WTPA44 PHFO 172100
TCDCP4

TROPICAL STORM GUILLERMO DISCUSSION NUMBER  23
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP102009
1100 AM HST MON AUG 17 2009

TROPICAL STORM GUILLERMO MAINTAINS ITS WEAKENING TREND. THE LOW 
LEVEL CENTER OF CIRCULATION IS TOTALLY EXPOSED WITH THE CLOSEST 
CONVECTION 100 NM NNW OF THE CENTER. THE LATEST MICROWAVE PASS
SHOWS HEAVY RAIN ASSOCIATED WITH THE CONVECTION TO THE NW...AND 
QUIKSCAT VERIFIES TROPICAL STORM FORCE WINDS ON THE NORTH SIDE OF 
THE CIRCULATION. 

STRONG SOUTHWEST SHEAR...IN EXCESS OF 40 KT THIS MORNING...CONTINUES 
TO WEAKEN THE SYSTEM...ALONG WITH SST/S BELOW FAVORABLE 
TEMPERATURES. WE HAVE DROPPED THE INITIAL INTENSITY TO 45 KT KEEPING 
IN LINE WITH THE WEAKENING TREND...COMPLYING WITH DVORAK 
CONSTRAINTS AND THE CURRENT ROUND OF SUBJECTIVE DVORAK CI NUMBERS. 
THE INITIAL MOTION OF GUILLERMO IS WEST NORTHWEST AT 16 KT AND IS 
EXPECTED TO CONTINUE AT THIS DIRECTION AND SPEED THROUGH 48 HOURS. 
THE TRACK REMAINS SIMILAR TO THE PREVIOUS FORECAST AND IS IN GOOD 
AGREEMENT WITH THE CONSENSUS MODELS. ALL TRACK GUIDANCE REMAINS 
TIGHTLY PACKED...WITH EVEN THE LEFT OUTLIER REMAINING NORTH OF THE 
MAIN HAWAIIAN ISLANDS AT ALL TIME STEPS.

THIS SYSTEM IS IN SPIN-DOWN MODE...KEPT ALIVE MAINLY THROUGH 
MOMENTUM AND A DESIRE TO STAY WITHIN DVORAK CONSTRAINTS. WITH THE 
SHEAR AND SST/S CREATING HOSTILE CONDITIONS FOR GUILLERMO...THE 
SYSTEM IS EXPECTED TO WEAKEN FURTHER...AND BECOME A REMNANT LOW IN 
48 HOURS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      17/2100Z 22.3N 146.0W    45 KT
 12HR VT     18/0600Z 23.3N 148.4W    40 KT
 24HR VT     18/1800Z 24.8N 151.5W    35 KT
 36HR VT     19/0600Z 26.2N 154.6W    30 KT
 48HR VT     19/1800Z 27.3N 158.2W    25 KT...REMNANT LOW
 72HR VT     20/1800Z 28.5N 165.1W    20 KT...DISSIPATING
 96HR VT     21/1800Z...DISSIPATED
 
$$

FORECASTER POWELL/MORRISON