科科斯群岛西南强热带气旋第14号“考特尼”(27U/27S.Courtney) - 西行发展，风眼开出，快速爆发超预期 - MFR:110KT JTWC:130KT

pocketbox

全球热带气旋监测公报
预报：黄奕武  签发：向纯怡  2025 年 03 月 31 日 18 时
“考特尼”向偏南方向移动

时       间：31日14时（北京时）

海       域：南印度洋

命       名：“考特尼”，COURTNEY

中心位置：南纬23.9度、东经88.5度

强度等级：强热带风暴

最大风力：11级（30米/秒，相当于我国的强热带风暴级）

中心气压：981百帕

参考位置：毛里求斯路易港偏东方向约3220公里的洋面上

变化过程：过去24小时，“考特尼”由16级减弱到11级

预报结论：“考特尼”将以每小时10公里左右的速度向偏南方向移动，强度逐渐减弱。


图1 卫星监测图像（北京时间2025年03月31日14时00分）

ygsj24

WTIO30 FMEE 311226
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 9/14/20242025
1.A SEVERE TROPICAL STORM 14 (COURTNEY)

2.A POSITION 2025/03/31 AT 1200 UTC:
WITHIN 20 NM RADIUS OF POINT 24.6 S / 88.8 E
(TWENTY FOUR    DECIMAL SIX   DEGREES SOUTH AND
EIGHTY EIGHT    DECIMAL EIGHT   DEGREES EAST)
MOVEMENT: SOUTH-SOUTH-EAST 8 KT

3.A DVORAK ANALYSIS: 2.5/3.5/W 0.5/6 H

4.A CENTRAL PRESSURE: 984 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 55 KT
RADIUS OF MAXIMUM WINDS (RMW): 54 KM

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 280 SE: 325 SW: 230 NW: 215
34 KT NE: 150 SE: 220 SW: 185 NW: 95
48 KT NE: 95 SE: 110 SW: 80 NW: 55
64 KT NE: 0 SE: 0 SW: 0 NW: 0

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1010 HPA / 900 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM

1.B FORECASTS (WINDS RADII IN KM):
12H: 2025/04/01 00 UTC: 25.4 S / 88.7 E, VENT MAX= 045 KT,
POST-TROPICAL DEPRESSION
28 KT NE: 325 SE: 345 SW: 250 NW: 0
34 KT NE: 0 SE: 195 SW: 150 NW: 0

24H: 2025/04/01 12 UTC: 26.0 S / 88.5 E, VENT MAX= 045 KT, REMNANT
LOW
28 KT NE: 0 SE: 295 SW: 260 NW: 0
34 KT NE: 0 SE: 155 SW: 140 NW: 0

36H: 2025/04/02 00 UTC: 26.3 S / 87.7 E, VENT MAX= 035 KT, REMNANT
LOW
28 KT NE: 0 SE: 230 SW: 260 NW: 0
34 KT NE: 0 SE: 120 SW: 120 NW: 0

48H: 2025/04/02 12 UTC: 26.1 S / 86.1 E, VENT MAX= 035 KT, REMNANT
LOW
28 KT NE: 0 SE: 230 SW: 230 NW: 0
34 KT NE: 0 SE: 0 SW: 95 NW: 0

60H: 2025/04/03 00 UTC: 25.5 S / 83.4 E, VENT MAX= 030 KT, FILLING UP
28 KT NE: 0 SE: 230 SW: 130 NW: 0

72H: 2025/04/03 12 UTC: 25.1 S / 80.2 E, VENT MAX= 025 KT, FILLING UP

2.B LONGER-RANGE OUTLOOK:
NIL


2.C ADDITIONAL INFORMATION:
T=2.5 CI=3.5

LITTLE CHANGE OVER THE LAST 6 HOURS: COURTNEY'S CLOUD PATTERN REMAINS
WELL SHEARED, WITH DEEP CONVECTION RELEGATED TO THE SOUTHEAST
QUADRANT OF THE SYSTEM, DETACHED QUITE FAR FROM THE LOW-LEVEL CENTER
(LLC). THE DEEP SHEAR ESTIMATED BY CIMSS IS NORTH-WESTERLY FOR 36KT,
WHICH IS CONSISTENT WITH THE LARGE-SCALE SITUATION THAT CURRENTLY
PLACES THE SYSTEM ON THE EASTERN FLANK OF AN UPPER TROUGH CIRCULATING
FURTHER WEST. THE PRESENCE OF CONVECTION STILL ALLOWS A SUBJECTIVE
DVORAK ANALYSIS, GIVING A CI OF 3.5 PER INERTIA.

COURTNEY'S TRACK CURVES SOUTH-SOUTHWEST UNDER THE INFLUENCE OF A
RIDGE TO THE NORTHEAST AND AN UPPER TROUGH TO THE SOUTHWEST AND
SOUTH. WITH THE PROGRESSIVE WEAKENING OF THE SYSTEM, THE STEERING
FLOW DROPS BACK INTO THE MID-TROPOSPHERE AND THEN INTO THE LOWER
LAYERS. BETWEEN MONDAY EVENING AND TUESDAY, COURTNEY SHOULD MOVE
SLOWLY WITHIN A BAROMETRIC COL AT 700HPA, THEN THE MOVEMENT SHOULD
ACCELERATE WESTWARDS FROM TUESDAY EVENING, AS THE REMNANT LOW IS
TAKEN UP IN THE TRADE WINDS ON THE NORTH FACE OF THE SUBTROPICAL LOW
LAYER. THE RSMC FORECAST IS BASED ON A COMPROMISE BETWEEN THE BEST
AVAILABLE GUIDANCE, WHOSE DISPERSION IS INCREASING FROM MONDAY
ONWARDS, INDUCING LOW CONFIDENCE IN THE SYSTEM'S TRACK BEYOND.

COURTNEY'S INTENSITY WILL CONTINUE TO GRADUALLY DECREASE AS A RESULT
OF INCREASINGLY STRONG NORTHWESTERLY WINDSHEAR ALONG THE UPPER
TROUGH, INJECTING DRY AIR OVER THE LOW LEVEL CENTER. IN ADDITION,
COURTNEY'S SOUTHWARD MOVEMENT MEANS THAT IT IS CIRCULATING OVER MUCH
COOLER SURFACE WATERS, WITH VIRTUALLY NO OCEAN HEAT POTENTIAL. FROM
MONDAY EVENING, IN AN INCREASINGLY BAROCLINIC ENVIRONMENT, COURTNEY
SHOULD LOSE ITS TROPICAL CHARACTERISTICS, EVOLVING INTO A
POST-TROPICAL SYSTEM AND THEN INTO A REMNANT LOW IN THE FORM OF A
VORTEX DEVOID OF DEEP CONVECTION. DRY AIR WILL SETTLE PERMANENTLY
OVER THE LLC, WITH NO POSSIBILITY OF REINTENSIFYING. GALE-FORCE
WINDS, THEN NEAR GALE FORCE WINDS, MAY PERSIST IN THE SOUTHERN
SEMICIRCLE DUE TO THE PRESSURE GRADIENT EFFECT UNTIL WEDNESDAY,
BEFORE THE SYSTEM DISSIPATES OVER THE FOLLOWING DAYS.

COURTNEY DOES NOT THREATEN ANY INHABITED LAND.=

9916-Bart

还是很美的

ygsj24

WTIO30 FMEE 311829
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 10/14/20242025
1.A POST-TROPICAL DEPRESSION 14 (COURTNEY)

2.A POSITION 2025/03/31 AT 1800 UTC:
WITHIN 30 NM RADIUS OF POINT 25.1 S / 88.9 E
(TWENTY FIVE DECIMAL ONE DEGREES SOUTH AND
EIGHTY EIGHT DECIMAL NINE DEGREES EAST)
MOVEMENT: SOUTH 4 KT

3.A DVORAK ANALYSIS: NIL
4.A CENTRAL PRESSURE: 985 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 50 KT
RADIUS OF MAXIMUM WINDS (RMW): 35 KM

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 230 SE: 285 SW: 270 NW: 195
34 KT NE: 95 SE: 195 SW: 175 NW: 110
48 KT NE: 35 SE: 110 SW: 110 NW: 35

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 500 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: SHALLOW

1.B FORECASTS (WINDS RADII IN KM):
12H: 2025/04/01 06 UTC: 25.8 S / 88.7 E, VENT MAX= 045 KT, POST-TROPICAL
DEPRESSION
28 KT NE: 120 SE: 285 SW: 285 NW: 140
34 KT NE: 0 SE: 175 SW: 150 NW: 75

24H: 2025/04/01 18 UTC: 26.1 S / 88.3 E, VENT MAX= 040 KT, REMNANT LOW
28 KT NE: 120 SE: 250 SW: 280 NW: 85
34 KT NE: 0 SE: 140 SW: 110 NW: 0

36H: 2025/04/02 06 UTC: 26.2 S / 87.0 E, VENT MAX= 035 KT, REMNANT LOW
28 KT NE: 120 SE: 175 SW: 165 NW: 85
34 KT NE: 0 SE: 110 SW: 0 NW: 0

48H: 2025/04/02 18 UTC: 25.8 S / 85.0 E, VENT MAX= 030 KT, FILLING UP
28 KT NE: 120 SE: 165 SW: 130 NW: 85

60H: 2025/04/03 06 UTC: 25.2 S / 81.5 E, VENT MAX= 030 KT, FILLING UP
28 KT NE: 120 SE: 165 SW: 130 NW: 85

72H: 2025/04/03 18 UTC: 25.9 S / 78.6 E, VENT MAX= 025 KT, FILLING UP

2.B LONGER-RANGE OUTLOOK:
NIL

2.C ADDITIONAL INFORMATION:
OVER THE LAST 6 HOURS, CONVECTION, WHICH HAD BEEN PUSHED AWAY IN THE
SOUTHEAST QUADRANT OF THE SYSTEM FAR FROM THE LOW-LEVEL CENTER, HAS
WEAKENED SIGNIFICANTLY AND HAS ALMOST COMPLETELY DISAPPEARED. THE
ABSENCE OF DEEP CONVECTION MEANS THAT DVORAK ESTIMATES CAN NO
LONGER BE MADE. THE DEEP SHEAR ESTIMATED BY CIMSS IS NORTH-WESTERLY
FOR MORE THAN 40KT, WHICH IS CONSISTENT WITH THE LARGE-SCALE SITUATION
THAT CURRENTLY PLACES THE SYSTEM ON THE EASTERN FLANK OF A TROUGH
CIRCULATING FURTHER WEST. THE 1517Z AND 1609Z ASCATS ENABLE US TO
ESTIMATE MAXIMUM WINDS OF THE ORDER OF 50 KT NEAR THE LOW LEVEL
CENTER AFTER DEBIASING. THEY ALSO HIGHLIGHT THE ASYMMETRICAL
STRUCTURE OF THE SYSTEM, WHICH JUSTIFIES CLASSIFYING COURTNEY AS A
POST-TROPICAL DEPRESSION.

COURTNEY'S TRACK CURVES SOUTH-SOUTHWEST UNDER THE INFLUENCE OF A
RIDGE TO THE NORTHEAST AND AN UPPER TROUGH TO THE SOUTHWEST AND
SOUTH. WITH THE PROGRESSIVE WEAKENING OF THE SYSTEM, THE STEERING
FLOW DROPS BACK INTO THE MID-TROPOSPHERE AND THEN INTO THE LOWER
LAYERS. BETWEEN THIS EVENING EVENING AND TOMORROW MORNING,
COURTNEY SHOULD MOVE SLOWLY WITHIN A BAROMETRIC COL AT 700HPA, THEN
THE MOVEMENT SHOULD ACCELERATE WESTWARDS FROM TUESDAY EVENING, AS
THE REMNANT LOW IS TAKEN UP IN THE TRADE WINDS ON THE NORTH FACE OF
THE SUBTROPICAL LOW LAYER. THE RSMC FORECAST IS BASED ON A COMPROMISE
BETWEEN THE BEST AVAILABLE GUIDANCE, WHOSE DISPERSION IS INCREASING
FROM MONDAY ONWARDS, INDUCING LOW CONFIDENCE IN THE SYSTEM'S TRACK
BEYOND.

COURTNEY'S INTENSITY CONTINUES TO GRADUALLY DECREASE AS A RESULT OF
INCREASINGLY STRONG NORTHWESTERLY WINDSHEAR ALONG THE UPPER
TROUGH, INJECTING DRY AIR OVER THE LOW LEVEL CENTER. IN ADDITION,
COURTNEY'S SOUTHWARD MOVEMENT MEANS THAT IT IS CIRCULATING OVER
MUCH COOLER SURFACE WATERS, WITH VIRTUALLY NO OCEAN HEAT POTENTIAL.
FROM MONDAY EVENING, IN AN INCREASINGLY BAROCLINIC ENVIRONMENT,
COURTNEY HAS LOST ITS TROPICAL CHARACTERISTICS, AND IS A POST-TROPICAL
SYSTEM THAT SHOULD EVOLVE IN THE NEXT DAYS INTO A REMNANT LOW IN THE
FORM OF A VORTEX DEVOID OF DEEP CONVECTION. DRY AIR WILL SETTLE
PERMANENTLY OVER THE LLC, WITH NO POSSIBILITY OF REINTENSIFYING.
GALE-FORCE WINDS, THEN NEAR GALE FORCE WINDS, MAY PERSIST IN THE
SOUTHERN SEMICIRCLE DUE TO THE PRESSURE GRADIENT EFFECT UNTIL
WEDNESDAY, BEFORE THE SYSTEM DISSIPATES OVER THE FOLLOWING DAYS.

COURTNEY DOES NOT THREATEN ANY INHABITED LAND.

LAST BULLETIN UNLESS RE-INTENSIFICATION ISSUED BY RSMC LA REUNION
REGARDS THIS SYSTEM. FURTHER INFORMATION ON THIS SYSTEM WILL BE
AVAILABLE IN THE DAILY BULLETIN ON TROPICAL WEATHER CONDITIONS OVER
THE SOUTHWEST INDIAN OCEAN ISSUED AT 12Z (AWIO20 FMEE).

ygsj24

WTXS31 PGTW 312100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 27S (COURTNEY) WARNING NR 019//
RMKS/
1. TROPICAL CYCLONE 27S (COURTNEY) WARNING NR 019   
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   311800Z --- NEAR 24.8S 88.8E
     MOVEMENT PAST SIX HOURS - 180 DEGREES AT 02 KTS
     POSITION ACCURATE TO WITHIN 020 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING SUBTROPICAL
   RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT
                            145 NM SOUTHEAST QUADRANT
                            120 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   REPEAT POSIT: 24.8S 88.8E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   010600Z --- 25.5S 88.6E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING SUBTROPICAL
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            140 NM SOUTHEAST QUADRANT
                            100 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 240 DEG/ 03 KTS
    ---
   24 HRS, VALID AT:
   011800Z --- 25.8S 88.0E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   SUBTROPICAL
   RADIUS OF 034 KT WINDS - 020 NM NORTHEAST QUADRANT
                            110 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
    ---
REMARKS:
312100Z POSITION NEAR 25.0S 88.7E.
31MAR25. TROPICAL CYCLONE 27S (COURTNEY), LOCATED APPROXIMATELY
885 NM SOUTH-SOUTHWEST OF THE COCOS ISLANDS, HAS TRACKED
SOUTHWARD AT 02 KNOTS OVER THE PAST SIX HOURS.
MINIMUM CENTRAL PRESSURE AT 311800Z IS 986 MB. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 311800Z IS 21 FEET. NEXT WARNINGS AT
010900Z AND 012100Z.
//
NNNN

1. WDXS31 PGTW 312100
   
2. MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
   
3. SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 27S (COURTNEY) WARNING
   
4. NR 019//
   
5. RMKS/
   
6. 1. FOR METEOROLOGISTS.
   
7. 2. 6 HOUR SUMMARY AND ANALYSIS.
   
8. 
   
9. SUMMARY:
   
10.    INITIAL POSITION: 24.8S 88.8E
    
11.    INITIAL INTENSITY: 55 KTS
    
12.    GEOGRAPHIC REFERENCE: 885 NM SOUTH-SOUTHWEST OF THE COCOS
    
13. ISLANDS
    
14.    MOVEMENT PAST 6 HOURS: SOUTHWARD AT 02 KTS
    
15.    SIGNIFICANT WAVE HEIGHT: 21 FEET
    
16. 
    
17. SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
    
18. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A BARREN
    
19. VORTEX NOW DEVOID OF DEEP CONVECTION DUE TO A COMBINATION OF HIGH
    
20. VERTICAL SHEAR (55 KT) AND COOLING SEA SURFACE TEMPERATURES OF NOW
    
21. 24 TO 25 DEGREES CELSIUS. GIVEN THE LACK OF DEEP CONVECTION AND
    
22. APPROACH TOWARD THE SUBTROPICAL JET TO THE SOUTH, 27S IS UNDERGOING
    
23. SUBTROPICAL TRANSITION AT THIS TIME. THE INITIAL INTENSITY IS SET
    
24. AT 55 KT BASED ON A 311610Z ASCAT-C SCATTEROMETER PASS SHOWING
    
25. WINDS UP TO 50 KT IN THE SOUTHWESTERN QUADRANT, ACCOUNTING FOR
    
26. ASCAT'S KNOWN LOW BIAS AT THESE WIND SPEEDS. OBJECTIVE DVORAK
    
27. INTENSITY ESTIMATES ARE TOO LOW DUE TO THE LACK OF CONVECTION,
    
28. WHICH IS TYPICAL FOR A COMPACT STORM IN ITS DECAY PHASE OVER COOLER
    
29. WATER.
    
30. 
    
31. INITIAL WIND RADII BASIS: SCATTEROMETER DATA
    
32. 
    
33. CURRENT STEERING MECHANISM: SURFACE-LEVEL SUBTROPICAL RIDGE TO THE
    
34. SOUTH
    
35. 
    
36. AGENCY DVORAK AND AUTOMATED FIXES:
    
37.    PGTW: T3.0 - 45 KTS
    
38.    KNES: T2.5 - 35 KTS
    
39.    DEMS: T3.0 - 45 KTS
    
40.    FIMP: T3.5 - 55 KTS
    
41.    CIMSS SATCON: 38 KTS AT 311617Z
    
42.    CIMSS ADT: 32 KTS AT 311515Z
    
43.    CIMSS AIDT: 37 KTS AT 311715Z
    
44.    CIMSS D-PRINT: 29 KTS AT 311715Z
    
45. 
    
46. FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE
    
47.    VWS: 30+ KTS
    
48.    SST: 24-25 CELSIUS
    
49.    OUTFLOW: WEAK POLEWARD
    
50. 
    
51. ANALYSIS CONFIDENCE:
    
52.    INITIAL POSITION: HIGH
    
53.    INITIAL INTENSITY: MEDIUM
    
54.    INITIAL WIND RADII: MEDIUM
    
55. 
    
56. 3. FORECAST REASONING.
    
57. 
    
58. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
    
59. THE FORECAST FROM THE PREVIOUS WARNING.
    
60. 
    
61. FORECAST DISCUSSION: TROPICAL CYCLONE 27S (COURTNEY) IS IN
    
62. SPIN-DOWN MODE WITHIN A HOSTILE ENVIRONMENT AND WILL STEADILY DECAY
    
63. OVER THE NEXT COUPLE OF DAYS. THE STORM MOTION IS NOW SLOWING AS
    
64. THE VORTEX BECOMES SHALLOWER AND COMES UNDER THE INFLUENCE OF THE
    
65. SURFACE SUBTROPICAL RIDGE TO ITS SOUTH, IMPARTING AN EASTERLY
    
66. STEERING FLOW IN THE LOWER TROPOSPHERE. THIS WILL RESULT IN A
    
67. GRADUAL TURN SOUTHWESTWARD OR WESTWARD IN THE NEAR TERM, WHICH MAY
    
68. BE ALREADY BEGINNING. THE JTWC FORECAST DEPICTS THIS TURN SLIGHTLY
    
69. SOONER (FARTHER NORTH) THAN THE PREVIOUS FORECAST, FOLLOWING THE
    
70. SHIFT IN THE MODEL GUIDANCE ENVELOPE. THE JTWC FORECAST TERMINATES
    
71. IN 24 HOURS DUE TO THE EXPECTATION THAT 27S WILL COMPLETE
    
72. SUBTROPICAL TRANSITION BY THEN, THOUGH THE CIRCULATION MAY RETAIN
    
73. GALE-FORCE WINDS SLIGHTLY BEYOND THAT TIME.
    
74. 
    
75. MODEL DISCUSSION: THE DYNAMICAL MODELS DISAGREE SLIGHTLY ON THE
    
76. TIMING AND LATITUDE OF THE TURN WESTWARD DUE TO THE SHALLOWING
    
77. VORTEX, BUT AGREE THAT SUCH A TURN IS IMMINENT, AND THE JTWC TRACK
    
78. FORECAST IS CLOSE TO THE MULTI-MODEL CONSENSUS. THE JTWC INTENSITY
    
79. FORECAST IS ALSO CLOSE TO THE MULTI-MODEL CONSENSUS, WHICH IS IN
    
80. TIGHT AGREEMENT ON STEADY DECAY DURING THE NEXT 24 HOURS.
    
81. 
    
82. FORECAST CONFIDENCE:
    
83.    TRACK 0 - 72 HR: MEDIUM
    
84.    INTENSITY 0 - 72 HR: HIGH//
    
85. NNNN

复制代码

pocketbox

全球热带气旋监测公报
预报：吕心艳  签发：张 玲  2025 年 04 月 01 日 10 时
“考特尼”变性为温带气旋

时       间：1日08时（北京时）

海       域：南印度洋

命       名：“考特尼”，COURTNEY

中心位置：南纬25.5度、东经88.8度

最大风力：9级（23米/秒）

中心气压：990百帕

参考位置：毛里求斯路易港偏东方向约3270公里的洋面上

变化过程：“考特尼”已变性为温带气旋

预报结论：“考特尼”将以每小时10公里左右的速度向偏南方向移动，强度逐渐减弱。

（这是关于“考特尼”的最后一期监测公报）


图1 卫星红外监测图像（北京时间2025年04月01日08时00分）

yhh

WTXS31 PGTW 010900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 27S (COURTNEY) WARNING NR 020//
RMKS/
1. TROPICAL CYCLONE 27S (COURTNEY) WARNING NR 020   
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   010600Z --- NEAR 25.0S 88.4E
     MOVEMENT PAST SIX HOURS - 250 DEGREES AT 03 KTS
     POSITION ACCURATE TO WITHIN 030 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING SUBTROPICAL
   RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
                            140 NM SOUTHEAST QUADRANT
                            110 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   REPEAT POSIT: 25.0S 88.4E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   011800Z --- 25.2S 87.9E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   SUBTROPICAL
   RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
                            110 NM SOUTHEAST QUADRANT
                            080 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
    ---
REMARKS:
010900Z POSITION NEAR 25.1S 88.3E.
01APR25. TROPICAL CYCLONE 27S (COURTNEY), LOCATED APPROXIMATELY
907 NM SOUTH-SOUTHWEST OF THE COCOS ISLANDS, HAS TRACKED WEST-
SOUTHWESTWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTI-SPECTRAL SATELLITE IMAGERY DEPICTS A COMPLETELY EXPOSED,
ELONGATED, LOW-LEVEL CIRCULATION CENTER (LLCC) WITH CONVECTION
HEAVILY SHEARED OFF TO THE SOUTHEAST. A 010232Z METOP-B ASCAT IMAGE
REVEALED THE ASYMMETRIC WIND FIELD WITH 40-45 KTS CONFINED TO THE
SOUTHERN SEMICIRCLE. ENVIRONMENTAL ANALYSIS INDICATES THAT TC 27S IS
PLACED WITHIN A HIGHLY UNFAVORABLE ENVIRONMENT CHARACTERIZED BY
VERY HIGH (OVER 50 KTS) NORTHWESTERLY VERTICAL WIND SHEAR,
SIGNIFICANT DRY AIR ENTRAINMENT, AND COOL (24-25 C) SEA SURFACE
TEMPERATURES. TC 27S IS EXPECTED TO TRACK FURTHER WESTWARD OVER THE
NEXT COUPLE DAYS, ALONG THE NORTHERN PERIPHERY OF A SHALLOW
SUBTROPICAL RIDGE POSITIONED TO THE SOUTH OF THE SYSTEM. INTENSITY
IS FORECAST TO CONTINUE DROPPING IN RESPONSE TO THE INCREASINGLY
HOSTILE ENVIRONMENT. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT
REGARDING BOTH THE WESTWARD TRACK AND THE CONTINUED WEAKENING TREND.
SUBTROPICAL TRANSITION IS FORECAST TO COMPLETE WITHIN THE NEXT 12
HOURS AS THE VORTEX FURTHER SHALLOWS AND BECOMES COMPLETELY TAKEN
OVER BY DRY AIR. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE
JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY
MONITORED FOR SIGNS OF REGENERATION. MINIMUM CENTRAL PRESSURE AT
010600Z IS 993 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 010600Z IS 20
FEET.//
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ygsj24

ABIO10 PGTW 011800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN
OCEAN/011800Z-021800ZAPR2025//
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: NONE.
   C. SUBTROPICAL SYSTEM SUMMARY:
      (1) THE AREA OF CONVECTION (REMNANTS 27S) PREVIOUSLY LOCATED
NEAR 25.0S 88.4E IS NOW LOCATED NEAR 24.8S 88.6E, APPROXIMATELY 888 NM
SOUTH-SOUTHWEST OF THE COCOS ISLANDS. THE SYSTEM IS CURRENTLY CLASSIFIED
AS A SUBTROPICAL STORM, GENERALLY CHARACTERIZED AS HAVING BOTH TROPICAL
AND MID-LATITUDE CYCLONE FEATURES. ENHANCED INFRARED SATELLITE IMAGERY
(EIR) DEPICTS AN EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH NO
APPARENT DEEP CONVECTION SUPPORTED BY A 011221Z SSMIS F16 91H MICROWAVE
IMAGE. ENVIRONMENTAL ANALYSIS REVEALS AN UNFAVORABLE ENVIRONMENT FOR
DEVELOPMENT WITH HIGH VERTICAL WIND SHEAR (VWS), WEAK UPPER-LEVEL
OUTFLOW AND COLD SEA SURFACE TEMPERATURES OF 24-25 C. BOTH
DETERMINISTIC AND ENSEMBLE MODELS GENERALLY AGREE THAT THE SYSTEM WILL
WEAKEN OVER THE NEXT 48 HOURS, ALTHOUGH THE GEFS MODEL SUGGESTS THAT
THE SYSTEM WILL MAINTAIN ITS INTENSITY DURING THIS PERIOD. FOR HAZARDS
AND WARNINGS, REFERENCE THE FLEET WEATHER CENTER SAN DIEGO HIGH WINDS
AND SEAS PRODUCT OR REFER TO LOCAL WMO DESIGNATED FORECAST AUTHORITY.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 38 TO 43 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 998 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN
THE NEXT 24 HOURS IS LOW.
      (2) NO OTHER SUBTROPICAL SYSTEMS.//
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