JTWC取消TCFA, 評級low

WTXS21 PGTW 290130
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 98S) CANCELLATION//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/280851Z MAR 21//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. REMARKS: THIS CANCELS REF A (WTXS21 PGTW 280900). THE AREA OF
CONVECTION (INVEST 98S) PREVIOUSLY LOCATED NEAR 11.0S 68.5E IS NOW
LOCATED NEAR 10.3S 69.5E, APPROXIMATELY 247 NM SOUTHWEST OF DIEGO
GARCIA. ANIMATED ENHANCED INFRARED (EIR) SATTELITE IMAGERY AND A
281357Z SSMIS 91GHZ MICROWAVE IMAGE SHOW DISORGANIZED CONVECTION TO
THE SOUTHWEST OF AN EXPOSED LOW-LEVEL CIRCULATION (LLC).
ENVIRONMENTAL ANALYSIS SHOWS INVEST 98S HAS POOR CONDITIONS FOR
DEVELOPMENT, WITH WEAK OUTFLOW ALOFT AND HIGH (20-30KTS)
NORTHEASTERLY VERTICAL WIND SHEAR (VWS), ALTHOUGH OVER WARM (29-30C)
SEA SURFACE TEMPERATURES. NUMERICAL MODELS GENERALLY AGREE THAT 98S
WILL WEAKEN WHILE TRACKING EAST-NORTHEAST OVER THE NEXT 24-48 HOURS.
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 IS DOWNGRADED TO LOW.//
NNNN

ABIO10 PGTW 290200
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR/HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN
REISSUED/290200Z-291800ZMAR2021//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/290121ZMAR21//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT CANCELLATION//
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 98S) PREVIOUSLY LOCATED
NEAR 11.7S 68.3E IS NOW LOCATED NEAR 10.3S 69.5E, APPROXIMATELY 247
NM SOUTHWEST OF DIEGO GARCIA. ANIMATED ENHANCED INFRARED (EIR)
SATTELITE IMAGERY AND A 281357Z SSMIS 91GHZ MICROWAVE IMAGE SHOW
DISORGANIZED CONVECTION TO THE SOUTHWEST OF AN EXPOSED LOW-LEVEL
CIRCULATION (LLC). ENVIRONMENTAL ANALYSIS SHOWS INVEST 98S HAS POOR
CONDITIONS FOR DEVELOPMENT, WITH WEAK OUTFLOW ALOFT AND HIGH (20-
30KTS) NORTHEASTERLY VERTICAL WIND SHEAR (VWS), ALTHOUGH OVER WARM
(29-30C) SEA SURFACE TEMPERATURES. NUMERICAL MODELS GENERALLY AGREE
THAT 98S WILL WEAKEN WHILE TRACKING EAST-NORTHEAST OVER THE NEXT 24-
48 HOURS. 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 IS DOWNGRADED TO LOW. SEE REF A (WTXS21
PGTW 290130) FOR FURTHER DETAILS.
      (2) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: DOWNGRADED AREA IN PARA 2.B.(1) TO
LOW//
NNNN

MFR12Z判定已減弱為低壓區

WARNING
BEGINNING OF VALIDITY: SUNDAY 28/03/2021 AT 1200 UTC.

PHENOMENON: FILLING UP 15 1002 HPA
POSITION: WITHIN 40 NM RADIUS OF POINT 11.0 S / 68.5 E
(ELEVEN    DECIMAL ZERO   DEGREES SOUTH AND
SIXTY EIGHT    DECIMAL FIVE   DEGREES EAST) AT 1200 UTC
MOVEMENT: NORTH-EAST 6 KT

THREAT AREAS:
SQUALLY WEATHER EXTENDING UP TO 300 NM IN THE SOUTHWESTERN
SEMI-CIRCLE.

CLOCKWISE CIRCULATION 20/25KT LOCALLY REACHING NEAR-GALE FORCE 30KT
IN THE WESTERN SEMI-CIRCLE.
STRONG GUSTS UNDER SQUALLS.