WTPA42 PHFO 122041
TCDCP2

HURRICANE FLOSSIE DISCUSSION NUMBER  17
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP092007
1100 AM HST SUN AUG 12 2007

SATELLITE IMAGES OVER THE PAST 6 HOURS INDICATE A WEAKENING OF
HURRICANE FLOSSIE IN TERMS OF WARMER CLOUD TOP TEMPERATURES AND A
RESTRICTED UPPER LEVEL OUTFLOW IN THE SOUTHEASTERN SEMICIRCLE.  A
1622 UTC MICROWAVE PASS ALSO SHOWED A BREAK IN THE EYEWALL TO THE
EAST.  THE DVORAK T-NUMBER ESTIMATES FROM PHFO AND SAB HAVE COME
DOWN TO 102 KT BUT THE CURRENT INTENSITIES HAVE BEEN KEPT UP AT 127
KT AND 115 KT RESPECTIVELY.  THE ADT INTENSITY ESTIMATE INDICATES
115 KT. GIVEN THE WEAKER PRESENTATION IN THE LATEST IMAGES THE
INITIAL INTENSITY WILL BE LOWERED A NOTCH TO 115 KT.

FLOSSIE IS MOVING IN A GENERAL WEST-NORTHWEST DIRECTION AT 12 KT TO
THE SOUTH OF A SUBTROPICAL RIDGE.  THE LARGE-SCALE MODELS ALL
DEVELOP AN UPPER LEVEL TROUGH NEAR THE HAWAIIAN ISLANDS WITHIN THE
NEXT COUPLE OF DAYS.  THE STRENGTH OF THE TROUGH AND THE EFFECTS OF
VERTICAL SHEAR FROM THE ASSOCIATED SOUTHERLY WINDS PLAY A KEY ROLE
IN DETERMINING THE FUTURE TRACK AND INTENSITY OF FLOSSIE.  THE
LATEST OBJECTIVE AIDS ARE LESS TIGHTLY PACKED THAN 6 HOURS AGO WITH
THE HWRF SHIFTING CONSIDERABLY AND BECOMING ONE OF THE NORTHERN
OUTLIERS.  NOGAPS IS ALSO A NORTHERN OUTLIER WHILE THE GFS AND UKMET
SOLUTIONS ARE ON THE SOUTH SIDE OF THE ENVELOPE.  THE FORECAST
TRACK IS SLIGHTLY FASTER THAN THE PREVIOUS PACKAGE DUE TO A SMALL
SPEED INCREASE IN THE GUIDANCE BUT THE ALIGNMENT REMAINS UNCHANGED
AND IS NORTH OF THE VARIOUS CONSENSUS TRACKS.

IT APPEARS VERTICAL SHEAR IS STARTING TO AFFECT FLOSSIE AS INDICATED
BY RESTRICTED OUTFLOW IN SATELLITE IMAGERY AND A CIMSS ANALYSIS
SHOWING 10 TO 15 KT OF SHEAR FROM THE SOUTHEAST.  SHEAR IS EXPECTED
TO INCREASE OVER THE NEXT SEVERAL DAYS AND SEA SURFACE TEMPERATURES
SHOULD SLOWLY DECREASE ALONG THE FORECAST TRACK UNTIL FLOSSIE
PASSES SOUTH OF THE BIG ISLAND.  THE CURRENT INTENSITY FORECAST
FOLLOWS THE PREVIOUS FORECAST AND IS ROUGHLY IN LINE WITH THE GFDL
BUT HIGHER THAN HWRF AND SHIPS.  THIS KEEPS FLOSSIE AT HURRICANE
STRENGTH AS IT PASSES SOUTH OF THE BIG ISLAND OF HAWAII ON TUESDAY.

THE CURRENT TRACK AND INTENSITY FORECAST MAY REQUIRE WATCHES FOR
PORTIONS OF THE HAWAIIAN ISLANDS EARLY ON MONDAY.

AIR FORCE RECONNAISSANCE IS ENROUTE AND IS SCHEDULED TO MAKE ITS
FIRST PASS THROUGH THE SYSTEM AT AROUND 13/0000 UTC.  
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      12/2100Z 13.9N 145.8W   115 KT
 12HR VT     13/0600Z 14.4N 147.5W   110 KT
 24HR VT     13/1800Z 15.3N 149.8W   100 KT
 36HR VT     14/0600Z 16.2N 151.8W    95 KT
 48HR VT     14/1800Z 17.0N 154.0W    90 KT
 72HR VT     15/1800Z 18.5N 157.8W    70 KT
 96HR VT     16/1800Z 20.0N 161.5W    55 KT
120HR VT     17/1800Z 21.3N 165.7W    50 KT
 
$$
FORECASTER KODAMA/BIRCHARD