Super Typhoon 25W(MAN-YI) landfall South of CASIGURAN/LUZON//TC 02S(BHEKI) Strong CAT 3 US above forecast//1709utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON 25W. 12HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ARE ISSUED ON 02S.

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.

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.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A RATHER IMPRESSIVE TROPICAL CYCLONE, WITH A WELL-DEFINED 22NM EYE WITH A EYE TEMPERATURE OF 11C. A SERIES OF THREE MHS 89GHZ MICROWAVE IMAGES BETWEEN 0400Z-0500Z REVEALED A STRONG EYEWALL COMPLETELY SURROUNDING A MICROWAVE EYE FEATURE, THROUGH THE NORTHEAST PORTION OF THE EYEWALL REMAINS RELATIVELY WEAK. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE 22NM EYE IN THE MSI AND AN EXTRAPOLATION OF THE MICROWAVE EYE FEATURE IN THE MICROWAVE IMAGES NOTED ABOVE. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE, HEDGED SLIGHTLY HIGHER THAN THE BULK OF THE AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T5.5 IN LIGHT OF THE HIGHER CIMSS ADT, AIDT AND DPRINT ESTIMATES NOTED ABOVE. ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE FOR THE TIME BEING, WITH LOW VERTICAL WIND SHEAR (VWS) AND GOOD POLEWARD OUTFLOW ALOFT. THOUGH SSTS REMAIN MARGINAL AT 26-27C, THE SYSTEM HAS BEEN ABLE TO STEADILY INTENSIFY OVER THE PAST DAY.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 02S WILL CONTINUE TO TRACK SOUTHWESTWARD FOR THE NEXT 12 TO 24 HOURS, ALONG THE WESTERN SIDE OF THE STEERING RIDGE TO THE EAST. HOWEVER, TRACK SPEEDS ARE EXPECTED TO SLOW DOWN AS A WEAKNESS IN THE STEERING RIDGE DEVELOPS TO THE SOUTH AND THE SYSTEM MOVES INTO A RELATIVELY WEAK STEERING PATTERN. THE PASSING TROUGH IS NOT EXPECTED TO BE STRONG ENOUGH TO INDUCE TC 02S TO TRACK POLEWARD AND THE PASSAGE OF A SUCCESSION OF TRANSIENT DEEP-LAYER ANTICYCLONES TO THE SOUTH WILL STEER TC 02S ONTO A MORE WESTWARD TRACK AFTER TAU 24. AFTER TAU 48, THE SYSTEM WILL ACCELERATE TOWARDS THE WEST-SOUTHWEST ALONG THE NORTHWEST SIDE OF A BUILDING STR THAT DEVELOPS SOUTHEAST OF MAURITIUS. IN TERMS OF INTENSITY, THE SYSTEM HAS LIKELY PEAKED IN INTENSITY, BUT A SLIGHT AMOUNT OF FURTHER INTENSIFICATION CANNOT BE RULED OUT AS CONDITIONS ARE EXPECTED TO REMAIN FAVORABLE FOR ABOUT ANOTHER 12 HOURS. AFTER TAU 12, THE SYSTEM IS EXPECTED TO MOVE INTO A REGION OF COOLER SSTS, AND SOUTHWESTERLY SHEAR IS FORECAST TO INCREASE, LEADING TO A GENERAL WEAKENING PHASE. AFTER TAU 36, THE SYSTEM WILL BE DECAPITATED BY VERY STRONG WESTERLY SHEAR, WHICH WILL ALSO USHER IN A WEDGE OF EXTREMELY DRY MID-LEVEL AIR OVER TOP OF THE SYSTEM, AND THE SYSTEM WILL RAPIDLY WEAKEN UP TO TAU 48. THEREAFTER THE REMNANT LOW-LEVEL VORTEX WILL SLOWLY DISSIPATE AS IT TRACKS WEST-SOUTHWESTWARD ALONG THE NORTHERN SIDE OF THE STRONG LOW- TO MID-LEVEL ANTICYCLONE TO THE SOUTH.

MODEL DISCUSSION: TRACK GUIDANCE IS IN GOOD AGREEMENT IN THE SHORT-TERM (THOUGH TAU 24) BUT BEGINS TO DIVERGE SIGNIFICANTLY BY TAU 36. TWO DISTINCT GROUPS EMERGE BY TAU 48; THE ECMWF, ECMWF ENSEMBLE AND THE NAVGEM, WHICH TAKE THE SYSTEM MUCH FURTHER SOUTH, ULTIMATELY TRACKING THE VORTEX VERY NEAR PORT MARUTHIN AND SOUTH OF MAURITIUS AND LA REUNION. MEANWHILE THE REMAINDER OF THE CONSENSUS INCLUDING GFS, GEFS, GALWEM, EGRR AND UKMET ENSEMBLE PASS THE SYSTEM FURTHER NORTH, KEEPING THE VORTEX NORTH OF MAURITIUS AND LA REUNION. THE JTWC FORECAST LIES ON THE SOUTHERN EDGE OF THE NORTHERN GROUPING OF MODELS AFTER TAU 24, WITH MEDIUM CONFIDENCE. INTENSITY GUIDANCE IS IN GOOD AGREEMENT THAT THE SYSTEM WILL RAPIDLY WEAKEN, ESPECIALLY AFTER TAU 24. THE JTWC FORECAST REMAINS WELL ABOVE THE GUIDANCE THROUGH TAU 24, BUT THEN FOLLOWS THE HWRF TREND THROUGH THE REMAINDER OF THE FORECAST.