WTPA42 PHFO 210920
TCDCP2

HURRICANE IOKE DISCUSSION NUMBER   6
NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI   CP012006
1100 PM HST SUN AUG 20 2006

HURRICANE IOKE CONTINUES TO INTENSIFY THIS EVENING. THE LATEST IR
IMAGERY FROM THE GOES11 AT 0800 UTC...THE LAST IMAGE RECEIVED
BEFORE ECLIPSE...SHOWED THE EYE HAS BECOME EVEN MORE PROMINENT THAN
WHEN THE 0600 UTC FIXES WERE MADE. SATELLITE FIXES WERE TIGHTLY
CLUSTERED AROUND THE LOCATION OF THIS EYE. THE SATELLITE AGENCIES
PROVIDED ESTIMATED CI VALUES RANGING FROM 3.5 TO 4.5. AODT YIELDED
4.6 AT PHFO. BASED ON THESE SUBJECTIVE SATELLITE ESTIMATES AND THE
IMPROVING APPEARANCE OF IOKE...THE INITIAL INTENSITY IS INCREASED
TO 70 KT. THE WIND RADII WERE ADJUSTED BASED ON A WINDSAT PASS
WHICH SHOWED GALE FORCE WINDS EXTENDING OUT AT LEAST 2 DEGREES OF
LATITUDE NORTHEAST OF THE CENTER. ALSO...HAVE INCREASED THE 12 FOOT
SEAS.

THE INITIAL MOTION OF IOKE IS 300 DEG AT 11 KT. TRACK MODELS
CONTINUE TO PROVIDE SOME SPREAD. HOWEVER...THE CONSENSUS MODEL...
CONU...WAS FOLLOWED CLOSELY FOR THIS ADVISORY. THIS CONSENSUS ALSO
HAPPENS TO BE VERY CLOSE TO THE GFSI. THIS TRACK IS SLIGHTLY TO THE
RIGHT OF THE PREVIOUS FORECAST TRACK. THE MODELS ARE SHOWING THE
INFLUENCE OF A MIDDLE AND UPPER LEVEL TROUGH LOCATED NORTHWEST OF
THE HURRICANE. THERE IS ALSO A RIDGE LOCATED EAST-NORTHEAST OF IOKE
ALONG LATITUDE 25N. THE DEEP LAYER STEERING FROM THESE FEATURES
WILL MAINTAIN THE PRESENT MOVEMENT OF IOKE TOWARD THE
WEST-NORTHWEST FOR THE NEXT 2 TO 3 DAYS. HOWEVER...A WEAKNESS IN
THE STEERING IS EXPECTED TO RESULT IN SOME SLOWING OF THE HURRICANE
BEYOND DAY 3.

THE SHIPS MODEL WAS USED FOR THE INTENSITY FORECAST. THIS MODEL HAS 
BEEN DOING QUITE WELL WITH THIS SYSTEM...WHICH WAS PREVIOUSLY INVEST 
AREA 91C. THE MODEL CORRECTLY FORECAST INTENSIFICATION TO HURRICANE 
INTENSITY A FEW DAYS AGO. INCREASING VERTICAL WIND SHEAR AS IOKE 
NEARS THE MIDDLE AND UPPER LEVEL TROUGH WILL LIKELY WEAKEN THE 
HURRICANE AFTER 72 HOURS.

ALL INTERESTS ON AND AROUND JOHNSTON ISLAND SHOULD IMMEDIATELY
PREPARE FOR THE ONSET OF THE OUTER WINDS FROM AN INTENSIFYING IOKE.
THE FORECAST CLOSEST APPROACH OF THIS HURRICANE TO THAT ISLAND
WOULD TAKE PLACE WITHIN ABOUT 36 HOURS OR LESS. THE PRESENT TRACK
WOULD TAKE IOKE SOUTHWEST OF THAT ISLAND...WHICH WOULD PLACE THAT
ISLAND IN THE RIGHT FRONT QUADRANT OF THE GALE WIND RADII OF THE
HURRICANE.

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      21/0900Z 11.7N 165.0W    70 KT
 12HR VT     21/1800Z 12.7N 166.7W    85 KT
 24HR VT     22/0600Z 14.2N 168.9W    95 KT
 36HR VT     22/1800Z 15.5N 170.6W   100 KT
 48HR VT     23/0600Z 16.8N 172.0W   100 KT
 72HR VT     24/0600Z 18.7N 174.2W    90 KT
 96HR VT     25/0600Z 21.2N 175.6W    80 KT
120HR VT     26/0600Z 23.3N 176.8W    70 KT
 
$$
FORECASTER HOUSTON