WTPA42 PHFO 251504
TCDCP2

HURRICANE IOKE DISCUSSION NUMBER  23
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP012006
500 AM HST FRI AUG 25 2006

THE CLOUD PATTERN OF HURRICANE IOKE RAPIDLY HAS RAPIDLY WEAKENED...
THEN RE-INTENSIFIED OVER THE PAST 6 HOURS. THE WELL-DEVELOPED AND
VERY WARM EYE COOLED AND THE VERY COLD AND SYMMETRICAL SURROUNDING
TOPS WARMED AND BECAME ELONGATED ALONG A NORTHEAST TO SOUTHWEST
AXIS THROUGH 10Z. SINCE 10Z...THE SURROUNDING TOPS HAVE COOLED AND
BECOME MORE SYMMETRICAL AND THE EYE HAS BECOME WARMER. PART OF
THESE CHANGES MAY HAVE BEEN DUE TO AN EYEWALL REPLACEMENT CYCLE BUT
WATER VAPOR IMAGERY SEEMS TO SHOW THAT SHEAR WAS ALSO A FACTOR.

SUBJECTIVE DVORAK ESTIMATES FOR 25/1130Z RANGED FROM 6.0 TO 7.0...OR
115 TO 140KT. AODT ESTIMATES WERE 5.8 AND 6.7. WE HAVE KEPT THE
INITIAL INTENSITY AT 140 KT. WE HAVE DECREASED THE WIND RADII A BIT
BASED ON A 0723Z QUIKSCAT PASS.
 
THE MODEL FORECASTS REMAIN IN CLOSE AGREEMENT...IF NOT QUITE AS
CLOSE AS EARLIER. WE HAVE ADJUSTED THE INITIAL MOTION SLIGHTLY
SOUTH TO BETTER MATCH THE RECENT MOTION OF THE HURRICANE. THE TRACK
GRADUALLY SHIFTS TO WEST SOUTHWEST...THEN BACK TO WEST NORTHWEST
AFTER 72 HOURS. WE HAVE SHIFTED THE TRACK FARTHER WEST AFTER 72
HOURS TO BETTER MATCH THE MODEL CONSENSUS. THE CURRENT FORECAST HAS
IOKE CROSSING THE DATELINE AND BECOMING A TYPHOON SHORTLY AFTER
27/06Z.
 
SHEAR OVER INOKE REMAINS QUITE LOW WITH THE CIMSS SHEAR ANALYSIS
SHOWING ONLY 1.8 M/S SHEAR. WHILE THE CIMSS ANALYSES CONSISTENTLY
SHOWED THE ENVIRONMENT FAVORABLE FOR CONTINUED INTENSIFICATION
THROUGH 25/06Z...THE 25/12Z OUTLOOK NOW SHOWS THE ENVIRONMENT
UNFAVORABLE FOR THE NEXT 24 HOURS. WE HAVE MODIFIED OUR INTENSITY
FORECAST TO SHOW SLOW WEAKENING AT 1/2 T-NUMBER PER DAY THROUGH THE
FORECAST PERIOD.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      25/1500Z 19.3N 175.1W   140 KT
 12HR VT     26/0000Z 19.5N 176.1W   135 KT
 24HR VT     26/1200Z 19.5N 177.4W   130 KT
 36HR VT     27/0000Z 19.1N 178.8W   125 KT
 48HR VT     27/1200Z 18.4N 179.8E   120 KT
 72HR VT     28/1200Z 17.6N 177.1E   110 KT
 96HR VT     29/1200Z 18.9N 174.3E   100 KT
120HR VT     30/1200Z 22.0N 172.1E    90 KT
 
$$
FORECASTER DONALDSON