037 
 WTNT45 KNHC 162059
 TCDAT5
 HURRICANE OMAR DISCUSSION NUMBER  14
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL152008
 500 PM EDT THU OCT 16 2008
  
 OMAR'S CENTRAL CONVECTION HAS DIMINISHED CONSIDERABLY...WHILE THE
 PRINCIPAL BAND TO ITS SOUTHEAST AND SOUTH STILL CONTAINS VIGOROUS
 DEEP CONVECTION.  CONSTRAINTS ON THE DVORAK TECHNIQUE ARE STILL
 FORCING TAFB AND SAB TO INDICATE ABOUT A 90 KT HURRICANE. 
 HOWEVER...BASED ON THE CONTINUING DETERIORATION OF THE CENTRAL
 FEATURES...THE INTENSITY IS REDUCED TO 65 KT.
 
 THE TROPICAL CYCLONE IS MOVING QUICKLY TOWARD THE NORTH-NORTHEAST...
 30 DEGREES AT 23 KT...UNDER THE INFLUENCE OF A DEEP-LAYER LOW TO
 ITS NORTH AND MID TO LOW LEVEL RIDGE TO ITS NORTHEAST. THE TRACK
 GUIDANCE IS TIGHTLY CLUSTERED THROUGH 72 HR ALONG A TRACK TOWARD
 THE NORTHEAST. BUT AS EXTRATROPICAL TRANSITION BEGINS...THE VARIOUS
 MODELS SPLIT INTO TWO DIFFERENT SOLUTIONS. THE NOGAPS...UKMET...AND
 GFDL MODELS SUGGEST THAT THE CYCLONE WILL UNDERGO SIGNIFICANT
 RE-INTENSIFICATION AND EXPANSION IN SIZE NEAR THE AZORES. IN
 CONTRAST...THE ECMWF...GFS...AND HWRF MODELS INDICATE THAT THE
 CYCLONE WILL CONTINUE TO WEAKEN...BE MUCH FARTHER TO THE WEST...AND
 EVENTUALLY BE ABSORBED BY A LARGE EXTRATROPICAL CYCLONE OFF OF
 SOUTHEASTERN CANADA. THE SOLUTION FAVORED BY THIS ADVISORY IS THE
 LATTER SCENARIO...THOUGH IT IS DIFFICULT THIS FAR IN ADVANCE
 EXACTLY WHEN AND HOW EXTRATROPICAL TRANSITION WILL OCCUR. THE
 FORECAST TRACK IS SLOWER THAN THE PREVIOUS ADVISORY AND WEST OF THE
 CORRECTED MODEL CONSENSUS.
  
 DESPITE BEING OVER VERY WARM WATER...THE STRONG SOUTHWESTERLY
 VERTICAL SHEAR AND DRY AIR BEING WRAPPED INTO THE INNER CORE
 SHOULD CONTINUE TO WEAKEN OMAR.  HOWEVER...THE RAPID MOTION OF THE
 CYCLONE TO THE NORTHEAST MAY SOMEWHAT OFFSET THE NEGATIVE IMPACT OF
 THE SHEAR.  THE FAST FORWARD MOTION MAY ALSO CONTRIBUTE TOWARD THE
 WINDS ON THE RIGHT SIDE OF THE VORTEX.  THUS ONLY GRADUAL WEAKENING
 IS INDICATED IN THE NEXT COUPLE OF DAYS.  THE SHIPS AND LGEM
 STATISTICAL MODELS SUGGEST MORE RAPID WEAKENING TO A TROPICAL
 DEPRESSION...THOUGH THESE TECHNIQUES ARE HEAVILY WEIGHTING THE
 LARGE NEGATIVE PERSISTENCE FACTOR.  THE INTENSITY FORECAST IS CLOSE
 TO THE GFDL AND HWRF SOLUTIONS AND IS SLIGHTLY LESS THAN INDICATED
 IN THE PREVIOUS ADVISORY.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      16/2100Z 22.1N  59.7W    65 KT
  12HR VT     17/0600Z 25.0N  57.6W    65 KT
  24HR VT     17/1800Z 28.2N  55.1W    60 KT
  36HR VT     18/0600Z 30.1N  53.2W    55 KT
  48HR VT     18/1800Z 32.2N  50.9W    50 KT
  72HR VT     19/1800Z 36.0N  46.0W    45 KT...BECOMING EXTRATROPICAL
  96HR VT     20/1800Z 38.0N  39.0W    40 KT...EXTRATROPICAL
 120HR VT     21/1800Z 38.0N  31.0W    35 KT...EXTRATROPICAL
  
 $$
 FORECASTER LANDSEA/STEWART