WTXS32 PGTW 072100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 27S (TWENTYSEVEN) WARNING NR 012// RMKS/ 1. TROPICAL CYCLONE 27S (TWENTYSEVEN) WARNING NR 012 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 071800Z --- NEAR 16.2S 106.0E MOVEMENT PAST SIX HOURS - 025 DEGREES AT 02 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 RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 000 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT REPEAT POSIT: 16.2S 106.0E --- FORECASTS: 12 HRS, VALID AT: 080600Z --- 15.4S 106.2E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 000 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 055 DEG/ 07 KTS --- 24 HRS, VALID AT: 081800Z --- 14.6S 107.3E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 000 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 090 DEG/ 12 KTS --- 36 HRS, VALID AT: 090600Z --- 14.6S 109.7E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 000 NM NORTHEAST QUADRANT 000 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 000 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 130 DEG/ 14 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 091800Z --- 16.4S 112.0E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 000 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 175 DEG/ 20 KTS --- 72 HRS, VALID AT: 101800Z --- 24.3S 112.7E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 072100Z POSITION NEAR 16.0S 106.0E. 07APR21. TROPICAL CYCLONE (TC) 27S (TWENTYSEVEN), LOCATED APPROXIMATELY 587 NM NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED NORTH-NORTHEASTWARD AT 02 KTS OVER THE PAST SIX HOURS. ENHANCED INFRARED SATELLITE IMAGERY SHOWS THAT THE CYCLONE REMAINS SHEARED FROM THE NORTHEAST, WITH UPPER-LEVEL OUTFLOW FROM NEARBY TC 26S NOW ADVECTING DIRECTLY OVER THE LOW-LEVEL CIRCULATION. HOWEVER, CONVECTION REMAINS VIGOROUS IN THE SOUTHWEST QUADRANT, WHERE A 071416Z ASCAT-C PASS SHOWED A LARGE PATCH OF 40 KT SURFACE WINDS. THE INITIAL INTENSITY OF 40 KTS IS ALSO SUPPORTED BY A SATCON ESTIMATE OF 42 KTS. TC 26S AND TC 27S ARE NOW WITHIN 500 NM OF EACH OTHER, AND THIS DISTANCE IS EXPECTED TO CLOSE GRADUALLY DURING THE FORECAST PERIOD. VERTICAL SHEAR SHOULD INCREASE AS THIS OCCURS, WHICH WILL LIMIT INTENSIFICATION OF 27S. HOWEVER, DURING THE NEXT 24- 36 HOURS, A SLIGHT INCREASE IN INTENSITY IS EXPECTED BY DYNAMICAL MODEL GUIDANCE, AND A PEAK INTENSITY OF 50 KTS IS FORECAST AT 36 HOURS. THEREAFTER, INCREASING SHEAR AND FORWARD MOTION SHOULD LEAD TO AN UNRAVELING OF THE VORTEX AND ABSORPTION INTO THE LARGER CIRCULATION OF TC 26S. THE FORECAST TRACK REMAINS SIMILAR TO THE PRIOR FORECAST, EXCEPT FOR A NUDGE NORTHWESTWARD IN THE NEAR TERM. ADVECTION AROUND THE NORTHERN AND THEN EASTERN SIDE OF TC 26S WILL RESULT IN EASTWARD MOTION THROUGH 36 HOURS AND THEN ACCELERATING SOUTHWARD MOTION THROUGH 72 HOURS, TAKING THE CYCLONE WITHIN 65 NM OF LEARMONTH, AUSTRALIA. DISSIPATION IS FORECAST BY 72 HOURS, REFLECTING THE AFOREMENTIONED ABSORPTION INTO TC 26S. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 071800Z IS 18 FEET. NEXT WARNINGS AT 080300Z, 080900Z, 081500Z AND 082100Z. REFER TO TROPICAL CYCLONE 26S (SEROJA) WARNINGS (WTXS31 PGTW) FOR SIX-HOURLY UPDATES. // NNNN