Tropical Storm GREG

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TROPICAL STORM GREG DISCUSSION NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
8 PM PDT SAT AUG 13 2005
A 14/0151Z SSMI OVERPASS SUGGESTS THAT THE CIRCULATION CENTER IS
PARTIALLY EXPOSED TO THE NORTHEAST OF THE DEEP CONVECTION. 
HOWEVER...THERE HAS BEEN AN IMPRESSIVE DEEP BURST OVER THE PAST 6
HOURS JUST SOUTHWEST OF THE CENTER.  SATELLITE INTENSITY ESTIMATES
FROM SAB AND TAFB ARE 45 KT...AND 35 KT FROM AFWA.  THE INITIAL
INTENSITY IS INCREASED TO 40 KT.  INTENSITY FORECAST PHILOSOPHY IS
SIMILAR TO THE PREVIOUS ADVISORY AND FOLLOWS THE SHIPS AND FSU
SUPERENSEMBLE MODELS. 
THE INITIAL MOTION IS 260/7.  DYNAMICAL MODELS CONTINUE TO SUGGEST
THAT GREG WILL BE STEERED INCREASINGLY WEST-SOUTHWESTWARD WITHIN
THE MID LEVEL FLOW OF A RIDGE SITUATED BETWEEN THE TWO TROPICAL
CYCLONES.  BEYOND DAY 3...THERE IS A SPLIT IN THE MODELS WITH THE
ECMWF/GFDL/GFS AND UKMET INDICATING A SHARP TURN TOWARD THE NORTH
INTO A BREAK IN THE RIDGE.  THE SECOND CLUSTER...NOGAPS/GFDN...AND
THE GFS BETA ADVECTION MODELS SUGGEST THAT THE AMPLITUDE OF THE
TROUGH WILL NOT BE DEEP ENOUGH TO INFLUENCE A TURN TO THE NORTH. 
THE OFFICIAL FORECAST IS A COMPROMISE BETWEEN THE TWO
SCENARIOS...SIMILAR TO THE PREVIOUS PACKAGE...BUT SLOWER AFTER DAY
3 TO HEDGE TOWARD THE CONU CONSENSUS MODEL. 
FORECASTER ROBERTS/STEWART
FORECAST POSITIONS AND MAX WINDS
INITIAL 14/0300Z 15.3N 115.6W 40 KT
12HR VT 14/1200Z 15.1N 116.2W 45 KT
24HR VT 15/0000Z 14.7N 117.2W 45 KT
36HR VT 15/1200Z 14.3N 118.5W 50 KT
48HR VT 16/0000Z 14.2N 120.0W 55 KT
72HR VT 17/0000Z 14.3N 122.6W 60 KT
96HR VT 18/0000Z 14.5N 125.0W 65 KT
120HR VT 19/0000Z 15.0N 127.5W 65 KT
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