WTPS31 PGTW 102100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 28P (TWENTYEIGHT) WARNING NR 001// RMKS/ 1. TROPICAL CYCLONE 28P (TWENTYEIGHT) 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: 101800Z --- NEAR 23.4S 167.2E MOVEMENT PAST SIX HOURS - 135 DEGREES AT 20 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE, RADAR AND SYNOPTIC DATA PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT REPEAT POSIT: 23.4S 167.2E --- FORECASTS: 12 HRS, VALID AT: 110600Z --- 26.0S 169.3E 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 - 080 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 140 DEG/ 16 KTS --- 24 HRS, VALID AT: 111800Z --- 28.4S 171.6E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 102100Z POSITION NEAR 24.1S 167.7E. 10APR21. TROPICAL CYCLONE (TC) 28P (TWENTYEIGHT), LOCATED APPROXIMATELY 99 NM SOUTHEAST OF NOUMEA, NEW CALEDONIA, HAS TRACKED SOUTHEASTWARD AT 20 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A CONSOLIDATING SYSTEM WITH WELL-ORGANIZED CORE CONVECTION AND CONVECTIVE BANDING. EARLIER RADAR IMAGERY FROM NEW CALEDONIA HAD SHOWN AN EYE FEATURE AND CURRENT RADAR IMAGERY STILL SHOWS TIGHTLY-CURVED BANDING WRAPPING INTO A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER. DESPITE THE SYSTEM'S HYBRID NATURE AND LOCATION WITHIN FAIRLY STRONG NORTHWESTERLY FLOW, AND PERSISTENT LOW TO MODERATE (15-20 KNOTS) VERTICAL WIND SHEAR (VWS), TC 28P WAS ABLE TO DEVELOP PERSISTENT CENTRAL CONVECTION AND SPIRAL BANDING OVER THE NORTHEAST, EAST AND SOUTHWEST QUADRANTS AS INDICATED ON A 101848Z SSMIS 91GHZ COLOR COMPOSITE IMAGE. SURFACE OBSERVATIONS FROM NOUMEA (91592) AT 10/1500Z ALONG THE NORTHERN FLANK OF THE SYSTEM WERE NNW AT 35 KNOTS WITH A MINIMUM SLP VALUE OF 999MB. ADDITIONAL SURFACE OBSERVATIONS FROM LA TONTOUTA (91590) FROM 10/1330-1400Z INDICATED GUSTS AS HIGH AS 48 KNOTS AND MINIMUM SLP NEAR 998MB. BASED ON THE IMPROVED SIGNATURE IN EIR, DVORAK INTENSITY ESTIMATES HAVE INCREASED TO T2.5-3.0 (35-45 KNOTS). THE INITIAL INTENSITY IS ASSESSED ON THE LOWER END OF DVORAK ESTIMATES AT 35 KNOTS, WHICH IS BETTER ALIGNED WITH SURFACE WIND AND SLP REPORTS. TC 28P IS EXPECTED TO BE A SHORT-LIVED SYSTEM AS IT TRACKS SOUTHEASTWARD WITHIN THE PERSISTENT NORTHWESTERLY FLOW ALONG THE SOUTHWESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE. VWS IS EXPECTED TO INCREASE TO 35 KNOTS BY TAU 24, WHICH WILL PRODUCE STEADY WEAKENING AND DISSIPATION NO LATER THAN TAU 24. NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT WITH A 100NM SPREAD IN SOLUTIONS AT TAU 24, THEREFORE, THERE IS MODERATE CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 101800Z IS 10 FEET. NEXT WARNINGS AT 110300Z, 110900Z AND 111500Z.// NNNN