WTPA42 PHFO 140929 TCDCP2 HURRICANE FLOSSIE DISCUSSION NUMBER 23 NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI EP092007 1100 PM HST MON AUG 13 2007 FLOSSIE IS SHOWING DEFINITE SIGNS OF WEAKENING. OVER THE PAST 6 HOURS...AIRCRAFT RECONNAISSANCE AND SATELLITE DATA HAVE SHOWN A CLEAR WEAKENING TREND FOR HURRICANE FLOSSIE. AIRCRAFT OBSERVATIONS SHOWED THE CENTRAL PRESSURE HAD RISEN TO 970 MB AT 0503 UTC AND THE EYEWALL WAS OPEN TO THE SOUTHEAST. SATELLITE IMAGERY SHOWED THE EYE DISAPPEARING BY 0500 UTC WITH THE CLOUD PATTERN BECOMING STRETCHED OUT TOWARD THE NORTHEAST. APPARENTLY SHEAR IS FINALLY TAKING ITS TOLL ON FLOSSIE. THE SATELLITE ESTIMATES GAVE CI NUMBERS OF 5.5 AND 5.0. WE USED A CONSERVATIVE 100 KT FOR THE INITIAL INTENSITY. BOTH AIRCRAFT OBSERVATIONS AND A 0430 UTC QUIKSCAT PASS SHOWED A VERY ASYMMETRICAL WIND FIELD. WE INCREASED THE WIND RADII ON THE NORTH SIDE OF FLOSSIE AND DECREASED THEM ON THE SOUTH SIDE. THE TROPICAL STORM FORCE WINDS ARE STILL FORECAST TO EXTEND OUT FAR ENOUGH TO THE NORTH TO AFFECT THE BIG ISLAND AS FLOSSIE PASSES SOUTH OF THE ISLAND TOMORROW. A TROPICAL STORM WARNING AND A HURRICANE WATCH CONTINUE FOR THE BIG ISLAND. WE STILL EXPECT THAT NO WATCHES OR WARNINGS WILL BE REQUIRED FOR THE ISLANDS EXCEPT THE BIG ISLAND. A NORTHWARD SHIFT IN THE TRACK COULD CHANGE THIS EXPECTATION...BUT THE RECENT WEAKENING TREND MAKES IT LESS LIKELY THAT FLOSSIE WILL HAVE A MAJOR IMPACT OUTSIDE OF THE BIG ISLAND. TRACK GUIDANCE HAS BECOME A BIT LESS TIGHTLY PACKED OVER THE PAST 6 HOURS BUT GENERALLY SHOWS A CONTINUED WEST NORTHWEST TRACK. WE HAVE KEPT THE TRACK NEARLY THE SAME EXCEPT FOR A SLIGHT SHIFT SOUTH AFTER 72 HOURS. THIS IS DUE TO THE EXPECTATION THAT FLOSSIE WILL WEAKEN FAIRLY RAPIDLY AND TRACK CLOSER TO THE LOW LEVEL STEERING FLOW. FORECAST POSITIONS AND MAX WINDS INITIAL 14/0900Z 16.4N 153.2W 100 KT 12HR VT 14/1800Z 17.2N 155.2W 85 KT 24HR VT 15/0600Z 18.0N 157.3W 75 KT 36HR VT 15/1800Z 19.0N 159.8W 65 KT 48HR VT 16/0600Z 19.8N 162.2W 55 KT 72HR VT 17/0600Z 21.0N 166.0W 40 KT 96HR VT 18/0600Z 22.2N 170.1W 35 KT 120HR VT 19/0600Z 23.4N 174.0W 25 KT $$ FORECASTER DONALDSON