ABIO10 PGTW 031800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN
/OCEAN/031800Z-041800ZAPR2021//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/031351ZAPR2021//
AMPN/REF A 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: NONE.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 99S) PREVIOUSLY LOCATED 
NEAR 11.0S 122.3E IS NOW LOCATED NEAR 10.7S 123.8E, APPROXIMATELY 
209 NM NORTH OF BROWSE ISLAND, AUSTRALIA. ANIMATED ENHANCED INFRARED 
(EIR) SATELLITE IMAGERY AND A 031054Z SSMIS 91GHZ MICROWAVE PARTIAL 
IMAGE DEPICT FORMATIVE CONVECTIVE BANDING WARPPING INTO AN OBSCURED 
LOW LEVEL CIRCULATION CENTER (LLCC). A 031148Z METOP-A ASCAT PASS 
REVEALS A TIGHT LLCC WITH A SWATH OF 30-35 KT WINDS IN THE SOUTHERN 
PERIPHERY. 90S IS CURRENTLY IN A FAVORABLE ENVIRONMENT WITH WARM (30 
CELSIUS) SEA SURFACE TEMPERATURES (SST) AND DUAL CHANNEL OUTFLOW 
BEING SLIGHTLY OFFSET BY LIGHT TO MODERATE (10-20 KNOT) VERTICAL WIND 
SHEAR (VWS). GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 99S WILL REMAIN 
QUASISTAIONARY AS IT CONSOLIDATES AND INTENSIFIES. MAXIMUM SUSTAINED 
SURFACE WINDS ARE ESTIMATED AT 2 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 A (WTXS21 PGTW 031400) FOR FURTHER 
DETAILS.
      (2) THE AREA OF CONVECTION (INVEST 90S) PREVIOUSLY LOCATED 
NEAR 9.5S 103.3E IS NOW LOCATED NEAR 10.8S 102.9E, APPROXIMATELY 168 
NM WEST OF CHRISTMAS ISLAND. ANIMATED EIR SATELLITE IMAGERY AND A 
031328Z METOP-A 89GHZ MICROWAVE IMAGE DEPICT FRAGMENTED DEEP 
CONVECTION EMBEDDED IN FORMATIVE BANDS WRAPPING AROUND AN ELONGATED 
AND OBSCURED LOW LEVEL CIRCULATION. 90S IS CURRENTLY IN A FAVORABLE 
ENVIRONMENT WITH WARM (30 CELSIUS) SST, LOW (05-10 KNOT) VWS, AND 
EXCELLENT POLEWARD OUTFLOW. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 
90S WILL CONTINUE TO TRACK GENERALLY SOUTHEASTWARD, REMAINING 
ELONGATED WHILE INTENSIFYING, POTENTIALLY REACHING WARNING THRESHOLD 
IN 2 TO 3 DAYS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 
TO 25 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 MEDIUM.
      (3) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.//
NNNN