HOME	PRODUCTS	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM DEBBY DISCUSSION NUMBER  19
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT THU AUG 24 2000
 
DEBBY IS AT BEST A MINIMAL TROPICAL STORM.  A NOAA HURRICANE HUNTER
AIRCRAFT FOUND A VERY POORLY DEFINED 1011 MB CENTER SOUTH OF EASTERN
CUBA WITH 35-40 KT WINDS AT 1500 FT WELL TO THE NORTHEAST.  SPORADIC
CONVECTION IS FIRING IN THIS AREA...AND THIS MAY VERY WELL MIX THOSE
WINDS DOWN TO THE SURFACE.  THE MAXIMUM WINDS WILL BE 35 KT FOR THIS
ADVISORY.

ALTHOUGH DEBBY SLIPPED A LITTLE SOUTH DURING THE NIGHT...THE INITIAL
MOTION IS NOW 270/16.  A STRONG LOW/MID LEVEL RIDGE NORTH OF THE
STORM IS PUSHING IT WESTWARD...AND THIS GENERAL MOTION SHOULD
CONTINUE FOR 24 HR.  AFTER THAT...THE STRONG UPPER LEVEL TROUGH
DEVELOPING OVER THE EASTERN U.S. SHOULD WEAKEN THE RIDGE AND
POSSIBLY ALLOW A SLOWER AND MORE NORTHWARD MOTION.  HOW FAR NORTH
WILL LIKELY DEPEND ON HOW WELL DEVELOPED DEBBY IS. THE OFFICIAL
FORECAST WILL BE SHIFTED WESTWARD FROM THE PREVIOUS PACKAGE BASED ON
THE CURRENT POSITION AND MOTION.  HOWEVER...SINCE THE GFDL...
UKMET...NOGAPS...AND AVN ARE ALL TO THE LEFT OF THE NEW FORECAST...
IT WOULD NOT BE SURPRISING IF DEBBY MOVED FURTHER WEST THAN
CURRENTLY FORECAST. 
 
THE UPPER LEVEL CYCLONE/CYCLONIC SHEAR AXIS OVER THE NORTHWESTERN
CARIBBEAN IS RATHER STRONGER THAN FORECAST LAST NIGHT...AND IS
CREATING STRONG VERTICAL SHEAR OVER DEBBY.  THIS FEATURE SHOULD
PERSIST FOR 24-36 HR...THUS FURTHER WEAKENING IS LIKELY.  DEBBY
COULD WEAKEN INTO A TROPICAL WAVE DURING THIS TIME. AFTER THAT
TIME...THERE IS A CHANCE THE SHEAR WILL DECREASE DEPENDING ON
EXACTLY WHERE DEBBY IS.  A MORE NORTHWARD MOTION WOULD GET DEBBY
TANGLED IN THE WESTERLY TROUGH...WHERE WESTERLY SHEAR WOULD AT LEAST
SLOW ANY RE-DEVELOPMENT.  A MORE SOUTHERLY TRACK WOULD HAVE A BETTER
CHANCE FOR RE-DEVELOPMENT.  THE INTENSIFY FORECAST WILL CALL FOR
SLIGHT STRENGTHENING AT 48 AND 72 HR TO REFLECT THIS POSSIBILITY.
 
FORECASTER BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     24/0900Z 19.6N  75.9W    35 KTS
12HR VT     24/1800Z 19.7N  78.2W    30 KTS
24HR VT     25/0600Z 20.8N  80.7W    30 KTS
36HR VT     25/1800Z 22.1N  82.5W    30 KTS
48HR VT     26/0600Z 23.5N  84.0W    35 KTS
72HR VT     27/0600Z 25.5N  85.5W    40 KTS
 
 
NNNN