ABIO10 PGTW 151800 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN /OCEAN/151800Z-161800ZMAR2022// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/150751ZMAR2022// 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: (1) THE AREA OF CONVECTION (INVEST 91B) PREVIOUSLY LOCATED NEAR 3.3N 87.1E IS NOW LOCATED NEAR 4.0N 87.9E, APPROXIMATELY 490 NM SOUTHEAST OF COLOMBO, SRI LANKA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS LARGE, DISORGANIZED CLUSTERS OF DEEP CONVECTION FLARING OVER A BROAD LOW-LEVEL CIRCULATION. A 151252Z SSMIS 91GHZ COLOR COMPOSITE MICROWAVE IMAGE SHOWS A BROAD, WEAKLY DEFINED LOW-LEVEL CIRCULATION CENTER WITH POORLY-ORGANIZED DEEP CONVECTIVE ORGANIZATION. ENVIRONMENTAL ANALYSIS IS MARGINALLY FAVORABLE WITH DEVELOPING POLEWARD OUTFLOW AND WARM (28-29C) SEA SURFACE TEMPERATURES (SSTS) OFFSET BY MODERATE TO HIGH (20-30KTS) VERTICAL WIND SHEAR (VWS). NUMERICAL MODELS CONTINUE TO INDICATE SLOW DEVELOPMENT OVER THE NEXT FEW DAYS AS THE DISTURBANCE TRACKS GENERALLY EASTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 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. 2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA): A. TROPICAL CYCLONE SUMMARY: (1) AT 15MAR22 0600Z, TROPICAL CYCLONE 20S (BILLY) WAS LOCATED NEAR 17.0S 97.2E, APPROXIMATELY 291 NM SOUTH OF THE COCOS ISLANDS, AUSTRALIA, AND HAD TRACKED WESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 55 KNOTS GUSTING TO 70 KNOTS. SEE REF A (WTXS31 PGTW 150900) FOR FURTHER DETAILS. (2) NO OTHER TROPICAL CYCLONES. B. TROPICAL DISTURBANCE SUMMARY: (1) THE AREA OF CONVECTION (REMNANTS OF TC 19S) PREVIOUSLY LOCATED NEAR 18.3S 37.7E IS NOW LOCATED NEAR 18.1S 38.1E, APPROXIMATELY 188 NM NORTHWEST OF EUROPA ISLAND. ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLC) WITH WEAK CONVECTIVE BANDING WRAPPING INTO THE CENTER. ENVIRONMENTAL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH FAIR RADIAL OUTFLOW AND LOW (05-10 KT) VERTICAL WIND SHEAR. THE PRIMARY LIMITING FACTOR IS PROXIMITY TO LAND. ECMWF INITIALIZES THIS SYSTEM BETTER THAN GFS AND MAINTAINS A QUASI-STATIONARY MOTION OVER THE NEXT DAY THEN A SLOW DRIFT INLAND OVER MOZAMBIQUE BY TAU 48 AT TROPICAL DEPRESSION STRENGTH. GFS IS NOT HANDLING THE SYSTEM WELL AND SHOWS A WEAK LOW PRESSURE AREA. WHILE MESOSCALE MODELS SHOW A LIMITED WINDOW FOR 30-35 KTS IN THE NEXT 24-36 HOURS. 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 MEDIUM. (2) THE AREA OF CONVECTION (INVEST 91S) PREVIOUSLY LOCATED NEAR 12.4S 50.7E IS NOW LOCATED NEAR 12.3S 50.3E, APPROXIMATELY 412 NM WEST OF THE COMOROS ISLANDS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES RAPIDLY WEAKENING AND INCONSISTENT CONVECTION FLARING OVER A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC). ENVIRONMENTAL ANALYSIS INDICATES A MARGINAL ENVIRONMENT WITH MODERATE TO HIGH (20-25 KNOTS) VERTICAL WIND SHEAR AND WEAK DIFFLUENT FLOW ALOFT. SST VALUES ARE CONDUCIVE AT 28C. NUMERICAL MODEL GUIDANCE INDICATES THE SYSTEM WILL TRACK SOUTHWARD ALONG THE EAST COAST OF MADAGASCAR THEN TRACK OVER NORTHERN MADAGASCAR BETWEEN TAU 24 TO TAU 36 WITH NO SIGNIFICANT DEVELOPMENT EXPECTED. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW. (3) NO OTHER SUSPECT AREAS. C. SUBTROPICAL SYSTEM SUMMARY: NONE.// NNNN