ZCZC MIATCDAT1 ALL TTAA00 KNHC DDHHMM TROPICAL STORM ALLISON SPECIAL DISCUSSION NUMBER 1 NATIONAL WEATHER SERVICE MIAMI FL 3 PM EDT TUE JUN 05 2001 REPORTS FROM AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT INDICATE THAT THE TROPICAL DISTURBANCE OVER THE NORTHWEST GULF OF MEXICO HAS A BROAD CLOSED LOW-LEVEL CIRCULATION. AS A RESULT OF THE 40 TO 50 KT SURFACE WINDS ON THE EAST SIDE...THE SYSTEM IS BEING UPGRADED DIRECTLY TO THE FIRST TROPICAL STORM OF THE ATLANTIC SEASON JUST OFF THE SOUTHEAST TEXAS COAST. INITIAL MOTION ESTIMATE IS 360/11. TROPICAL STORM ALLISON IS EXPECTED TO TRACK NORTHWARD ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE WHOSE AXIS IS LOCATED EAST-WEST ACROSS THE SOUTHERN U.S. FROM GEORGIA TO LOUISIANA. THE BROAD CENTER SHOULD MOVE INLAND OVER EXTREME SOUTHEAST TEXAS OR SOUTHWEST LOUISIANA LATER TONIGHT AND THEN TURN MORE TOWARD THE NORTHEAST AS A SHORTWAVE TROUGH OVER THE SOUTHERN PLAINS GRADUALLY PICKS UP THE SYSTEM. THIS SCENARIO IS CONSISTENT WITH MOST OF THE DYNAMICAL MODEL GUIDANCE. SOME SLIGHT STRENGTHENING IS POSSIBLE BEFORE LANDFALL EVEN THOUGH ALLISON IS MORE LIKE A HYBRID SYSTEM. HOWEVER...IT IS UNLIKELY THAT THE CYCLONE WOULD GET ABOVE 55 KT BEFORE DUE TO THE COOL OFFSHORE SEA SURFACE TEMPERATURES. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 05/1900Z 28.3N 94.7W 50 KTS 12HR VT 06/0600Z 30.1N 94.2W 45 KTS...INLAND 24HR VT 06/1800Z 31.6N 93.9W 30 KTS...INLAND DISSIPATING 36HR VT 07/0600Z 33.1N 93.2W 25 KTS...INLAND DISSIPATING 48HR VT 07/1800Z 34.4N 92.0W 20 KTS...INLAND DISSIPATING NNNN