459 
 WTNT44 KNHC 111448
 TCDAT4
 HURRICANE IVAN DISCUSSION NUMBER  37
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 11 AM EDT SAT SEP 11 2004
  
 SATELLITE IMAGES SHOW THAT IVAN CONTINUES TO BE WELL-ORGANIZED WITH
 A DISTINCT EYE SURROUNDED BY VERY DEEP CONVECTION. AN ELONGATED
 UPPER-LOW OVER THE BAHAMAS IS DISRUPTING THE OUTFLOW A LITTLE BIT
 IN THE NORTHERN SEMICIRCLE. THE OUTFLOW IS WELL-ESTABLISHED
 ELSEWHERE. INITIAL INTENSITY IS REDUCED TO 125 KNOTS ASSUMING SOME
 WEAKENING DUE TO THE INTERACTION WITH JAMAICA. A BETTER ESTIMATE OF
 THE INITIAL INTENSITY WILL BE AVAILABLE WHEN ANOTHER RECONNAISSANCE
 PLANE REACHES THE AREA LATER TODAY. THE SHEAR IS LOW AND THE
 HURRICANE WILL BE MOVING OVER AN AREA OF HIGH OCEAN HEAT CONTENT.
 THEREFORE IVAN COULD GAIN SOME STRENGTH BEFORE REACHING CUBA.
  
 THE AVERAGE MOTION DURING THE PAST FEW HOURS HAS BEEN BASICALLY
 WESTWARD...PARALLELING THE SOUTH COAST OF JAMAICA. WATER VAPOR
 IMAGES SHOW A MID-LEVEL HIGH PRESSURE SYSTEM OVER THE EASTERN GULF
 OF MEXICO AND FLORIDA. THIS FEATURE MAY KEEP THE HURRICANE ON A
 SLOW WEST TO WEST-NORTHEAST TRACK FOR A LITTLE LONGER.
 THEREAFTER...A RIDGE IS FORECAST TO STRENGTHEN OVER THE WESTERN
 ATLANTIC AND THE BAHAMAS AND A WEAKNESS SHOULD DEVELOP OVER THE
 GULF OF MEXICO. THIS PATTERN CALLS FOR A GRADUAL TURN OF THE
 HURRICANE TO THE NORTHWEST AND NORTH-NORTHWEST THROUGH 72 HOURS. A
 GENERAL NORTHWARD TRACK IS EXPECTED THEREAFTER. THE OFFICIAL
 FORECAST HAS BEEN SHIFTED A LITTLE BIT WESTWARD BASED ON
 THE LATEST MODEL GUIDANCE HEAVILY WEIGHTED ON THE GLOBAL MODEL
 CONSENSUS.
  
 FORECASTER AVILA
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      11/1500Z 17.9N  78.7W   125 KT
  12HR VT     12/0000Z 18.5N  79.8W   135 KT
  24HR VT     12/1200Z 19.6N  81.0W   135 KT
  36HR VT     13/0000Z 21.0N  82.0W   135 KT
  48HR VT     13/1200Z 22.8N  83.0W   125 KT  OVER WESTERN CUBA
  72HR VT     14/1200Z 27.0N  84.5W   115 KT
  96HR VT     15/1200Z 31.5N  83.9W    65 KT...INLAND
 120HR VT     16/1200Z 36.0N  82.0W    25 KT...INLAND
  
  
 $$