ABIO10 PGTW 100830 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN /REISSUED/100830Z-101800ZAPR2021// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/100752ZAPR2021// REF/B/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/100751ZAPR2021// NARR/REFS A AND A ARE TROPICAL CYCLONE WARNINGS.// 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 10APR21 0600Z, TROPICAL CYCLONE 27S (ODETTE) WAS LOCATED NEAR 21.3S 113.0E, APPROXIMATELY 86 NM NORTHWEST OF LEARMONTH, AUSTRALIA, AND HAD TRACKED SOUTHWARD AT 24 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 30 KNOTS GUSTING TO 40 KNOTS. SEE REF A (WTXS32 PGTW 100900) FOR THE FINAL WARNING ON THIS SYSTEM. (2) AT 10APR21 0600Z, TROPICAL CYCLONE 26S (SEROJA) WAS LOCATED NEAR 20.9S 108.2E, APPROXIMATELY 340 NM WEST-NORTHWEST OF LEARMONTH, AUSTRALIA, AND HAD TRACKED SOUTHWARD AT 03 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 60 KNOTS GUSTING TO 75 KNOTS. SEE REF B (WTXS31 PGTW 100900) FOR FURTHER DETAILS. (3) NO OTHER TROPICAL CYCLONES. B. TROPICAL DISTURBANCE SUMMARY: (1) THE AREA OF CONVECTION (INVEST 91S) PREVIOUSLY LOCATED NEAR 11.7S 97.5E IS NOW LOCATED NEAR 13.3S 100.0E, APPROXIMATELY 200 NM EAST-SOUTHEAST OF COCOS ISLANDS, AUSTRALIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 100715Z GMI 89GHZ MICROWAVE IMAGE REVEAL DISORGANIZED BANDING WRAPPING INTO A BROAD, ELONGATED LOW LEVEL CIRCULATION (LLC) WITH FLARING CONVECTION IN THE SOUTHERN PERIPHERY. A 100308Z ASCAT-B PASS DEPICTS A BROAD LLC STRETCHED FROM THE NORTHWEST TO THE SOUTHEAST WITH 20-25 KT WINDS IN THE NORTHERN SEMI-CIRCLE. INVEST 91S IS IN A MARGINAL ENVIRONMENT FOR TROPICAL DEVELOPMENT WITH MINIMAL POLEWARD OUTFLOW AND MODERATE (15-20KTS) VERTICAL WIND SHEAR OFFSET BY WARM (28-29C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT INVEST 91S WILL INTENSIFY SLIGHTLY OVER THE NEXT 48-72 HOURS AS IT TRACKS TO THE SOUTHEAST. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW. (2) NO OTHER SUSPECT AREAS. C. SUBTROPICAL SYSTEM SUMMARY: NONE. 3. JUSTIFICATION FOR REISSUE: ISSUED FINAL WARNING FOR TC 27S.// NNNN