WTXS31 PGTW 100900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 26S (SEROJA) WARNING NR 024// RMKS/ 1. TROPICAL CYCLONE 26S (SEROJA) WARNING NR 024 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 100600Z --- NEAR 20.9S 108.2E MOVEMENT PAST SIX HOURS - 180 DEGREES AT 03 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT REPEAT POSIT: 20.9S 108.2E --- FORECASTS: 12 HRS, VALID AT: 101800Z --- 22.5S 109.5E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 140 DEG/ 18 KTS --- 24 HRS, VALID AT: 110600Z --- 25.4S 112.0E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 135 DEG/ 27 KTS --- 36 HRS, VALID AT: 111800Z --- 29.2S 116.3E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING EXTRATROPICAL RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 135 DEG/ 33 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 120600Z --- 33.6S 122.2E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 085 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT --- REMARKS: 100900Z POSITION NEAR 21.3S 108.5E. 10APR21. TROPICAL CYCLONE 26S (SEROJA), LOCATED APPROXIMATELY 340 NM WEST-NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTHWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS DEEP CONVECTIVE ACTIVITY WRAPPING INTO A WELL DEFINED LOW LEVEL CIRCULATION CENTER (LLCC). OVER THE PAST FEW HOURS, THE SYSTEM HAS SHOWN HINTS OF DEVELOPING A SMALL INFRARED EYE, THOUGH IT HAS YET TO FORM FOR LONGER THAN AN HOUR. A 100720Z GMI 37GHZ MICROWAVE IMAGE INDICATED A LARGE AND VERY SYMMETRICAL MICROWAVE EYE FEATURE, WHICH LENT HIGH CONFIDENCE TO AN UPDATED INITIAL POSITION. THE INITIAL INTENSITY IS ASSESSED AT 60 KNOTS WITH MODERATE CONFIDENCE BASED ON AN AVERAGE OF MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T4.0 (65 KTS) FROM BOTH PGTW AND APRF AND AN ADT ESTIMATE OF T3.1 (47 KTS). A 100530Z KNES FIX OBTAINED A T4.5 (77 KTS) ESTIMATE BASED ON THE TRANSIENT EYE AT THAT MOMENT IN TIME. THE SYSTEM LIES IN A FAVORABLE ENVIRONMENT CONSISTING OF LOW (10-15 KTS) VWS, ROBUST POLEWARD OUTFLOW AND WARM (28C) SSTS. THE CIMSS SHEAR ANALYSIS REVEALS 20 KNOTS OF SHEAR, HOWEVER BASED ON THE OVERALL STRUCTURE OF THE SYSTEM, WITH LITTLE TILT EVIDENT IN THE MICROWAVE IMAGERY, ARGUES FOR A LOWER SHEAR ESTIMATE. BASED ON THE UPDATED INITIAL POSITION, TC 26S APPEARS TO HAVE STARTED THE LONG AWAITED TURN TO THE SOUTH, HAVING ROUNDED THE RIDGE AXIS. THE SYSTEM SHOULD NOW BEGIN ACCELERATING SOUTHEASTWARD THROUGH THE REMAINDER OF THE FORECAST PERIOD. AS THE SYSTEM MOVES SOUTHEASTWARD, VWS IS EXPECTED TO REMAIN RELATIVELY LOW WHILE POLEWARD OUTFLOW REMAINS ROBUST, ALLOWING FOR A PERIOD OF INTENSIFICATION THROUGH TAU 24. THEREAFTER RAPIDLY INCREASING VWS, MOVEMENT OF LAND AND INTERACTION BAROCLINIC ZONE WILL CONSPIRE TO RAPIDLY WEAKEN TC 26S. THE SYSTEM IS EXPECTED TO BEGIN EXTRA- TROPICAL TRANSITION JUST AFTER LANDFALL, AS IT BEGINS TO INTERACT WITH THE BAROCLINIC ZONE. FULL TRANSITION TO A STRONG, NEAR STORM- FORCE EXTRA-TROPICAL SYSTEM IS EXPECTED NO LATER THAN TAU 48 ALONG THE SOUTHWEST COAST OF AUSTRALIA. DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH THE DURATION OF THE FORECAST, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 100600Z IS 30 FEET. NEXT WARNINGS AT 101500Z, 102100Z, 110300Z AND 110900Z. REFER TO TROPICAL CYCLONE 27S (ODETTE) WARNINGS (WTXS32 PGTW) FOR SIX-HOURLY UPDATES.// NNNN