WTPA45 PHFO 242058
TCDCP5

TROPICAL STORM HILDA DISCUSSION NUMBER  10
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   EP112009
1100 AM HST MON AUG 24 2009

NORTHEASTERLY SHEAR CONTINUES TO AFFECT TROPICAL STORM HILDA THIS
MORNING. INITIAL VISIBLE IMAGES REVEALED THAT THE LOW LEVEL CENTER
APPEARED TO BE A BIT FARTHER NORTH THAN INFRARED DATA
SUGGESTED. THIS HAS BEEN CONFIRMED BY 37 GHZ MICROWAVE DATA FROM
1543 UTC AND 1637 UTC.  THUS...THE INITIAL POSITION HAS BEEN
ADJUSTED TOWARD THE NORTH ACCORDINGLY. MOST OF THE DEEP CONVECTION
OCCUPIES THE SOUTHERN SEMICIRCLE OF THE CIRCULATION THOUGH
RECENT IMAGES ALSO SHOW A BURST OF CONVECTION NEAR THE CENTER.
UPPER LEVEL OUTFLOW IS GOOD TOWARD THE SOUTH BUT RESTRICTED IN THE
NORTH WHICH ALSO INDICATES THE INFLUENCE OF VERTICAL SHEAR. DVORAK
INTENSITY ESTIMATES CAME IN AT 55 KT FROM CPHC...JTWC AND SAB.
SATCON AND AMSU ESTIMATES CAME IN AT 50 KT AND ADT INDICATED 40 KT.
FOR NOW...WILL HOLD THE INITIAL INTENSITY AT 55 KT THOUGH THIS MAY
BE GENEROUS.
 
HILDA CONTINUES TO MOVE SOUTH OF THE SUBTROPICAL RIDGE WHICH IS
EXPECTED TO MAINTAIN A GENERAL WEST-NORTHWESTWARD MOTION ON THE
CYCLONE OVER THE NEXT 48 HOURS. BETWEEN 48 AND 72 HOURS...THE GFS
SHOWS THAT HILDA WILL BE SOUTHEAST OF A MID-LEVEL ANTICYCLONE
NORTHWEST OF THE HAWAIIAN ISLANDS AND SOUTHWEST OF A DEEP
MID-LATITUDE TROUGH.  THIS PATTERN IS EXPECTED TO IMPART MORE OF A
WEST-SOUTHWESTWARD STEERING CURRENT. MOST OF THE OBJECTIVE
AIDS...INCLUDING THE TRUSTED HWRF...GFDL AND CONSENUS ARE IN
AGREEMENT.  THE FORECAST FOLLOWS THIS TREND AND IS CLOSE TO THE
TRUSTED AIDS THOUGH SLIGHTLY SLOWER THAN THE PREVIOUS PACKAGE. THE
NOGAPS AND ECMWF SOLUTIONS SHOW A SLOWER MOTION AND A TURN TOWARD
THE NORTHWEST AND BEAR WATCHING OVER THE NEXT COUPLE OF DAYS. 
 
WHILE SHEAR APPEARS TO BE INHIBITING DEVELOPMENT AT THE
MOMENT...THERE DOES NOT APPEAR TO BE ANY OBVIOUS FACTOR THAT WOULD
PREVENT HILDA FROM EVENTUALLY BECOMING A HURRICANE ALONG ITS CURRENT
FORECAST TRACK.  OBJECTIVE AIDS SHOW WIDE VARIATION WITH GHMI
SHOWING 90 KT AND HWRF INDICATING 50 KT BY 120 HOURS. FOR NOW...THE
FORECAST CALLS FOR SLIGHT NEAR-TERM WEAKENING BUT A RESUMPTION OF
SLOW INTENSIFICATION...ESPECIALLY BEYOND 36 HOURS SINCE SHEAR IS
EXPECTED TO EASE. SST/S WILL REMAIN BETWEEN 27C AND 28C SO NO
PROBLEM HERE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      24/2100Z 14.9N 145.9W    55 KT
 12HR VT     25/0600Z 15.0N 147.2W    50 KT
 24HR VT     25/1800Z 15.1N 148.8W    55 KT
 36HR VT     26/0600Z 15.0N 150.2W    55 KT
 48HR VT     26/1800Z 14.8N 151.7W    60 KT
 72HR VT     27/1800Z 14.5N 154.0W    65 KT
 96HR VT     28/1800Z 14.9N 156.9W    70 KT
120HR VT     29/1800Z 15.7N 160.3W    75 KT
 
$$
FORECASTER KODAMA