MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 13W (SOUDELOR) WARNING NR 30// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON (TY) 13W (SOUDELOR), LOCATED APPROXIMATELY 324 NM SOUTH OF KADENA AB, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A 30NM EYE WITH DECAYING DEEP CONVECTION OVER THE NORTHERN SEMI-CIRCLE AND CURVED DEEP CONVECTIVE BANDING PERSISTING OVER THE SOUTHERN SEMI- CIRCLE. THERE IS GOOD CONFIDENCE IN THE CURRENT POSITION BASED ON THE EYE FEATURE. A 061240Z METOP-B IMAGE REVEALS CONCENTRIC EYEWALLS WITH A SMALL INNER EYEWALL OF ABOUT 50NM DIAMETER AND A LARGER, 160NM DIAMETER EYEWALL, SEPARATED BY A WELL-DEFINED MOAT FEATURE. THIS DOUBLE EYEWALL CONFIGURATION HAS PERSISTED FOR ABOUT 18 HOURS WITH LITTLE CHANGE IN INTENSITY; THE CURRENT INTENSITY IS ASSESSED AT 90 KNOTS BASED ON CURRENT INTENSITY ESTIMATES RANGING FROM 77 TO 102 KNOTS. UPPER-LEVEL ANALYSIS INDICATES A GENERALLY FAVORABLE ENVIRONMENT WITH LOW VERTICAL WIND SHEAR AND RADIAL OUTFLOW; HOWEVER, DRY AIR IS EVIDENT OVER THE NORTHWESTERN PERIPHERY OF THE SYSTEM IN THE ISHIGAKI-JIMA SOUNDING AND RECENT TOTAL PRECIPITABLE WATER IMAGERY. 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 WEST-NORTHWESTWARD TRAJECTORY THROUGH TAU 48 UNDER THE STEERING INFLUENCE OF THE DOMINANT STR. IN THE SHORT TERM, TY 13W IS FORECAST TO RE-INTENSIFY AFTER THE SYSTEM COMPLETES THE CURRENT EYEWALL REPLACEMENT CYCLE (ERC); HOWEVER, THERE IS A GREAT DEAL OF UNCERTAINTY IN TIMING AN ERC AS THEY CAN PERSIST FOR 2 TO 3 DAYS. THIS UNCERTAINTY IS REFLECTED IN THE INTENSITY GUIDANCE, WHICH VARIES SIGNIFICANTLY IN THE DEGREE OF RE- INTENSIFICATION THROUGH TAU 36. THE JTWC FORECAST CONTINUES TO REFLECT A RE-INTENSIFICATION TO 105 KNOTS BY TAU 24 DUE TO ENHANCED POLEWARD OUTFLOW, INCREASING SST AND INCREASING OCEAN HEAT CONTENT. NEAR TAU 36, TY 13W IS FORECAST TO MAKE LANDFALL OVER TAIWAN THEN WEAKEN RAPIDLY AS IT TRANSITS ACROSS THE MOUNTAINOUS TERRAIN THEN RE-EMERGE OVER THE TAIWAN STRAIT AS A WEAK TYPHOON. BY TAU 48, TY SOUDELOR WILL 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