WTXS32 PGTW 052100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 27S (TWENTYSEVEN) WARNING NR 004// RMKS/ 1. TROPICAL CYCLONE 27S (TWENTYSEVEN) WARNING NR 004 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 051800Z --- NEAR 16.2S 105.5E MOVEMENT PAST SIX HOURS - 135 DEGREES AT 04 KTS POSITION ACCURATE TO WITHIN 050 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 105 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT REPEAT POSIT: 16.2S 105.5E --- FORECASTS: 12 HRS, VALID AT: 060600Z --- 16.1S 105.8E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 075 DEG/ 02 KTS --- 24 HRS, VALID AT: 061800Z --- 16.0S 106.2E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 065 DEG/ 04 KTS --- 36 HRS, VALID AT: 070600Z --- 15.7S 106.9E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 015 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 055 DEG/ 04 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 071800Z --- 15.3S 107.5E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 000 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 010 NM SOUTHWEST QUADRANT 010 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 085 DEG/ 04 KTS --- 72 HRS, VALID AT: 081800Z --- 15.1S 109.1E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 125 DEG/ 08 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 091800Z --- 16.9S 111.6E MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 052100Z POSITION NEAR 16.2S 105.6E. 05APR21. TROPICAL CYCLONE (TC) 27S (TWENTYSEVEN), LOCATED APPROXIMATELY 609 NM NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTHEASTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY INDICATES AN ELONGATED AREA OF FLARING DEEP CONVECTION OBSCURING THE LOW- LEVEL CIRCULATION CENTER (LLCC). A 051808Z AMSR2 89GHZ COLOR COMPOSITE IMAGE REVEALS SHALLOW BANDING WRAPPING INTO AN EXPOSED LLCC POSITIONED ON THE NORTHEAST EDGE OF AN ISOLATED CONVECTIVE BURST, WHICH SUPPORTS THE INITIAL POSITION WITH FAIR CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 40 KNOTS BASED ON RECENT ASCAT DATA AND IS HEDGED ABOVE THE PGTW DVORAK ESTIMATE OF T2.5 (35 KNOTS). UPPER-LEVEL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH MODERATE NORTHEASTERLY VERTICAL WIND SHEAR OFFSET SLIGHTLY BY ENHANCED POLEWARD OUTFLOW. HOWEVER, ANIMATED WATER VAPOR IMAGERY INDICATES PULSES OF OUTFLOW FROM TC 26S IMPINGING ON THE NORTHWEST PERIPHERY OF THE SYSTEM. THE FORECAST PHILOSOPHY HAS BEEN REVISED SIGNIFICANTLY BASED ON THE LIKELY BINARY INTERACTION SCENARIO WITH THE LARGER, MORE DOMINANT TC 26S. TC 27S IS FORECAST TO DRIFT SLOWLY EAST-NORTHEASTWARD UNDER THE LOW-LEVEL NEAR-EQUATORIAL RIDGE TO THE NORTH THROUGH TAU 36. BY TAU 48, TC 27S IS EXPECTED TO APPROACH WITHIN 450NM OF TC 26S, WHICH WILL BECOME THE DOMINANT STEERING INFLUENCE THROUGH THE REMAINDER OF THE FORECAST PERIOD. SPECIFICALLY, TC WILL TURN NORTHEASTWARD THEN EASTWARD TO SOUTHEASTWARD AS IT ACCELERATES AROUND THE NORTHERN PERIPHERY OF TC 26S. THE SYSTEM WILL PEAK OPTIMISTICALLY AT 55 KNOTS BY TAU 48 BUT WILL RAPIDLY DISSIPATE AFTER TAU 48 AS IT BECOMES ABSORBED IN THE OUTER PERIPHERY OF TC 26S. NUMERICAL MODEL GUIDANCE IS IN POOR AGREEMENT DUE TO THE COMPLEX SCENARIO / BINARY INTERACTION. THE JTWC FORECAST TRACK IS GENERALLY ALIGNED WITH EGRI, AFUI, AVNI AND UEMI WITH LOW CONFIDENCE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 051800Z IS 14 FEET. NEXT WARNINGS AT 060300Z, 060900Z, 061500Z AND 062100Z. REFER TO TROPICAL CYCLONE 26S (SEROJA) WARNINGS (WTXS31 PGTW) FOR SIX-HOURLY UPDATES.// BT #0001 NNNN