WTPS31 PGTW 280300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE WARNING// RMKS/ 1. TROPICAL CYCLONE 08P (EIGHT) WARNING NR 001 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 280000Z --- NEAR 16.1S 160.0E MOVEMENT PAST SIX HOURS - 145 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 060 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 - 120 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT REPEAT POSIT: 16.1S 160.0E --- FORECASTS: 12 HRS, VALID AT: 281200Z --- 17.4S 161.2E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 275 NM NORTHEAST QUADRANT 200 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 165 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 150 DEG/ 09 KTS --- 24 HRS, VALID AT: 290000Z --- 19.0S 162.1E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 315 NM NORTHEAST QUADRANT 250 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 155 DEG/ 11 KTS --- 36 HRS, VALID AT: 291200Z --- 21.0S 163.2E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 260 NM NORTHEAST QUADRANT 285 NM SOUTHEAST QUADRANT 145 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 175 DEG/ 11 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 300000Z --- 23.2S 163.5E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 255 NM NORTHEAST QUADRANT 305 NM SOUTHEAST QUADRANT 160 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 180 DEG/ 17 KTS --- 72 HRS, VALID AT: 310000Z --- 30.0S 163.7E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 285 NM NORTHEAST QUADRANT 330 NM SOUTHEAST QUADRANT 200 NM SOUTHWEST QUADRANT 165 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 165 DEG/ 22 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 010000Z --- 38.3S 167.0E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 050 KT WINDS - 205 NM NORTHEAST QUADRANT 165 NM SOUTHEAST QUADRANT 105 NM SOUTHWEST QUADRANT 135 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 415 NM NORTHEAST QUADRANT 405 NM SOUTHEAST QUADRANT 270 NM SOUTHWEST QUADRANT 265 NM NORTHWEST QUADRANT --- REMARKS: 280300Z POSITION NEAR 16.4S 160.3E. TROPICAL CYCLONE 08P (EIGHT), LOCATED APPROXIMATELY 486 NM WEST OF PORT VILA, VANUATU, HAS TRACKED SOUTHEASTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES DEEP FLARING CONVECTION ORIENTED NORTHWEST-SOUTHEAST ALONG AN ACTIVE MONSOON TROUGH IN THE SOUTH PACIFIC CONVERGENCE ZONE (SPCZ). A CONCENTRATION OF DEEP CONVECTION HAS BEEN WRAPPING INTO A LOW-LEVEL CIRCULATION CENTER (LLCC), WITH A 272311Z ASCAT PASS DEPICTING 35 TO 40 KNOT WINDS SURROUNDING THE LLCC. THE INITIAL POSITION IS PLACED WITH GOOD CONFIDENCE, AND THE INITIAL INTENSITY IS SET AT 35 KNOTS BASED PRIMARILY ON THE AFOREMENTIONED ASCAT PASS. THIS IS CORROBORATED BY THE DVORAK ESTIMATE OF T2.5 FROM PGTW. UPPER- LEVEL ANALYSIS INDICATES THE PRESENCE OF MODERATE NORTHWESTERLY VERTICAL WIND SHEAR (15-20 KNOTS) ORIENTED PARALLEL TO THE SPCZ, WHICH SHOULD LIMIT ANY RAPID DEVELOPMENT. HOWEVER, THE WIND FIELD IS EXPECTED TO EXPAND AS THE SYSTEM GRADUALLY MOVES POLEWARD AND TAPS INTO MID-LATITUDE DYNAMICS. TC 08P WILL CONTINUE TO MOVE TOWARD THE SOUTH-SOUTHEAST AROUND A SUBTROPICAL RIDGE CENTERED OVER THE EASTERN COAST OF AUSTRALIA. AFTER TAU 72, WITH INCREASE BAROCLINICITY AND STRONGER VERTICAL WIND SHEAR, TC 08P IS EXPECTED TO BEGIN EXTRA TROPICAL TRANSITION AND COMPLETELY LOSE ITS TROPICAL CHARACTERISTICS BY TAU 96 IN THE VICINITY OF NEW ZEALAND. GLOBAL MODELS ARE IN GOOD AGREEMENT, SO THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 280000Z IS 12 FEET. NEXT WARNINGS AT 280900Z, 281500Z, 282100Z AND 290300Z.//