WDPN33 PGTW 061500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 31W (HAIYAN) WARNING NR 14// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON 31W (HAIYAN), LOCATED APPROXIMATELY 113 NM EAST- NORTHEAST OF KOROR, PALAU, HAS TRACKED WESTWARD AT 18 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (EIR) REVEALS STY 31W HAS MAINTAINED A PERSISTENT RING OF DEEP CONVECTION AROUND A SMALL 8NM EYE WHILE SOME DETACHED DEEP CONVECTIVE BANDING HAS FORMED ALONG THE WESTERN SEMI-CIRCLE. THIS IS FURTHER SUPPORTED BY A 061027Z TRMM MICROWAVE IMAGE WHICH DEPICTS AN INTENSE CONVECTIVE CORE AND IMPROVED CONVECTIVE BANDING IN ALL QUADRANTS. THERE IS HIGH CONFIDENCE IN THE INITIAL POSITION BASED ON THE SMALL EYE SEEN IN THE EIR ANIMATION. THE INITIAL INTENSITY HAS BEEN INCREASED TO 140 KNOTS DUE TO THE IMPROVING STRUCTURE AND CONGRUENT DVORAK INTENSITY ESTIMATES FROM ALL REPORTING AGENCIES. UPPER-LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH NEAR-RADIAL OUTFLOW AND LOW (05 TO 10 KNOTS) VERTICAL WIND SHEAR. STY 31W IS CURRENTLY TRACKING ALONG THE SOUTHERN PERIPHERY OF THE DEEP-LAYERED SUBTROPICAL RIDGE (STR), WHICH IS ENTRENCHED TO THE NORTH. 3. FORECAST REASONING. A. NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. STY 31W IS EXPECTED TO MAINTAIN A WEST-NORTHWESTWARD TRACK ALONG THE SOUTHERN EDGE OF THE STR THROUGH TAU 72. DUE TO VERY FAVORABLE ENVIRONMENTAL CONDITIONS, FURTHER INTENSIFICATION IS FORECAST OVER THE NEXT 24 HOURS WITH A PEAK INTENSITY EXPECTED OVER THE WARM OPEN WATERS OF THE PHILIPPINE SEA. STY HAIYAN WILL MAKE LANDFALL OVER THE CENTRAL PHILIPPINES JUST SLIGHTLY AFTER TAU 36 AND WILL SLIGHTLY WEAKEN AS IT TRACKS ACROSS THE ISLANDS. STY 31W IS EXPECTED TO RE-EMERGE OVER THE SOUTH CHINA SEA AS A 110 KNOT TYPHOON. DYNAMIC MODEL GUIDANCE IS IN EXCEPTIONALLY TIGHT AGREEMENT THROUGH THIS PORTION OF THE FORECAST. C. IN THE EXTENDED TAUS, STY 31W IS FORECAST TO WEAKEN AFTER TAU 72 AS IT TRACKS OVER MARGINAL SSTS IN THE WESTERN SOUTH CHINA SEA AND BEGINS TO ENCOUNTER LAND, MAKING LANDFALL AFTER TAU 96, WHICH WILL START TO DISSIPATE THE SYSTEM. DYNAMIC GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH THE EXTENDED TAUS, THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST.// NNNN