WTPA45 PHFO 241450
TCDCP5

TROPICAL STORM HILDA DISCUSSION NUMBER   9
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP112009
500 AM HST MON AUG 24 2009

HILDA/S SATELLITE SIGNATURE HAS CHANGED LITTLE OVERNIGHT...AND
DVORAK CURRENT INTENSITY ESTIMATES REMAIN A CONSENSUS 3.5 FROM THE 
FIX AGENCIES...WITH AN ADT VALUE OF 3.4 FROM UW-CIMSS AT 1130 UTC.
WITH THIS CONSENSUS...AND LACK OF MICROWAVE PASSES TO AID WITH THE
ANALYSIS OF THE INNER STRUCTURE...THE CURRENT INTENSITY WILL BE
HELD AT 55 KT FOR THIS PACKAGE. 

THE INITIAL MOTION IS 275/11...AS HILDA REMAINS IN DEEP EASTERLY
FLOW TO THE SOUTH OF AN EAST-WEST RIDGE ALOFT ALONG 20N...AND A
SURFACE RIDGE ALONG 35N. THIS SETUP IS PROVIDING MODERATE EAST TO
NORTHEAST SHEAR OVER HILDA...AND IS INHIBITING OUTFLOW IN THE
NORTHERN SEMICIRCLE...WITH THE CENTER LOCATED ON THE NORTHERN EDGE
OF THE COLD CLOUD TOPS. THE CURRENT TRACK FORECAST CLOSELY FOLLOWS
THE PREVIOUS ADVISORY THROUGH 36 HOURS...WITH LITTLE CHANGE IN THE
SYNOPTIC SETTING EXPECTED. AFTER 36 HOURS...A MID-LEVEL HIGH
CURRENTLY NORTHEAST OF HILDA WILL BECOME LESS INFLUENTIAL...AND 
A MID-LEVEL HIGH BUILDING NORTHWEST OF THE CYCLONE WILL BECOME THE
PRIMARY STEERING MECHANISM. TRACK GUIDANCE RESPONDS BY SLOWING
HILDA/S FORWARD MOTION...AND BY TURNING HILDA ON A TRACK SLIGHTLY
SOUTH OF DUE WEST. THE LATEST TRACK FORECAST IS SLIGHTLY SLOWER
THAN...AND TO THE LEFT OF...THE PREVIOUS ADVISORY...AND CLOSE TO
THE TVCN.

THE FORECAST TRACK TAKES HILDA OVER WATERS SUFFICIENTLY WARM TO
SUPPORT A HURRICANE...AS IT HAS BEEN FOR THE LAST COUPLE OF DAYS.
SHEAR HAS BEEN THE INHIBITING FACTOR IN INTENSIFICATION THUS FAR...
BUT WITH HILDA ABLE TO SLOWLY INTENSIFY IN THE FACE OF MODERATE
SHEAR OVER THE PAST 2 DAYS...THIS TREND IS FORECAST TO CONTINUE...
WITH HILDA BECOMING A HURRICANE BY TUESDAY. SOME EASING OF THE
VERTICAL WIND SHEAR IS FORECAST ON DAYS 3 AND 4...AND SHOULD ALLOW
HILDA TO CONTINUE TO INTENSIFY AS A HURRICANE. THE INTENSITY
FORECAST IS CLOSE TO BOTH SHIPS AND LGEM...BUT IT IS WORTH NOTING
THAT THESE MODELS HAVE SLOWED THEIR INTENSIFICATION RATE FROM THE
PREVIOUS TWO RUNS. 
  
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      24/1500Z 14.4N 145.4W    55 KT
 12HR VT     25/0000Z 14.5N 147.0W    55 KT
 24HR VT     25/1200Z 14.7N 148.8W    60 KT
 36HR VT     26/0000Z 14.8N 150.3W    65 KT
 48HR VT     26/1200Z 14.6N 151.8W    65 KT
 72HR VT     27/1200Z 14.4N 154.6W    70 KT
 96HR VT     28/1200Z 14.3N 157.4W    70 KT
120HR VT     29/1200Z 14.4N 160.6W    75 KT
 
$$

FORECASTER BIRCHARD