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TROPICAL DEPRESSION TWO DISCUSSION NUMBER   4
NATIONAL WEATHER SERVICE MIAMI FL
10 AM EST THU AUG 20 1998
 
SATELLITE IMAGES SHOW THAT THE DEPRESSION IS FAIRLY WELL
ORGANIZED...AND MAY BE A TROPICAL STORM.  WE WILL AWAIT THE AIR
FORCE RECON OBSERVATIONS LATER TODAY TO SEE IF WE SHOULD NAME THE
SYSTEM.  THE ANTICYLONIC OUTFLOW IS VERY IMPRESSIVE OVER THE
NORTHERN SEMICIRCLE AND RAWINSONDE OBSERVATIONS FROM THE
NORTHEASTERN CARIBBEAN SHOW NO HIGH LEVEL WESTERLIES TO IMPEDE
DEVELOPMENT.  SO...STRENGTHENING IS PREDICTED AS IN THE PREVIOUS
ADVISORY.
 
THE CYCLONE WAS APPARENTLY MOVING FASTER OVERNIGHT THAN EARLIER
REPORTED AND HAS BEEN RELOCATED FARTHER TO THE WEST-NORTHWEST.
MOTION ESTIMATE IS NOW 290/20.  THE GLOBAL MODELS SHOW A BROAD
TROUGH AT 500 MB MOVING OFF THE NORTHEAST U.S. COAST IN A COUPLE OF
DAYS AND THIS SHOULD PARTIALLY BREAK DOWN THE SUBTROPICAL RIDGE OVER
THE WESTERN ATLANTIC.  CONSEQUENTLY MOST OF THE TRACK PREDICTION
MODELS TURN THE CYCLONE TO THE NORTHWEST AND SLOW THE FORWARD SPEED
LATER IN THE PERIOD...AS DOES THE OFFICIAL FORECAST.  HOWEVER WE ARE
CONCERNED ABOUT THE POSSIBILITY OF A MORE WESTWARD TRACK SINCE THE
STATE-OF-THE-ART  GFDL MODEL DOES NOT SHOW MUCH OF A NORTHWARD
TREND.
 
THE NOAA G-4 JET AND BOTH NOAA P-3 PLANES WILL FLY A SYNOPTIC
SURVEILLANCE MISSION LATER TODAY AND THIS WILL GIVE US A BETTER
PICTURE OF THE STEERING ENVIRONMENT.
 
PASCH
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     20/1500Z 18.0N  58.0W    30 KTS
12HR VT     21/0000Z 19.2N  61.0W    40 KTS
24HR VT     21/1200Z 20.5N  64.0W    50 KTS
36HR VT     22/0000Z 21.7N  67.0W    55 KTS
48HR VT     22/1200Z 23.0N  70.0W    60 KTS
72HR VT     23/1200Z 25.5N  73.5W    75 KTS
 
 
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