Tropical Storm FABIAN
ZCZC MIATCDAT5 ALL TTAA00 KNHC DDHHMM TROPICAL STORM FABIAN DISCUSSION NUMBER 5 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 PM EDT THU AUG 28 2003 THE SYSTEM'S CLOUD PATTERN HAS GRADUALLY BECOME BETTER ORGANIZED DURING THE DAY. BANDING FEATURES ARE MORE PROMINENT ON THE VISIBLE IMAGES AND CENTRAL CONVECTION HAS INCREASED. SATELLITE INTENSITY ESTIMATES ARE 45 KT FROM TAFB AND SAB AND 35 KT FROM AFWA. INITIAL INTENSITY IS SET CONSERVATIVELY AT 40 KT. IT IS INTERESTING TO NOTE THAT THE CENTER OF THE CYCLONE PASSED NEAR OR JUST NORTH OF A DATA BUOY AND THAT PLATFORM REPORTED ONLY ABOUT 10 KT WINDS. ALTHOUGH THIS OBSERVATION SEEMS TOO LOW...IT IS ROUGHLY CONSISTENT WITH AN EARLIER SEAWINDS SCATTEROMETER PASS. THIS IS ALSO WHAT WOULD BE EXPECTED FOR A STORM MOVING SO RAPIDLY WESTWARD. THE STORM HAS A LARGE CIRCULATION ENVELOPE...AND ENVIRONMENTAL CONDITIONS...SST AND SHEAR...FAVOR GRADUAL STRENGTHENING. THE MOTION CONTINUES TO BE QUICKLY WESTWARD...275/19. THERE IS A STRONG DEEP LAYER MEAN HIGH PRESSURE AREA SITUATED TO THE NORTH OF FABIAN. THIS STEERING REGIME IS EXPECTED TO PREVAIL THROUGHOUT THE FORECAST PERIOD. HOWEVER THE TRACK GUIDANCE IS UNANIMOUS ON A DECREASE IN FORWARD SPEED...WHICH IS ALSO SHOWN IN THE OFFICIAL FORECAST. THE PREDICTED DECELERATION MAY BE DUE TO A SLIGHT WEAKNESS IN THE RIDGE CREATED BY A DISTURBANCE NEAR 24N49W. OTHERWISE...THERE ARE NO APPARENT REASONS FOR A SIGNIFICANT NORTHWARD EXCURSION DURING THE NEXT FEW DAYS. THE NHC FORECAST TRACK IS ALONG THE SAME TRAJECTORY BUT SLIGHTLY FASTER THAN THE PREVIOUS ONE. IT IS ALSO ALONG THE SOUTHERN EDGE OF THE MODEL SUITE. THE 4-5 DAY FORECAST POINTS IMPLY A TRACK JUST TO THE NORTH OF THE LESSER ANTILLES...BUT THERE ARE LARGE AVERAGE ERRORS AT THESE TIME RANGES. IT IS WAY...WAY...TOO EARLY TO SPECIFY WHETHER FABIAN WILL POSE A THREAT TO LAND AREAS FARTHER WEST. FORECASTER PASCH FORECAST POSITIONS AND MAX WINDS INITIAL 28/2100Z 15.2N 39.2W 40 KT 12HR VT 29/0600Z 15.7N 41.4W 45 KT 24HR VT 29/1800Z 16.2N 44.0W 50 KT 36HR VT 30/0600Z 16.8N 46.5W 55 KT 48HR VT 30/1800Z 17.4N 49.0W 60 KT 72HR VT 31/1800Z 18.5N 53.5W 65 KT 96HR VT 01/1800Z 19.5N 58.0W 70 KT 120HR VT 02/1800Z 20.5N 62.5W 70 KT NNNN