WTPS31 PGTW 110900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 28P (TWENTYEIGHT) WARNING NR 003// RMKS/ 1. TROPICAL CYCLONE 28P (TWENTYEIGHT) WARNING NR 003 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 110600Z --- NEAR 26.1S 169.2E MOVEMENT PAST SIX HOURS - 140 DEGREES AT 19 KTS POSITION ACCURATE TO WITHIN 040 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 BECOMING EXTRATROPICAL RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT REPEAT POSIT: 26.1S 169.2E --- FORECASTS: 12 HRS, VALID AT: 111800Z --- 28.3S 171.4E 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 - 060 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 135 DEG/ 14 KTS --- 24 HRS, VALID AT: 120600Z --- 30.3S 173.6E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 110900Z POSITION NEAR 26.6S 169.7E. 11APR21. TROPICAL CYCLONE 28P (TWENTYEIGHT), LOCATED APPROXIMATELY 294 NM SOUTHEAST OF NOUMEA, NEW CALEDONIA, HAS TRACKED SOUTHEASTWARD AT 19 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES THAT TC 28P HAS MAINTAINED A COMPACT AND SYMMETRIC CONVECTIVE SIGNATURE WITH MODERATE CONVECTIVE BANDS WRAPPING INTO THE LOW LEVEL CIRCULATION CENTER (LLCC). A 100520Z SSMIS 89GHZ MICROWAVE IMAGE REVEALED THAT WHILE THE MSI INDICATED A SYMMETRIC CORE, IT IS VERY ASYMMETRIC, WITH CURVED CONVECTIVE BANDING LIMITED TO THE SOUTHWESTERN SECTORS OF THE CIRCULATION, WITH ONLY SHALLOW BANDS TO THE NORTHEAST. HOWEVER, THE MICROWAVE DATA ALSO REVEALED A WEAK BUT WELL DEFINED EYE-LIKE FEATURE WHICH LENT HIGH CONFIDENCE TO THE INITIAL POSITION. THE INITIAL INTENSITY IS HELD AT 40 KNOTS WITH FAIR CONFIDENCE, HEDGED SLIGHTLY HIGHER THAN THE PGTW DVORAK INTENSITY ESTIMATE OF T2.0 (30 KTS) BASED ON A PREVIOUS ASCAT PASS WHICH REVEALED SOME 40 KNOT WINDS IN THE EASTERN SEMICIRCLE, AND AN ADT ESTIMATE OF T2.8 (41 KTS). TC 28P IS EXPECTED TO CONTINUE ACCELERATING SOUTHEASTWARD THROUGH THE DURATION OF THE FORECAST ALONG THE WESTERN PERIPHERY OF A DEEP-LAYER STR. THE SYSTEM IS IN AN AREA OF MODERATE TO HIGH (20-25 KTS) NORTHWESTERLY SHEAR AND MOVING OVER WATERS COOLER THAN 26C, THOUGH POLEWARD OUTFLOW REMAINS STRONG ENOUGH TO LIMIT WEAKENING FOR THE PRESENT. OVER THE NEXT FEW HOURS HOWEVER, SHEAR IS FORECAST TO DRAMATICALLY INCREASE TO ABOVE 35 KTS, WHICH COMBINED WITH THE MOVEMENT OVER PROGRESSIVELY COOLER WATERS, WILL RAPIDLY WEAKEN AND ULTIMATELY DISSIPATE TC 28P NO LATER THAN TAU 24. NUMERICAL MODEL GUIDANCE IS IN GOOD OVERALL AGREEMENT, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 110600Z IS 18 FEET. NEXT WARNINGS AT 111500Z, 112100Z AND 120300Z.// NNNN