676 
 WTPZ42 KNHC 151451
 TCDEP2
 HURRICANE ISIS DISCUSSION NUMBER  30
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 8 AM PDT WED SEP 15 2004
  
 INFRARED SATELLITE IMAGERY AND A TRMM OVERPASS AT 0636Z SHOW THAT
 ISIS HAS FORMED A RAGGED BUT PERSISTENT EYE.  SATELLITE INTENSITY
 ESTIMATES ARE 65 KT FROM TAFB AND SAB...AND 45 KT FROM AFWA.  BASED
 ON THE EYE AND THE STRONGER INTENSITY ESTIMATES...ISIS IS UPGRADED
 TO A 65 KT HURRICANE.
 
 THE INITIAL MOTION IS 300/5.  ISIS IS EMBEDDED IN WEAK STEERING
 CURRENTS AND WILL GO NOWHERE FAST DURING THE NEXT FIVE DAYS.  MOST
 DYNAMICAL GUIDANCE CALLS FOR A SLOW WESTWARD DRIFT...AND THE
 OFFICIAL FORECAST TRACK WILL FOLLOW THAT SCENARIO.
 
 EXCEPT FOR THE INCREASED INITIAL INTENSITY...THERE IS LITTLE CHANGE
 IN THE INTENSITY FORECAST PHILOSOPHY.  ISIS WILL LINGER NEAR THE
 26C SEA SURFACE TEMPERATURE ISOTHERM IN A LOW SHEAR ENVIRONMENT. 
 WHILE THE PROXIMITY OF COOLER WATER JUST TO THE NORTH WILL LIKELY
 LEAD TO A GRADUAL WEAKENING...ISIS SHOULD REMAIN AT TROPICAL STORM
 OR BETTER INTENSITY FOR THE NEXT FIVE DAYS.  SHOULD THE CYCLONE
 DRIFT NORTH OF THE FORECAST TRACK...IT WOULD ENCOUNTER THAT COOLER
 WATER AND WEAKEN FASTER THAN CURRENTLY FORECAST.
  
 FORECASTER BEVEN
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      15/1500Z 17.9N 132.0W    65 KT
  12HR VT     16/0000Z 18.0N 132.3W    65 KT
  24HR VT     16/1200Z 18.0N 132.6W    60 KT
  36HR VT     17/0000Z 18.0N 132.9W    60 KT
  48HR VT     17/1200Z 18.0N 133.2W    55 KT
  72HR VT     18/1200Z 18.0N 134.0W    50 KT
  96HR VT     19/1200Z 18.0N 134.5W    45 KT
 120HR VT     20/1200Z 18.0N 135.0W    40 KT
  
  
 $$