WDPN32 PGTW 170900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 25W (MAN-YI) WARNING NR 034// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 15.8N 121.9E INITIAL INTENSITY: 130 KTS GEOGRAPHIC REFERENCE: 89 NM NORTHEAST OF MANILA, PHILIPPINES MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 13 KTS SIGNIFICANT WAVE HEIGHT: 53 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THAT 25W, AFTER HAVING PASSED OVER CATANDUANES ISLAND ABOUT 18 HOURS AGO, HAS BEEN ABLE TO STEADILY REORGANIZE AND INTENSIFY AND HAS REGAINED SUPER TYPHOON STATUS AS IT APPROACHES A SECOND LANDFALL. CIMSS ADT HISTORY INDICATES A STEADILY WARMING EYE, NOW SITTING AT ALMOST 16C AND COOLING CLOUD TOPS, WHICH HAVE DRIVEN UP BOTH THE SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES OVER THE PAST SIX HOURS. ANIMATED MSI SHOWED A 15NM EYE AT ANALYSIS TIME, WHICH WAS LOCATED ABOUT 17NM OFFSHORE OF BORLONGAN BEACH. SUBSEQUENT IMAGERY SHOWS THE OUTER EYEWALL PUSHING ASHORE BY 0630Z, WITH THE EYE RAPIDLY SHRINKING AS THE SYSTEM MOVES INLAND. A PAIR OF HIGH-RESOLUTION MICROWAVE PASSES, FROM AMSR2 AND GMI AT 0445Z AND 0449Z RESPECTIVELY SHOWED A STADIUM EYE AND A SECONDARY EYEWALL, INDICATING THE SYSTEM WAS IN THE PROCESS OF AN EYEWALL REPLACEMENT CYCLE (EWRC). HOWEVER, THE EWRC WAS NOT ABLE TO FINISH AND HAD LITTLE IF ANY IMPACT ON THE INTENSIFICATION OF THE SYSTEM. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE IN THE MSI AS WELL AS RADAR DATA FROM PAGASA. THE INITIAL INTENSITY IS ASSESSED WITH HIGH CONFIDENCE, ON THE HIGHER END OF THE AVAILABLE INTENSITY ESTIMATES NOTED ABOVE. WHILE THE ENVIRONMENT ITSELF IS FAVORABLE IN TERMS OF GOOD OUTFLOW ALOFT AND LOW SHEAR, WITH THE SYSTEM MOVING OVER LAND IT WILL QUICKLY BE TORN APART BY THE RUGGED TERRAIN FEATURES. INITIAL WIND RADII BASIS: OTHER; PERSISTENCE. CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED AT 20N 140E. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T6.5 - 127 KTS RJTD: T7.0 - 140 KTS RCTP: T6.5 - 127 KTS KNES: T6.5 - 127 KTS DEMS: T6.5 - 127 KTS CIMSS SATCON: 129 KTS AT 170430Z CIMSS ADT: 127 KTS AT 170530Z CIMSS AIDT: 124 KTS AT 170530Z CIMSS D-MINT: 131 KTS AT 170448Z CIMSS D-PRINT: 118 KTS AT 170530Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 28-29 CELSIUS OUTFLOW: STRONG RADIAL OTHER FACTORS: TERRAIN INTERACTION. ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: HIGH INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: STY 25W IS IN THE PROCESS OF MAKING ITS SECOND LANDFALL NOW, NEAR BORLONGAN BEACH, JUST NORTHEAST OF DIPACULAO, PHILIPPINES. THE SYSTEM IS EXPECTED TO RAPIDLY CROSS NORTH-CENTRAL LUZON OVER THE NEXT 12 HOURS AND REEMERGE INTO THE SOUTH CHINA SEA TO THE SOUTHWEST OF VIGAN. THE SYSTEM WILL THEN CONTINUE TRACKING RATHER QUICKLY OFF TO THE NORTHWEST THROUGH TAU 12, ALONG THE WESTERN SIDE OF THE STEERING RIDGE. THE STR CURRENTLY NEAR 20N 140E WILL PUSH WESTWARD AND BUILD OVER TAIWAN, PUTTING STY 25W ON THE SOUTHERN SIDE OF THE STEERING GRADIENT. IN RESPONSE, 25W WILL TURN WESTWARD AFTER TAU 24, AND CONTINUE TRACKING IN A GENERAL WESTWARD DIRECTION THROUGH ABOUT TAU 48. IN TERMS OF INTENSITY, THE SYSTEM HAS REACHED ITS SECOND PEAK AND NOW HAVING MADE LANDFALL, WILL RAPIDLY WEAKEN DUE TO TERRAIN INTERACTION. THE SYSTEM IS EXPECTED TO BE A FAIRLY STRONG TYPHOON AS IT MOVES BACK OVER WATER IN ABOUT 12 HOURS, WITH AN INTENSITY IN THE NEIGHBORHOOD OF 80 KNOTS. HOWEVER, THE WEAKENED VORTEX WILL BE MORE SUSCEPTIBLE TO SHEAR AND DRY AIR AND WILL BEGIN TO WEAKEN IMMEDIATELY AS DRY MID-LEVEL AIR STARTS TO PUSH IN FROM THE WEST. BY TAU 36, SOUTHWESTERLY SHEAR PICKS UP TO 30 KNOTS OR GREATER, AND THE VORTEX WILL BE DECAPITATED AND SMOTHERED BY DRY AIR, MARKING THE ONSET OF RAPID WEAKENING. AS THIS PROCESS OCCURS, THE SYSTEM TURNS TOWARDS THE SOUTHWEST, MOVING ALONG THE GENERAL LOW-LEVEL FLOW FROM THE NORTHEAST. THE SYSTEM WILL FULLY DISSIPATE BY TAU 96 OFF THE EASTERN COAST OF VIETNAM. MODEL DISCUSSION: TRACK GUIDANCE IS IN GOOD AGREEMENT IN THE FIRST 24 HOURS OF THE FORECAST, WITH LITTLE IN THE WAY OF EITHER ALONG- OR CROSS-TRACK UNCERTAINTY. HOWEVER, BY TAU 36, THE MODELS BEGIN TO RAPIDLY DIVERGE IN BOTH HOW FAR NORTH THE SYSTEM TRACKS AND HOW FAST ITS FORWARD MOTION WILL BE. GFS AND THE GEFS ENSEMBLE MEAN CONTINUE TO MARK THE SOUTHERN EDGE OF THE GUIDANCE ENVELOPE AND MOVE THE SYSTEM AT THE FASTEST PACE WESTWARD. THE ECMWF REMAINS ON THE NORTHERN SIDE OF THE GUIDANCE PACKAGE AND REMAINS THE SLOWEST OF THE MODELS. BY TAU 72, WHILE CROSS-TRACK SPREAD REMAINS MODEST AT 150NM, ALONG TRACK UNCERTAINTY INCREASES TO 245NM BETWEEN THE GEFS ENSEMBLE MEAN AND THE ECMWF, WHICH LOSES THE VORTEX AT THIS POINT. THE JTWC FORECAST LIES CLOSE TO THE CONSENSUS MEAN THROUGH THE FORECAST PERIOD, WITH MEDIUM CONFIDENCE THROUGH TAU 72, DECREASING TO LOW THEREAFTER. INTENSITY GUIDANCE IS IN GOOD AGREEMENT ON THE OVERALL WEAKENING TREND, WITH ONLY MINIMAL DIFFERENCES IN THE RATE OF WEAKENING. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN