[StBernard] TD THREE Discussion 1

[Westley Annis]

000
WTNT43 KNHC 151440
TCDAT3
TROPICAL DEPRESSION THREE DISCUSSION NUMBER   1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL032009
1100 AM AST SAT AUG 15 2009
 
SATELLITE IMAGERY AND QUIKSCAT DATA INDICATE THAT THE BROAD AREA OF
LOW PRESSURE OVER THE EASTERN ATLANTIC HAS FORMED A WELL-DEFINED
CIRCULATION AND SUFFICIENTLY ORGANIZED CONVECTION TO BE DESIGNATED A
TROPICAL DEPRESSION.  THE INITIAL INTENSITY IS 30 KT BASED ON THE
QUIKSCAT DATA...AS WELL AS SATELLITE INTENSITY ESTIMATES OF 30 AND
35 KT FROM SAB AND TAFB.

THE SYSTEM IS CONSOLIDATING SOUTH OF WHERE THE CENTER WAS BEING
TRACKED YESTERDAY...AND THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN
265/15.  SOME ERRATIC MOTION IS POSSIBLE TODAY AS THE DEPRESSION
INTERACTS WITH THE ELONGATED MONSOON/TROPICAL WAVE CIRCULATION THAT
SPAWNED IT.  OVERALL...DEEP-LAYER HIGH PRESSURE OVER THE CENTRAL
AND EASTERN ATLANTIC SHOULD STEER THE CYCLONE GENERALLY WESTWARD
FOR THE NEXT COUPLE OF DAYS...FOLLOWED BY A TURN TOWARD THE WEST-
NORTHWEST.  THE TRACK MODEL GUIDANCE IS IN GOOD AGREEMENT WITH
THIS SCENARIO...AND THERE IS A FAIRLY TIGHT CLUSTER OF THE MODELS
AROUND THE 5 DAY FORECAST POINT.  ONE EXCEPTION IS THE ECMWF...
WHICH FORECASTS SIGNIFICANTLY MORE NORTHWARD MOTION THAN THE OTHER
MODELS AND AT THIS TIME IS A RIGHT OUTLIER.

THE CYCLONE IS IN DEEP-LAYER EASTERLY FLOW WITH LIGHT/MODERATE
VERTICAL WIND SHEAR FORECAST FOR AT LEAST THE NEXT 4 DAYS.  ALL
INTENSITY GUIDANCE FORECASTS THE SYSTEM TO BECOME A HURRICANE BY
THE END OF THE FORECAST PERIOD...WITH THE HWRF FORECASTING A MAJOR
HURRICANE.  THE INTENSITY FORECAST THUS CALLS FOR GRADUAL
STRENGTHENING TO A TROPICAL STORM IN 12 HR AND A HURRICANE IN 72-96
HR IN BEST AGREEMENT WITH THE INTENSITY CONSENSUS MODELS.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      15/1500Z 11.5N  34.0W    30 KT
 12HR VT     16/0000Z 11.3N  36.1W    35 KT
 24HR VT     16/1200Z 11.3N  38.9W    40 KT
 36HR VT     17/0000Z 11.8N  41.7W    45 KT
 48HR VT     17/1200Z 12.4N  44.4W    50 KT
 72HR VT     18/1200Z 14.0N  50.5W    60 KT
 96HR VT     19/1200Z 16.5N  57.0W    75 KT
120HR VT     20/1200Z 19.0N  63.0W    90 KT
 
$$
FORECASTER BEVEN