Tropical Depression SIXTEEN

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TROPICAL DEPRESSION SIXTEEN DISCUSSION NUMBER   6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT FRI SEP 26 2003

AN SSM/I OVERPASS AT 0014Z SHOWED THE CENTER OF TROPICAL DEPRESSION
SIXTEEN HAS BECOME EXPOSED TO THE WEST OF THE MAIN CONVECTION. 
WHILE SATELLITE INTENSITY ESTIMATES ARE ALL OF TROPICAL STORM
STRENGTH...THEY ARE ALL BASED ON A CENTER CLOSER TO THE CONVECTION
THAN INDICATED BY THE MICROWAVE DATA.  THUS...THE SYSTEM WILL
REMAIN A 30 KT DEPRESSION FOR THIS ADVISORY.
 
THE CYCLONE HAS TURNED TO THE RIGHT OVER THE PAST SEVERAL HOURS AND
THE INITIAL MOTION IS NOW 330/14.  THE DEPRESSION IS SOUTH OF A
LARGE DEEP-LAYER LOW OVER THE EASTERN ATLANTIC AND EAST OF AN
UPPER-LEVEL TROUGH.  THE GFS... CANADIAN...AND NOGAPS MODELS
SUGGEST THESE FEATURES SHOULD CAUSE THE DEPRESSION TO RE-CURVE TO
THE NORTHEAST DURING THE NEXT TWO TO THREE DAYS.  THE UKMET IS AN
OUTLIER CALLING FOR THE SYSTEM TO SLOW AND DRIFT WESTWARD.  THE
OFFICIAL FORECAST CALLS FOR RECURVATURE...BUT AT A SLOWER FORWARD
SPEED THAN THAT OF THE GFS AND NOGAPS.  THE INITIAL MOTION AND
SPEED REQUIRES THE FORECAST TRACK TO BE SHIFTED CONSIDERABELY TO
THE RIGHT...AND THE LATTER PART OF THE FORECAST TRACK MAY HAVE TO
BE SHIFTED MORE TO THE EAST OVER THE NEXT DAY OR SO IF CURRENT
TRENDS CONTINUE.

NONE OF THE LARGE-SCALE MODELS FORECAST A FAVORABLE UPPER-LEVEL WIND
PATTERN OVER THE CYCLONE DURING THE NEXT 72 HR.  IF SHEAR WERE THE
ONLY FACTOR...THE DEPRESSION WOULD LIKELY DISSIPATE.  HOWEVER...
THERE COULD BE DYNAMICAL FORCING FROM THE DEEP-LAYER TROUGH THAT
COULD PARTLY COMPENSATE FOR THE SHEAR...AND THE GFS..NOGAPS...AND
CANADIAN ALL CALL FOR THE CYCLONE TO INTENSIFY AFTER RECURVATURE. 
IN LIGHT OF THIS...THE INTENSITY FORECAST WILL STILL CALL FOR SOME
STRENGTHENING...BUT AT A SLOWER RATE THAN IN THE PREVIOUS FORECAST.


FORECASTER BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      27/0300Z 18.6N  42.3W    30 KT
 12HR VT     27/1200Z 20.0N  43.4W    30 KT
 24HR VT     28/0000Z 21.9N  44.6W    35 KT
 36HR VT     28/1200Z 23.6N  45.5W    40 KT
 48HR VT     29/0000Z 24.8N  46.1W    45 KT
 72HR VT     30/0000Z 26.0N  46.0W    50 KT
 96HR VT     01/0000Z 27.5N  45.0W    50 KT
120HR VT     02/0000Z 29.5N  43.0W    50 KT
 
 
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