WTPA42 PHFO 121517
TCDCP2

HURRICANE FLOSSIE DISCUSSION NUMBER  16
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP092007
500 AM HST SUN AUG 12 2007

DANGEROUS HURRICANE FLOSSIE CONTINUES TO TRAVEL ACROSS THE OPEN 
WATERS OF THE NORTH CENTRAL PACIFIC OCEAN. THE SYSTEM HAS TAKEN 
ADVANTAGE OF ITS VERY FAVORABLE TROPICAL ENVIRONMENT FAR FROM ANY 
SIGNIFICANT LAND MASSES. THE CURRENT MOTION IS 280 DEGREES AT 10 KT. 
AS WAS NOTED 6 HOURS EARLIER...SHORT-TERM WOBBLES OF THE EYE ARE 
CLEARLY EVIDENT IN SATELLITE IMAGERY. HOWEVER...IT APPEARS THE 
AVERAGE TRACK OF FLOSSIE REMAINS CLOSE TO THE PREVIOUS FORECASTS. 
 
IN ADDITION TO THE WELL-DEFINED EYE AND EYEWALL STRUCTURE OF 
HURRICANE FLOSSIE...THE TROPICAL CYCLONE HAS MAINTAINED AN EXTREMELY 
IMPRESSIVE OUTFLOW OVERNIGHT. DURING A RECENT COORDINATION CALL WITH 
THE TYPHOON DUTY OFFICER AT JTWC...IT WAS POINTED OUT THAT AN UPPER 
TROPOSPHERIC TROUGH HAS BEEN DIGGING SOUTHWARD ALONG LONGITUDE 137W. 
THIS TROUGH AXIS...WHICH IS NORTH NORTHEAST OF FLOSSIE APPEARS TO BE 
PROVIDING AN EXCELLENT OUTFLOW CHANNEL. THE POSITIVE INFLUENCE OF 
THIS UPPER LEVEL ANTICYCLONIC CIRCULATION ALONG WITH THE WARM 
TROPICAL OCEAN APPEAR TO BE MAINTAINING FLOSSIE/S INTENSITY. THE 
UW/CIMMS ADT ESTIMATE FOR 1130 UTC WAS 6.0. THE MOST RECENT 
SATELLITE INTENSITY ESTIMATES OF 6.0 FROM JTWC AND 6.5 FROM SAB AND 
HFO SUGGESTED THAT FLOSSIE HAS MAXIMUM WIND SPEEDS OF 120 KT. 

THE LATEST MODEL TRACK GUIDANCE CONTINUES TO BE MORE TIGHTLY 
CLUSTERED IN THE 72 TO 120 HOUR FORECAST TIME FRAME THAN THE RUNS 
MADE 12 HOURS AGO. NOGAPS CONTINUES TO BE THE MAJOR MODEL BRINGING 
FLOSSIE ACROSS THE HAWAIIAN ISLANDS...WITH THE GFDL RUN BRINGING THE 
SYSTEM CLOSE TO SOUTH POINT ON THE BIG ISLAND AFTER 72 HOURS. 
THEREFORE...THE CONSENSUS MODELS WERE FOLLOWED CLOSELY IN THE LATEST 
FORECAST TRACK. 

ONCE AGAIN...THE INTENSITY FORECAST REMAINS THE BIGGEST QUESTION AT 
THE MOMENT. THE GLOBAL MODELS CONTINUE TO SHOW INCREASING VERTICAL 
WIND SHEAR ALONG THE FUTURE PATH OF FLOSSIE. THIS SHEAR APPEARS TO 
BE THE MOST HOSTILE BEYOND THE 48 HOUR TIME FRAME. SLIGHTLY COOLER 
SEA SURFACE TEMPERATURES AND DECREASED OCEAN HEAT CONTENT ALONG THE 
FORECAST TRACK ALSO IMPLY FUTURE WEAKENING OF THE TROPICAL CYCLONE. 
THE CURRENT INTENSITY FORECAST REMAINS IN LINE WITH THE GFDL 
GUIDANCE. KEEP IN MIND THAT OUR ERRORS IN FORECASTING INTENSITY ARE 
STILL LARGE...ESPECIALLY AT 48 AND 72 HOURS...AND BEYOND. 

THE CURRENT TRACK AND INTENSITY FORECAST MAY REQUIRE WATCHES FOR 
PORTIONS OF THE HAWAIIAN ISLANDS ON MONDAY.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      12/1500Z 13.7N 144.6W   120 KT
 12HR VT     13/0000Z 14.1N 146.3W   110 KT
 24HR VT     13/1200Z 15.0N 148.5W   105 KT
 36HR VT     14/0000Z 15.8N 150.6W   100 KT
 48HR VT     14/1200Z 16.6N 152.7W    95 KT
 72HR VT     15/1200Z 18.0N 156.1W    75 KT
 96HR VT     16/1200Z 19.3N 159.5W    55 KT
120HR VT     17/1200Z 20.8N 163.9W    50 KT
 
$$
FORECASTER HOUSTON