Tropical Storm BONNIE
ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM BONNIE DISCUSSION NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT TUE AUG 10 2004
AN AIRCRAFT RECONNAISSANCE MISSION FROM 17 TO 23Z FOUND A MAXIMUM
WIND OF 43 KT AT 850-MB FLIGHT LEVEL AND 1004 MB. ALSO SATELLITE
IMAGERY SHOWS A SPUTTERING VERY SMALL AREA OF DEEP CONVECTION.
THEREFORE THE MAXIMUM SURFACE WIND IS REDUCED FROM 45 KT TO 40 KT.
THE INITIAL MOTION ESTIMATE IS 010/04. THE TRACK GUIDANCE REMAINS
IN GOOD AGREEMENT ABOUT AN ACCELERATION TOWARD THE NORTHEAST IN
ADVANCE OF A MID LATITUDE TROUGH DIGGING SOUTHWARD INTO THE NORTHERN
GULF OF MEXICO. THE OFFICIAL FORECAST TRACK IS SHIFTED A LITTLE
TO THE LEFT OF THE PREVIOUS ADVISORY FOLLOWING A CONSENSUS OF THE
GLOBAL TRACK GUIDANCE MODELS.
BONNIE HAS ONLY ABOUT 24 HOURS TO INTENSIFY BEFORE ENCOUNTERING
STRONG SOUTHWESTERLY VERTICAL WIND SHEAR. SINCE THE CURRENT TREND
HAS BEEN FOR SLIGHT WEAKENING...SIGNIFICANT INTENSIFICATION IS
BECOMING LESS LIKELY. THE GFDL MODEL BRINGS THE WINDS TO 82 KT
BEFORE LANDFALL...BUT NONE OF THE OTHER GUIDANCE SHOWS MUCH
STRENGTHENING. THE SHIPS MODEL GOES TO ONLY 45 KT BEFORE LANDFALL.
THE PREVIOUS ADVISORY FORECAST 70 KT WINDS BEFORE LANDFALL AND THIS
ADVISORY FORECAST BACKS OFF TO 60 KT WHICH MAY STILL BE TOO HIGH.
THE TRACK AND INTENSITY FORECASTS REQUIRE A TROPICAL STORM WATCH FOR
NORTHWEST FLORIDA.
FORECASTER LAWRENCE
FORECAST POSITIONS AND MAX WINDS
INITIAL 11/0300Z 25.0N 90.4W 40 KT
12HR VT 11/1200Z 26.0N 90.1W 50 KT
24HR VT 12/0000Z 27.6N 89.0W 60 KT
36HR VT 12/1200Z 29.8N 86.7W 60 KT
48HR VT 13/0000Z 32.5N 83.2W 30 KT...INLAND
72HR VT 14/0000Z 42.0N 75.0W 30 KT...EXTRATROPICAL
96HR VT 15/0000Z...ABSORBED BY FRONTAL SYSTEM
$$
NNNN