WTPA42 PHFO 120246
TCDCP2

HURRICANE FLOSSIE DISCUSSION NUMBER  14
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP092007
500 PM HST SAT AUG 11 2007

A BURST OF EYEWALL CONVECTION AND SIGNIFICANT WARMING IN THE EYE
ITSELF AS DETECTED IN INFRARED DATA PUSHED SUBJECTIVE DVORAK
INTENSITY ESTIMATES TO 127 KT FROM BOTH PHFO AND SAB.  THE
OBJECTIVE DVORAK ESTIMATE CAME IN AT 120 KT.  SINCE CLOUD
TOP TEMPERATURES HAVE WARMED SOMEWHAT SINCE THE FIX...WILL FAVOR
THE MORE CONSERVATIVE VALUE OF 120 KT AS THE INITIAL INTENSITY OR
CATEGORY 4 ON THE SAFFIR-SIMPSON SCALE.  

FLOSSIE IS MOVING TOWARD THE WEST NORTHWEST AT 11 KT TO THE SOUTH OF
A SUBTROPICAL RIDGE.  OBJECTIVE AIDS CONTINUE THIS TREND THOUGH THE
DIFFERENCES...AND THE UNCERTAINTY...BECOME SIGNIFICANT BEYOND DAY 1. 
THE GFDL...BAM-DEEP AND NOGAPS CONTINUE TO BE THE NORTHERN OUTLIERS
WHILE THE GFS AND GFS ENSEMBLE ARE THE SOUTHERN OUTLIERS.  OF
INTEREST IS THE LARGE SHIFT OF THE HWRF WHICH NOW LIES IN THE
SOUTHERN CLUSTER ALONG WITH THE GFS...ECMWF AND JAPANESE SPECTRAL
MODELS.  THE DECIDING FACTOR CONTINUES TO DEPEND ON THE EVENTUAL
STRENGTH OF THE SUBTROPICAL RIDGE AND THE EFFECTS OF INCREASING
VERTICAL SHEAR AND COOLER SEA SURFACE TEMPERATURES ON THE
INTENSITY.  IF THE SHEAR AND COOLER WATER SIGNIFICANTLY WEAKEN
FLOSSIE...THE TRACK WILL FOLLOW THE SOUTHERN GROUP WITH A WEST OR
WEST-NORTHWEST MOTION MORE IN LINE WITH THE LOWER LEVEL WINDS.  IF
FLOSSIE IS ABLE TO MAINTAIN ITS INTENSITY...THE TRACK WILL BE
TOWARD THE NORTHWEST AND CLOSE TO THE HAWAIIAN ISLANDS.  FOR
NOW...WILL KEEP THE FORECAST CLOSE TO THE PREVIOUS FORECAST AND
ROUGHLY DOWN THE MIDDLE OF THE ENVELOPE.  

AS FOR INTENSITY...FLOSSIE MAY HAVE REACHED ITS PEAK WITH
SEA SURFACE TEMPERATURES BENEATH THE FORECAST TRACK STEADILY
DECREASING.  VERTICAL SHEAR IS ALSO EXPECTED IN INCREASE
CONSIDERABLY BEYOND DAY 2 NEAR 150W.  THESE FACTORS SHOULD COMBINE
TO WEAKEN FLOSSIE STEADILY WITH ITS INTENSITY FORECAST TO DROP
BELOW HURRICANE STRENGTH AFTER DAY 3.  THIS TREND IS IN LINE WITH
THE SHIPS GUIDANCE.
 
IT IS IMPORTANT TO NOTE THAT ALTHOUGH THE CURRENT FORECAST KEEPS THE
CENTER OF FLOSSIE SOUTH OF THE HAWAIIAN ISLANDS...A CLOSER APPROACH
CANNOT BE RULED OUT.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      12/0300Z 13.4N 142.2W   120 KT
 12HR VT     12/1200Z 13.8N 143.9W   115 KT
 24HR VT     13/0000Z 14.4N 146.1W   105 KT
 36HR VT     13/1200Z 15.2N 148.3W    95 KT
 48HR VT     14/0000Z 15.9N 150.5W    85 KT
 72HR VT     15/0000Z 17.4N 154.6W    65 KT
 96HR VT     16/0000Z 18.6N 158.2W    50 KT
120HR VT     17/0000Z 20.2N 161.6W    40 KT
 
$$
FORECASTER KODAMA