WTPS31 PGTW 282100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 04P (TUNI) WARNING NR 005// RMKS/ 1. TROPICAL CYCLONE 04P (TUNI) WARNING NR 005 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 281800Z --- NEAR 14.7S 172.8W MOVEMENT PAST SIX HOURS - 115 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 035 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT REPEAT POSIT: 14.7S 172.8W --- FORECASTS: 12 HRS, VALID AT: 290600Z --- 16.0S 171.5W MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 140 DEG/ 08 KTS --- 24 HRS, VALID AT: 291800Z --- 17.2S 170.4W MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 135 DEG/ 08 KTS --- 36 HRS, VALID AT: 300600Z --- 18.3S 169.2W MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 135 DEG/ 08 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 301800Z --- 19.4S 168.0W MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL --- REMARKS: 282100Z POSITION NEAR 15.0S 172.5W. TROPICAL CYCLONE (TC) 04P (TUNI), LOCATED APPROXIMATELY 124 NM WEST OF PAGO PAGO, AMERICAN SAMOA, HAS TRACKED EAST-SOUTHEASTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. TC 04P HAS STRUGGLED TO ORGANIZE DUE TO PERSISTENT VERTICAL WIND SHEAR. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS PERSISTENT DEEP CONVECTION WITH TWO SEPARATE, DISTINCT AREAS OF DEEP CONVECTION--ONE AREA OVER THE EAST QUADRANT OF THE LOW-LEVEL CIRCULATION CENTER (LLCC) AND ANOTHER AREA DISPLACED FURTHER EAST. A 281756Z SSMIS 91GHZ IMAGE SHOWS AN EXPOSED, ELONGATED LLCC POSITIONED ALONG THE WESTERN EDGE OF A LINEAR AREA OF DEEP CONVECTION. BASED ON THIS MICROWAVE IMAGE, THERE IS FAIR CONFIDENCE IN THE CURRENT POSITION. THE INITIAL INTENSITY REMAINS ASSESSED AT 40 KNOTS PRIMARILY BASED ON RECENT ASCAT IMAGERY SHOWING 40 KNOT WINDS NEAR THE CENTER. TC 04P IS FORECAST TO BEGIN TURNING SOUTHEASTWARD AS IT TRANSITIONS TO THE STEERING INFLUENCE OF THE SUBTROPICAL RIDGE WITHIN THE NEXT 12 HOURS. TC 04P IS EXPECTED TO INTENSIFY SLIGHTLY TO A PEAK OF 45 KNOTS BY TAU 12 UNDER MARGINALLY-FAVORABLE CONDITIONS. HOWEVER, AFTER TAU 24, VWS IS FORECAST TO INCREASE MARKEDLY WITH SST VALUES DROPPING BELOW 26 CELSIUS, WHICH WILL SERVE TO WEAKEN THE SYSTEM. ADDITIONALLY, THE SYSTEM WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT) BY TAU 24 AS IT INTERACTS WITH A WEAK BAROCLINIC ZONE. TC 04P WILL COMPLETE ETT BY TAU 48 AS IT GAINS FRONTAL CHARACTERISTICS AND IS EXPECTED TO REMAIN A GALE-FORCE LOW. WITH THE EXCEPTION OF NAVGEM AND GFDN, DYNAMIC GUIDANCE IS IN BETTER AGREEMENT. HOWEVER, DUE TO POSITIONAL UNCERTAINTY AND A LARGE SPREAD IN DYNAMIC MODEL SOLUTIONS, THERE IS LOW OVERALL CONFIDENCE IN THE JTWC FORECAST TRACK. THE JTWC FORECAST TRACK IS POSITIONED FASTER THAN THE MULTI-MODEL CONSENSUS TO OFFSET THE MUCH SLOWER, UNREALISTIC NAVGEM AND GFDN SOLUTIONS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 281800Z IS 13 FEET. NEXT WARNINGS AT 290300Z, 290900Z, 291500Z AND 292100Z.//