARD THE NORTHEAST WITH SOME ACCELERATION IS EXPECTED TOMORROW AS THE TROPICAL CYCLONE FEELS THE INFLUENCE OF A TROUGH MOVING INTO THE EASTERN UNITED STATES. ALTHOUGH THERE IS STILL SOME SPREAD...THE GUIDANCE IS PRETTY CONSISTENT IN SHOWING SEAN MOVING A FAIR DISTANCE TO THE NORTHWEST OF BERMUDA. THE LATEST GFS/ECMWF MODELS CAME IN VERY CLOSE TO THE PREVIOUS NHC FORECAST...AND ONLY SMALL CHANGES WERE MADE TO THE NEW NHC TRACK. ALL OF THE GLOBAL MODELS SHOW SEAN BECOMING EXTRATROPICAL IN TWO DAYS...AND THEN BEING ABSORBED BY A FRONTAL BOUNDARY BY DAY 3. FORECAST POSITIONS AND MAX WINDS INIT 09/2100Z 28.7N 70.5W 55 KT 65 MPH 12H 10/0600Z 29.4N 70.5W 60 KT 70 MPH 24H 10/1800Z 30.6N 69.5W 65 KT 75 MPH 36H 11/0600Z 32.7N 67.0W 60 KT 70 MPH 48H 11/1800Z 35.8N 62.7W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 12/1800Z...ABSORBED $$ FORECASTER BLAKE