443 
 WTNT41 KNHC 270838
 TCDAT1
 HURRICANE FRANCES DISCUSSION NUMBER  10
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 5 AM EDT FRI AUG 27 2004
  
 FOR A COUPLE OF HOURS BEFORE 0600Z THERE WAS A WELL-DEFINED EYE
 EMBEDDED WITHIN A SYMMETRIC AREA OF DEEP CONVECTION. THIS GAVE THE
 APPEARANCE OF A STRONGER HURRICANE SINCE OBJECTIVE NUMBERS WERE
 NEAR 5.0 AND A SUBJECTIVE CLASSIFICATION WOULD GIVE A 5.5 ON THE
 DVORAK SCALE DURING THAT PERIOD. AT THE CLASSIFICATION TIME...06Z...
 THE EYE BECAME LESS DEFINED AND CONVECTION WEAKENED A LITTLE. THIS
 RESULTED IN THE SAME 4.5 T-NUMBERS THAT WERE PROVIDED AT 00Z.
 THEREAFTER...MORE RECENT SATELLITE IMAGES SHOW A RAGGED EYE SO...
 THE INITIAL INTENSITY HAS BEEN INCREASED TO 80 KNOTS.  THE OUTFLOW
 REMAINS VERY WELL ESTABLISHED AND THE OCEAN IS WARM. IN ADDITION...
 GLOBAL MODELS DEVELOP A LARGE UPPER-LEVEL ANTICYCLONE OVER/AROUND
 FRANCES WITH THE CIRCULATION OF THE HURRICANE EXTENDING UP TO 200
 MB. THIS PATTERN IS COMMON IN INTENSE HURRICANES. THEREFORE...
 ADDITIONAL STRENGTHENING IS INDICATED. THE INTENSITY FORECAST
 ASSUMES THAT THE UNFAVORABLE UPPER-LEVEL WESTERLIES CURRENTLY
 OBSERVED IN THE AREA WHERE THE HURRICANE IS EXPECTED TO BE IN 3
 DAYS WILL WEAKEN AS SUGGESTED BY GLOBAL MODELS.
  
 FRANCES APPEARS TO BE MOVING TOWARD THE WEST-NORTHWEST OR 295
 DEGREES AT 12 KNOTS. THE SUBTROPICAL RIDGE IS EXPECTED TO WEAKEN
 TEMPORARILY AS A MID-LEVEL TROUGH MOVES EASTWARD. THIS WOULD RESULT
 IN A DECREASE IN FORWARD SPEED AND PERHAPS A TURN MORE TO THE
 NORTHWEST. IN FACT...THE HURRICANE MAY BE DOING SO AS WE SPEAK.
 HOWEVER...UNANIMOULSY ALL GLOBAL MODELS ARE REBUILDING THE
 SUBTROPICAL RIDGE. THIS PATTERN WOULD FORCE THE HURRICANE TO MAKE A
 LEFT TURN IN A COUPLE OF DAYS. THE STRENGTH OF THE SUBTROPICAL
 RIDGE WILL CONTROL HOW MUCH THE HURRICANE WILL TURN WESTWARD. THE
 GFS AND THE CANADIAN GLOBAL MODELS ARE THE MOST AGGRESSIVE BRINGING
 THE HURRICANE WESTWARD BASICALLY ALONG 20 NORTH FOR THE NEXT
 SEVERAL DAYS. THE UK AND THE GFDL HAVE ALSO SHIFTED THE TRACK MORE
 TO THE WEST BUT NOT AS MUCH AS THE GFS. THE OFFICIAL FORECAST IS
 HALFWAY BETWEEN THE GFS AND THE UK MODELS. THE TREND OF THE GLOBAL
 MODELS SUGGEST THAT THIS HURRICANE MUST BE MONITORED VERY CAREFULLY
 OVER THE NEXT SEVERAL DAYS.
  
 ONCE AGAIN...IT SHOULD BE STRESSED THAT 4- AND 5-DAY FORECAST POINTS
 CAN EASILY BE IN ERROR BY SEVERAL HUNDRED MILES.
  
 FORECASTER AVILA
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      27/0900Z 14.5N  48.4W    80 KT
  12HR VT     27/1800Z 15.3N  50.3W    85 KT
  24HR VT     28/0600Z 16.5N  52.0W    95 KT
  36HR VT     28/1800Z 18.0N  53.5W   100 KT
  48HR VT     29/0600Z 19.0N  55.5W   100 KT
  72HR VT     30/0600Z 20.5N  58.5W   105 KT
  96HR VT     31/0600Z 21.0N  61.5W   105 KT
 120HR VT     01/0600Z 21.5N  65.0W   105 KT
  
  
 $$