015 
 WTNT41 KNHC 272100
 TCDAT1
 HURRICANE FRANCES DISCUSSION NUMBER  12
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 5 PM EDT FRI AUG 27 2004
  
 FRANCES HAS CONTINUED TO RAPIDLY INTENSIFY AS INDICATED BY A DVORAK
 SATELLITE INTENSITY ESTIMATE OF T5.5...OR 102 KT...FROM BOTH TAFB
 AND SAB. THE INNER-CORE CONVECTION HAS INCREASED IN VERTICAL DEPTH
 AND AREAL COVERAGE...AND THE OUTFLOW IS EXCELLENT AND CONTINUES TO
 IMPROVE AND EXPAND OUTWARD.
  
 THE MOTION IS 305/09. FRANCES HAS MADE A SLIGHT NORTHWESTWARD JOG AS
 ALLUDED TO IN THE PREVIOUS ADVISORY...BUT THIS IS EXPECTED TO BE
 SHORT-LIVED AS THE SHORTWAVE TROUGH LOCATED DUE NORTH OF FRANCES
 MOVES EASTWARD AND THE RIDGE BUILDS BACK IN BEHIND THE TROUGH. THIS
 SHOULD TURN FRANCES BACK TO THE WEST-NORTHWEST ON SATURDAY. THERE
 IS NOW MUCH LESS DIVERGENCE IN THE NHC MODEL SUITE AFTER 48 HOURS
 ...AND IN THE LONGER TIME PERIODS. ALL OF THE MODELS NOW AGREE THAT
 THE HIGH ZONAL FLOW FORECAST TO DEVELOP ACROSS THE NORTHERN U.S.
 AND THE NORTH ATLANTIC AFTER 48HR WILL ALLOW FOR A STRONG
 SUBTROPICAL RIDGE TO THE SOUTH TO EXTEND EAST-WEST FROM THE AZORES
 TO BERMUDA AND INTO THE SOUTHEASTERN U.S.  THE LATEST GFS AND
 CANADIAN MODELS HAVE SHIFTED FARTHER NORTH...WHILE THE UKMET AND
 GFDL MODELS HAVE SHIFTED A LITTLE MORE TO THE SOUTH AND WEST. ALL
 OF THESE MODELS ARE CONVERGING NICELY ABOUT THE PREVIOUS SEVERAL
 NHC FORECAST TRACKS...SO I SEE NO REASON AT THIS TIME TO MAKE ANY
 SIGNIFICANT CHANGES TO THE PREVIOUS TRACK FORECASTS. THE OFFICIAL
 TRACK IS JUST AN EXTENSION OF THE PREVIOUS TRACK AND IS CLOSE TO
 THE GUNA MODEL CONSENSUS.
  
 FRANCES IS FORECAST TO REMAIN IN A LOW SHEAR ENVIRONMENT AND OVER
 INCREASING SSTS THROUGHOUT THE PERIOD. THE SHIPS INTENSITY MODEL 
 NOW MAKES FRANCES A 113 KT MAJOR HURRICANE IN 48 HOURS...SINCE THE
 'SELF-INDUCED' VERTICAL SHEAR HAS DECREASED OWING TO THE GFS
 FORECAST POSITONS BEING CLOSER TO THE OFFICIAL TRACK FORECAST.
 THERE WILL LIKELY BE SEVERAL FLUCTUATIONS IN THE INTENSITY OVER THE
 NEXT 5 DAYS...BUT CATEGORY FOUR INTENSITY SEEMS LIKELY SOME TIME
 DURING THAT PERIOD...AND CATEGORY 5 STRENGTH IS EVEN POSSIBLE.
  
 FORECASTER STEWART
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      27/2100Z 15.7N  49.8W   100 KT
  12HR VT     28/0600Z 16.9N  51.2W   105 KT
  24HR VT     28/1800Z 17.9N  52.8W   110 KT
  36HR VT     29/0600Z 18.9N  54.5W   115 KT
  48HR VT     29/1800Z 19.7N  56.4W   115 KT
  72HR VT     30/1800Z 20.6N  60.0W   115 KT
  96HR VT     31/1800Z 21.5N  64.5W   115 KT
 120HR VT     01/1800Z 22.5N  69.0W   115 KT
  
  
 $$