MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (LAN) WARNING NR 11// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 25W (LAN), LOCATED APPROXIMATELY 314 NM NORTH- NORTHWEST OF KOROR, HAS TRACKED NORTHWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS BROAD DEEP CONVECTIVE BANDING WRAPPING INTO A PARTIALLY-EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC). HOWEVER, A 172159Z SSMIS 37GHZ COLOR IMAGE DEPICTS CONVECTIVE BANDING WRAPPING TIGHTLY INTO A WELL- DEFINED CENTER, WHICH INDICATES A STRENGTHENING LLCC. CONSEQUENTLY, THE INITIAL INTENSITY IS ASSESSED AT 65 KNOTS BASED ON DVORAK INTENSITY ESTIMATES OF T4.0 FROM ALL AGENCIES. UPPER-LEVEL ANALYSIS SHOWS AN EXCELLENT ENVIRONMENT WITH LOW VERTICAL WIND SHEAR, STRONG POLEWARD OUTFLOW ENHANCED BY THE TUTT, WARM SST (30C) AND HIGH OCEAN HEAT CONTENT VALUES. AFTER A BRIEF PERIOD OF QUASI-STATIONARY MOTION ASSOCIATED WITH THE WEAKENING SUBTROPICAL RIDGE TO THE NORTH, TY 25W CONTINUES TO TRACK NORTHWARD UNDER THE STEERING INFLUENCE OF THE BUILDING STEERING RIDGE TO THE EAST. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 25W IS FORECAST TO TRACK NORTHWARD UNDER THE STEERING INFLUENCE OF THE BUILDING SUBTROPICAL RIDGE TO THE EAST. DESPITE THE COMPLEX, EVOLVING SYNOPTIC STEERING PATTERN, DYNAMIC MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT WITH MINOR DIFFERENCES IN TRACK SPEED. TY LAN IS FORECAST TO INTENSIFY STEADILY THROUGH TAU 72 TO A PEAK INTENSITY OF 130 KNOTS DUE TO THE VERY FAVORABLE CONDITIONS. C. IN THE EXTENDED PERIOD, TY 25W WILL WEAKEN SLIGHTLY AS THE SYSTEM BEGINS EXTRA-TROPICAL TRANSITION (ETT) NEAR TAU 96 AND INTERACTS WITH UPPER-LEVEL WESTERLIES. TY 25W WILL REMAIN A VERY LARGE SYSTEM WITH EXTENSIVE GALE-FORCE WINDS, ENHANCED BY A COLD SURGE OVER THE RYUKYU ISLANDS AND A STRONG BAROCLINIC SYSTEM OVER JAPAN. THE SYSTEM WILL COMPLETE ETT JUST PRIOR TO MAKING LANDFALL OVER HONSHU BUT WILL REMAIN A STRONG TYPHOON STRENGTH EXTRA-TROPICAL LOW. OVERALL, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN