557 
 WTNT44 KNHC 180305
 TCDAT4
 HURRICANE DEAN DISCUSSION NUMBER  20...CORRECTED
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL042007
 1100 PM EDT FRI AUG 17 2007
 
 ...CORRECTED ERRONEOUS INDICATOR OF INLAND AT 96 HOURS IN TABLE...
  
 DEAN HAS BEEN STEADILY INTENSIFYING TONIGHT.  THE U.S. AIR FORCE
 RECONNAISSANCE AIRCRAFT RECENTLY MEASURED MAXIMUM FLIGHT-LEVEL
 WINDS OF 138 KT...CORRESPONDING TO ABOUT 124 KT AT THE SURFACE.  IN
 ADDITION...THE AIRCRAFT IS EQUIPPED WITH THE STEPPED-FREQUENCY
 MICROWAVE RADIOMETER WHICH MEASURED WINDS AS STRONG AS 123 KT THIS
 EVENING.  NOT SURPRISINGLY...THE CENTRAL PRESSURE HAS BEEN
 DROPPING...WITH THE LATEST AIRCRAFT MEASUREMENT BEING 937 MB.  THE
 ADVISORY INTENSITY IS SET TO 125 KT...WHICH IS ALSO CONSISTENT WITH
 DVORAK INTENSITY ESTIMATES.  THE AIRCRAFT DATA ALSO INDICATE THE
 STORM HAS BECOME A GOOD BIT LARGER...AND WIND RADII HAVE BEEN
 EXPANDED IN ALL QUADRANTS.  DEAN MIGHT ALSO HAVE A CLOSE ENCOUNTER
 WITH NOAA BUOY 42059...LESS THAN 100 N MI DIRECTLY AHEAD OF THE
 CENTER OF THE HURRICANE...IN A FEW HOURS.
 
 THE INITIAL MOTION ESTIMATE IS 275/16...JUST A LITTLE SLOWER THAN
 BEFORE.  THE OVERALL TRACK FORECAST REASONING HAS NOT CHANGED...AND
 THE MODELS ARE IN GOOD AGREEMENT THROUGH 72 HOURS ON A TRACK TOWARD
 THE NORTHWESTERN CARIBBEAN.  THEREAFTER...THE MODELS NOTABLY
 DISAGREE AND HAVE GENERALLY SHIFTED A BIT TO THE SOUTH...INCLUDING
 THE NORTHERN OUTLYING GFDL.  THE OFFICIAL FORECAST...HOWEVER...HAS
 NOT CHANGED NOTICEABLY...SINCE THE MODELS MIGHT SHIFT BACK THE
 OTHER WAY.  THE SIGNIFICANT SPREAD IN THE MODELS AT DAYS FOUR AND
 FIVE IS INDICATIVE OF THE LARGE UNCERTAINTIES TYPICAL OF THOSE
 LONGER FORECAST RANGES.  THE NHC WIND SPEED PROBABILITY TEXT AND
 GRAPHICAL PRODUCTS INCLUDED IN THIS ADVISORY PACKAGE ALSO REFLECT
 THESE UNCERTAINTIES.  THE CHANCES OF TROPICAL STORM FORCE WINDS ARE
 SIMILAR AT EACH LOCATION ALONG THE ENTIRE WESTERN AND NORTHERN
 COASTS OF THE GULF OF MEXICO...AND IT IS TOO EARLY TO DIFFERENTIATE
 THE RISK OF HURRICANE FORCE WINDS BETWEEN ANY OF THESE LOCATIONS.
 
 THE FUTURE INTENSITY OF DEAN...GIVEN THE WEAK SHEAR AND WARM WATERS
 AHEAD...WILL LIKELY BE CONTROLLED BY INTERNAL STRUCTURAL CHANGES
 AND/OR BRIEF INTERACTIONS WITH LAND.  THE OFFICIAL FORECAST CALLS
 FOR AN INTENSITY NEAR THE CATEGORY 4/5 THRESHOLD THROUGH 72
 HOURS...AND IS ONLY LOWERED ON DAYS 4 AND 5 DUE TO POTENTIAL
 PASSAGE OVER YUCATAN.
 
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      18/0300Z 14.9N  65.9W   125 KT
  12HR VT     18/1200Z 15.5N  68.4W   130 KT
  24HR VT     19/0000Z 16.4N  71.7W   135 KT
  36HR VT     19/1200Z 17.3N  75.0W   135 KT
  48HR VT     20/0000Z 18.2N  78.4W   135 KT
  72HR VT     21/0000Z 20.0N  85.5W   140 KT
  96HR VT     22/0000Z 22.5N  91.5W   110 KT
 120HR VT     23/0000Z 25.0N  97.5W   110 KT...NEAR COAST OF MEXICO
  
 $$
 FORECASTER KNABB