ABIO10 PGTW 050530
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN
/REISSUED/050530Z-051800ZFEB2021//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/050151ZFEB2021//
REF/B/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/050451ZFEB2021//
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 05FEB21 0000Z, TROPICAL CYCLONE 18S (EIGHTEEN) WAS 
LOCATED NEAR 25.1S 112.3E, APPROXIMATELY 195 NM SOUTH-SOUTHWEST OF 
LEARMONTH, 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 
050300) FOR THE FINAL WARNING ON THIS SYSTEM.
      (2) NO OTHER TROPICAL CYCLONES.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 90S) PREVIOUSLY LOCATED 
NEAR 11.6S 81.4E IS NOW LOCATED NEAR 12.6S 81.4E, APPROXIMATELY 615 
NM EAST-SOUTHEAST OF DIEGO GARCIA. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY DEPICTS A RAPIDLY-CONSOLIDATING, COMPACT SYSTEM WITH DEEP 
CONVECTIVE BANDING WRAPPING INTO THE LOW-LEVEL CIRCULATION CENTER 
(LLCC). A 050334Z ASCAT-B BULLSEYE IMAGE REVEALS A WELL-DEFINED 
CENTER WITH 30-40 KNOT WINDS. A 050332Z MHS 89GHZ MICROWAVE IMAGE 
INDICATES CURVED DEEP CONVECTIVE BANDING WRAPPING TIGHTLY INTO THE 
LLCC. UPPER-LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH 
ROBUST EQUATORWARD OUTFLOW, EXPANDING POLEWARD OUTFLOW AND MODERATE 
(20 KNOTS) EASTERLY VERTICAL WIND SHEAR. GLOBAL MODELS INDICATE A 
SLOW SOUTHWARD TRACK WITH RAPID DEVELOPMENT OVER THE NEXT TWO DAYS. 
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 30 TO 35 KNOTS. 
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 996 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 
050500) FOR FURTHER DETAILS.
      (2) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: UPGRADED AREA IN PARA 2.B.(1) TO 
HIGH.//
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