880 
 WTNT44 KNHC 142053
 TCDAT4
 TROPICAL STORM DEAN DISCUSSION NUMBER   6
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL042007
 500 PM EDT TUE AUG 14 2007
  
 DEAN'S STRUCTURE HAS NOT IMPROVED DURING THE AFTERNOON. CONVECTION
 HAS WANED AND REMAINS ESPECIALLY LIMITED IN THE NORTHEASTERN
 SEMICIRCLE...THOUGH THIS MAY BE A DIURNAL FLUCTUATION. BOTH TAFB
 AND SAB GAVE DVORAK ESTIMATES OF T2.5 OR 35 KT...WHILE AN AMSU PASS
 AT 1623 UTC SUGGESTED A SUBSTANTIALLY STRONGER INTENSITY. GIVEN THE
 LACK OF CONVECTIVE VIGOR...THE INTENSITY OF DEAN IS KEPT AT 35 KT.
 
 INITIAL MOTION OF DEAN IS 265 DEGREES AT 18 KT...A BIT SLOWER THAN
 THE LAST ADVISORY.  DEAN IS SOUTH OF A DEEP-LAYERED RIDGE WHICH
 SHOULD STEER THE CYCLONE TOWARD THE WEST OR WEST-NORTHWEST FOR THE
 NEXT FEW DAYS.  THE MODEL GUIDANCE SHIFTED SOMEWHAT TO THE WEST AND
 FASTER COMPARED TO THE 06 UTC RUNS...PERHAPS DUE TO A WEAKER AND
 LESS DIGGING TROUGH OFF OF THE U.S. EAST COAST BY DAY 5.  THE
 OFFICIAL TRACK FORECAST IS TO THE LEFT OF AND FASTER THAN THE
 PREVIOUS ADVISORY...BUT REMAINS TO THE RIGHT OF THE CONSENSUS OF
 THE GFS...GFDL...AND HWRF.  COMPARED TO THE OTHER MODELS...TRACK
 SOLUTIONS FOR THE NOGAPS AND ECMWF ARE SLOWER BECAUSE THEY DO NOT
 APPEAR TO HAVE A GOOD HANDLE ON DEAN'S FAST INITIAL FORWARD SPEED.
 
 DEAN IS CURRENTLY EXPERIENCING MODERATE NORTHEASTERLY SHEAR...IS
 OVER 27.5C SSTS...AND IS WITHIN A MOIST ENVIRONMENT.  THE SHEAR
 SHOULD DROP WHILE THE SSTS WARM OVER THE NEXT FEW DAYS...SO THE
 ENVIRONMENT APPEARS TO BE CONDUCIVE FOR GRADUAL INTENSIFICATION. 
 THE INTENSITY FORECAST IS CLOSE A CONSENSUS OF THE HWRF...
 GFDL...SHIPS...AND LGEM THROUGH 72 HR.  THEREAFTER...THE INTENSITY
 FORECAST RELIES PRIMARILY UPON THE GFDL AND LGEM MODELS.  BY DAY
 5...DEAN IS FORECAST TO BE A STRENGTHENING HURRICANE AND COULD
 REACH MAJOR HURRICANE STATUS BY THEN.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      14/2100Z 11.6N  41.0W    35 KT
  12HR VT     15/0600Z 11.7N  43.6W    40 KT
  24HR VT     15/1800Z 12.0N  46.9W    45 KT
  36HR VT     16/0600Z 12.3N  50.2W    50 KT
  48HR VT     16/1800Z 12.6N  53.5W    60 KT
  72HR VT     17/1800Z 14.0N  59.5W    70 KT
  96HR VT     18/1800Z 15.5N  64.5W    85 KT
 120HR VT     19/1800Z 17.5N  69.5W    95 KT
  
 $$
 FORECASTER LANDSEA/KNABB