WTPA42 PHFO 231241 CCA TCDCP2 HURRICANE IOKE DISCUSSION NUMBER 14...CORRECTED NWS CENTRAL PACIFIC HURRICANE CENTER HONOLULU HI CP012006 1100 PM HST TUE AUG 22 2006 INTENSITY ESTIMATES FROM THE VARIOUS AGENCIES INDICATE THAT IOKE HAS MAINTAINED STRENGTH OVER THE PAST SIX HOURS. ALTHOUGH THE EYE HAS BECOME LESS DEFINED IN SATELLITE IMAGERY ONCE AGAIN...THERE WAS A RENEWED BURST OF DEEP CONVECTION AROUND THE CENTER AS THE HURRICANE MADE ITS CLOSEST APPROACH TO JOHNSTON ISLAND EARLIER THIS EVENING. THE 0507Z SSMI PASS SHOWED THAT JOHNSTON ISLAND WAS SQUARELY IN THE EASTERN EYEWALL OF IOKE. THE INITIAL MOTION IS 315/8. IOKE IS CURRENTLY HEADING NORTHWEST TOWARD A WEAKNESS IN THE SUBTROPICAL RIDGE AND AN EXTRATROPICAL LOW NEAR 28N 178E. MODEL GUIDANCE REMAINS IN EXCELLENT AGREEMENT THAT THE EXTRATROPICAL LOW WILL RETROGRADE WESTWARD AND WEAK LOW LEVEL RIDGING TO THE NORTH WILL ALLOW IOKE TO CONTINUE ON A NORTHWEST TRACK THROUGH THE NEXT 72 HOURS. THEREAFTER...STRONGER RIDGING TO THE NORTH AND NORTHWEST OF IOKE IS EXPECTED TO TURN THE HURRICANE ON A WEST-SOUTHWESTERLY COURSE. SATELLITE DERIVED HIGH LEVEL WIND ANALYSES INDICATE THAT IOKE IS SKIRTING THE WESTERN PERIPHERY OF AN UPPER LEVEL JET STREAK TO THE NORTHEAST OF THE CYCLONE. THERE IS STRONG SHEAR JUST TO THE NORTHEAST OF IOKE...BUT THE CORE OF THE HURRICANE REMAINS UNDER RELATIVELY WEAK SHEAR. MODEL GUIDANCE SUGGESTS THAT STRENGTHENING UPPER LEVEL RIDGING OVER IOKE WILL ACTUALLY REDUCE SHEAR THROUGH THE NEXT 72 HOURS. IN THE LONGER TERM...IOKE WILL LIKELY BEGIN TO FEEL THE INFLUENCE OF A RATHER STRONG DIGGING TROUGH BETWEEN 160W AND 170W...WITH INCREASING NORTHERLY SHEAR INDUCING WEAKENING. FORECAST POSITIONS AND MAX WINDS INITIAL 23/0900Z 17.2N 170.5W 90 KT 12HR VT 23/1800Z 17.9N 171.3W 90 KT 24HR VT 24/0600Z 18.7N 172.4W 90 KT 36HR VT 24/1800Z 19.4N 173.4W 90 KT 48HR VT 25/0600Z 20.2N 174.7W 90 KT 72HR VT 26/0600Z 20.9N 176.9W 90 KT 96HR VT 27/0600Z 20.3N 179.0W 85 KT 120HR VT 28/0600Z 19.5N 179.3E 80 KT $$ FORECASTER R BALLARD/HOUSTON