老農民版夜神月

  熱帶低壓  
編號：15-20202021 ( 98 S )
名稱：無

  基本資料     
擾動編號日期：2021 年 03 月 25 日 17 時
撤編日期　　：2021 年 03 月 31 日 00 時
登陸地點　　：無

  巔峰時期資料  
近中心最強風速
法國留尼旺氣象局 (MFR) ：30 kt
聯合颱風警報中心(JTWC)：30 kt ( TD )
海平面最低氣壓：998 百帕

  擾動編號資料  
98S.INVEST.15kts.996mb.7.8S.63.8E

以上資料來自：MFR、JTWC、颱風論壇整理製作

老農民版夜神月

JTWC18Z降DB,順便把12Z也改為DB

SH, 98, 2021032912, , BEST, 0, 91S, 700E, 20, 1006, DB, 0, , 0, 0, 0, 0, 1008, 140, 30, 0, 0, S, 0, , 0, 0, INVEST, S,
SH, 98, 2021032918, , BEST, 0, 85S, 702E, 20, 1006, DB, 0, , 0, 0, 0, 0, 1008, 140, 30, 0, 0, , 0, , 0, 0, INVEST, ,

老農民版夜神月

JTWC取消評級

(1) THE AREA OF CONVECTION (INVEST 98S) PREVIOUSLY LOCATED
NEAR 10.3S 69.3E HAS DISSIPATED AND IS NO LONGER SUSPECT FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE IN THE NEXT 24 HOURS.

dom

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

老農民版夜神月

MFR晚間展望亦有提及98S，本報對其的評級為低

Tropical Depression 15-20202021:

Position at 09UTC: 11.5oS / 68.5oE
Max 10mn winds: 30 kt
Motion: ENE, 6 kt
Estimated minimum pressure: 1000 hPa

Until mid-week, Tropical Depression 15 will encounter unfavourable conditions which will lead to its gradual weakening and eventually make it vanish within the NET.
For more informations, please refer to bulletins WTIO20 and WTIO30 issued at 06UTC and following.

On the extreme East of the basin, the low pressure area which was recently in the Australian AoR is now located by 10.3S / 88.1E as of 09UTC, with 15 to 20 kt max winds and an elongated circulation. In the coming days, moderate wind shear and a dry mid-troposphere combined with a lack of equatorward low-level convergence should seriously limit chances of development.

By the end of the week, poleward surface convergence due to strengthening trade winds should help increase vorticity within the NET. Some models suggest that this could initiate a possible cyclogenesis from Friday or Saturday close to 70E, potentially from one of the pre-existing vorticity areas mentionned above. This potential system could benefit from good upper divergence on the edge of a rebuilding mid-tropospheric ridge. Thus chances of a new cyclogenesis increase at the end of the forecast range.

The risk of development of a Moderate Tropical Storm to the South-West of the Chagos archipelago becomes very low from Friday.

老農民版夜神月

JTWC18Z亦將定強略下調至25節,目前看來其升格為TC的機率已是不太高

98S INVEST 210328 1800 10.5S 69.2E SHEM 25 1006

TPXS11 PGTW 281831

A. TROPICAL DISTURBANCE 98S (W OF DIEGO GARCIA)

B. 28/1745Z

C. 10.40S

D. 69.20E

E. THREE/GOES-IO

F. T1.5/2.0/W0.5/24HRS  STT: S0.0/03HRS

G. IR/EIR

H. REMARKS: 17A/PBO XPSD LLCC/ANMTN. THIS SYSTEM IS TOO SHEARED
TO CLASSIFY A DT. MET AND PT YIELDS 1.5. DBO PT.

I. ADDITIONAL POSITIONS:
   28/1358Z  10.68S  68.75E  SSMS


   HEINS

dom

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.