WTXS31 PGTW 090300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 26S (SEROJA) WARNING NR 019// RMKS/ 1. TROPICAL CYCLONE 26S (SEROJA) WARNING NR 019 02 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 090000Z --- NEAR 19.0S 110.1E MOVEMENT PAST SIX HOURS - 235 DEGREES AT 10 KTS POSITION ACCURATE TO WITHIN 020 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT REPEAT POSIT: 19.0S 110.1E --- FORECASTS: 12 HRS, VALID AT: 091200Z --- 19.7S 109.1E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 210 DEG/ 04 KTS --- 24 HRS, VALID AT: 100000Z --- 20.4S 108.7E 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 015 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 170 DEG/ 07 KTS --- 36 HRS, VALID AT: 101200Z --- 21.7S 109.0E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 015 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 155 DEG/ 12 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 110000Z --- 23.8S 110.1E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 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 015 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 140 DEG/ 25 KTS --- 72 HRS, VALID AT: 120000Z --- 31.1S 117.7E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 96 HR POSIT: 125 DEG/ 31 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 130000Z --- 38.0S 130.5E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY EXTRATROPICAL RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT --- REMARKS: 090300Z POSITION NEAR 19.2S 109.8E. 09APR21. TROPICAL CYCLONE (TC) 26S (SEROJA), LOCATED APPROXIMATELY 299 NM NORTHWEST OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTHWESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. MULTISPECTRAL SATELLITE IMAGERY SHOWS A GRADUALLY ORGANIZING CYCLONE, WITH DEEP CONVECTIVE COVERAGE INCREASING DURING THE LAST 6 HOURS. A 082240Z SSMIS MICROWAVE IMAGE SHOWED TWO PRIMARY BANDS IN THE NORTHERN AND SOUTHERN SEMICIRCLES WRAPPING INTO THE LOW LEVEL CENTER (LLC). FULL AZIMUTHAL COVERAGE OF DEEP CONVECTION AROUND THE LLC HAS NOT YET COMPLETED, INDICATING THAT THE PERIOD OF QUICKEST INTENSIFICATION HAS LIKELY NOT BEGUN YET. THE CURRENT INTENSITY IS HELD AT 45 KTS BASED ON A PGTW DVORAK ESTIMATE OF T3.0 AND A SATCON ESTIMATE OF 44 KTS. THE LARGE-SCALE ENVIRONMENT REMAINS FAVORABLE, WITH LOW SHEAR AND EXPANSIVE UPPER- LEVEL OUTFLOW. SEROJA AND TC 27S (ODETTE) ARE NOW CLOSELY INTERTWINED, SEPARATED BY ONLY 320 NM. ODETTE IS THE SMALLER CYCLONE, AND IS NOT EXPECTED TO PREVENT SEROJA FROM INTENSIFYING, BUT ITS PRESENCE MAY CAUSE SOME DISRUPTION. ARC CLOUDS EMANATING FROM THE EASTERN SIDE OF ODETTE ARE SEEN JUST TO THE NORTH OF SEROJA, INDICATING A DRIER, COOLER AIR MASS MODIFIED BY DOWNDRAFTS THAT MAY FOLLOW THE LOW-LEVEL FLOW INTO SEROJA'S CIRCULATION AND PERIODICALLY INTERRUPT CONVECTION. HOWEVER, A PERIOD OF SWIFT INTENSIFICATION REMAINS EXPECTED BETWEEN 12 AND 36 HOURS ONCE SEROJA COMPLETES FORMATION OF AN INNER CORE. A LEVELING OFF OF INTENSITY PRIOR TO LANDFALL IN WESTERN AUSTRALIA IS EXPECTED DUE TO INCREASING VERTICAL SHEAR TO 20-25 KTS AS THE CYCLONE APPROACHES THE JET STREAM, AS WELL AS POSSIBLE ENTRAINMENT OF A MID-LATITUDE DRY AIR MASS. THE FORECAST SHOWS PEAK INTENSITY OF 85 KTS AT 48 HOURS, THOUGH SINCE LANDFALL OCCURS BETWEEN THE 48 AND 72 HOUR FORECAST POINTS, THE PEAK INTENSITY PRIOR TO LANDFALL COULD BE A TAD HIGHER. THE TRACK FORECAST PHILOSOPHY REMAINS UNCHANGED, WITH A SLOWING OF FORWARD MOTION EXPECTED THROUGH 24 HOURS DUE TO INTERACTION WITH TC ODETTE, AND THEN ACCELERATION SOUTHEASTWARD ALONG THE FLANK OF THE DEEP- LAYER RIDGE OVER WESTERN AUSTRALIA. THIS FORECAST IS SLIGHTLY FASTER THAN THE PREVIOUS ONE THROUGH 24 HOURS DUE TO SEROJA'S SHORT TERM MOTION, AND SHIFTED SLIGHTLY SOUTHWEST BEYOND 36 HOURS, FOLLOWING THE TREND IN THE MODEL GUIDANCE. THE EXACT TIMING OF LANDFALL NEAR GERALDTON, AUSTRALIA BETWEEN 48 AND 72 HOURS HAS ABOVE-AVERAGE UNCERTAINTY DUE TO UNCERTAINTY IN HOW MUCH TC SEROJA WILL BE SLOWED DOWN BY INTERACTION WITH TC ODETTE PRIOR TO MAKING ITS SOUTHEASTWARD MOVE TOWARD THE COAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 090000Z IS 21 FEET. NEXT WARNINGS AT 090900Z, 091500Z, 092100Z AND 100300Z. REFER TO TROPICAL CYCLONE 27S (ODETTE) WARNINGS (WTXS32 PGTW) FOR SIX-HOURLY UPDATES. // NNNN