WTPS31 PGTW 030900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 23P (NIRAN) WARNING NR 010// RMKS/ 1. TROPICAL CYCLONE 23P (NIRAN) WARNING NR 010 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 030600Z --- NEAR 14.8S 147.9E MOVEMENT PAST SIX HOURS - 315 DEGREES AT 01 KTS POSITION ACCURATE TO WITHIN 025 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE, RADAR AND SYNOPTIC DATA PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT REPEAT POSIT: 14.8S 147.9E --- FORECASTS: 12 HRS, VALID AT: 031800Z --- 14.8S 148.4E MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 010 NM SOUTHEAST QUADRANT 010 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 190 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 170 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 115 DEG/ 08 KTS --- 24 HRS, VALID AT: 040600Z --- 15.5S 149.9E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 010 NM SOUTHEAST QUADRANT 010 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 200 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 210 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 115 DEG/ 15 KTS --- 36 HRS, VALID AT: 041800Z --- 16.8S 152.8E MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 010 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 220 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 200 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 120 DEG/ 19 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 050600Z --- 18.6S 156.2E MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 240 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 230 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 125 DEG/ 27 KTS --- 72 HRS, VALID AT: 060600Z --- 24.3S 166.3E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING SUBTROPICAL RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 010 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 280 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 180 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 125 DEG/ 31 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 070600Z --- 30.6S 178.4E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 190 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 150 NM NORTHWEST QUADRANT --- REMARKS: 030900Z POSITION NEAR 14.8S 148.0E. 03MAR21. TROPICAL CYCLONE 23P (NIRAN), LOCATED APPROXIMATELY 175 NM NORTHEAST OF CAIRNS, AUSTRALIA, HAS TRACKED NORTHWESTWARD AT 01 KNOT OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE SYSTEM HAS MAINTAINED OVERALL CONVECTIVE SIGNATURE AS THE COMPACT FEEDER BANDS WRAPPED TIGHTER INTO AN OBSCURED LOW LEVEL CIRCULATION THAT IS UNDER OVERSHOOTING CLOUD TOPS AND A DIMPLE FEATURE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A MICROWAVE EYE IN THE 030624Z SSMIS 37GHZ IMAGE AND CONFIRMS THE QUASI-STATIONARY MOTION OF THE CYCLONE. THE INITIAL INTENSITY OF 70KTS IS BASED ON AN OVERALL ASSESSMENT OF DVORAK INTENSITY ESTIMATES OF T4.5/77KTS (PGTW/KNES), T3.5/55KTS (ABRF), T4.0/65KTS (KNES), AND T3.8/61KTS (ADT) AND REFLECTS THE SLIGHTLY IMPROVED CONDITION OF THE SYSTEM. THE ENVIRONMENT IS OVERALL FAVORABLE WITH LOW (10-15KT) VERTICAL WIND SHEAR, VERY WARM (29-30C) SSTS, PARTLY OFFSET BY LIMITED OUTFLOW ALOFT. TC 23P IS QUASI-STATIONARY IN A COL BETWEEN THE NEAR EQUATORIAL RIDGE (NER), EXTENDING FROM THE NORTH TO SOUTHEAST OF THE SYSTEM, AND THE SUBTROPICAL RIDGE TO THE WEST OVER AUSTRALIA. THE NER IS EXPECTED TO BUILD AND BECOME THE DOMINANT STEERING MECHANISM AND SLOWLY NUDGE THE SYSTEM OUT OF THE COL, AND BY TAU 24, DRIVE IT SOUTHEASTWARD, PASSING JUST SOUTH OF NEW CALEDONIA AFTER TAU 60, AND BY TAU 96, SHOULD BE APPROXIMATELY 420NM NORTH-NORTHEAST OF AUCKLAND, NEW ZEALAND. THE MARGINALLY FAVORABLE ENVIRONMENT WILL PROMOTE A SLOW INTENSIFICATION TO A PEAK OF 90KTS BY TAU 48. AFTERWARD, INCREASING VWS AND COOLING SSTS WILL BEGIN TO ERODE THE CYCLONE DOWN TO 70KTS BY TAU 96. CONCURRENTLY, BY TAU 72, IT WILL BEGIN SUBTROPICAL TRANSITION AND BY TAU 96 WILL TRANSFORM INTO A SUBTROPICAL SYSTEM. NUMERICAL MODELS ARE IN GENERAL AGREEMENT WITH THE TRACK FORECAST WITH SIGNIFICANT VARIATIONS IN ALONG TRACK SPEED IN THE NEAR-TERM AS THE TC EXITS FROM THE COL AND ACROSS TRACK SPREAD TO OVER 820NM BY TAU 96, LENDING LOW CONFIDENCE IN THE JTWC TRACK FORECAST THAT IS LAID CLOSE TO THE MODEL CONSENSUS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 030600Z IS 26 FEET. NEXT WARNINGS AT 031500Z, 032100Z, 040300Z AND 040900Z.// NNNN