ABIO10 PGTW 271800 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN /271800Z-281800ZDEC2021// 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: NONE. B. TROPICAL DISTURBANCE SUMMARY: (1) THE AREA OF CONVECTION (INVEST 97S) PREVIOUSLY LOCATED NEAR 13.9S 132.5E IS NOW LOCATED OVER LAND NEAR 14.2S 131.9E, APPROXIMATELY 119 NM SOUTH-SOUTHEAST OF DARWIN. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 271000Z SSMIS 91GHZ MICROWAVE IMAGE DEPICT A BROAD LOW-LEVEL CIRCULATION (LLC) WITH FORMATIVE CONVECTIVE BANDING AND FLARING CONVECTION WITHIN THE SOUTH- SOUTHEASTERN PERIPHERY OF THE SYSTEM. ENVIRONMENTAL ANALYSIS INDICATES FAVORABLE CONDITIONS FOR DEVELOPMENT SUPPORTED BY ROBUST POLEWARD OUTFLOW OFFSET BY HIGH (25-30KTS) VERTICAL WIND SHEAR. GLOBAL MODELS ARE IN AGREEMENT THAT THE SYSTEM IS EXPECTED TO TRACK EASTWARD OVER THE GULF OF CARPENTERIA WITHIN THE NEXT 24 TO 36 HOURS WITH POTENTIAL FOR DEVELOPMENT OF A TROPICAL CYCLONE. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 999 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS MEDIUM. (2) NO OTHER SUSPECT AREAS. C. SUBTROPICAL SYSTEM SUMMARY: NONE.// NNNN