MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 13W (SOUDELOR) WARNING NR 27// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 13W (SOUDELOR), LOCATED APPROXIMATELY 435 NM SOUTH- SOUTHEAST OF KADENA AB, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS THINNING CONVECTION DUE TO DRY AIR ENTRAINMENT ALONG THE WESTERN QUADRANT WITH A 25NM EYE THAT SUPPORTS THE CURRENT POSITION WITH HIGH CONFIDENCE. A 051637Z AMSR-2 89GHZ MICROWAVE IMAGE DEPICTS A MICROWAVE EYE FEATURE, OPEN ON THE NORTHWESTERN QUADRANT, WITH BROKEN SPIRAL BANDING WRAPPING INTO THE EYE. THE WIND RADII HAVE BEEN ADJUSTED BASED ON A 051301Z ASCAT PASS. THE INITIAL INTENSITY OF 95 KNOTS IS BASED ON DECREASING DVORAK CURRENT INTENSITY ESTIMATES FROM ALL AGENCIES AND IS SUPPORTED BY A RECENT SATCON INTENSITY ESTIMATE OF 96 KNOTS. UPPER LEVEL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH LOW VERTICAL WIND SHEAR AND GOOD DUAL CHANNEL OUTFLOW; HOWEVER, SIGNIFICANT DRY AIR AND PRESSURE ON THE WESTERN PERIPHERY IS CAUSING THE DEGRADED SATELLITE AND MICROWAVE SIGNATURE. 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 BE HAMPERED BY THE SUBSIDENCE AND DRY AIR ALONG THE WESTERN PERIPHERY. 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 AFTER 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