Typhoon 24W(YINSING) 2nd intensity peak//25W(MAN-YI)//26W(TORAJI) approaching the PHILIPPINES///INVEST 94W//18L(RAFAEL)//0909utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON 24W, 25W AND 26W.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: AS INDICATED IN ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI), TYPHOON (TY) 24W HAS RESTRENGTHENED OVER THE PAST SIX HOURS, WITH A 15NM OBLONG EYE AND AN EYE TEMPERATURE OF PLUS 11.8C (BRIEFLY). CONSEQUENTLY, SUBJECTIVE DVORAK INTENSITY ESTIMATES INCREASED AND NOW RANGE FROM T5.5 TO T6.0 (102-115 KNOTS). A 090534Z AMSR2 89GHZ COLOR COMPOSITE MICROWAVE IMAGE SHOWS A COMPACT SYSTEM WITH A SYMMETRIC EYEWALL SURROUNDING A ROUND MICROWAVE EYE FEATURE, AND SPIRAL BANDING LOCATED PRIMARILY OVER THE EASTERN SEMICIRCLE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE MSI AND MICROWAVE IMAGERY. THE INITIAL INTENSITY OF 110 KNOTS IS ASSESSED WITH MEDIUM CONFIDENCE, WITH OBJECTIVE AND SUBJECTIVE ESTIMATES RANGING FROM 103 TO 117 KNOTS.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TY 24W IS EXPECTED TO TRACK WESTWARD THROUGH TAU 12 THEN TURN SHARPLY WEST-SOUTHWESTWARD TO SOUTHWESTWARD AS IT TRACKS ALONG A NARROW EXTENSION OF THE STR. A MAJOR SHORTWAVE TROUGH PROPAGATING OVER SOUTHEAST CHINA WILL WEAKEN THIS STR EXTENSION BRIEFLY BEFORE FILLING AND TRANSITING INTO THE EAST CHINA SEA BY TAU 24. THIS WILL LIKELY SLOW THE SPEED OF ADVANCE BY TAU 12. AFTER TAU 24, THE STR EXTENSION WILL REBUILD TO THE NORTHWEST DRIVING THE SYSTEM SOUTHWESTWARD OVER VIETNAM. TY 24W IS EXPECTED TO ENCOUNTER SIGNIFICANT DRY AIR ENTRAINMENT AND SLIGHTLY COOLER SST (26C), WHICH WILL SERVE TO RAPIDLY WEAKEN THE SYSTEM THROUGH TAU 72. ADDITIONALLY, INCREASING VERTICAL WIND SHEAR (20-25 KNOTS) AND INTERACTION WITH LAND WILL AID IN WEAKENING THE SYSTEM AFTER TAU 48.

MODEL DISCUSSION: BOTH THE 081800Z EPS AND THE 090000Z GEFS ENSEMBLES SUPPORT THE JTWC TRACK AND INTENSITY FORECAST WITH MEDIUM CONFIDENCE THROUGH THE FORECAST PERIOD. THE 090000Z COAMPS-TC ENSEMBLE (GFS VERSION) ALSO SUPPORTS THE JTWC TRACK FORECAST AND SHOWS A TROPICAL DEPRESSION STRENGTH SYSTEM AFTER TAU 60. RELIABLE INTENSITY GUIDANCE INDICATES RAPID WEAKENING AFTER TAU 12, WITH DISSIPATION FORECAST NEAR TAU 72.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL STORM 25W (MAN-YI) AND ITS CONSOLIDATING CENTRAL CONVECTION, OBSCURING THE LOW-LEVEL CIRCULATION CENTER (LLCC). SYSTEM IS STILL UTILIZING THE MODERATE TO STRONG POLEWARD OUTFLOW, ENHANCED BY A BAND OF SOUTHWESTERLY FLOW STRETCHING NORTHWEST OF TS 25W. THE DIVERGENCE ALOFT IS STRONGER OVER THE NORTHEASTERN QUADRANT OF THE SYSTEM, THEREFORE EQUATORWARD OUTFLOW IS PRESENT, BUT WEAK. A 090528Z F18 SSMIS MICROWAVE PASS SHOWS THE MAJORITY OF THE CONVECTIVE ACTIVITY PRESENT TO THE EAST AND SOUTHEAST OF THE LLCC. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE AFOREMENTIONED SSMIS PASS, AS WELL AS ANIMATED EIR IMAGERY. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON OBJECTIVE ESTIMATES LISTED BELOW AND PERSISTENCE.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TS 25W WILL TRACK NORTHWESTWARD THROUGH TAU 36 STEERED PRIMARILY BY THE SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. AS THE SYSTEM CONTINUES TO INTENSIFY, REACHING PEAK INTENSITY OF 50 KTS NEAR TAU 36, ANOTHER STR WILL BECOME THE DOMINANT UPPER-LEVEL FEATURE, LEADING TS 25W ON A MORE WESTWARD TRACK. AS THE SYSTEM TRANSITS WEST, IT WILL BE EXPOSED TO INCREASINGLY STRONG VERTICAL WIND SHEAR, REACHING 25-30 KTS BY TAU 48. ADDITIONALLY, IT WILL INTERACT WITH A POCKET OF DRY AIR, FURTHER HINDERING ITS DEVELOPMENT AT THAT STAGE, LEADING TO STEADY WEAKENING THROUGHOUT THE REST OF FORECAST PERIOD. AT TAU 72 THE SYSTEM STEERING PATTERN WILL DIRECT IT ON A WEST-SOUTHWESTWARD TRACK, AS IT PASSES NORTH OF THE NORTHERN MARIANA ISLANDS.

MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT, WITH A CROSS-TRACK SPREAD OF 80 NM BY TAU 36 AND 200 NM BY TAU 72, WITH ALL THE CONSENSUS MEMBERS FORECASTING A GENERALLY NORTHWESTWARD TRACK THROUGH TAU 36, FOLLOWED BY A GRADUAL TURN WESTWARD AND THEN TO THE SOUTHWEST. THE CROSS-TRACK SPREAD INCREASES TO NEARLY 300 NM BY THE TIME TS 25W PASSES THE NORTHERN MARIANAS, WITH MODERATE UNCERTAINTY TO THE TRACK PROXIMITY TO ROTA AND GUAM. THE JTWC TRACK FORECAST IS LAID ON THE SOUTHERN SIDE, BUT IN CLOSE PROXIMITY TO THE MULTI-MODEL CONSENSUS. INTENSITY MODEL GUIDANCE IS ALSO IN FAIR AGREEMENT WITH ALL MODELS REFLECTING THE STEADY INTENSIFICATION THROUGH THE INITIAL 24 HOURS, FOLLOWED BY WEAKENING TOWARDS THE END OF THE FORECAST PERIOD. INTENSITY GUIDANCE UNCERTAINTY INCREASES SIGNIFICANTLY AFTER TAU 72, WITH POTENTIAL FOR RE-INTENSIFICATION AROUND TAU 120, AS INDICATED BY HAFS, AS WELL AS THE MULTI-MODEL CONSENSUS.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A RAPIDLY CONSOLIDATING SYSTEM, WITH A SYMMETRIC CENTRAL DENSE OVERCAST OBSCURING THE LOW-LEVEL CIRCULATION CENTER (LLCC). A 090709Z SSMIS 91GHZ COLOR COMPOSITE MICROWAVE IMAGE SUPPORTS THE INITIAL POSITION WITH MEDIUM CONFIDENCE AND SHOWS A COMPACT SYSTEM WITH CONVECTIVE BANDING WRAPPING TIGHTLY INTO A DEFINED LLCC, WHICH IS POSITIONED DIRECTLY UNDER THE CORE CONVECTION. ENVIRONMENTAL CONDITIONS ARE HIGHLY FAVORABLE WITH RADIAL OUTFLOW AND LOW VERTICAL WIND SHEAR. THE INITIAL INTENSITY OF 30 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE HIGH END OF THE AGENCY DVORAK ESTIMATES, CONSISTENT WITH THE IMPRESSIVE CONVECTIVE APPEARANCE.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY. FORECAST DISCUSSION: TROPICAL DEPRESSION (TD) 26W IS FORECAST TO TRACK WESTWARD TO WEST-NORTHWESTWARD THROUGH TAU 48, WITH LANDFALL ANTICIPATED NEAR TAU 48. DUE TO THE FAVORABLE ENVIRONMENT AND RAPIDLY IMPROVING CONVECTIVE ORGANIZATION, THE SYSTEM WILL LIKELY REACH TROPICAL STORM STRENGTH QUICKLY AND CONTINUE TO INTENSIFY AT A FASTER-THAN-CLIMATOLOGICAL RATE, REACHING A PEAK OF 60 KNOTS BY TAU 36. HOWEVER, THERE IS MODERATE POTENTIAL FOR RAPID INTENSIFICATION (RI), WHICH COULD ALLOW THE SYSTEM TO REACH MINIMAL TYPHOON STRENGTH PRIOR TO LANDFALL. UNFORTUNATELY, RI GUIDANCE IS VERY LIMITED AT THIS TIME. AFTER CROSSING LUZON AND WEAKENING, THE SYSTEM SHOULD TRACK WEST-NORTHWESTWARD TO NORTHWESTWARD ALONG THE SOUTHWEST PERIPHERY OF THE STR, WITH STEADY WEAKENING DUE TO INCREASING VWS AND DRY AIR ENTRAINMENT.

MODEL DISCUSSION: THE 090000Z ECMWF ENSEMBLE (EPS) INDICATES A FAIRLY TIGHT CLUSTER OF SOLUTIONS THROUGH TAU 48, WITH LANDFALL LIKELY OVER THE CENTRAL TO NORTHEAST COAST OF LUZON. AFTER TAU 48, THE ECMWF ENSEMBLE DIVERGES WITH INCREASING UNCERTAINTY AFTER TAU 72. THE 090000Z GFS ENSEMBLE (GEFS) SHOWS A SIMILAR PLUME OF SOLUTIONS. THE PRIMARY SOURCE OF THE LARGE SPREAD AND INCREASING UNCERTAINTY AFTER TAU 72 IS DUE TO UNCERTAINTY IN THE SYSTEM'S INTENSITY AND UNCERTAINTY IN THE DEGREE OF WEAKENING OF THE STR OVER SOUTHEAST CHINA. IF THE SYSTEM IS STRONGER THAN EXPECTED, IT MAY TRACK MORE NORTHWESTWARD TOWARD THE HONG KONG REGION AND IF IT WEAKENS SIGNIFICANTLY, IT MAY STALL AND TURN EQUATORWARD UNDER THE LOW-LEVEL STEERING FLOW.

THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED NEAR 6.0N 151.6E IS NOW LOCATED NEAR 6.5N 149.5E, APPROXIMATELY 153 NM WEST-SOUTHWEST OF CHUUK. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A VERY BROAD AREA OF FLARING, DISORGANIZED DEEP CONVECTION. A PARTIAL 082354Z ASCAT METOP-B PASS SHOWS A BROAD CIRCULATION WITH WIND SPEEDS OF 15-20 KNOTS ON THE WEST SIDE OF THE SEMI-CIRCLE. ENVIRONMENTAL ANALYSIS REVEALS A FAVORABLE ENVIRONMENT FOR FURTHER DEVELOPMENT WITH LOW VERTICAL WIND SHEAR OF 5-10 KTS, GOOD UPPER-LEVEL POLEWARD AND EQUATORWARD OUTFLOW, AND WARM SEA SURFACE TEMPERATURES OF 29-30C. SURFACE OBSERVATIONS FROM CHUUK (PTKK) INDICATE EASTERLY TO EAST-SOUTHEASTERLY SUSTAINED WINDS OF 5- 10 KNOTS AND SLP NEAR 1008.9MB. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 94W WILL SLOWLY CONSOLIDATE AS IT TRACKS WEST-NORTHWESTWARD OVER THE NEXT 24-48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 13 TO 18 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1008 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.