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TROPICAL DEPRESSION NINE DISCUSSION NUMBER   2
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT THU SEP 12 2002
 
THE DEPRESSION IS VERY CLOSE TO TROPICAL STORM STATUS.  THE EAST 
GULF BUOY BRIEFLY REPORTED SUSTAINED WINDS TO 33 KT BEFORE DROPPING 
BACK DOWN...AND DEEP CONVECTION HAS DEVELOPED JUST NORTHEAST OF THE 
CENTER.  HOWEVER...GIVEN THE STRONGLY SHEARED AND SEMI-TROPICAL 
NATURE OF THIS SYSTEM...I WOULD LIKE TO SEE MORE PERSISTENT EVIDENCE 
OF TROPICAL STORM FORCE WINDS BEFORE GIVING THIS THING A NAME.

THE DEPRESSION IS CURRENTLY IN A WEAK STEERING ENVIRONMENT IN 
BETWEEN TWO MID-LEVEL RIDGES...ONE CENTERED OVER NORTHEASTERN 
TEXAS...AND ANOTHER ONE IN THE SOUTHEASTERN BAHAMAS.  THE CYCLONE 
HAS A PARTIAL BAROCLINIC STRUCTURE WITH A WESTWARD TILT WITH HEIGHT. 
DURING THE FIRST HALF OF THE FORECAST PERIOD...MOST OF THE MODEL 
GUIDANCE ROTATES THE LOW-LEVEL CENTER COUNTER-CLOCKWISE AROUND THE 
MID-LEVEL CENTER.  GLOBAL MODELS ARE IN AGREEMENT THAT THE RIDGE TO 
THE NORTHWEST OF THE DEPRESSION WILL WEAKEN AS AN UPPER-LEVEL LOW 
OVER THE U.S. SOUTHWEST ADVANCES EASTWARD.  THIS WOULD THEN BEGIN TO 
ACCELERATE THE CYCLONE NORTHEASTWARD BY THE END OF THE FORECAST 
PERIOD.  THE OFFICIAL FORECAST IS SHIFTED JUST A LITTLE BIT TO THE 
LEFT OF THE PREVIOUS ADVISORY...BUT REMAINS TO THE RIGHT OF MOST OF 
THE CURRENT GUIDANCE.  SHOULD THE DEPRESSION OVERCOME THE SHEARING 
ENVIRONMENT AND CONTINUE TO ORGANIZE...THEN I SUSPECT WE WILL HAVE 
TO MAKE ADDITIONAL WESTWARD ADJUSTMENTS TO THE FORECAST TRACK.

AS WITH OUR LAST TWO SYSTEMS...MOST OF OUR INTENSITY GUIDANCE IS OF 
QUESTIONABLE VALUE BECAUSE OF THE NON-TROPICAL ASPECTS OF THE 
DEPRESSION.  THE UPPER-ENVIRONMENT IS NOT IDEAL...BUT AT LEAST IT IS 
DIFLUENT...SO SOME MODEST STRENGTHENING IS FORECAST...ROUGHLY IN 
ACCORD WITH THE SHIPS GUIDANCE.
 
FORECASTER FRANKLIN
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     12/0900Z 26.9N  86.4W    30 KTS
12HR VT     12/1800Z 27.4N  85.9W    35 KTS
24HR VT     13/0600Z 28.1N  85.7W    40 KTS
36HR VT     13/1800Z 28.9N  85.6W    45 KTS
48HR VT     14/0600Z 30.0N  85.5W    45 KTS...INLAND
72HR VT     15/0600Z 33.0N  83.0W    25 KTS...INLAND
 
 
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