WTPA42 PHFO 112054 TCDCP2 HURRICANE FLOSSIE DISCUSSION NUMBER 13 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092007 1100 AM HST SAT AUG 11 2007 FLOSSIE CONTINUES TO BE AN IMPRESSIVE SYSTEM WITH GOOD UPPER LEVEL OUTFLOW IN NORTH AND SOUTH QUADRANTS AND A SOLID EYEWALL AROUND A 17 NM EYE AS SEEN IN GOES IMAGERY. THE 1448 UTC SSM/I PASS ALSO INDICATED A SINGLE CLOSED EYEWALL. OBJECTIVE DVORAK SHOWED 117 KT AND SUBJECTIVE DVORAK INTENSITY ESTIMATES FROM PHFO AND SAB CAME UP WITH 115 KT SO THE INITIAL INTENSITY WILL BE HELD AT 115 KT. THE CURRENT MOVEMENT REMAINS TOWARD THE WEST AT 10 KT AS FLOSSIE TRACKS SOUTH OF A SUBTROPICAL RIDGE. OBJECTIVE AIDS ARE GENERALLY IN AGREEMENT FOR DAYS 1 AND 2 WITH A WEST-NORTHWEST TRACK. HOWEVER...THE DIFFERENCES...AND THE UNCERTAINTY...INCREASE BEYOND DAY 2. NOGAPS...HWRF...GFDL AND BAM-DEEP ARE ON THE RIGHT SIDE OF THE GUIDANCE ENVELOPE WITH A MORE SIGNIFICANT TURN TO THE NORTHWEST AND A PASSAGE EAST OF THE HAWAIIAN ISLANDS. THE GFS...ECMWF AND THE JAPANESE SPECTRAL MODELS ARE ON THE LEFT SIDE OF THE ENVELOPE. THE OUTCOME WILL DEPEND ON THE STRENGTH OF THE SUBTROPICAL RIDGE AFTER DAY 2 AND THE EFFECTS OF INCREASING VERTICAL SHEAR AND COOLER SEA SURFACE TEMPERATURES. IF THE SHEAR AND COOLER WATER TAKE A SIGNIFICANT TOLL ON FLOSSIE...THE SOUTHERN TRACK WILL BE MORE LIKELY. IF FLOSSIE CAN OVERCOME THESE FACTORS...THE TRACK WILL FAVOR A CLOSER APPROACH TO THE HAWAIIAN ISLANDS. THE FORECAST TRACK GENERALLY FOLLOWS THE PREVIOUS FORECAST...ROUGHLY DOWN THE MIDDLE OF THE ENVELOPE...WITH A NORTHWARD NUDGE CLOSER TO THE BIG ISLAND. SEA SURFACE TEMPERATURES WILL DECREASE ALONG THE FORECAST TRACK WITH FLOSSIE CROSSING THE 26.5C ISOTHERM OVER THE NEXT DAY OR SO. THE VERTICAL SHEAR IS ALSO EXPECTED TO INCREASE AFTER DAY 2 ONCE FLOSSIE CROSSES 150W. THESE FACTORS SHOULD CONTRIBUTE TO A STEADY WEAKENING WITH THE INTENSITY FORECAST TO DROP BELOW HURRICANE STRENGTH AFTER DAY 3. 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 11/2100Z 13.0N 141.1W 115 KT 12HR VT 12/0600Z 13.4N 142.6W 115 KT 24HR VT 12/1800Z 13.9N 144.8W 105 KT 36HR VT 13/0600Z 14.5N 147.0W 95 KT 48HR VT 13/1800Z 15.2N 149.2W 85 KT 72HR VT 14/1800Z 16.7N 153.6W 65 KT 96HR VT 15/1800Z 18.1N 157.4W 50 KT 120HR VT 16/1800Z 19.5N 160.4W 40 KT $$ FORECASTER KODAMA