MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 13W (SOUDELOR) WARNING NR 28// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 13W (SOUDELOR), LOCATED APPROXIMATELY 391 NM SOUTH- SOUTHEAST OF KADENA AB, HAS TRACKED WEST-NORTHWESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN INCREASE IN CORE CONVECTION SURROUNDING A CONSTRICTING 14NM EYE. WATER VAPOR IMAGERY SHOWS INCREASED MOISTURE WITHIN THE CYCLONE'S STRUCTURE, ILLUSTRATING REDUCED DRY AIR ENTRAINMENT. A 052256Z SSMIS 91GHZ MICROWAVE IMAGE SHOWS A CLOSED MICROWAVE EYE FEATURE WITH INCREASED CONVECTION WITHIN THE SPIRAL BANDING. THE CURRENT POSITION IS BASED ON THE EYE FEATURE IN THE ABOVE IMAGERY WITH HIGH CONFIDENCE. THE CURRENT INTENSITY HAS BEEN HELD AT 95 KNOTS BASED ON AN ASSESSMENT OF AGENCY CURRENT INTENSITY ESTIMATES AND SUPPORTED BY AN IMPROVEMENT IN THE CONVECTIVE STRUCTURE OVER THE PAST COUPLE HOURS. UPPER LEVEL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH LOW VERTICAL WIND SHEAR AND GOOD DUAL CHANNEL OUTFLOW; HOWEVER, DRY AIR AND PRESSURE ON THE WESTERN PERIPHERY IS STILL AFFECTING THE SYSTEM. TY SOUDELOR IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A DEEP-LAYERED SUB-TROPICAL RIDGE (STR) TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 13W WILL CONTINUE ON A WESTWARD TRAJECTORY THROUGH TAU 72 UNDER THE STEERING INFLUENCE OF THE DOMINANT STR. OVER THE NEXT 12 HOURS, TY 13W WILL CONTINUE TO BATTLE THE SUBSIDENCE AND DRY AIR ALONG THE WESTERN PERIPHERY BUT IS EXPECTED TO MAINTAIN INTENSITY. AS TY SOUDELOR APPROACHES THE COAST OF TAIWAN, EXPECT SOME INTENSIFICATION AS SEA SURFACE TEMPERATURES INCREASE AND POLEWARD OUTFLOW IMPROVES DUE TO A RE-ORIENTING UPPER LEVEL RIDGE TO THE NORTH. JUST BEFORE TAU 48, TY 13W WILL MAKE LANDFALL OVER THE CENTRAL COAST OF TAIWAN AND BEGIN TO RAPIDLY WEAKEN DUE TO THE RUGGED TERRAIN OF THE ISLAND. TY SOUDELOR WILL CROSS THE TAIWAN STRAIT AND MAKE A SECOND LANDFALL OVER THE EASTERN COAST OF CHINA NEAR QUANZHOU. C. IN THE EXTENDED TAUS, TY SOUDELOR WILL APPROACH THE WESTERN EXTENT OF THE STEERING STR AND TURN POLEWARD. THE CYCLONE WILL CONTINUE TO DETERIORATE AS IT TRACKS INLAND, LEADING TO ITS DISSIPATION OVER LAND BY THE END OF THE FORECAST PERIOD. DYNAMIC MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT THROUGHOUT THE FORECAST PERIOD, LENDING HIGH CONFIDENCE IN THE JTWC TRACK FORECAST.// NNNN NNNN