262 
 WTNT45 KNHC 271459
 TCDAT5
 HURRICANE ERNESTO DISCUSSION NUMBER  12
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL052006
 1100 AM EDT SUN AUG 27 2006
  
 ERNESTO'S CLOUD PATTERN IS STILL A BIT RAGGED-LOOKING BUT THERE ARE
 SOME BANDING FEATURES OVER THE EASTERN SEMICIRCLE...AND CIRRUS
 OUTFLOW IS EXPANDING OVER THE WESTERN PART OF THE CIRCULATION.  THE
 LAST AIRCRAFT-EXTRAPOLATED CENTRAL PRESSURE WAS 997 MB...SUGGESTING
 THAT THERE HAS BEEN LITTLE OR NO STRENGTHENING OVER THE PAST
 SEVERAL HOURS.  WITH THE UPPER-LEVEL CYCLONE SHIFTING WESTWARD
 TOWARD YUCATAN...THE SHEAR OVER ERNESTO IS QUICKLY DIMINISHING.  
 THUS THE PRIMARY CONSIDERATION IN THE INTENSITY FORECAST OVER THE
 NEXT COUPLE OF DAYS WILL BE HOW MUCH THE TROPICAL CYCLONE INTERACTS
 WITH LAND.  ON THE CURRENT FORECAST TRACK...THE CENTER WOULD BE
 OVER CUBA FROM HOUR 24 TO 48 HOURS.  THIS SHOULD CAUSE SOME
 WEAKENING AND THE OFFICIAL WIND SPEED FORECAST FOLLOWS THE DECAY
 SHIPS MODEL RATHER CLOSELY.  HOWEVER...AFTER THE CENTER MOVES INTO
 THE SOUTHEASTERN GULF OF MEXICO...SIGNIFICANT RESTRENGTHENING IS
 POSSIBLE.  IT SHOULD BE NOTED THAT THE OFFICIAL FORECAST INTENSITY
 AT 96 HOURS ASSUMES SOME WEAKENING DUE TO INTERACTION WITH LAND. 
 HOWEVER....ERNESTO COULD APPROACH CATEGORY 3 STATUS PRIOR TO THE
 PROJECTED LANDFALL IN WESTERN FLORIDA. 
 
 INITIAL MOTION IS ESTIMATED AT 310/8.  A CONTINUED NORTHWESTWARD
 TRACK IS INDICATED BY MOST OF THE NUMERICAL GUIDANCE OVER THE NEXT
 COUPLE OF DAYS.  THIS WOULD TAKE ERNESTO OVER A SIGNIFICANT PORTION
 OF CUBA.  A MID-TROPOSPHERIC ANTICYCLONE OVER THE SOUTHEASTERN
 UNITED STATES IS EXPECTED TO SHIFT EASTWARD AS A SHORTWAVE TROUGH
 DROPS INTO THE LOWER MISSISSIPPI IN 3-5 DAYS.  THIS SHOULD CAUSE A
 MORE NORTHWARD HEADING LATER IN THE FORECAST PERIOD.  THE 0600 UTC
 RUNS OF THE GFS HAS SHIFTED A LITTLE TO THE WEST OF THE PREVIOUS
 RUN BUT THE 0600 UTC NOGAPS HAS SHIFTED TO THE EAST.  THE OFFICIAL
 FORECAST TRACK IS NUDGED SLIGHTLY MORE TO THE RIGHT TO BE CLOSER TO
 THE MODEL CONSENSUS.  THIS IS EAST OF THE LATEST GFDL MODEL TRACK.
 
 A TROPICAL STORM OR HURRICANE WATCH MAY BE REQUIRED FOR THE FLORIDA
 KEYS AS EARLY AS 2100 UTC TODAY.
 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      27/1500Z 17.6N  73.7W    65 KT
  12HR VT     28/0000Z 18.6N  74.9W    75 KT
  24HR VT     28/1200Z 20.0N  76.5W    85 KT...INLAND
  36HR VT     29/0000Z 21.5N  78.3W    75 KT...INLAND
  48HR VT     29/1200Z 23.1N  80.3W    65 KT...INLAND
  72HR VT     30/1200Z 25.5N  82.5W    85 KT
  96HR VT     31/1200Z 28.0N  82.5W    80 KT...INLAND
 120HR VT     01/1200Z 31.0N  81.0W    60 KT
  
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