WTPA42 PHFO 152038
TCDCP2

TROPICAL STORM FLOSSIE DISCUSSION NUMBER  29
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP092007
1100 AM HST WED AUG 15 2007

VERTICAL WIND SHEAR CONTINUES TO HAVE A NEGATIVE IMPACT ON
FLOSSIE...DESPITE THE RECENT FLARE-UP OF THUNDERSTORMS ON THE NORTH
SIDE OF THE PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER. CURRENT
DVORAK INTENSITY ESTIMATES ARE 3.0 FROM HFO AND JTWC...AND 3.5 FROM
SAB. FLOSSIE PASSED DIRECTLY OVER NOAA BUOY 51002 AROUND 1700
UTC...WITH SUSTAINED WINDS OF 37 KT AT 1500 UTC. THE INTENSITY FOR
THIS ADVISORY HAS BEEN LOWERED TO 40 KT...PRIMARILY BASED ON THE
BUOY OBSERVATIONS...WHICH ARE IN LINE WITH THE SATELLITE ESTIMATES. 

FLOSSIE IS EXPECTED TO BE STEERED WESTWARD BY THE LOW LEVEL TRADE
FLOW...AS IT WILL NOT BE ABLE TO ORGANIZE IN THE VERTICAL DUE TO
INCREASING SOUTHWESTERLY SHEAR. THE TRACK FORECAST THROUGH 72 HOURS
HAS BEEN NUDGED SOUTHWARD FROM THE PREVIOUS ADVISORY...AND
INDICATES A SLOWER FORWARD MOTION...BASED ON CURRENT TRENDS. THE
TRACK FORECAST LIES ON THE SOUTHERN SIDE OF A TIGHTLY BUNCHED MODEL
ENVELOPE THROUGH 48 HOURS. 

DESPITE MOVING TOWARD AN AREA OF HIGHER OCEANIC HEAT
CONTENT...INCREASING VERTICAL WIND SHEAR WILL PREVENT FLOSSIE FROM
INTENSIFYING. A SHARPENING UPPER TROUGH NORTHWEST OF THE MAIN
HAWAIIAN ISLANDS IS RESPONSIBLE FOR THIS SOUTHWESTERLY SHEAR. THE
TROUGH IS FORECAST TO MOVE WEST IN TANDEM WITH FLOSSIE...LEADING
SHIPS TO DISSIPATE FLOSSIE IN 36 HOURS. THE OFFICIAL FORECAST
DEPICTS A WEAKENING TREND...WHICH FOLLOWS HWF GUIDANCE CLOSELY
THROUGH 24 HOURS...AND IS A BLEND OF THE INTENSITY MODELS
THEREAFTER. THIS FORECAST KEEPS FLOSSIE ON A WESTWARD TRACK UNTIL
DISSIPATION.

THE 403RD WING OF THE AIR FORCE RESERVE 53RD WEATHER RECONNAISSANCE
SQUADRON IS NO LONGER FLYING MISSIONS INTO FLOSSIE AND IS RETURNING
TO THE MAINLAND. MANY THANKS FROM CPHC FOR THEIR TIMELY AND
CRITICAL DATA. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      15/2100Z 17.3N 158.5W    40 KT
 12HR VT     16/0600Z 17.4N 160.0W    40 KT
 24HR VT     16/1800Z 17.8N 162.5W    35 KT
 36HR VT     17/0600Z 18.4N 165.2W    30 KT
 48HR VT     17/1800Z 18.9N 167.8W    30 KT
 72HR VT     18/1800Z 19.9N 173.1W    25 KT...DISSIPATING
 96HR VT     19/1800Z 20.3N 178.0W    20 KT...REMNANT LOW
120HR VT     20/1800Z 20.6N 177.0E    20 KT...REMNANT LOW
 
$$
FORECASTER BIRCHARD/CRAIG