WTPS32 PGTW 090900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 31P (VAIANU) WARNING NR 014// RMKS/ 1. TROPICAL CYCLONE 31P (VAIANU) WARNING NR 014 02 ACTIVE TROPICAL CYCLONES IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 090600Z --- NEAR 26.8S 179.0E MOVEMENT PAST SIX HOURS - 165 DEGREES AT 06 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING SUBTROPICAL RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 200 NM SOUTHEAST QUADRANT 170 NM SOUTHWEST QUADRANT 140 NM NORTHWEST QUADRANT REPEAT POSIT: 26.8S 179.0E --- FORECASTS: 12 HRS, VALID AT: 091800Z --- 28.0S 179.1E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 160 NM NORTHEAST QUADRANT 190 NM SOUTHEAST QUADRANT 160 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 190 DEG/ 07 KTS --- 24 HRS, VALID AT: 100600Z --- 29.3S 178.8E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 240 NM SOUTHEAST QUADRANT 240 NM SOUTHWEST QUADRANT 190 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 215 DEG/ 08 KTS --- 36 HRS, VALID AT: 101800Z --- 30.7S 177.7E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 190 NM NORTHEAST QUADRANT 250 NM SOUTHEAST QUADRANT 230 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT --- REMARKS: 090900Z POSITION NEAR 27.1S 179.0E. 09APR26. TROPICAL CYCLONE 31P (VAIANU), LOCATED APPROXIMATELY 523 NM SOUTH OF SUVA, FIJI, HAS TRACKED SOUTH-SOUTHEASTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED IMAGERY DEPICTS A PARTIALLY EXPOSED LLCC WITH A BURST OF CONVECTION OVER THE SOUTHERN SEMICIRCLE. THE SYSTEM EXHIBITS A HYBRID STRUCTURE CONSISTING OF SWIRLING MID-LEVEL CLOUDS AND LITTLE CENTRAL CONVECTION, LOCATED IN AN UNFAVORABLE ENVIRONMENT CHARACTERIZED BY 30 KTS OF VWS AND 25 DEGREE CELSIUS SST. ENVIRONMENTAL ANALYSIS REVEALS WEAK TEMPERATURE ADVECTION AND AN UPPER LEVEL TROUGH DIRECTLY ALOFT. THE POSITION AND INTENSITY ARE ASSESSED WITH HIGH CONFIDENCE BASED ON THE EXPOSED CENTER AND A 082330Z OSCAT-3 IMAGE DEPICTING 50 KT WINDS, RESPECTIVELY. THE SYSTEM WILL BE STEERED TOWARDS THE SOUTH BY A DEEP LAYER RIDGE TO THE EAST. TC 31P WILL TURN TOWARDS THE SOUTHWEST AS A RIDGE APPROACHES NEW ZEALAND FROM THE WEST AND INDUCES A MORE WESTWARD MOTION. WEAK BAROCLINIC FORCING WILL CAUSE THE SYSTEM TO COMPLETE SUBTROPICAL TRANSITION BY TAU 12 AND HELP TO SUSTAIN ITS INTENSITY THROUGH TAU 24, FOLLOWED BY GRADUAL WEAKENING. THE FORECAST TRACK AND INTENSITY ARE SET WITH HIGH CONFIDENCE BASED ON THE MULTI-MODEL CONSENSUS. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION. MINIMUM CENTRAL PRESSURE AT 090600Z IS 981 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 090600Z IS 27 FEET. REFER TO TROPICAL CYCLONE 30P (MAILA) WARNINGS (WTPS31 PGTW) FOR SIX-HOURLY UPDATES.// NNNN