ABIO10 PGTW 151800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN
/OCEAN/151800Z-161800ZJAN2021//
REF/A/MSG JOINT TYPHOON WRNCEN PEARL HARBOR HI/142151ZJAN21//
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 13.6S 73.9E IS NOW LOCATED NEAR 11.8S 62.3E, APPROXIMATELY 323 
NM SOUTHWEST OF DIEGO GARCIA. ANIMATED ENHANCED INFRARED SATELLITE 
IMAGERY AND A 151152Z SSMIS 91GHZ MICROWAVE IMAGE SHOW A 
CONSOLIDATING LLCC OBSCURED BY FLARING CONVECTION SHEARED TO THE 
WEST WITH CONVECTIVE BANDING WRAPPING INTO THE CIRCULATION FROM THE 
SOUTH. 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 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS 
ESTIMATED TO BE NEAR 1001 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A 
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS MEDIUM.
      (2) THE AREA OF CONVECTION (INVEST 90S) PREVIOUSLY LOCATED 
NEAR 14.2S 95.7E IS NOW LOCATED NEAR 15.9S 94.7E, APPROXIMATELY 257 
NM SOUTH-SOUTHWEST OF COCOS ISLAND. ANIMATED ENHANCED INFRARED 
SATELLITE IMAGERY AND A 151458Z MHS METOP-B 89GHZ IMAGE SHOW A 
CONSOLIDATING LOW LEVEL CIRCULATION OBSCURED BY FLARING CONVECTION.  
INVEST 90S IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH GOOD 
POLEWARD OUTFLOW ALOFT, LOW TO MODERATE (15-25KTS) VERTICAL WIND 
SHEAR, AND WARM (29-30C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE 
IN GOOD AGREEMENT THAT INVEST 90S WILL TRACK SOUTHWESTWARD, 
INTENSIFYING TO WARNING THRESHOLD WITHIN THE NEXT 24-36 HOURS. 
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. 
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. THE 
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE 
WITHIN THE NEXT 24 HOURS REMAINS HIGH. SEE REF A (WTXS21 PGTW 
142200) FOR FURTHER DETAILS.
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