000 WTNT44 KNHC 070850 TCDAT4 TROPICAL DEPRESSION FOURTEEN DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142011 500 AM AST WED SEP 07 2011 DATA FROM AN EARLIER ASCAT PASS SUGGESTED THAT THE CYCLONE WAS NEAR TROPICAL STORM STRENGTH. HOWEVER...THE CLOUD PATTERN HAS NOT BECOME SIGNIFICANTLY BETTER ORGANIZED AND DVORAK T-NUMBERS FROM BOTH AGENCIES ARE 2.0...WHICH DO NOT SUPPORT NAMING THE SYSTEM AT THIS TIME. NORMALLY WE WOULD EXPECT SIGNIFICANT STRENGTHENING OF A TROPICAL CYCLONE IN THIS LOCATION AT THIS TIME OF YEAR. MOST OF THE INTENSITY GUIDANCE...HOWEVER...DOES NOT CALL FOR MUCH OF AN INCREASE IN STRENGTH FOR THE NEXT 72 HOURS OR SO. THE REASONS FOR THIS ARE NOT CLEAR...BUT WATER VAPOR IMAGERY DOES SHOW A WEAK UPPER-LEVEL TROUGH OR SHEAR AXIS ABOUT 500 MILES TO THE NORTHWEST OF THE DEPRESSION...AND THIS COULD BE AN INHIBITING FACTOR. LATE IN THE FORECAST PERIOD...THE GFDL MODEL SHOWS CONSIDERABLE INTENSIFICATION...BUT IT IS ONE OF FEW MODELS TO DO SO. THE NHC INTENSITY FORECAST IS ABOVE THE OPERATIONAL MODEL CONSENSUS BUT QUITE CLOSE TO A CONSENSUS THAT INCLUDES THE HURRICANE FORECAST IMPROVEMENT PROJECT...HFIP...MODELS. THIS IS ALSO THE SAME AS THE PREVIOUS OFFICIAL WIND SPEED FORECAST. THERE HAS BEEN SOME SCATTER IN THE CENTER FIXES...BUT A SMOOTHED ESTIMATE OF THE INITIAL MOTION IS 280/17. OVER THE NEXT DAY OR TWO...THE TROPICAL CYCLONE WILL BE MOVING TO THE SOUTH OF A STRENGTHENING SUBTROPICAL RIDGE WHICH IS LIKELY TO CAUSE SOME ADDITIONAL INCREASE IN FORWARD SPEED. BY DAYS 2-3...HOWEVER...THE RIDGE BEGINS TO WEAKEN AND THE CYCLONE SHOULD BEGIN A GRADUAL TURN TO THE RIGHT WITH DECREASING FORWARD SPEED. THE TRACK GUIDANCE CONTINUES TO SHOW QUITE A BIT OF SPREAD...WITH THE GFDL AND GFS AMONG THE FASTEST OF THE MODELS AND THE ECMWF AND HWRF SIGNIFICANTLY SLOWER. THE OFFICIAL FORECAST FOR THIS PACKAGE IS ONLY SLIGHTLY FASTER THAN THE PREVIOUS ONE AND NEAR OR A LITTLE TO THE LEFT OF THE MULTI-MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INIT 07/0900Z 12.0N 39.9W 30 KT 35 MPH 12H 07/1800Z 12.6N 42.7W 35 KT 40 MPH 24H 08/0600Z 13.3N 46.8W 40 KT 45 MPH 36H 08/1800Z 14.0N 51.0W 45 KT 50 MPH 48H 09/0600Z 14.6N 54.5W 50 KT 60 MPH 72H 10/0600Z 16.7N 60.5W 55 KT 65 MPH 96H 11/0600Z 19.5N 65.5W 60 KT 70 MPH 120H 12/0600Z 22.5N 69.5W 65 KT 75 MPH $$ FORECASTER PASCH