ABIO10 PGTW 041800 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN /OCEAN/041800Z-051800ZNOV2021// RMKS/ 1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA): A. TROPICAL CYCLONE SUMMARY: NONE. B. TROPICAL DISTURBANCE SUMMARY: (1) AN AREA OF CONVECTION (INVEST 90A) HAS PERSISTED NEAR 10.7N 69.4E, APPROXIMATELY 537 NM SOUTH-SOUTHWEST OF MUMBAI, INDIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 041334Z SSMIS 91GHZ IMAGE INDICATE SHALLOW BANDING WRAPPING INTO A BROAD LOW-LEVEL CIRCULATION CENTER (LLCC) WITH LIMITED DEEP CONVECTIVE BANDING OVER THE NORTHWEST QUADRANT. A 040441Z ASCAT-B IMAGE DEPICTS 20-25 KT WINDS OVER THE WESTERN PERIPHERY WITH WEAKER WINDS ELSEWHERE. GLOBAL MODELS INDICATE SLOW, MINIMAL DEVELOPMENT AS THE SYSTEM TRACKS WESTWARD, ENVIRONMENTAL CONDITIONS ARE MARGINALLY FAVORABLE WITH ROBUST POLEWARD OUTFLOW AND LOW TO MODERATE (10-20KT) VERTICAL WIND SHEAR OFFSET BY DRY AIR ENTRAINMENT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW. (2) NO OTHER SUSPECT AREAS. 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: NONE. C. SUBTROPICAL SYSTEM SUMMARY: NONE.// NNNN