WTXS32 PGTW 042100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 27S (TWENTYSEVEN) WARNING NR 001// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/040752ZAPR2021// AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.// RMKS/ 1. TROPICAL CYCLONE 27S (TWENTYSEVEN) WARNING NR 001 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 041800Z --- NEAR 14.9S 104.8E MOVEMENT PAST SIX HOURS - 190 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 025 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT REPEAT POSIT: 14.9S 104.8E --- FORECASTS: 12 HRS, VALID AT: 050600Z --- 15.3S 104.8E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 145 DEG/ 02 KTS --- 24 HRS, VALID AT: 051800Z --- 15.6S 105.0E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 020 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 100 DEG/ 03 KTS --- 36 HRS, VALID AT: 060600Z --- 15.7S 105.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 090 DEG/ 02 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 061800Z --- 15.7S 106.1E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 000 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 065 DEG/ 02 KTS --- 72 HRS, VALID AT: 071800Z --- 15.3S 107.0E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 105 DEG/ 04 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 081800Z --- 15.8S 108.7E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 165 DEG/ 06 KTS --- 120 HRS, VALID AT: 091800Z --- 18.0S 109.4E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT --- REMARKS: 042100Z POSITION NEAR 15.0S 104.8E. 04APR21. TROPICAL CYCLONE 27S (TWENTYSEVEN), LOCATED APPROXIMATELY 690 NM NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTHWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS A DISORGANIZED SYSTEM WITH TWO AREAS OF DEEP FLARING CONVECTION. THE LOW LEVEL CIRCULATION (LLC) IS OBSCURED BY THE SMALLER AREA WITH THE BIGGER AREA TO THE EAST EMBEDDED IN A LARGE FORMATIVE BAND LOOSELY WRAPPING TOWARD THE LLC. ANOTHER BAND, ALBEIT MUCH SHALLOWER AND MORE FRAGMENTED, IS FEEDING IN FROM THE SOUTH. THE INITIAL POSITION AND INTENSITY ARE EXTRAPOLATED WITH GOOD CONFIDENCE FROM A DEFINED LLC IN THE 041425Z ASCAT PASS SHOWING A SWATH OF 35-KT WIND BARBS 40NM TO THE SOUTH IN THE SOUTHERN QUADRANT. ANALYSIS INDICATES A MARGINALLY FAVORABLE ENVIRONMENT WITH MODERATE (15-20KT) VERTICAL WIND SHEAR, ROBUST POLEWARD OUTFLOW ALOFT, AND WARM (29C) SEA SURFACE TEMPERATURE. THESE ARE OFFSET BY COLD DRY AIR INTRUSION FROM THE SOUTHWEST, AS INDICATED IN A RECENT TOTAL PRECIPITABLE WATER LOOP. THE CYCLONE IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF A LOW REFLECTION OF THE NEAR EQUATORIAL RIDGE (NER) TO THE NORTHEAST. AFTER TAU 24, TC 27S WILL TRACK MORE EASTWARD AS THE NER WEAKENS AND RECEDES WESTWARD. AFTER TAU 48, THE SYSTEM WILL TURN MORE POLEWARD AS A NEAR EQUATORIAL RIDGE TO THE SOUTHEAST ASSUMES STEERING. CONCURRENTLY, A BINARY INTERACTION WITH TC 26S WILL COMMENCE. THE MARGINALLY FAVORABLE ENVIRONMENT WILL FUEL A SLOW INTENSIFICATION TO A PEAK OF 65KTS. AFTERWARD, THE CYCLONE WILL RAPIDLY WEAKEN TO 50KTS BY TAU 120 AS OUTFLOW FROM TC 26S, BEING THE LARGER AND MORE DOMINANT CYCLONE, WILL BEGIN TO SUPPRESS TC 27S. THERE IS A LARGE DISCREPANCY AMONG THE NUMERICAL MODELS DUE TO THE LARGE VARIANCE IN THE PROJECTED TRACKS CAUSED BY DIFFERENT SOLUTIONS TO THE BINARY INTERACTION WITH TC 26S, LENDING LOW CONFIDENCE TO THE JTWC TRACK FORECAST THAT IS LAID CLOSE TO THE MODEL CONSENSUS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 041800Z IS 12 FEET. NEXT WARNINGS AT 050900Z AND 052100Z. REFER TO TROPICAL CYCLONE 26S (TWENTYSIX) WARNINGS (WTXS31 PGTW) FOR SIX- HOURLY UPDATES. 2. THIS CANCELS AND SUPERSEDES REF A (WTXS22 PGTW 040800).// NNNN