000 WTNT41 KNHC 042032 TCDAT1 TROPICAL STORM FLORENCE DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL AL062012 500 PM AST SAT AUG 04 2012 AFTER LOOKING A LITTLE RAGGED EARLIER...CONVECTION HAS REDEVELOPED NEAR THE CENTER OF FLORENCE...WHICH APPEARS TO BE THE START OF A CENTRAL DENSE OVERCASE PATTERN. SUBJECTIVE SATELLITE INTENSITY ESTIMATES WERE 35 KT AND 45 KT FROM SAB AND TAFB RESPECTIVELY. SINCE A TRMM MICROWAVE PASS FROM EARLIER TODAY SUGGESTED THAT SOME PRIMITIVE INNER CORE FEATURES HAD FORMED...AND BOTH AMSU AND ADT DATA INDICATE A STRONGER CYCLONE...THE INITIAL INTENSITY WILL BE BUMPED UP TO 45 KT. THE CURRENT SYMMETRIC OUTFLOW PATTERN WITH FLORENCE APPEARS FAVORABLE FOR FURTHER INTENSIFICATION. HOWEVER...THE SYSTEM IS PASSING OVER WATERS COOLER THAN 26.5C...AND IS APPROACHING A MORE STABLE AND DRY ENVIRONMENT AS INDICATED BY EUMETSAT RGB AIRMASS IMAGERY. THE INTENSITY GUIDANCE HAS A WIDE RANGE OF POSSIBILITIES. THE STATISTICAL-BASED TOOLS FORECAST FLORENCE TO BE NEAR OR ABOVE HURRICANE STRENGTH IN A DAY OR TWO...WHICH IS CONTRASTED WITH THE WEAKENING FORECAST BY THE HWRF/GFDL MODELS. THE OFFICIAL FORECAST IS JUST A BIT ABOVE THE INTENSITY CONSENSUS AND IS HIGHER THAN THE PREVIOUS ONE. GIVEN THE EARLIER MICROWAVE STRUCTURE...IT IS TEMPTING TO RAISE THE WIND PREDICTION MORE THAN WHAT IS INDICATED BELOW...BUT I HAVE ELECTED TO REMAIN CONSERVATIVE ON THIS FORECAST CONSIDERING THE MARGINAL ENVIRONMENT. THE INITIAL MOTION ESTIMATE IS A LITTLE SLOWER...295/13. A BUILDING MID-TROPOSPHERIC HIGH OVER THE EASTERN ATLANTIC OCEAN IS EXPECTED TO CAUSE FLORENCE TO BEND TO A WESTWARD HEADING DURING THE NEXT DAY OR TWO. HOWEVER...THE GLOBAL MODELS HAVE A WIDER SPREAD THAN EARLIER TODAY...WITH THE ECMWF AND GFS SHOWING LITTLE RUN-TO-RUN CONSISTENCY. GENERALLY THE MODELS THAT ARE FORECASTING A MORE POWERFUL SYSTEM...SUCH AS THE GFS...ARE CAUSING FLORENCE TO TURN NORTHWESTWARD AROUND DAY 4 IN RESPONSE TO A WEAKNESS IN THE RIDGE. A WEAKER CYCLONE...AS INDICATED BY THE ECMWF...WOULD PROBABLY JUST CONTINUE MOVING WESTWARD. SINCE THE LATEST INTENSITY FORECAST IS BETWEEN THESE TWO EXTREMES...THE LATEST NHC FORECAST IS CLOSE TO THE MODEL CONSENSUS...JUST A BIT NORTH OF THE PREVIOUS FORECAST IN THE LONG RANGE PERIOD. FORECAST POSITIONS AND MAX WINDS INIT 04/2100Z 15.3N 31.7W 45 KT 50 MPH 12H 05/0600Z 15.8N 33.4W 50 KT 60 MPH 24H 05/1800Z 16.2N 35.7W 50 KT 60 MPH 36H 06/0600Z 16.6N 38.1W 45 KT 50 MPH 48H 06/1800Z 17.1N 41.2W 45 KT 50 MPH 72H 07/1800Z 18.5N 47.8W 40 KT 45 MPH 96H 08/1800Z 20.5N 54.0W 35 KT 40 MPH 120H 09/1800Z 23.0N 59.0W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ FORECASTER BLAKE