514 
 WTPA43 PHFO 062048
 TCDCP3
 
 HURRICANE ISELLE DISCUSSION NUMBER  27
 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP092014
 1100 AM HST WED AUG 06 2014
  
 ISELLE HAS NOT WEAKENED OVER THE PAST SIX HOURS...AND IN FACT 
 APPEARS TO HAVE STRENGTHENED A BIT. AIR FORCE HURRICANE HUNTERS 
 RECENTLY FOUND MAXIMUM FLIGHT LEVEL WINDS OF 85 KT...WHICH SUGGESTS 
 ABOUT 77 KT WHEN ADJUSTED TO THE SURFACE...AND THE SFMR FOUND 
 MAXIMUM SURFACE WINDS OF 72 KNOTS. THIS DATA SUGGESTS RAISING THE 
 ADVISORY INTENSITY TO 80 KT. THE WIND RADII HAVE BEEN ADJUSTED 
 SOMEWHAT TO BETTER MATCH WHAT WAS FOUND BY RECONNAISANCE...BUT MAY 
 STILL BE A BIT GENEROUS. ISELLE IS IN AN ENVIRONMENT OF MARGINAL SEA 
 SURFACE TEMPERATURES OF 26C...BUT THE WIND SHEAR OVER THE SYSTEM IS 
 CURRENTLY WEAK. A CLEARLY DEFINED EYE FEATURE HAS REDEVELOPED IN THE 
 INFRARED AND VISIBLE IMAGERY OVER THE PAST 12 HOURS. 
 
 THE GLOBAL MODELS AND THE SHIPS GUIDANCE BOTH SHOW THE SHEAR 
 REMAINING RELATIVELY WEAK THROUGH THE NEXT 24 HOURS...THOUGH THE SEA 
 SURFACE TEMPERATURES WILL REMAIN MARGINAL. SINCE THERE APPEARS TO BE 
 LESS OF A WINDOW FOR ISELLE TO WEAKEN SIGNIFICANTLY BEFORE REACHING 
 THE ISLANDS...WE ARE UPGRADING THE TROPICAL STORM WARNING FOR THE 
 BIG ISLAND TO A HURRICANE WARNING. THE FORECAST TRACK AND WIND RADII 
 ALSO NECESSITATE ISSUING A TROPICAL STORM WARNING FOR MAUI COUNTY. 
 IT IS IMPORTANT TO NOTE THAT REGARDLESS OF WHETHER ISELLE REACHES 
 THE BIG ISLAND AS A TROPICAL STORM OR MINIMAL HURRICANE...THE 
 IMPACTS WILL STILL BE VERY SIMILAR. 
  
 ALTHOUGH THE SEA SURFACE TEMPERATURES INCREASE ALONG THE FORECAST 
 TRACK BEYOND 36 HOURS...NORTHERLY WIND SHEAR IS EXPECTED TO INCREASE 
 SIGNIFICANTLY OVER ISELLE AS AN UPPER LEVEL TROUGH DIGS RAPIDLY JUST 
 TO THE NORTHWEST OF HAWAII. THIS SHOULD RESULT IN MORE RAPID 
 WEAKENING IN THE LONGER TERM.
 
 THE FORECAST TRACK PHILOSOPHY HAS NOT CHANGED. ISELLE WILL CONTINUE 
 TO GRADUALLY GAIN LATITUDE TO THE SOUTH OF A RELATIVELY WEAK 
 SUBTROPICAL RIDGE SEVERAL HUNDRED MILES NORTH OF THE HAWAIIAN 
 ISLANDS. THIS FORECAST IS ESSENTIALLY A CONTINUATION OF THE PREVIOUS 
 TRACK FORECAST. 
 
 
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  06/2100Z 17.2N 145.9W   80 KT  90 MPH
  12H  07/0600Z 17.7N 148.2W   75 KT  85 MPH
  24H  07/1800Z 18.3N 151.2W   70 KT  80 MPH
  36H  08/0600Z 18.9N 154.3W   65 KT  75 MPH
  48H  08/1800Z 19.6N 157.6W   55 KT  65 MPH
  72H  09/1800Z 20.7N 163.4W   45 KT  50 MPH
  96H  10/1800Z 22.1N 168.3W   40 KT  45 MPH
 120H  11/1800Z 23.4N 172.7W   40 KT  45 MPH
  
 $$
 FORECASTER R BALLARD