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TROPICAL DEPRESSION ONE DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT SAT JUL 31 2004
 
THE LOW PRESSURE AREA OFF THE NORTHEAST FLORIDA COAST HAS SHOWN
INCREASING CONVECTIVE ORGANIZATION THIS AFTERNOON...WITH SATELLITE
INTENSITY ESTIMATES OF 30 KT FROM TAFB AND 25 KT FROM SAB.  THUS...
ADVISORIES ARE BEING INITIATED ON THE SYSTEM AS TROPICAL DEPRESSION
ONE WITH 25 KT WINDS.  WHILE THE DEPRESSION HAS A LARGE CYCLONIC
ENVELOPE...THE CENTER WAS VERY POORLY DEFINED ON THE RECONNAISSANCE
FLIGHT THIS MORNING...AND IT WOULD NOT BE A SURPRISE IF THE FLIGHT
SCHEDULED FOR 0000Z FINDS THE SAME.
 
THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 315/8.  THE DEPRESSION IS
CURRENTLY BEING STEERED BY THE WESTERN END OF THE SUBTROPICAL
RIDGE...WHILE WATER VAPOR IMAGERY AND LARGE-SCALE MODELS SHOW
DEEP-LAYER TROUGHING OVER THE CENTRAL UNITED STATES MOVING EASTWARD.
ALL GUIDANCE SHOWS THE CYCLONE RECURVING NORTHEASTWARD AHEAD OF THE
TROUGH...WITH THE BIGGEST DIFFERENCES IN THE GUIDANCE BEING HOW
FAST IT MOVES AFTER RECURVATURE.  THE OFFICIAL FORECAST TRACK WILL
CALL FOR THE SYSTEM TO TURN NORTHWARD AT ABOUT 24 HR AND
NORTHEASTWARD AFTER 36 HR...BRUSHING THE SOUTHEASTERN U.S. COAST.
WHILE THE OFFICIAL TRACK CALLS FOR LANDFALL IN NORTH CAROLINA...
SEVERAL MODELS RECURVE THE CYCLONE SHARPLY ENOUGH TO KEEP THE
CENTER OFFSHORE.
 
THIS LARGE AND POORLY DEFINED SYSTEM WILL LIKELY TAKE TIME TO
CONSOLIDATE EVEN THOUGH CONDITIONS GENERALLY APPEAR FAVORABLE FOR
INTENSIFICATION.  THE INTENSITY FORECAST THUS CALLS FOR SLOW
STRENGTHENING UNTIL THE SYSTEM REACHES THE COAST.  WHAT
INTENSIFICATION MAY OCCUR AFTER THE CYCLONE CLEARS THE U.S. EAST
COAST IS QUESTIONABLE...AS THE LARGE SCALE MODELS DISAGREE ON
WHETHER IT WILL DISSIPATE OR STRENGTHEN DURING INTERACTION WITH THE
WESTERLIES.  FOR NOW...THE INTENSITY FORECAST WILL COMPROMISE
BETWEEN THE TWO EXTREMES AND KEEP A STEADY 40 KT UNTIL
EXTRATROPICAL TRANSITION.

THE PROXIMITY TO THE COAST REQUIRES A TROPICAL STORM WATCH TO BE
ISSUED FOR PORTIONS OF THE COASTS OF NORTH AND SOUTH CAROLINA AT
THIS TIME.  A TROPICAL STORM WARNING MAY BE REQUIRED IN A LATER
ADVISORY.
 
FORECASTER BEVEN
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      31/2100Z 30.6N  78.6W    25 KT
 12HR VT     01/0600Z 31.5N  79.3W    30 KT
 24HR VT     01/1800Z 32.9N  79.2W    35 KT
 36HR VT     02/0600Z 34.0N  78.0W    40 KT...INLAND
 48HR VT     02/1800Z 35.2N  76.6W    40 KT...INLAND
 72HR VT     03/1800Z 37.5N  73.5W    40 KT...OVER WATER
 96HR VT     04/1800Z 40.0N  69.0W    40 KT
120HR VT     05/1800Z 46.0N  57.5W    40 KT...EXTRATROPICAL
 
 
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