WTXS32 PGTW 061500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 27S (TWENTYSEVEN) WARNING NR 007// RMKS/ 1. TROPICAL CYCLONE 27S (TWENTYSEVEN) WARNING NR 007 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 061200Z --- NEAR 16.2S 106.0E MOVEMENT PAST SIX HOURS - 090 DEGREES AT 02 KTS POSITION ACCURATE TO WITHIN 040 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 - 085 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT REPEAT POSIT: 16.2S 106.0E --- FORECASTS: 12 HRS, VALID AT: 070000Z --- 16.1S 106.1E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 360 DEG/ 01 KTS --- 24 HRS, VALID AT: 071200Z --- 16.0S 106.1E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 010 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 010 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 360 DEG/ 03 KTS --- 36 HRS, VALID AT: 080000Z --- 15.5S 106.1E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 010 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 020 DEG/ 03 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 081200Z --- 15.0S 106.3E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT 105 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 100 DEG/ 06 KTS --- 72 HRS, VALID AT: 091200Z --- 15.4S 108.7E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 015 NM SOUTHEAST QUADRANT 015 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 135 DEG/ 10 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 101200Z --- 18.3S 111.6E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 175 DEG/ 12 KTS --- 120 HRS, VALID AT: 111200Z --- 23.2S 111.9E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 061500Z POSITION NEAR 16.2S 106.0E. 06APR21. TROPICAL CYCLONE 27S (TWENTYSEVEN), LOCATED APPROXIMATELY 587 NM NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED EASTWARD AT 02 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A DISORGANIZED AND OVERALL WEAKENED SYSTEM, WITH FLARING DEEP CONVECTION SHEARED SOUTHWEST OF THE ASSESSED LOW LEVEL CIRCULATION CENTER (LLCC). A 061154Z SSMIS 91GHZ COMPOSITE MICROWAVE IMAGE CONFIRMED THE LIMITED EXTENT OF THE DEEP CONVECTION, WHICH IS CONFINED TO THE SOUTHWEST QUADRANT, AND SHOWED THE LOW LEVEL BANDING FEATURES TO GOOD EFFECT. HOWEVER THE LLCC IS RATHER ILL DEFINED AND PROVIDED ONLY MODERATE CONFIDENCE TO THE INITIAL POSITION. BASED ON THE OVERALL DECREASE IN CONVECTION AND THE SHEARED STRUCTURE OF THE SYSTEM, DVORAK INTENSITY ESTIMATES HAVE STARTED TO COME DOWN TO THE T2.5 (35 KTS) RANGE FROM BOTH PGTW AND APRF, WHICH COMBINED WITH A T2.7 ADT ESTIMATE, LEND HIGH CONFIDENCE TO THE INITIAL INTENSITY. THE SYSTEM LIES IN A MARGINAL ENVIRONMENT WITH MODERATE (15-20 KTS) NORTHEASTERLY VWS BEING OFFSET BY WARM (29C) SSTS AND ROBUST POLEWARD OUTFLOW AND SOME DRY AIR IN THE MID-LEVELS. THE OVERALL STEERING PATTERN REMAINS WEAK, BUT TC 27S IS EXPECTED TO VERY SLOWLY DRIFT NORTHWARD OVER THE NEXT 48 HOURS ALONG THE EASTERN PERIPHERY OF A WEAK NEAR EQUATORIAL RIDGE (NER). AFTER TAU 48, THE SYSTEM WILL START TO ACCELERATE EAST, THEN SOUTHEAST AND ULTIMATELY SOUTHWARD AS THE BINARY INTERACTION WITH TC 26S BECOMES THE DOMINANT STEERING INFLUENCE. TC 27S WILL RAPIDLY TRANSIT ACROSS THE NORTHERN AND NORTHEASTERN PERIPHERY OF TC 26S AND ULTIMATELY DISSIPATE OR MERGE WITH TC 26S BY TAU 120. IN THE UPPER LEVELS, THE GENERAL EAST- NORTHEAST FLOW AND OUTFLOW FROM TC 26S ARE COMBINING TO IMPINGE ON THE EASTERN SIDE OF THE SYSTEM, AND LIMIT DEVELOPMENT. THIS GENERAL PATTERN IS EXPECTED TO CONTINUE THROUGH TAU 48, BUT ONCE THE SYSTEM BEGINS TO MOVE INTO THE NORTHERN PERIPHERY OF TC 26S, IT DEVELOPS A SHORT-LIVED POINT SOURCE ALOFT, ALLOWING FOR A BURST OF INTENSIFICATION, REACHING A PEAK OF 50 KTS BY TAU 72. AFTER MOVING TO THE EAST OF TC 26S BY TAU 96, THE OUTFLOW ENVIRONMENT BECOMES CONVERGENT, ALLOWING FOR RAPID WEAKENING AND DISSIPATION BY TAU 120. DYNAMIC MODEL GUIDANCE IS IN VERY POOR AGREEMENT, WITH SEVERAL CONSENSUS MEMBERS DEPICTING A SCENARIO IN WHICH TC 27S DOES NOT INTERACT WITH TC 26S AND INSTEAD TRACKS NORTHWESTWARD. THE JTWC FORECAST REMAINS CONSISTENT WITH THE PREVIOUS FORECAST WITH LOW CONFIDENCE IN LIGHT OF THE COMPLEXITIES OF THE BINARY INTERACTION FORECAST AND VERY HIGH UNCERTAINTY DEPICTED IN THE MDOEL GUIDANCE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 061200Z IS 16 FEET. NEXT WARNINGS AT 062100Z, 070300Z, 070900Z AND 071500Z. REFER TO TROPICAL CYCLONE 26S (SEROJA) WARNINGS (WTXS31 PGTW) FOR SIX-HOURLY UPDATES.// NNNN