ABIO10 PGTW 131800 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN/131800Z- 141800ZAPR2023// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/131351ZAPR2023// AMPN/REF A IS A TROPICAL CYCLONE WARNING.// RMKS/ 1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA): A. TROPICAL CYCLONE SUMMARY: NONE. B. TROPICAL DISTURBANCE SUMMARY: NONE. C. SUBTROPICAL SYSTEM SUMMARY: NONE. 2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA): A. TROPICAL CYCLONE SUMMARY: (1) AT 13APR23 1200Z, TROPICAL CYCLONE 18S (ILSA) WAS LOCATED NEAR 19.5S 119.1E, APPROXIMATELY 327 NM EAST-NORTHEAST OF LEARMONTH, AUSTRALIA, AND HAD TRACKED SOUTH- SOUTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 130 KNOTS GUSTING TO 160 KNOTS. SEE REF A (WTXS31 PGTW 131500) FOR FURTHER DETAILS. (2) NO OTHER TROPICAL CYCLONES. B. TROPICAL DISTURBANCE SUMMARY: NONE. C. SUBTROPICAL SYSTEM SUMMARY: NONE.// NNNN