MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 25W (HAIMA) WARNING NR 17// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON 25W (HAIMA), LOCATED APPROXIMATELY 385 NM EAST- NORTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 16 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A HIGHLY SYMMETRIC AND TIGHTLY WOUND SPIRAL SYSTEM WITH A WELL-DEFINED 31 NM EYE, GIVING HIGH CONFIDENCE TO THE INITIAL POSITION. THE INITIAL INTENSITY OF 145 KNOTS IS BASED ON RECENT DVORAK ESTIMATES RANGING FROM T7.0 TO T7.5 (140 TO 155 KNOTS) AND A SATCON ESTIMATE OF 140 KNOTS. UPPER-LEVEL ANALYSIS SHOWS EXCELLENT RADIAL OUTFLOW DIRECTLY OVER THE SYSTEM AND LOW VERTICAL WIND SHEAR. THERE IS A PROMINENT ANTICYCLONE FEATURE TO THE NORTH BLOCKING THE NORMALLY ESTABLISHED POLEWARD OUTFLOW CHANNEL, BUT GIVEN THE IMPRESSIVE CURRENT INTENSITY THE RESTRICTION TO FLOW IS HAVING LIMITED IMPACT. SEA SURFACE TEMPERATURES ARE VERY FAVORABLE NEAR 29 TO 30 CELSIUS. CURRENTLY STY HAIMA IS TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE TO THE NORTH. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING BULLETIN. B. STY HAIMA WILL CONTINUE TO TRACK WESTWARD GUIDED BY THE CURRENT STEERING RIDGE. THE INTENSITY IS EXPECTED TO MAINTAIN AT SUPER TYPHOON STRENGTH FOR THE NEXT 18 HOURS UNTIL THE SYSTEM BEGINS TO INTERACT WITH LUZON AND BEGIN TO WEAKEN. BY TAU 30 STY HAIMA WILL REEMERGE OVER WATER REORGANIZING AS A TYPHOON AND CONTINUE NORTHWESTWARD UNDER STILL FAVORABLE CONDITIONS. THE SYSTEM IS EXPECTED TO MAKE LANDFALL AGAIN JUST EAST OF HONG KONG AROUND TAU 42 AND SIGNIFICANTLY WEAKEN AS IT TRACKS INLAND AND STARTS TO TURN NORTHWEST ROUNDING THE RIDGE AXIS. C. IN THE EXTENDED TAUS, STY HAIMA WILL ROUND THE RIDGE AXIS AND SHIFT TO A NORTHEASTERN TRACK. THE SYSTEM WILL REMAIN FOR AN EXTENSIVE PERIOD OVER LAND AND WEAKEN SIGNIFICANTLY. BY TAU 120 THE REMNANTS OF STY HAIMA WILL REEMERGE OVER WATER COMPLETELY DISSIPATED. DYNAMIC MODEL GUIDANCE IS IN VERY GOOD AGREEMENT AS THE SYSTEM TRACKS WEST THROUGH TAU 72 AND MAKES LANDFALL NEAR HONG KONG. HOWEVER, BEYOND TAU 72 THERE IS SOME SPREAD IN THE TRACK AS THE SYSTEM ROUNDS THE RIDGE AXIS WITH A LARGE DEGREE OF VARIABILITY WHERE THE REMNANTS OF THE SYSTEM WILL EMERGE OVER WATER. OVERALL THERE IS HIGH CONFIDENCE IN THE FORECAST TRACK.// NNNN NNNN