WTXS31 PGTW 132100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 18S (ILSA) WARNING NR 021// RMKS/ 1. TROPICAL CYCLONE 18S (ILSA) WARNING NR 021 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 131800Z --- NEAR 20.5S 119.9E MOVEMENT PAST SIX HOURS - 145 DEGREES AT 13 KTS POSITION ACCURATE TO WITHIN 010 NM POSITION BASED ON EYE FIXED BY A COMBINATION OF SATELLITE, RADAR AND SYNOPTIC DATA PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 085 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT REPEAT POSIT: 20.5S 119.9E --- FORECASTS: 12 HRS, VALID AT: 140600Z --- 21.9S 123.1E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 24 HR POSIT: 105 DEG/ 21 KTS --- 24 HRS, VALID AT: 141800Z --- 22.8S 127.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY --- 36 HRS, VALID AT: 150600Z --- 22.8S 133.1E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 48 HR POSIT: 065 DEG/ 20 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 151800Z --- 21.1S 136.9E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 72 HR POSIT: 025 DEG/ 09 KTS --- 72 HRS, VALID AT: 161800Z --- 17.8S 138.6E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 132100Z POSITION NEAR 20.8S 120.7E. 13APR23. TROPICAL CYCLONE 18S (ILSA), LOCATED APPROXIMATELY 341 NM EAST-NORTHEAST OF LEARMONTH, AUSTRALIA, HAS TRACKED SOUTHEASTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A COMPOSITE RADAR LOOP FROM BROOME SHOW THE SYSTEM HAS MADE LANDFALL AND IS ACCELERATING INLAND. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A SHARPLY-OUTLINED 14-NM EYE IN BOTH ANIMATIONS. THE INITIAL INTENSITY OF 115 KNOTS IS BASED ON CIMSS AUTOMATED FIXES DMN AND OPEN-AIIR AND CONSISTENT WITH THE RATE OF DEGRADATION AFTER LANDFALL. TC ILSA WILL CONTINUE TO TRACK FURTHER INLAND OVER NORTH CENTRAL AUSTRALIA AND RAPIDLY DECAY DUE TO HIGH VWS AND LAND INTERACTION, AND DISSIPATE BY TAU 48. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION.// NNNN