303 
 WTNT43 KNHC 100850
 TCDAT3
 TROPICAL STORM CHARLEY DISCUSSION NUMBER   4
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 5 AM EDT TUE AUG 10 2004
  
 THE DEEP CONVECTION THAT FORMED NEAR THE CENTER OVERNIGHT HAS
 PERSISTED DURING THE PAST FEW HOURS AS THE CYCLONE APPEARS TO BE
 GETTING BETTER ORGANIZED.  WHILE OUTER BANDS OF DEEP CONVECTION ARE
 CURRENTLY MINIMAL BUT INCREASING...THE CIRCULATION OCCUPIES A LARGE
 ENVELOPE AND OUTFLOW IS EXCELLENT IN ALL DIRECTIONS.  DVORAK CI
 NUMBERS ARE A CONSENSUS 2.5...AND ON THIS BASIS THE SYSTEM IS
 UPGRADED TO TROPICAL STORM CHARLEY WITH AN INTENSITY OF 35 KT.
 
 CHARLEY CONTINUES TO SPEED ALONG AT 285/21...SLIGHTLY FASTER THAN
 PREVIOUSLY...PERHAPS IN PART DUE TO THE INCREASED DEPTH OF THE
 CONVECTION.  MOST TRACK GUIDANCE INDICATES THAT THIS
 WEST-NORTHWESTWARD MOTION SHOULD CONTINUE FOR ABOUT THE NEXT TWO
 DAYS...WITH STEERING PROVIDED BY THE SUBTROPICAL RIDGE CENTERED
 NORTH OF THE GREATER ANTILLES.  HOWEVER...THE MODELS DIVERGE
 THEREAFTER AS CHARLEY REACHES A WEAKNESS IN THE RIDGE CAUSED BY A
 MID-LATITUDE TROUGH OVER THE EASTERN UNITED STATES.  WHILE THE
 NOGAPS...GFDL...AND UKMET NOW TAKE THE SYSTEM OVER THE YUCATAN
 PENINSULA...WELL TO THE LEFT OF THE PREVIOUS FORECAST...THE GFS
 TAKES CHARLEY INTO THE EASTERN GULF OF MEXICO AT DAYS FOUR AND
 FIVE.  GIVEN THE WIDE SPREAD...THE OFFICIAL FORECAST IS NUDGED ONLY
 SLIGHTLY TO THE LEFT OF THE PREVIOUS FORECAST...AND A LITTLE FASTER
 GIVEN THE CURRENT MOTION.
 
 THE ENVIRONMENT AHEAD OF CHARLEY IS QUITE FAVORABLE...WITH VERY WEAK
 VERTICAL SHEAR AND AN INCREASINGLY WARM OCEAN.  THE GFDL MAKES
 CHARLEY A HURRICANE WITHIN THREE DAYS...AND SHIPS DOES SO IN LESS
 THAN TWO DAYS.  THE OFFICIAL FORECAST IS CLOSER TO THE GFDL
 INTENSITY GUIDANCE...BUT INDICATES MORE INTENSIFICATION THAN THE
 PREVIOUS ADVISORY DUE TO THE IMPROVING ORGANIZATION OF THE SYSTEM.
  
 FORECASTER KNABB/FRANKLIN
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      10/0900Z 13.0N  66.3W    35 KT
  12HR VT     10/1800Z 13.9N  69.3W    40 KT
  24HR VT     11/0600Z 15.0N  72.9W    45 KT
  36HR VT     11/1800Z 16.3N  76.2W    50 KT
  48HR VT     12/0600Z 17.5N  79.0W    55 KT
  72HR VT     13/0600Z 19.5N  82.5W    65 KT
  96HR VT     14/0600Z 22.5N  86.0W    75 KT
 120HR VT     15/0600Z 26.0N  88.0W    80 KT
  
  
 $$