MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (LAN) WARNING NR 19// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 25W (LAN), LOCATED APPROXIMATELY 478 NM SOUTH-SOUTHEAST OF KADENA AB, HAS TRACKED NORTHWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED MULTI-SPECTRAL SATELLITE IMAGERY SHOWS DEEP CONVECTIVE BANDING WRAPPING INTO A LARGE, CONSOLIDATING, LOW LEVEL CIRCULATION CENTER (LLCC). THE SYSTEM HAS BEGUN TO CONSOLIDATE, THOUGH IT REMAINS VERY BROAD, COVERING OVER 850 NM. A 192131Z 91 GHZ SSMIS IMAGE AND A 192206Z 37 GHZ WINDSAT DEPICT DEEP CONVECTIVE BANDING WRAPPING INTO A WELL DEFINED MICROWAVE EYE FEATURE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON EXTRAPOLATION OF THE MICROWAVE EYE FEATURE AND THE PGTW SATELLITE FIX. THE INITIAL INTENSITY OF 85 KNOTS IS HEDGED ABOVE DVORAK INTENSITY ASSESSMENTS OF T4.5 (77 KNOTS) FROM BOTH PGTW AND RJTD AND IS SUPPORTED BY A SATCON ESTIMATE OF 83 KNOTS. ENVIRONMENTAL ANALYSIS INDICATES THAT THE SYSTEM IS IN AN AREA OF LOW (5-15 KNOT) VERTICAL WIND SHEAR (VWS) AND IS TRACKING THROUGH AN AREA OF VERY WARM (30 TO 31 CELSIUS) SEA SURFACE TEMPERATURES. TYPHOON LAN CURRENTLY HAS AN OUTFLOW CHANNEL THAT EXITS THE POLEWARD SIDE OF THE STORM, WRAPS AROUND THE EASTERN PERIPHERY, AND EXTENDS EQUATORWARD. TY 25W IS TRACKING NORTH-NORTHEAST ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) LOCATED TO THE NORTHEAST. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 25W IS FORECAST TO TRACK NORTH-NORTHEASTWARD OVER THE NEXT 12-24 HOURS UNDER THE INFLUENCE OF THE STR. AFTER CROSSING THE RIDGE AXIS AROUND TAU 24, THE SYSTEM WILL BEGIN TO ACCELERATE AND RECURVE BACK TO THE NORTHEAST ON A TRACK THAT WILL PASS ALONG THE EAST COAST OF JAPAN. FAVORABLE ENVIRONMENTAL CONDITIONS WILL PERSIST AND POLEWARD OUTFLOW WILL BE ENHANCED AS THE SYSTEM APPROACHES THE MID-LATITUDE WESTERLIES. THIS ENHANCED OUTFLOW WILL ALLOW FOR A PERIOD OF RAPID INTENSIFICATION WITH THE SYSTEM REACHING A PEAK INTENSITY OF 115 KNOTS AROUND TAU 36. AFTER TAU 36, THE SYSTEM WILL BEGIN TO GRADUALLY WEAKEN AS IT BEGINS TO INTERACT WITH A PASSING MID-LATITUDE TROUGH AND BECOMES EMBEDDED IN THE MID-LATITUDE WESTERLIES, INCREASING VERTICAL WIND SHEAR. THE TROUGH INTERACTION AND WESTERLIES WILL CAUSE TY 25W TO BEGIN EXTRA- TROPICAL TRANSITION. DYNAMIC MODEL GUIDANCE IS IN STRONG AGREEMENT, LENDING HIGH CONFIDENCE IN THIS PORTION OF THE JTWC TRACK FORECAST. C. AFTER TAU 72, TY LAN WILL CONTINUE TO ACCELERATE NORTHEASTWARD AS IT BECOMES FULLY EMBEDDED IN THE BAROCLINIC ZONE. INCREASING VWS AND THE SYSTEM TRACKING THROUGH COOLER (<26 CELSIUS) SEA SURFACE TEMPERATURES WILL WEAKEN THE SYSTEM FROM TAU 72 THROUGH THE DURATION OF THE FORECAST PERIOD. SHORTLY AFTER TAU 72, THE SYSTEM IS FORECAST TO MAKE A BRIEF LANDFALL BETWEEN KYOTO AND TOKYO. THE SYSTEM?S NORTHEASTERLY TRACK WILL TAKE IT BACK OUT OVER THE PACIFIC OCEAN SOUTH OF SENDAI. TY LAN WILL CONTINUE TO TRACK TO THE NORTHEAST AND COMPLETE EXTRA-TROPICAL TRANSITION BY TAU 96, BECOMING A HURRICANE-FORCE COLD CORE LOW WITH AN EXPANSIVE WIND FIELD. DYNAMIC MODEL GUIDANCE IS IN TIGHT AGREEMENT FOR THE TRACK DIRECTION, HOWEVER, VARIATIONS IN THE TRACK SPEED AFTER TAU 48 LEAD TO A SIGNIFICANT SPREAD IN THE GUIDANCE BY TAU 96. DUE TO THE UNCERTAINTY IN STORM SPEED IN THE LATER TAUS, THERE IS LOW CONFIDENCE IN THIS PORTION OF THE JTWC TRACK FORECAST.// NNNN NNNN