WTPS32 PGTW 311500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 16P (SIXTEEN) WARNING NR 004// RMKS/ 1. TROPICAL CYCLONE 16P (SIXTEEN) WARNING NR 004 03 ACTIVE TROPICAL CYCLONES IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 311200Z --- NEAR 13.4S 175.1E MOVEMENT PAST SIX HOURS - 135 DEGREES AT 14 KTS POSITION ACCURATE TO WITHIN 045 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT REPEAT POSIT: 13.4S 175.1E --- FORECASTS: 12 HRS, VALID AT: 010000Z --- 15.6S 177.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 145 DEG/ 17 KTS --- 24 HRS, VALID AT: 011200Z --- 18.3S 179.6E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 155 DEG/ 15 KTS --- 36 HRS, VALID AT: 020000Z --- 21.0S 179.2W MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 095 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 170 DEG/ 14 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 021200Z --- 23.7S 178.6W MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 311500Z POSITION NEAR 14.0S 175.7E. 31JAN21. TROPICAL CYCLONE (TC) 16P (SIXTEEN), LOCATED APPROXIMATELY 340 NM NORTHWEST OF SUVA, FIJI, HAS TRACKED SOUTHEASTWARD AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 310924Z MHS 89GHZ IMAGE DEPICT WEAKENING DEEP CONVECTION FLARING OVER AND OBSCURING THE LOW-LEVEL CIRCULATION CENTER. HOWEVER, A 311018Z ASCAT-C IMAGE REVEALS A DEFINED CENTER, WHICH SUPPORTS THE INITIAL POSITION WITH FAIR CONFIDENCE, WITH 40-45 KNOT WINDS OVER THE NORTHEAST QUADRANT. THE INITIAL INTENSITY IS ASSESSED AT 45 KNOTS BASED ON A PGTW DVORAK INTENSITY ESTIMATE OF T3.0 (45 KNOTS) AND THE ASCAT-C DATA. ENVIRONMENTAL CONDITIONS ARE FORECAST TO REMAIN FAVORABLE THROUGH TAU 12, HOWEVER, CONDITIONS WILL DEGRADE RAPIDLY AFTER THIS TIME DUE TO STRONG VERTICAL WIND SHEAR AND INTERACTION WITH TC 15P. TC 16P IS EXPECTED TO UNDERGO BINARY INTERACTION WITH TC 15P, WHICH IS CURRENTLY LOCATED ABOUT 418NM SSE. TC 16P IS FORECAST TO TRACK SOUTHEASTWARD THROUGH TAU 12 UNDER THE STEERING INFLUENCE OF A NEAR EQUATORIAL RIDGE POSITIONED TO THE NORTHEAST. HOWEVER, AFTER TAU 12, TC 16P WILL ACCELERATE SOUTH-SOUTHEASTWARD WITHIN THE EASTERN PERIPHERY OF TC 15P. BY TAU 36, TC 16P WILL APPROACH TC 15P WITHIN ABOUT 150NM AS IT RAPIDLY WEAKENS. BY TAU 48, TC 16P WILL DISSIPATE AND BECOME ABSORBED INTO TC 15P. THE JTWC FORECAST REMAINS CONSISTENT WITH THE PREVIOUS FORECAST TRACK AND IS POSITIONED CLOSE TO THE MULTI-MODEL CONSENSUS. IN LIGHT OF THE HIGHLY UNCERTAIN NATURE OF THE BINARY INTERACTION, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 311200Z IS 18 FEET. NEXT WARNINGS AT 312100Z, 010300Z, 010900Z AND 011500Z. REFER TO TROPICAL CYCLONE 15P (ANA) WARNINGS (WTPS31 PGTW) FOR SIX-HOURLY UPDATES. REFER TO TROPICAL CYCLONE 17P (LUCAS) WARNINGS (WTPS33 PGTW) FOR SIX-HOURLY UPDATES.// NNNN