ABIO10 PGTW 152130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN
/REISSUED/152130Z-161800ZJAN2021//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/151951ZJAN2021//
REF/B/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/152051ZJAN2021//
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 15JAN21 1800Z, TROPICAL CYCLONE 10S (TEN) WAS LOCATED 
NEAR 16.4S 94.1E, APPROXIMATELY 1590 NM EAST-SOUTHEAST OF DIEGO 
GARCIA, AND HAD TRACKED 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 152100) FOR FURTHER 
DETAILS.
      (2) NO OTHER TROPICAL CYCLONES.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 99S) PREVIOUSLY LOCATED 
NEAR 11.9S 68.9E IS NOW LOCATED NEAR 12.3S 67.5E, APPROXIMATELY 
407NM  SOUTHWEST OF DIEGO GARCIA. ANIMATED ENHANCED INFRARED 
SATELLITE IMAGERY AND A 151152Z SSMIS 91GHZ MICROWAVE IMAGE SHOW A  
CONSOLIDATING LOW LEVEL CIRCULATION (LLC) OBSCURED BY FLARING 
CONVECTION SHEARED TO THE WEST WITH CONVECTIVE BANDING WRAPPING INTO 
THE CIRCULATION FROM THE SOUTH. A 1642Z ASCAT METOP-B IMAGE SHOWS 25-
30 KNOT WINDS WRAPPING INTO THE LLC FROM THE SW QUADRANT.  INVEST 
99S IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH GOOD OUTFLOW 
ALOFT, LOW TO MODERATE (15-25KTS) VERTICAL  WIND SHEAR, AND WARM (28-
29C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN GOOD AGREEMENT 
THAT INVEST 99S WILL CONTINUE TO TRACK WEST-SOUTHWESTWARD AS IT 
SLOWLY INTENSIFIES.  MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED 
AT 28 TO 33 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE 
NEAR 1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT 
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO HIGH. SEE 
REF B (WTXS21 PGTW 142100) FOR FURTHER DETAILS.
      (2) THE AREA OF CONVECTION (INVEST 90S) PREVIOUSLY LOCATED 
NEAR 14.2S 95.7E IS NOW THE SUBJECT OF A TROPICAL CYCLONE WARNING. 
SEE PARA. 2.A.(1) 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 HIGH 
AND UPGRADED AREA 2.B.(2) TO WARNING STATUS.//
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