ABIO10 PGTW 041500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN /REISSUED/041500Z-041800ZAPR2021// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/041351ZAPR2021// REF/B/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/040752ZAPR2021// NARR/REF A IS A TROPICAL CYCLONE WARNING. REF B IS A TROPICAL CYCLONE FORMATION ALERT.// 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 04APR21 1200Z, TROPICAL CYCLONE 26S (TWENTYSIX) WAS LOCATED NEAR 10.4S 123.2E, APPROXIMATELY 454 NM NORTH OF BROOME, AUSTRALIA, AND HAD TRACKED WEST-SOUTHWESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 35 KNOTS GUSTING TO 45 KNOTS. SEE REF A (WTXS31 PGTW 041500) FOR FURTHER DETAILS. (2) NO OTHER TROPICAL CYCLONES. B. TROPICAL DISTURBANCE SUMMARY: (1) THE AREA OF CONVECTION (INVEST 99S) PREVIOUSLY LOCATED NEAR 10.4S 123.9E IS NOW THE SUBJECT OF A TROPICAL CYCLONE WARNING. SEE PARA. 2.A.(1) FOR FURTHER DETAILS. (2) THE AREA OF CONVECTION (INVEST 90S) PREVIOUSLY LOCATED NEAR 13.8S 105.2E IS NOW LOCATED NEAR 14.2S 104.9E, APPROXIMATELY 228 NM SOUTH OF CHRISTMAS ISLAND. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 040936Z SSMIS F-16 91GHZ MICROWAVE IMAGE DEPICT PERSISTENT DEEP CONVECTION OVERHEAD A TIGHTENING LOW LEVEL CIRCULATION CENTER (LLCC) WITH FRAGMENTED BANDING WRAPPING IN FROM THE EAST. A 041310Z METOP-A ASCAT PASS REVEALS A SLIGHTLY ELONGATED LLCC WITH A LARGE AREA OF 30 TO 35 KNOT WINDS BEGINNING TO WRAP AROUND THE LLCC FROM THE SOUTH; HOWEVER, THE OVERALL WIND FIELD REMAINS LARGELY ASYMMETRIC. 90S IS CURRENTLY IN A FAVORABLE ENVIRONMENT WITH WARM (30 CELSIUS) SEA SURFACE TEMPERATURES, LOW (5 TO 15 KNOT) VERTICAL WIND SHEAR, AND EXCELLENT POLEWARD OUTFLOW. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 90S WILL REMAIN ELONGATED AND ASYMMETRIC WITH ONLY SLIGHT INTENSIFICATION; HOWEVER, THE MODEL FIELDS MAY NOT BE WELL REPRESENTING THE ACTUAL INITIAL CONDITIONS AS EVIDENCED BY THE PREVIOUSLY MENTIONED ASCAT PASS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1003 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS HIGH. SEE REF B (WTXS22 PGTW 040800) FOR FURTHER DETAILS. (3) NO OTHER SUSPECT AREAS. C. SUBTROPICAL SYSTEM SUMMARY: NONE. 3. JUSTIFICATION FOR REISSUE: UPGRADED AREA IN PARA 2.B.(1) TO WARNING STATUS.// NNNN