Hurricane GUILLERMO
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HURRICANE GUILLERMO DISCUSSION NUMBER 17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP102009
200 AM PDT SUN AUG 16 2009
FINAL-T DVORAK ESTIMATES FROM TAFB AND SAB HAVE FALLEN TO T4.5...AND
THE LATEST OBJECTIVE ADT FROM UW-CIMSS IS T4.7. THE INITIAL
INTENSITY IS THEREFORE LOWERED TO 85 KT. GUILLERMO HAS BEEN
REMARKABLY TOUGH IN WITHSTANDING THE 24.5C WATER IT IS NOW
OVER...BUT THE HURRICANE WILL SOON HAVE TO ALSO CONTEND WITH
WEST-SOUTHWESTERLY SHEAR INCREASING TO 20-25 KT WITHIN THE NEXT
12-24 HOURS. THE OFFICIAL INTENSITY FORECAST THUS SHOWS FAIRLY
QUICK WEAKENING OVER THE NEXT COUPLE OF DAYS...WITH GUILLERMO
BECOMING A REMNANT LOW NORTH OF THE HAWAIIAN ISLANDS WITHIN 96
HOURS.
THE INITIAL MOTION IS 280/13. GUILLERMO WILL CONTINUE TO BE STEERED
WEST-NORTHWESTWARD AROUND THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL
RIDGE WHILE COMING UNDER GREATER INFLUENCE OF A MID- TO UPPER-LEVEL
LOW EXPECTED TO DEVELOP NEAR HAWAII OVER THE NEXT 24 HOURS. THE
NEW OFFICIAL TRACK FORECAST SHOWS VERY LITTLE CHANGE FROM THE
PREVIOUS FORECAST AND LIES VERY CLOSE TO THE MODEL CONSENSUS.
FORECAST POSITIONS AND MAX WINDS
INITIAL 16/0900Z 19.8N 137.4W 85 KT
12HR VT 16/1800Z 20.3N 139.4W 75 KT
24HR VT 17/0600Z 21.2N 142.1W 60 KT
36HR VT 17/1800Z 22.2N 144.8W 45 KT
48HR VT 18/0600Z 23.3N 147.5W 40 KT
72HR VT 19/0600Z 26.0N 153.0W 30 KT
96HR VT 20/0600Z 29.0N 159.0W 25 KT...REMNANT LOW
120HR VT 21/0600Z...DISSIPATED
$$
FORECASTER BERG
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