科科斯群岛以西二级热带气旋“格兰特”(03U/09S.Grant) - 逐渐西行

ygsj24

IDW24400
Australian Bureau of Meteorology
Tropical Cyclone Warning Centre

Media: The Standard Emergency Warning Signal should NOT be used with this
warning.

TOP PRIORITY FOR IMMEDIATE BROADCAST

TROPICAL CYCLONE ADVICE NUMBER 10
Issued at 5:38 am WST on Wednesday 24 December 2025

Headline:
Tropical Cyclone Grant will pass close to the Cocos (Keeling) Islands later
today or early Christmas Day.

Areas Affected:
Warning zone: Cocos (Keeling) Islands.

Watch zone: None.

Cancelled zone: None.

Details of Tropical Cyclone Grant 03U at 3:30 am CCT:
Intensity: Category 1, sustained winds near the centre of 65 kilometres per
hour with wind gusts to 95 kilometres per hour.
Location: within 45 kilometres of 12.3 degrees South 98.5 degrees East,
estimated to be 180 kilometres east of Cocos (Keeling) Islands.
Movement: west northwest at 8 kilometres per hour.

Tropical Cyclone Grant (03U) is located over the Indian Ocean, to the east of
the Cocos (Keeling) Islands. It is forecast to move generally westwards, and
could strengthen to category 2 this evening. It is expected to pass close to
the Cocos (Keeling) Islands later today (Christmas Eve) or early on Thursday
(Christmas Day).

Hazards:
GALES with DAMAGING WIND GUSTS to 100 km/h could develop at the Cocos (Keeling)
Islands from as early as late morning today, but more likely from this
afternoon. As the destructive core of Tropical Cyclone Grant passes close to
the Cocos (Keeling) Islands a period of DESTRUCTIVE WIND GUSTS to 140 km/h are
possible late this evening or early Thursday morning.

HEAVY RAINFALL which may lead to FLASH FLOODING is possible this morning,
becoming more likely this afternoon.

Tides may rise above the normal high tide mark on the Wednesday (today) and
Thursday evening high tides, with LARGE WAVES and MINOR FLOODING of low-lying
coastal areas, and strong currents in the lagoon.

Recommended Action:
For the latest alerts and warnings from the Cocos (Keeling) Islands Emergency
Management Committee visit www.emergency.wa.gov.au or download the Emergency WA
app.

Next Advice:
The next advice will be issued by 7:30 am CCT Wednesday 24 December.


A map showing the track of the cyclone is available at:
http://www.bom.gov.au/cyclone

	Time (CCT)	Intensity Category	Latitude (decimal deg.)	Longitude (decimal deg.)	Estimated Position Accuracy (km)
0hr	4 am December 24	1	12.3S	98.5E	45
+6hr	10 am December 24	1	12.2S	98.1E	70
+12hr	4 pm December 24	1	12.2S	97.7E	85
+18hr	10 pm December 24	2	12.1S	97.2E	95
+24hr	4 am December 25	2	12.0S	96.7E	95
+36hr	4 pm December 25	2	12.0S	95.4E	105
+48hr	4 am December 26	2	12.0S	94.0E	120
+60hr	4 pm December 26	2	12.1S	92.4E	135
+72hr	4 am December 27	2	12.2S	90.9E	165

pocketbox

IDW27700
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
at: 0131 UTC 24/12/2025
Name: Tropical Cyclone Grant
Identifier: 03U
Data At: 0000 UTC
Latitude: 12.2S
Longitude: 98.2E
Location Accuracy: within 25nm (45 km)
Movement Towards: west northwest (287 deg)
Speed of Movement: 5 knots (9 km/h)
Maximum 10-Minute Wind: 35 knots (65 km/h)
Maximum 3-Second Wind Gust: 50 knots (95 km/h)
Central Pressure: 996 hPa
Radius of 34-knot winds NE quadrant: 25 nm (45 km)
Radius of 34-knot winds SE quadrant: 50 nm (95 km)
Radius of 34-knot winds SW quadrant: 40 nm (75 km)
Radius of 34-knot winds NW quadrant:
Radius of 48-knot winds NE quadrant:
Radius of 48-knot winds SE quadrant:
Radius of 48-knot winds SW quadrant:
Radius of 48-knot winds NW quadrant:
Radius of 64-knot winds:   nm (  km)
Radius of Maximum Winds: 15 nm (30 km)
Dvorak Intensity Code: T2.0/2.5/W1.0/24HRS SST:S0.0/06HRS
Pressure of outermost isobar: 1004 hPa
Radius of outermost closed isobar: 120 nm (220 km)
FORECAST DATA
Date/Time    : Location    : Loc. Accuracy: Max Wind   : Central Pressure
(UTC)        : degrees     :      nm  (km): knots(km/h): hPa
+06:  24/0600: 12.1S  97.8E:     040 (075):  040  (075):  993
+12:  24/1200: 12.1S  97.4E:     045 (085):  045  (085):  990
+18:  24/1800: 12.0S  96.9E:     055 (100):  050  (095):  987
+24:  25/0000: 12.0S  96.3E:     055 (105):  050  (095):  987
+36:  25/1200: 12.0S  95.0E:     065 (120):  060  (110):  980
+48:  26/0000: 12.0S  93.6E:     065 (125):  060  (110):  981
+60:  26/1200: 12.1S  92.0E:     075 (140):  055  (100):  984
+72:  27/0000: 12.2S  90.5E:     090 (165):  055  (100):  984
+96:  28/0000: 12.9S  86.5E:     115 (215):  055  (100):  985
+120: 29/0000: 13.7S  82.1E:     135 (245):  060  (110):  982
REMARKS:
Tropical Cyclone Grant has continued having deeper convection over the last 6
hours but not shown strong signs of strengthening yet. There is not great
confidence in the position of the low level centre due to the lack of a strong
cloud signature in IR and no recent useful scatterometry passes.

Dvorak analysis: Uncertain DT 1.5 to 2.0 based on a 0.2-0.4 wrap curved band
pattern. MET is 2.5 with a W- 24 hour trend, PAT is decreased to 2.0 based on
EIR imagery. FT=2.0 (based off PAT), CI=2.5. Objective guidance estimates
(1-min mean) at 0000 UTC are ADT 37 kn, AiDT 31 kn, DPRINT 31 kn, DMINT (1838
UTC) 29 kn and SATCON (2030 UTC) 38 kn.  

Intensity was set at 35 kn with gales to the south and east of the low level
centre. This is based on the 1144 UTC SAR pass which showed gales to the south
and east of the system.  

CIMMS upper wind analysis at 1800 UTC indicates NE'ly shear over Grant is 10-15
kn. Dry air remains present around the system, and has potentially contributed
to the observed period of no deep convection.  

Over the last 6 hours upper support was minimal, with weak poleward outflow and
low upper divergence. However over the last hour the system may have started
reacting to increased upper divergence due to interactions with a short wave
trough to the south. This may remain for a period and combined with low shear
may allow the system to start strengthening today, possibly reaching category 2
Wednesday evening as it moves over the Cocos (Keeling) Islands.

The medium term intensity forecast remains mixed due to the mid-week
amplification of the subtropical jet. NWP guidance varies in the handling of
this, with some guidance showing weakening on Thursday and Friday likely due to
dry air being ingested, and other guidance maintaining a stronger system
through until the next week. The current forecast maintains category 2
intensity until early next week where an intensification to category 3 is
possible. Being a small system, it is likely that the intensity will continue
to fluctuate on short timescales.

Track guidance continues to show good confidence in a general westward motion.
Recent guidance does suggest a period of west north-westerly motion during
Wednesday which would take Grant further to the north of the Cocos (Keeling)
Islands. There remains some short term variation in the speed of motion,
however the current forecast track has Grant passing close to the Cocos
(Keeling) Islands between late on Christmas Eve and during the morning of
Christmas Day. Grant is expected to be a category 2 system at this time,
however there is around a 5% chance it intensifies into a category 3 system
prior to this, with the chance of category 3 impacts at the Cocos (Keeling)
Islands being even lower.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 24/0730 UTC.

---

IDW24400

Australian Bureau of Meteorology
Tropical Cyclone Warning Centre

Media: The Standard Emergency Warning Signal should NOT be used with this warning.

TOP PRIORITY FOR IMMEDIATE BROADCAST
TROPICAL CYCLONE ADVICE NUMBER 11
Issued at 8:58 am WST on Wednesday 24 December 2025

Headline:
Tropical Cyclone Grant will begin impacting the Cocos (Keeling) Islands later today and early Christmas Day.

Areas Affected:
Warning Zone
Cocos (Keeling) Islands.

Watch Zone
None.

Cancelled Zone
None.

Details of Tropical Cyclone Grant 03U at 6:30 am CCT:
Intensity: Category 1, sustained winds near the centre of 65 kilometres per hour with wind gusts to 95 kilometres per hour.

Location: within 45 kilometres of 12.2 degrees South 98.2 degrees East, estimated to be 150 kilometres east of Cocos (Keeling) Islands.

Movement: west northwest at 9 kilometres per hour.

Tropical Cyclone Grant (03U) is located over the Indian Ocean, to the east of the Cocos (Keeling) Islands. It is forecast to move generally westwards, and could strengthen to category 2 later this evening. It is expected to pass close to the Cocos (Keeling) Islands later this evening (Christmas Eve) or early on Thursday (Christmas Day).

Hazards:
GALES with DAMAGING WIND GUSTS to 120 km/h could develop at the Cocos (Keeling) Islands from around midday today, but more likely from this afternoon. DESTRUCTIVE WIND GUSTS to 140 km/h are possible late this evening or early Thursday morning as the core of Tropical Cyclone Grant passes near the Islands.

HEAVY RAINFALL which may lead to FLASH FLOODING is possible this morning, becoming more likely this afternoon and overnight tonight.

Tides may rise above the normal high tide mark on the Wednesday (today) high tide, with LARGE WAVES and MINOR FLOODING of low-lying coastal areas, and strong currents in the lagoon.

Recommended Action:
For the latest alerts and warnings from the Cocos (Keeling) Islands Emergency Management Committee visit www.emergency.wa.gov.au or download the Emergency WA app.

Next Advice:
The next advice will be issued by 10:30 am CCT Wednesday 24 December.

A map showing the track of the cyclone is available at: http://www.bom.gov.au/cyclone

	Time (CCT)	Intensity Category	Latitude (decimal deg.)	Longitude (decimal deg.)	Estimated Position Accuracy (km)
0hr	7 am December 24	1	12.2S	98.2E	45
+6hr	1 pm December 24	1	12.1S	97.8E	75
+12hr	7 pm December 24	1	12.1S	97.4E	85
+18hr	1 am December 25	2	12.0S	96.9E	100
+24hr	7 am December 25	2	12.0S	96.3E	105
+36hr	7 pm December 25	2	12.0S	95.0E	120
+48hr	7 am December 26	2	12.0S	93.6E	125
+60hr	7 pm December 26	2	12.1S	92.0E	140
+72hr	7 am December 27	2	12.2S	90.5E	165

pocketbox

全球热带气旋监测公报
预报：曹越男  签发：向纯怡  2025 年 12 月 24 日 10 时
“格兰特”向西偏北方向移动

时  间: 24日08时（北京时）

海  域: 澳大利亚附近海域

命  名: “格兰特”，GRANT

中心位置:  南纬12.2度，东经98.2度

强度等级:  一级热带气旋

最大风力: 8级，18米/秒，相当于我国的热带风暴级

中心气压: 995百帕

参考位置: 距离科科斯（基林）群岛偏东方向约150公里

变化过程: 过去24小时，“格兰特”强度变化不大

预报结论: “格兰特”将以每小时10公里左右的速度向西偏北方向移动，强度逐渐加强



图1  卫星红外监测图像（北京时间2025年12月24日08时00分）

ygsj24

WTXS32 PGTW 240300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 09S (GRANT) WARNING NR 014//
RMKS/
1. TROPICAL CYCLONE 09S (GRANT) WARNING NR 014   
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   240000Z --- NEAR 12.1S 98.2E
     MOVEMENT PAST SIX HOURS - 290 DEGREES AT 06 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   REPEAT POSIT: 12.1S 98.2E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   241200Z --- 11.9S 97.5E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 270 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   250000Z --- 11.9S 96.5E
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT
                            020 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 265 DEG/ 06 KTS
    ---
   36 HRS, VALID AT:
   251200Z --- 12.0S 95.3E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 010 NM NORTHEAST QUADRANT
                            015 NM SOUTHEAST QUADRANT
                            015 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
                            025 NM SOUTHEAST QUADRANT
                            025 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 260 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   260000Z --- 12.2S 93.9E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 010 NM NORTHEAST QUADRANT
                            015 NM SOUTHEAST QUADRANT
                            015 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
                            025 NM SOUTHEAST QUADRANT
                            025 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 265 DEG/ 08 KTS
    ---
   72 HRS, VALID AT:
   270000Z --- 12.6S 90.6E
   MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
                            025 NM SOUTHEAST QUADRANT
                            025 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 265 DEG/ 10 KTS
    ---
   LONG RANGE OUTLOOK:
    ---
   96 HRS, VALID AT:
   280000Z --- 13.1S 86.4E
   MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
                            025 NM SOUTHEAST QUADRANT
                            025 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   VECTOR TO 120 HR POSIT: 260 DEG/ 10 KTS
    ---
   120 HRS, VALID AT:
   290000Z --- 13.7S 82.3E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 010 NM NORTHEAST QUADRANT
                            020 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            030 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
    ---
REMARKS:
240300Z POSITION NEAR 12.0S 98.0E.
24DEC25. TROPICAL CYCLONE 09S (GRANT), LOCATED APPROXIMATELY 76
NM EAST OF THE COCOS ISLANDS, HAS TRACKED WEST-NORTHWESTWARD AT
06 KNOTS OVER THE PAST SIX HOURS.
MINIMUM CENTRAL PRESSURE AT 240000Z IS 997 MB. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 240000Z IS 16 FEET.
NEXT WARNINGS AT 241500Z AND 250300Z.//
NNNN

1. WDXS32 PGTW 240300
   
2. MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
   
3. SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 09S (GRANT) WARNING NR
   
4. 014//
   
5. RMKS/
   
6. 1. FOR METEOROLOGISTS.
   
7. 2. 6 HOUR SUMMARY AND ANALYSIS.
   
8. 
   
9. SUMMARY:
   
10.    INITIAL POSITION: 12.1S 98.2E
    
11.    INITIAL INTENSITY: 40 KTS
    
12.    GEOGRAPHIC REFERENCE: 76 NM EAST OF THE COCOS ISLANDS
    
13.    MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 06 KTS
    
14.    SIGNIFICANT WAVE HEIGHT: 16 FEET
    
15. 
    
16. SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
    
17. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
    
18. CYCLONE 09S (GRANT) WITH SIGNIFICANTLY IMPROVED CENTRAL CONVECTION
    
19. AND AN APPARENT DROP IN VERTICAL WIND SHEAR OVER THE PAST 6 HOURS.
    
20. CLOUD ELEMENTS WITHIN THE EASTERN PORTION OF THE CIRCULATION ARE NO
    
21. LONGER BEING PRESSED INWARD AND OUTFLOW APPEARS TO BE LESS
    
22. RESTRICTED. HOWEVER, DRIER AIR CONTINUES TO BE PULLED INTO THE
    
23. VORTEX FROM THE WEST AND NORTH. A 232330Z SSMIS 91 GHZ MICROWAVE
    
24. IMAGE REVEALED TWO DISTINCT LOBES OF DEEP CONVECTION WITHIN THE
    
25. EASTERN AND WESTERN SEMICIRCLES OF THE CIRCULATION AND DEFINED
    
26. LOW-LEVEL CLOUD LINES WRAPPING INTO THE CENTER. THE INITIAL
    
27. POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON THE COMBINATION
    
28. OF ANIMATED MSI AND THE SSMIS MICROWAVE IMAGE. THE INITIAL
    
29. INTENSITY OF 40 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE
    
30. AGENCY DVORAK AND CIMSS OBJECTIVE INTENSITY ESTIMATES LISTED BELOW.
    
31. ENVIRONMENTAL ANALYSIS INDICATES THAT 09S IS IN A MARGINALLY
    
32. FAVORABLE ENVIRONMENT CHARACTERIZED BY MODERATE POLEWARD OUTFLOW,
    
33. LOW (10-15 KTS) NORTHEASTERLY VERTICAL WIND SHEAR, SLIGHT DRY AIR
    
34. ENTRAINMENT, AND WARM (27-28 C) SEA SURFACE TEMPERATURES.
    
35. 
    
36. INITIAL WIND RADII BASIS: PERSISTENCE WITH SLIGHT ADJUSTMENTS BASED
    
37. ON THE OBJECTIVE BEST TRACK
    
38. 
    
39. CURRENT STEERING MECHANISM: NORTHEASTERN PERIPHERY OF A SUBTROPICAL
    
40. RIDGE (STR) CENTERED FAR TO THE SOUTHWEST.
    
41. 
    
42. AGENCY DVORAK AND AUTOMATED FIXES:
    
43.    PGTW: T3.0 - 45 KTS
    
44.    DEMS: T3.0 - 45 KTS
    
45.    APRF: T2.5 - 35 KTS
    
46.    CIMSS SATCON: 38 KTS AT 240030Z
    
47.    CIMSS ADT: 39 KTS AT 240030Z
    
48.    CIMSS AIDT: 31 KTS AT 240030Z
    
49.    CIMSS D-MINT: 35 KTS AT 232314Z
    
50.    CIMSS D-PRINT: 32 KTS AT 240030Z
    
51. 
    
52. FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
    
53.    VWS: 10-15 KTS
    
54.    SST: 27-28 CELSIUS
    
55.    OUTFLOW: MODERATE POLEWARD
    
56. 
    
57. ANALYSIS CONFIDENCE:
    
58.    INITIAL POSITION: MEDIUM
    
59.    INITIAL INTENSITY: MEDIUM
    
60.    INITIAL WIND RADII: LOW
    
61. 
    
62. 3. FORECAST REASONING.
    
63. 
    
64. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
    
65. THE FORECAST FROM THE PREVIOUS WARNING.
    
66. 
    
67. FORECAST DISCUSSION: TC 09S IS FORECAST TO TRACK NORTHWESTWARD FOR
    
68. ONLY ANOTHER 12 HOURS BEFORE THE TRACK FLATTENS TO A MORE WESTWARD
    
69. TRAJECTORY AS THE SYSTEM TRACKS ALONG THE NORTHERN PERIPHERY OF
    
70. RIDGING TO BOTH THE SOUTHEAST AND SOUTHWEST. THE WESTWARD MOVEMENT
    
71. WILL PERSIST THROUGH AROUND TAU 60. NEAR TAU 60, THE STR TO THE
    
72. SOUTHEAST OF 09S IS EXPECTED TO BUILD AND MERGE WITH THE STR THAT
    
73. IS TO THE SOUTHWEST. AFTER THE TWO RIDGES MERGE, THE RESULTING
    
74. RIDGING COMPLEX WILL BE ORIENTED IN A NORTHEAST-SOUTHWEST
    
75. ORIENTATION. AS A RESULT, 09S IS FORECAST TO TRACK
    
76. WEST-SOUTHWESTWARD WITH INCREASING TRACK SPEEDS THROUGH THE
    
77. REMAINDER OF THE FORECAST PERIOD. REGARDING INTENSITY, 09S IS
    
78. FORECAST TO STEADILY INTENSIFY OVER THE NEXT 36 HOURS TO 65 KTS AS
    
79. SHEAR REMAINS LOW (AROUND 10 KTS) AND THE VORTEX MOISTENS. NEAR TAU
    
80. 36, NORTHERLY SHEAR IS EXPECTED TO RISE TO AROUND 15-20 KTS AND DRY
    
81. AIR IS EXPECTED TO BEGIN PENETRATING THE VORTEX FROM THE NORTH.
    
82. THESE TWO FACTORS WILL ACT TO HALT THE INTENSIFICATION TREND AND
    
83. WEAKEN THE SYSTEM THROUGH TAU 96. AFTER TAU 96, MODELS GENERALLY
    
84. AGREE ON THE SYSTEM REMOISTENING AND SHEAR LOWERING, CAUSING 09S TO
    
85. BEGIN REINTENSIFYING.
    
86. 
    
87. MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN GOOD
    
88. AGREEMENT WITH A MERE 100 NM CROSS-TRACK SPREAD AT TAU 120 WITH
    
89. LITTLE ALONG-TRACK SPREAD. THE JTWC TRACK FORECAST IS PLACED CLOSE
    
90. TO THE MULTI-MODEL CONSENSUS WITH OVERALL HIGH CONFIDENCE. MODELS
    
91. GENERALLY AGREE ON INTENSIFICATION THROUGH TAU 36, AND THEN
    
92. WEAKENING THROUGH TAU 96 BEFORE REINTENSIFYING. HOWEVER,
    
93. INTENSITIES RANGE SIGNIFICANTLY AT TAU 36 WITH HWRF SUGGESTING 45
    
94. KTS WHILE HAFS-A SUGGESTS 80 KTS. DTOP (A RAPID INTENSIFICATION
    
95. AID) IS ALSO TRIGGERED THIS MODEL RUN, ADDING UNCERTAINTY TO THE
    
96. INTENSITY FORECAST. THE JTWC INTENSITY FORECAST IS PLACED CLOSE TO
    
97. THE CONSENSUS WITH MEDIUM CONFIDENCE.
    
98. 
    
99. FORECAST CONFIDENCE:
    
100.    TRACK 00-72 HR: HIGH
     
101.    TRACK 72-120 HR: HIGH
     
102.    INTENSITY 00-72 HR: MEDIUM
     
103.    INTENSITY 72-120 HR: MEDIUM//
     
104. NNNN

复制代码

pocketbox

IDW24400

Australian Bureau of Meteorology
Tropical Cyclone Warning Centre

Media: The Standard Emergency Warning Signal should NOT be used with this warning.

TOP PRIORITY FOR IMMEDIATE BROADCAST
TROPICAL CYCLONE ADVICE NUMBER 12
Issued at 11:55 am WST on Wednesday 24 December 2025

Headline:
Tropical Cyclone Grant will continue impacting the Cocos (Keeling) Islands today and during Christmas Day.

Areas Affected:
Warning Zone
Cocos (Keeling) Islands.

Watch Zone
None.

Cancelled Zone
None.

Details of Tropical Cyclone Grant 03U at 9:30 am CCT:
Intensity: Category 1, sustained winds near the centre of 65 kilometres per hour with wind gusts to 95 kilometres per hour.

Location: within 45 kilometres of 12.1 degrees South 97.9 degrees East, estimated to be 115 kilometres east of Cocos (Keeling) Islands.

Movement: west northwest at 10 kilometres per hour.

Tropical Cyclone Grant (03U) is located over the Indian Ocean, to the east of the Cocos (Keeling) Islands. It is forecast to move generally westwards, and could strengthen to category 2 overnight tonight. It is expected to pass close to the Cocos (Keeling) Islands later this evening (Christmas Eve) or early on Thursday (Christmas Day).

Hazards:
GALES with DAMAGING WIND GUSTS to 120 km/h could develop at the Cocos (Keeling) Islands from around midday today, but more likely from this afternoon. DESTRUCTIVE WIND GUSTS to 140 km/h are possible later this evening or early Thursday morning as the core of Tropical Cyclone Grant passes near the Islands.

HEAVY RAINFALL which may lead to FLASH FLOODING is possible and becoming more likely this afternoon and overnight tonight.

Tides may rise above the normal high tide mark on the Wednesday evening's high tide, with LARGE WAVES and MINOR FLOODING of low-lying coastal areas, and strong currents in the lagoon.

Recommended Action:
For the latest alerts and warnings from the Cocos (Keeling) Islands Emergency Management Committee visit www.emergency.wa.gov.au or download the Emergency WA app.

Next Advice:
The next advice will be issued by 1:30 pm CCT Wednesday 24 December.

A map showing the track of the cyclone is available at: http://www.bom.gov.au/cyclone

	Time (CCT)	Intensity Category	Latitude (decimal deg.)	Longitude (decimal deg.)	Estimated Position Accuracy (km)
0hr	10 am December 24	1	12.1S	97.9E	45
+6hr	4 pm December 24	1	12.0S	97.6E	70
+12hr	10 pm December 24	1	11.9S	97.1E	85
+18hr	4 am December 25	2	11.9S	96.6E	100
+24hr	10 am December 25	2	11.9S	96.0E	105
+36hr	10 pm December 25	2	12.0S	94.9E	115
+48hr	10 am December 26	2	12.0S	93.7E	120
+60hr	10 pm December 26	2	12.1S	92.3E	135
+72hr	10 am December 27	2	12.3S	90.7E	165

xiaoqianWX

？

桑美和伊欧凯

xiaoqianWX 发表于 2025-12-24 12:03
？

可能是个平西王

pocketbox

IDW27700
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
at: 0714 UTC 24/12/2025
Name: Tropical Cyclone Grant
Identifier: 03U
Data At: 0600 UTC
Latitude: 11.9S
Longitude: 97.8E
Location Accuracy: within 20nm (35 km)
Movement Towards: west northwest (292 deg)
Speed of Movement: 5 knots (10 km/h)
Maximum 10-Minute Wind: 35 knots (65 km/h)
Maximum 3-Second Wind Gust: 50 knots (95 km/h)
Central Pressure: 996 hPa
Radius of 34-knot winds NE quadrant: 25 nm (45 km)
Radius of 34-knot winds SE quadrant: 50 nm (95 km)
Radius of 34-knot winds SW quadrant: 40 nm (75 km)
Radius of 34-knot winds NW quadrant:
Radius of 48-knot winds NE quadrant:
Radius of 48-knot winds SE quadrant:
Radius of 48-knot winds SW quadrant:
Radius of 48-knot winds NW quadrant:
Radius of 64-knot winds:   nm (  km)
Radius of Maximum Winds: 15 nm (30 km)
Dvorak Intensity Code: T2.5/2.5/W0.5/24HRS SST:S0.0/06HRS
Pressure of outermost isobar: 1004 hPa
Radius of outermost closed isobar: 150 nm (280 km)
FORECAST DATA
Date/Time    : Location    : Loc. Accuracy: Max Wind   : Central Pressure
(UTC)        : degrees     :      nm  (km): knots(km/h): hPa
+06:  24/1200: 11.7S  97.5E:     030 (060):  040  (075):  993
+12:  24/1800: 11.7S  97.1E:     040 (080):  050  (095):  987
+18:  25/0000: 11.8S  96.6E:     050 (090):  050  (095):  987
+24:  25/0600: 11.9S  96.0E:     055 (100):  055  (100):  984
+36:  25/1800: 11.8S  94.8E:     060 (115):  060  (110):  980
+48:  26/0600: 11.9S  93.3E:     065 (125):  060  (110):  981
+60:  26/1800: 12.0S  91.9E:     075 (140):  055  (100):  984
+72:  27/0600: 12.3S  90.2E:     090 (165):  055  (100):  985
+96:  28/0600: 13.0S  86.0E:     105 (195):  060  (110):  982
+120: 29/0600:             :              :            :     
REMARKS:
Tropical Cyclone Grant has maintained its intensity of category 1 with tighter
banding but with warming convection. It's recent movement has been to the
northwest, but it is expected to take a more westerly track from tonight. There
is moderate confidence in the position with microwave and visible imagery used.

Dvorak analysis: Uncertain DT 2.0 to 2.5 based on a 0.3-0.5 wrap curved band
pattern, using the stronger eastern curved band. MET is 3.0 with a S 24 hour
trend, PAT is decreased to 2.5. FT=2.5 (based off PAT), CI=2.5. Objective
guidance estimates (1-min mean) at 0600 UTC are ADT 45 kn, AiDT 32 kn, DPRINT
32 kn, DMINT (2330 UTC) 33 kn and SATCON (0130 UTC) 38 kn.  ADT is using the
CDO pattern and therefore may be over estimating intensity.  

Intensity was set at 35 kn with gales to the south and east of the low level
centre. This is based on the 1144 UTC SAR pass which showed gales to the south
and east of the system and where strongest convection is occurring.

CIMMS upper wind analysis at 0000 UTC indicates NE'ly shear over Grant is 10-15
kn. Dry air remains present around the system, but appears to not be affecting
the system too much.  

During this morning the system was reacting to increased upper divergence due
to interactions with a short wave trough to the south. However since then,
convection has warmed and become patchy in the curved band as the diurnal
minimum is occurring.  In the next 24 hours, low shear and some weak upper
divergence may allow the system to strengthen further, possibly reaching
category 2 Wednesday evening as it moves near the Cocos (Keeling) Islands.

From later Thursday and Friday, the intensity forecast remains mixed due to the
mid-week amplification of the subtropical jet. NWP guidance varies in the
handling of this, with some guidance showing weakening on from later Thursday
likely due to dry air being ingested, and other guidance maintaining a stronger
system through until the next week. The current forecast maintains category 2
intensity until early next week where an intensification to category 3 is
possible. Being a small system, it is likely that the intensity will continue
to fluctuate on short timescales.

The system has taken a more northwesterly track over the last 6 hours, which
was well captured by the ECMWF. But with the restrengthening of the ridge to
the east overnight tonight, the system is likely to take a more westerly track
tonight, passing close to the Cocos (Keeling) Islands, possibly as a category 2
system. In the longer term there is good agreement in guidance that the system
will continue moving west, out of the Australian region during the weekend.

Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 24/1330 UTC.

---

IDW24400

Australian Bureau of Meteorology
Tropical Cyclone Warning Centre

Media: The Standard Emergency Warning Signal should NOT be used with this warning.

TOP PRIORITY FOR IMMEDIATE BROADCAST
TROPICAL CYCLONE ADVICE NUMBER 13
Issued at 2:53 pm WST on Wednesday 24 December 2025

Headline:
Tropical Cyclone Grant will continue impacting the Cocos (Keeling) Islands today and during Christmas Day.

Areas Affected:
Warning Zone
Cocos (Keeling) Islands.

Watch Zone
None.

Cancelled Zone
None.

Details of Tropical Cyclone Grant 03U at 12:30 pm CCT:
Intensity: Category 1, sustained winds near the centre of 65 kilometres per hour with wind gusts to 95 kilometres per hour.

Location: within 35 kilometres of 11.9 degrees South 97.8 degrees East, estimated to be 110 kilometres east northeast of Cocos (Keeling) Islands.

Movement: west northwest at 10 kilometres per hour.

Tropical Cyclone Grant (03U) is located over the Indian Ocean, to the east northeast of the Cocos (Keeling) Islands. It is forecast to move generally westwards, and could strengthen to category 2 overnight tonight. It is expected to pass close to the Cocos (Keeling) Islands later this evening (Christmas Eve) or early on Thursday (Christmas Day).

Hazards:
GALES with DAMAGING WIND GUSTS to 120 km/h could develop at the Cocos (Keeling) Islands this afternoon or evening. DESTRUCTIVE WIND GUSTS to 140 km/h are possible late this evening or early Thursday morning as the core of Tropical Cyclone Grant passes near the Islands. Conditions are forecast to ease from Thursday afternoon.

HEAVY RAINFALL which may lead to FLASH FLOODING is possible, becoming more likely this evening and overnight tonight.

Tides may rise above the normal high tide mark on the Wednesday evening's high tide, with LARGE WAVES and MINOR FLOODING of low-lying coastal areas, and strong currents in the lagoon.

Recommended Action:
For the latest alerts and warnings from the Cocos (Keeling) Islands Emergency Management Committee visit www.emergency.wa.gov.au or download the Emergency WA app.

Next Advice:
The next advice will be issued by 4:30 pm CCT Wednesday 24 December.

A map showing the track of the cyclone is available at: http://www.bom.gov.au/cyclone

	Time (CCT)	Intensity Category	Latitude (decimal deg.)	Longitude (decimal deg.)	Estimated Position Accuracy (km)
0hr	1 pm December 24	1	11.9S	97.8E	35
+6hr	7 pm December 24	1	11.7S	97.5E	60
+12hr	1 am December 25	2	11.7S	97.1E	80
+18hr	7 am December 25	2	11.8S	96.6E	90
+24hr	1 pm December 25	2	11.9S	96.0E	100
+36hr	1 am December 26	2	11.8S	94.8E	115
+48hr	1 pm December 26	2	11.9S	93.3E	125
+60hr	1 am December 27	2	12.0S	91.9E	140
+72hr	1 pm December 27	2	12.3S	90.2E	165

Enceladus

根据部分模式的预测，这个旋可能会比较长寿，长达十五到二十天

pocketbox

全球热带气旋监测公报
预报：曹越男、徐立  签发：向纯怡  2025 年 12 月 24 日 18 时
“格兰特”向西偏北方向移动

时  间: 24日14时（北京时）

海  域: 澳大利亚附近海域

命  名: “格兰特”，GRANT

中心位置:  南纬11.9度，东经97.8度

强度等级:  一级热带气旋

最大风力: 8级，18米/秒，相当于我国的热带风暴级

中心气压: 996百帕

参考位置: 距离科科斯（基林）群岛偏东方向约105公里

变化过程: 过去24小时，“格兰特”强度变化不大

预报结论: “格兰特”将以每小时10公里左右的速度向西偏北方向移动，强度逐渐加强



图1  卫星红外监测图像（北京时间2025年12月24日14时00分）