ZCZC MIATCDAT1 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION ONE DISCUSSION NUMBER 6 NATIONAL WEATHER SERVICE MIAMI FL 5 PM EDT TUE JUL 28 1998 THE INITIAL MOTION ESTIMATE IS 280/21 AND THIS IS SOMEWHAT FASTER THAN THE PREVIOUS ADVISORY. THE 12Z AVIATION MODEL SHOWS THE DEPRESSION TURNING TOWARD THE NORTH-NORTHWEST INTO A WEAKNESS IN THE SUBTROPICAL HIGH PRESSURE RIDGE...THIS IS EXACTLY THE SAME SCENARIO AS THE 00Z MODEL RUN AND ALL OF THE TRACK GUIDANCE MODELS ARE SIMILAR TO THE LAST PACKAGE. SO THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS ADVISORY EXCEPT A LITTLE FASTER DURING THE FIRST 24 HOURS FOLLOWED BY CONSIDERABLE DECELERATION. AS BEFORE...THE GFDL AND NOGAPS MODELS LOSE THE CIRCULATION IN 24 HOURS. SATELLITE IMAGERY SHOWS A WELL-DEFINED LOW-LEVEL CLOUD STRUCTURE AND DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB ARE AT MINIMAL TROPICAL STORM STRENGTH WHILE KGWC GAVE A 2.0 T NUMBER. HOWEVER I PREFER TO WAIT FOR THE APPEARANCE OF SOME MORE DEEP CONVECTION BEFORE UPGRADING TO A TROPICAL STORM. THE FORECAST...AS IN THE PREVIOUS ADVISORY...IS FOR GRADUAL STRENGTHENING FOLLOWING THE SHIPS STATISTICAL/DYNAMICAL INTENSITY MODEL. THIS SYSTEM IS FAIRLY LARGE AND THE WIND SPEED RADII IN THE FORECAST/ADVISORY ARE INCREASED A LITTLE FROM THE PREVIOUS ADVISORY. LAWRENCE FORECAST POSITIONS AND MAX WINDS INITIAL 28/2100Z 13.5N 36.7W 30 KTS 12HR VT 29/0600Z 14.0N 39.5W 35 KTS 24HR VT 29/1800Z 15.0N 43.0W 40 KTS 36HR VT 30/0600Z 16.0N 46.0W 45 KTS 48HR VT 30/1800Z 17.5N 48.2W 50 KTS 72HR VT 31/1800Z 20.0N 51.5W 55 KTS NNNN