|
Show Selection: |
| #373065 (Received by flhurricane at: 4:50 AM 02.Sep.2010) TCDAT4 TROPICAL STORM GASTON DISCUSSION NUMBER 4 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092010 500 AM AST THU SEP 02 2010 SATELLITE IMAGES INDICATE THAT GASTON HAS GENERALLY CHANGED LITTLE IN ORGANIZATION THIS MORNING. THUNDERSTORM ACTIVITY REMAINS CONFINED TO A CURVED BAND OVER THE WESTERN SEMICIRCLE...BUT THE CLOUD TOPS HAVE BEEN WARMING SLIGHTLY DURING THE LAST COUPLE OF HOURS. DVORAK DATA T-NUMBERS ARE 35 KT FROM BOTH TAFB AND SAB...AND THE INITIAL INTENSITY IS HELD AT THAT VALUE. CONDITIONS GENERALLY APPEAR FAVORABLE FOR A GRADUAL INTENSIFICATION DURING THE NEXT SEVERAL DAYS AS GASTON REMAINS IN A LOW WIND SHEAR ENVIRONMENT AND OVER WARM WATERS. HOWEVER...WATER VAPOR IMAGERY SHOWS THAT GASTON IS PARTIALLY EMBEDDED IN A DRY MID- TO UPPER-LEVEL AIR MASS WHICH COULD PROVE TO BE A LIMITING FACTOR. GIVEN THE UNCERTAINTY...THE OFFICIAL INTENSITY FORECAST IS UNCHANGED FROM EARLIER...LYING IN BETWEEN THE DYNAMICAL MODEL GUIDANCE AND THE MORE AGGRESSIVE STATISTICAL MODEL OUTPUT. GASTON CONTINUES TO DECELERATE AS IT FEELS THE EFFECTS OF A DEEP LAYER TROUGH TO ITS NORTH...AND THE INITIAL MOTION ESTIMATE IS NOW 280/8. GASTON IS FORECAST TO SLOW DOWN EVEN MORE OVER THE NEXT COUPLE OF DAYS AS THE STORM REMAINS IN WEAK STEERING CURRENTS. BY 48-72 HOURS...GLOBAL MODELS SHOW SOME MID-LEVEL RIDGING BUILDING TO THE NORTH OF GASTON AND THAT SHOULD STEER THE SYSTEM WESTWARD OR EVEN WEST-SOUTHWESTWARD AT A SLIGHTLY FASTER SPEED. THE OFFICIAL TRACK FORECAST IS A LITTLE SLOWER AND SLIGHTLY TO THE SOUTH OF THE PREVIOUS ONE IN BEST AGREEMENT WITH THE MULTI-MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 02/0900Z 13.5N 38.2W 35 KT 12HR VT 02/1800Z 13.6N 39.0W 40 KT 24HR VT 03/0600Z 13.8N 40.1W 45 KT 36HR VT 03/1800Z 14.0N 41.2W 50 KT 48HR VT 04/0600Z 14.2N 42.5W 55 KT 72HR VT 05/0600Z 14.6N 45.9W 65 KT 96HR VT 06/0600Z 15.0N 50.0W 75 KT 120HR VT 07/0600Z 16.0N 55.0W 85 KT $$ FORECASTER CANGIALOSI/KIMBERLAIN |
