257 
 WTPZ42 KNHC 140301
 TCDEP2
 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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