ABIO10 PGTW 201500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN
/REISSUED/201500Z-201800ZSEP2021//
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) AN AREA OF CONVECTION (INVEST 90S) HAS PERSISTED NEAR 9.9S 
84.1E, APPROXIMATELY 700 NM EAST-SOUTHEAST OF DIEGO GARCIA.  
ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 201324Z SSMIS 91GHZ 
MICROWAVE IMAGE DEPICTS DEVELOPING CENTRAL CONVECTION AROUND A 
POORLY DEFINED LOW LEVEL CIRCULATION CENTER (LLC). UPPER LEVEL 
ANALYSIS INDICATES  THE SYSTEM HAS ENTERED AN AREA OF MODERATE (15-
20 KTS) VERTICAL WIND SHEAR OFFSET BY DEVELOPING POLEWARD OUTFLOW 
AND WARM (26-28C) SEA SURFACE TEMPERATURES (SSTS). NUMERIC WEATHER 
PREDICTION MODELS ARE IN GOOD AGREEMENT 90S WILL TRACK WESTWARD AS 
IT FURTHER DEVELOPS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED 
AT 20 TO 30 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 MEDIUM.
      (2) NO OTHER SUSPECT AREAS.
   B. TROPICAL DISTURBANCE SUMMARY: NONE.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: INVEST 90S UPGRADED TO MEDIUM//
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