迪戈加西亚东南强热带气旋第5号“格兰特”(03U/09S.Grant) - 逐渐西行 - MFR:110KT JTWC:120KT

ERROL_150

微波扫描上LLCC逐渐裸露




大约2天后风切下降，SST上升，有一个发展窗口

并且靠近马达加斯加时会进入MJO相对中层湿区，有利于环流扩张，GFS认为马岛东部巅峰环流会比前两次巅峰稍大，可以一定程度对抗15kt左右的中高层风切

pocketbox

全球热带气旋监测公报
预报：徐立、曹越男  签发：王海平  2026 年 01 月 01 日 18 时
“格兰特”减弱为强热带风暴

时  间: 1日14时（北京时，下同）

海  域: 西南印度洋

命  名: “格兰特”，GRANT

中心位置:  南纬16.0度，东经68.8度

强度等级:  强热带风暴

最大风力: 10级，28米/秒，相当于我国的强热带风暴级

中心气压: 989百帕

参考位置: 距离毛里求斯东北方向约1275公里

变化过程: 过去24小时，“格兰特”强度由15级减弱为10级

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，强度逐渐减弱



图1  卫星红外监测图像（北京时间2026年1月1日14时00分）

“伊格吉”在澳大利亚西北部洋面生成

时  间: 1日14时

海  域: 澳大利亚附近海域

命  名: “伊格吉”，IGGY

中心位置:  南纬12.9度，东经108.0度

强度等级:  一级热带气旋

最大风力: 8级，20米/秒，相当于我国的热带风暴级

中心气压: 997百帕

参考位置: 距离西澳大利亚州卡拉萨西北方向约1275公里

变化过程: “伊格吉”于今天下午在澳大利亚西北部洋面生成

预报结论: “伊格吉”将以每小时16公里左右的速度向南偏东方向移动，强度逐渐增强



图2  卫星红外监测图像（北京时间2026年1月1日14时00分）

pocketbox

WTIO30 FMEE 011234
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 22/5/20252026
1.A MODERATE TROPICAL STORM 5 (GRANT)

2.A POSITION 2026/01/01 AT 1200 UTC:
WITHIN 20 NM RADIUS OF POINT 15.9 S / 68.2 E
(FIFTEEN    DECIMAL NINE   DEGREES SOUTH AND
SIXTY EIGHT    DECIMAL TWO   DEGREES EAST)
MOVEMENT: WEST 5 KT

3.A DVORAK ANALYSIS: 3.0/3.5/W 0.5/6 H

4.A CENTRAL PRESSURE: 992 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 45 KT
RADIUS OF MAXIMUM WINDS (RMW): 56 KM

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 75 SE: 110 SW: 150 NW: 140
34 KT NE: 0 SE: 65 SW: 95 NW: 95

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1009 HPA / 700 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS (WINDS RADII IN KM):
12H: 2026/01/02 00 UTC: 15.8 S / 67.6 E, VENT MAX= 040 KT, MODERATE
TROPICAL STORM
28 KT NE: 95 SE: 120 SW: 140 NW: 130
34 KT NE: 0 SE: 75 SW: 85 NW: 75

24H: 2026/01/02 12 UTC: 15.4 S / 66.7 E, VENT MAX= 035 KT, MODERATE
TROPICAL STORM
28 KT NE: 95 SE: 110 SW: 140 NW: 120
34 KT NE: 0 SE: 0 SW: 95 NW: 65

36H: 2026/01/03 00 UTC: 15.1 S / 65.6 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 0 SE: 120 SW: 140 NW: 0

48H: 2026/01/03 12 UTC: 15.1 S / 64.4 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 0 SE: 150 SW: 155 NW: 0

60H: 2026/01/04 00 UTC: 15.4 S / 62.6 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 110 SE: 155 SW: 140 NW: 0

72H: 2026/01/04 12 UTC: 15.8 S / 60.5 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 110 SE: 165 SW: 150 NW: 120

2.B LONGER-RANGE OUTLOOK:
96H: 2026/01/05 12 UTC: 16.5 S / 56.3 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 140 SE: 185 SW: 185 NW: 140

120H: 2026/01/06 12 UTC: 17.9 S / 51.9 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 140 SE: 195 SW: 205 NW: 150

2.C ADDITIONAL INFORMATION:
T=3.0 CI=3.5

OVER THE LAST 6 HOURS, GRANT'S CLOUD PATTERN HAS BECOME MORE SHEARED
WITH A LOW-LEVEL VORTEX BECOMING SLIGHTLY MORE EXPOSED AT THE EASTERN
EDGE OF THE CONVECTIVE MASS AND A CENTER A LITTLE LESS THAN 30 NM
FROM THE CDO. SUBJECTIVE DVORAK ANALYSIS YIELDS A DT OF 3.0. IN
ADDITION, CLOUD TOPS HAVE WARMED COMPARED TO THIS MORNING. ESTIMATED
INTENSITY IS DOWN TO 45 KT AT 12UTC, IN LINE WITH THE DVORAK ANALYSIS
AND IN GOOD AGREEMENT WITH MOST OF CIMSS AIDS (SATCON, AIDT, DMINT).

IN TERMS OF TRACK FORECAST, THE SYSTEM'S SLOWDOWN WILL CONTINUE
THROUGH FRIDAY WITH A TEMPORARY WEST-NORTHWESTWARD MOVEMENT DRIVEN BY
THE BUILDING OF A RIDGE LOCATED TO THE WEST THAT WILL GRADUALLY SLIDE
SOUTH OF THE SYSTEM. FROM SATURDAY, AS THE RIDGE RETRACTS TO THE
SOUTH-SOUTHEAST, THE TRACK IS EXPECTED TO SHIFT WEST THEN
WEST-SOUTHWESTWARDS. THERE REMAINS SIGNIFICANT UNCERTAINTY BOTH IN
TERMS OF FORWARD SPEED AND NORTH-SOUTH SPREAD.

IN TERMS OF INTENSITY, ENVIRONMENTAL CONDITIONS ARE UNFAVORABLE IN
THE SHORT TERM WITH QUITE STRONG EAST-NORTHEASTERLY WIND SHEAR WHICH
IS NOW MORE IMPACTFUL DUE TO THE SYSTEM'S SLOWDOWN. THIS LEADS TO DRY
AIR DISRUPTION AND A WEAKENING TREND UNTIL SATURDAY, WITH GRANT
EXPECTED TO WEAKEN NEAR TROPICAL DEPRESSION STAGE. FROM SUNDAY OR
MONDAY, CONDITIONS COULD IMPROVE SLIGHTLY, WITH SLIGHTLY LOWER WIND
SHEAR, MORE MID-LEVEL MOISTURE AND WITH VERY WARM UNDERLYING SST.
HOWEVER, THE PERSISTENCE OF A MODERATE SOUTH TO SOUTHEASTERLY WIND
SHEAR AND THE LACK OF SURFACE CONVERGENCE COULD LIMIT CHANCES OF
REINTENSIFICATION. THERE IS A LOT OF SPREAD BETWEEN MODELS, WITH SOME
(INCLUDING GFS) FORECASTING REINTENSIFICATION AND OTHERS (SUCH AS
IFS) FAVORING A FILLING OF THE SYSTEM. THE RSMC PERSISTS FORECASTING
NO SIGNIFICANT REINTENSIFICATION, LEAVING THE SYSTEM AT A RELATIVELY
WEAK STAGE UNTIL TUESDAY, ALTHOUGH THIS WILL NEED TO BE CONFIRMED.

NO SIGNIFICANT IMPACT IS EXPECTED ON THE MAIN ISLANDS OF THE
MASCARENE ARCHIPELAGO OVER THE NEXT 72 HOURS.
IN SAINT BRANDON, AS THE SYSTEM IS FORECAST TO PASS CLOSE BETWEEN
SUNDAY AND MONDAY, AT TROPICAL DEPRESSION STAGE ACCORDING TO THE
CURRENT FORECAST, HEAVY THUNDERY SHOWERS ARE EXPECTED. THE
PROBABILITY OF GALE-FORCE WINDS IS ESTIMATED TO BE LOW ACCORDING TO
THE CURRENT FORECAST, BUT GIVEN THE FORECAST UNCERTAINTY, THIS WILL
NEED TO BE CONFIRMED.

pocketbox

WTXS32 PGTW 011500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 09S (GRANT) WARNING NR 031//
RMKS/
1. TROPICAL CYCLONE 09S (GRANT) WARNING NR 031   
   02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   011200Z --- NEAR 16.0S 68.2E
     MOVEMENT PAST SIX HOURS - 270 DEGREES AT 05 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
                            025 NM SOUTHEAST QUADRANT
                            045 NM SOUTHWEST QUADRANT
                            050 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            075 NM NORTHWEST QUADRANT
   REPEAT POSIT: 16.0S 68.2E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   020000Z --- 15.9S 67.3E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 295 DEG/ 05 KTS
    ---
   24 HRS, VALID AT:
   021200Z --- 15.5S 66.4E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 010 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 285 DEG/ 05 KTS
    ---
   36 HRS, VALID AT:
   030000Z --- 15.2S 65.4E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            000 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 270 DEG/ 07 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   031200Z --- 15.2S 64.0E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 000 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            000 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 260 DEG/ 11 KTS
    ---
   72 HRS, VALID AT:
   041200Z --- 15.8S 59.6E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            000 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 260 DEG/ 10 KTS
    ---
   LONG RANGE OUTLOOK:
    ---
   96 HRS, VALID AT:
   051200Z --- 16.6S 55.5E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
                            020 NM SOUTHEAST QUADRANT
                            010 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 120 HR POSIT: 250 DEG/ 09 KTS
    ---
   120 HRS, VALID AT:
   061200Z --- 17.9S 51.8E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            000 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            060 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
    ---
REMARKS:
011500Z POSITION NEAR 16.0S 68.0E.
01JAN26. TROPICAL CYCLONE 09S (GRANT), LOCATED APPROXIMATELY 591
NM SOUTH-SOUTHWEST OF DIEGO GARCIA, HAS TRACKED WESTWARD AT 05
KNOTS OVER THE PAST SIX HOURS.
MINIMUM CENTRAL PRESSURE AT 011200Z IS 993 MB. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 011200Z IS 21 FEET. NEXT WARNINGS AT
020300Z AND 021500Z.
REFER TO TROPICAL CYCLONE 11S (IGGY) WARNINGS (WTXS31 PGTW)
FOR SIX-HOURLY UPDATES.//
NNNN

1. WDXS32 PGTW 011500
   
2. MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
   
3. SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 09S (GRANT) WARNING NR
   
4. 031//
   
5. RMKS/
   
6. 1. FOR METEOROLOGISTS.
   
7. 2. 6 HOUR SUMMARY AND ANALYSIS.
   
8. 
   
9. SUMMARY:
   
10.    INITIAL POSITION: 16.0S 68.2E
    
11.    INITIAL INTENSITY: 50 KTS
    
12.    GEOGRAPHIC REFERENCE: 591 NM SOUTH-SOUTHWEST OF DIEGO GARCIA
    
13.    MOVEMENT PAST 6 HOURS: WESTWARD AT 05 KTS
    
14.    SIGNIFICANT WAVE HEIGHT: 21 FEET
    
15. 
    
16. SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
    
17. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) PAINTS A
    
18. SIGNIFICANTLY DIFFERENT PICTURE THAN IT DID 24 HOURS AGO. OVER THE
    
19. PAST 12 HOURS, PERSISTENT, STRONG EASTERLY SHEAR HAS TAKEN ITS
    
20. TOLL, AND THE LOW LEVEL CIRCULATION CENTER (LLCC) IS NOW FULLY
    
21. EXPOSED TO THE EAST OF SMALL REGION OF DETERIORATING CONVECTION. IN
    
22. ADDITION TO THE IMPACT OF THE SHEAR, THE SYSTEM IS NEARLY ENCIRCLED
    
23. BY DRY AIR, PARTICULARLY NOTABLE ON THE EASTERN AND NORTHERN
    
24. PERIPHERY AND DEPICTED WELL IN A 010851Z NOAA-20 ATMS 89GHZ IMAGE.
    
25. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE
    
26. EXPOSED LLCC IN THE ANIMATED MSI. THE INITIAL INTENSITY IS ASSESSED
    
27. WITH MEDIUM CONFIDENCE, BASED ON THE RAPID DETERIORATION OF THE
    
28. CONVECTION AND VORTEX DECOUPLING. WHILE DVORAK CURRENT INTENSITY
    
29. (CI) ESTIMATES REMAIN ELEVATED, THE FINAL-T NUMBERS ARE DROPPING
    
30. INTO THE T3.0 TO T3.5 (45-55 KNOTS) RANGE, MORE IN LINE WITH THE
    
31. OBJECTIVE ESTIMATES NOTED BELOW. THE ENVIRONMENT IS MARGINAL AT
    
32. BEST, WITH MODERATE TO HIGH EASTERLY SHEAR, WEAK OUTFLOW ALOFT,
    
33. SIGNIFICANT DRY AIR OVER THE EASTERN HALF OF THE SYSTEM AND
    
34. MODERATELY WARM SSTS.
    
35. 
    
36. INITIAL WIND RADII BASIS: PERSISTENCE
    
37. 
    
38. CURRENT STEERING MECHANISM: NORTHWESTERN PERIPHERY OF A DEEP-LAYER
    
39. SUBTROPICAL RIDGE (STR) FAR TO THE SOUTHEAST.
    
40. 
    
41. AGENCY DVORAK AND AUTOMATED FIXES:
    
42.    PGTW: T4.5 - 77 KTS
    
43.    DEMS: T5.5 - 102 KTS
    
44.    FMEE: T3.5 - 55 KTS
    
45.    CIMSS SATCON: 51 KTS AT 010853Z
    
46.    CIMSS ADT: 59 KTS AT 011200Z
    
47.    CIMSS AIDT: 52 KTS AT 011230Z
    
48.    CIMSS D-MINT: 47 KTS AT 010853Z
    
49.    CIMSS D-PRINT: 46 KTS AT 011200Z
    
50. 
    
51. FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
    
52.    VWS: 20-25 KTS
    
53.    SST: 27-28 CELSIUS
    
54.    OUTFLOW: WEAK POLEWARD
    
55.    OTHER FACTORS: DRY MID-LEVEL AIR ALONG THE EASTERN AND NORTHERN
    
56. FLANKS.
    
57. 
    
58. ANALYSIS CONFIDENCE:
    
59.    INITIAL POSITION: HIGH
    
60.    INITIAL INTENSITY: MEDIUM
    
61.    INITIAL WIND RADII: LOW
    
62. 
    
63. 3. FORECAST REASONING.
    
64. 
    
65. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
    
66. THE FORECAST FROM THE PREVIOUS WARNING.
    
67. 
    
68. FORECAST DISCUSSION: OVER THE PAST 12 HOURS, TC 09S HAS TAKEN A
    
69. WEST-NORTHWESTWARD TRAJECTORY, ALONG THE NORTHWESTERN SIDE OF THE
    
70. STR FAR TO THE SOUTHEAST. TRACK SPEEDS HAVE SLOWED AS THE SYSTEM
    
71. HAS RUN INTO A BUILDING RIDGE OVER NORTHERN MADAGASCAR. TC 09S WILL
    
72. CONTINUE ITS WEST-NORTHWESTWARD TRACK OVER THE NEXT 36 HOURS, AS
    
73. THE STR TO THE EAST BUILDS TOWARDS THE WEST-SOUTHWEST, AND THE
    
74. RIDGE OVER MADAGASCAR ELONGATES AND PINCHES INTO A NARROW
    
75. NORTHWEST-SOUTHEAST ORIENTED RIDGE AXIS. AFTER TAU 36, THE SYSTEM
    
76. TURNS FIRST WEST, THEN SOUTHWEST THROUGH TAU 120 AS THE STR SLIDES
    
77. BY TO THE SOUTH AND REPOSITIONS TO THE SOUTHEAST OF TC 09S BY THE
    
78. END OF THE FORECAST PERIOD. THE FORECAST INTENSITY SCENARIO IS A
    
79. BIT MORE COMPLICATED AND UNCERTAIN. ALL AVAILABLE MODEL GUIDANCE
    
80. INDICATES THE SYSTEM WILL CONTINUE TO FACE ELEVATED EASTERLY SHEAR
    
81. AND SIGNIFICANT DRY AIR INTRUSION OVER THE NEXT 24 HOURS OR SO. THE
    
82. SYSTEM IS UNLIKELY TO BE ABLE TO ACHIEVE VORTEX ALIGNMENT IN THE
    
83. NEAR-TERM IN LIGHT OF THE SHEAR AND DRY AIR, AND INTENSITY IS
    
84. LIKELY TO DROP PRECIPITOUSLY. THE FORECAST CALLS FOR ANOTHER 15
    
85. KNOTS OR SO OF WEAKENING, BEFORE FLATTENING OUT AND CONDITIONS
    
86. STABILIZE AFTER TAU 24. THE MAJORITY OF THE MODELS SHOW A GRADUAL
    
87. MOISTENING OF THE ENVIRONMENT AND DECREASED SHEAR STARTING BETWEEN
    
88. TAU 36 AND TAU 48, WHICH WILL ALLOW THE SYSTEM TO REINTENSIFY
    
89. BEYOND TAU 48. HOWEVER, THE PEAK INTENSITY REACHED IN THE LONG-TERM
    
90. FORECAST WILL DEPEND ON WHETHER THE SYSTEM SURVIVES AS A TROPICAL
    
91. CYCLONE JUST HOW LOW THE INTENSITY GETS IN THE NEAR-TERM.
    
92. 
    
93. MODEL DISCUSSION: DETERMINISTIC, ENSEMBLE AND ARTIFICIAL
    
94. INTELLIGENCE (AI) MODELS ARE GENERALLY GOOD AGREEMENT ON THE
    
95. OVERALL TRACK SCENARIO, BUT DO SHOW A FAIR AMOUNT OF BOTH CROSS-
    
96. AND ALONG-TRACK SPREAD, PARTICULARLY IN THE LONG-TERM FORECAST. AT
    
97. TAU 72, THE GUIDANCE ENVELOPE EXHIBITS A CROSS-TRACK SPREAD BETWEEN
    
98. THE ECMWF TO THE NORTH AND THE GEFS MEAN TO THE SOUTH, OF 90NM.
    
99. ALONG-TRACK SPREAD BETWEEN THE SLOW ECMWF AND FAST GEFS MEAN IS
    
100. APPROXIMATELY 155NM AT THE SAME TIME. BY TAU 120, THE SPREADS OPEN
     
101. UP TO 165NM AND 170NM RESPECTIVELY, BETWEEN THE SAME MODELS. THE
     
102. JTWC FORECAST IS POSITIONED CLOSE TO THE AI CONSENSUS AND
     
103. MULTI-MODEL CONSENSUS MEANS WITH MEDIUM CONFIDENCE. INTENSITY
     
104. GUIDANCE IS IN GOOD AGREEMENT, WITH ALL MODELS DEPICTING A
     
105. WEAKENING IN THE NEAR-TERM, TO A LOW-POINT BETWEEN 30-35 KNOTS,
     
106. FOLLOWED BY A REINTENSIFICATION PHASE WHICH PEAKS AROUND TAU 96
     
107. BETWEEN 45-60 KNOTS. THE JTWC FORECAST IS PLACED CLOSE TO THE
     
108. CONSENSUS MEAN AND COAMPS-TC (GFS) THROUGH THE FORECAST PERIOD WITH
     
109. MEDIUM CONFIDENCE.
     
110. 
     
111. FORECAST CONFIDENCE:
     
112.    TRACK 00-72 HR: HIGH
     
113.    TRACK 72-120 HR: MEDIUM
     
114.    INTENSITY 00-72 HR: MEDIUM
     
115.    INTENSITY 72-120 HR: LOW//
     
116. NNNN

复制代码

ygsj24

ygsj24

WTIO30 FMEE 020058
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 24/5/20252026
1.A MODERATE TROPICAL STORM 5 (GRANT)

2.A POSITION 2026/01/02 AT 0000 UTC:
WITHIN 20 NM RADIUS OF POINT 15.9 S / 67.6 E
(FIFTEEN    DECIMAL NINE   DEGREES SOUTH AND
SIXTY SEVEN    DECIMAL SIX   DEGREES EAST)
MOVEMENT: WEST 3 KT

3.A DVORAK ANALYSIS: 2.5/2.5/S 0.0/6 H

4.A CENTRAL PRESSURE: 999 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 35 KT
RADIUS OF MAXIMUM WINDS (RMW): 65 KM

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 0 SE: 0 SW: 140 NW: 140
34 KT NE: 0 SE: 0 SW: 0 NW: 95
48 KT NE: 0 SE: 0 SW: 0 NW: 0
64 KT NE: 0 SE: 0 SW: 0 NW: 0

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

1.B FORECASTS (WINDS RADII IN KM):
12H: 2026/01/02 12 UTC: 15.6 S / 66.6 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 100 SE: 155 SW: 215 NW: 0

24H: 2026/01/03 00 UTC: 15.3 S / 65.4 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 100 SE: 175 SW: 215 NW: 0

36H: 2026/01/03 12 UTC: 15.6 S / 63.7 E, VENT MAX= 025 KT, TROPICAL
DISTURBANCE

48H: 2026/01/04 00 UTC: 15.8 S / 61.7 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 100 SE: 205 SW: 215 NW: 0

60H: 2026/01/04 12 UTC: 16.1 S / 59.7 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 100 SE: 215 SW: 215 NW: 0

72H: 2026/01/05 00 UTC: 16.4 S / 57.3 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 100 SE: 220 SW: 215 NW: 0

2.B LONGER-RANGE OUTLOOK:
96H: 2026/01/06 00 UTC: 17.4 S / 53.2 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 110 SE: 250 SW: 215 NW: 0

120H: 2026/01/07 00 UTC: 19.1 S / 49.7 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 120 SE: 280 SW: 215 NW: 95

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

OVER THE LAST 6 HOURS, CLOUD CONDITIONS HAVE IMPROVED SLIGHTLY AND
COLDER TOPS ARE VISIBLE. HOWEVER, GRANT IS STILL SUBJECT TO MODERATE
NORTHWEST SHEAR OF 20KT ACCORDING TO CIMSS ANALYSES. THE 2102Z GCOM
AMSR2 MICROWAVE IMAGE HAS MADE IT POSSIBLE TO LOCATE THE CENTER OF
THE LOWER LAYERS 25NM EAST OF THE CONVECTION. SUBJECTIVE ANALYSIS
GIVES A DT OF 3.0, A MET-PT OF 2.5 AND A FINAL T OF 2.5+, WHICH
CORRESPONDS TO A MAX WIND OF 35KT. THIS VALUE, ALTHOUGH HIGHER THAN
MOST OBJECTIVE ANALYSES, TAKES INTO ACCOUNT THE RESUMPTION OF
CONVECTION OVER THE LAST FEW HOURS.  IN ADDITION, A CLOUDY RING IS
STILL VISIBLE ON THE 37GHZ MICROWAVE IMAGE. THEREFORE, THE VALUE OF
35KT IS USED FOR THE INTENSITY ESTIMATE, AND GRANT REMAINS A MODERATE
TROPICAL STORM FOR THIS NETWORK.

IN TERMS OF TRACK, LITTLE CHANGE. THE LOW SPEED IS MAINTAINED THROUGH
FRIDAY WITH A TEMPORARY WEST-NORTHWESTWARD MOVEMENT DRIVEN BY THE
BUILDING OF A RIDGE LOCATED TO THE WEST THAT WILL GRADUALLY SLIDE
SOUTH OF THE SYSTEM. FROM SATURDAY, AS THE RIDGE RETRACTS TO THE
SOUTH-SOUTHEAST, THE TRACK IS EXPECTED TO SHIFT WEST THEN
WEST-SOUTHWESTWARDS AS THE SYSTEM LOSES INTENSITY AND FIND ITSELF
CAUGHT IN THE TRADE WINDS. THERE REMAINS SIGNIFICANT UNCERTAINTY BOTH
IN TERMS OF FORWARD SPEED AND NORTH-SOUTH SPREAD.

IN TERMS OF INTENSITY, ENVIRONMENTAL CONDITIONS ARE UNFAVORABLE IN
THE SHORT TERM WITH QUITE STRONG NORTHEASTERLY WIND SHEAR WHICH IS
NOW MORE IMPACTFUL DUE TO THE SYSTEM'S SLOWDOWN. THIS LEADS TO DRY
AIR DISRUPTION AND A WEAKENING TREND UNTIL SATURDAY. THE SYSTEM
SHOULD THEREFORE QUICKLY BE DOWNGRADED TO A TROPICAL DEPRESSION
DURING THE DAY DESPITE THE RESUMPTION OF CONVECTION TONIGHT AND COULD
EVEN DROP TO TROPICAL DISTURBANCE LEVEL ON SATURDAY. FROM SUNDAY OR
MONDAY, CONDITIONS COULD IMPROVE SLIGHTLY, WITH SLIGHTLY LOWER WIND
SHEAR, MORE MID-LEVEL MOISTURE AND WITH VERY WARM UNDERLYING SST.
HOWEVER, THE PERSISTENCE OF A MODERATE SOUTH TO SOUTHEASTERLY WIND
SHEAR AND THE LACK OF SURFACE CONVERGENCE COULD LIMIT CHANCES OF
REINTENSIFICATION. THERE IS A LOT OF SPREAD BETWEEN MODELS, WITH SOME
(INCLUDING GFS) FORECASTING REINTENSIFICATION AND OTHERS (SUCH AS
IFS) FAVORING A FILLING OF THE SYSTEM. THE RSMC PERSISTS FORECASTING
NO SIGNIFICANT REINTENSIFICATION, LEAVING THE SYSTEM AT A RELATIVELY
WEAK STAGE UNTIL TUESDAY, ALTHOUGH THIS WILL NEED TO BE CONFIRMED.

NO SIGNIFICANT IMPACT IS EXPECTED ON THE MAIN ISLANDS OF THE
MASCARENE ARCHIPELAGO OVER THE NEXT 72 HOURS.
IN SAINT BRANDON, AS THE SYSTEM IS FORECAST TO PASS CLOSE BETWEEN
SUNDAY AND MONDAY, AT TROPICAL DEPRESSION STAGE ACCORDING TO THE
CURRENT FORECAST, HEAVY THUNDERY SHOWERS ARE EXPECTED. THE
PROBABILITY OF GALE-FORCE WINDS IS ESTIMATED TO BE LOW ACCORDING TO
THE CURRENT FORECAST, BUT GIVEN THE FORECAST UNCERTAINTY, THIS WILL
NEED TO BE CONFIRMED.=

ygsj24

WTXS32 PGTW 020300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 09S (GRANT) WARNING NR 032//
RMKS/
1. TROPICAL CYCLONE 09S (GRANT) WARNING NR 032   
   02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   020000Z --- NEAR 15.8S 67.3E
     MOVEMENT PAST SIX HOURS - 285 DEGREES AT 04 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            085 NM SOUTHWEST QUADRANT
                            085 NM NORTHWEST QUADRANT
   REPEAT POSIT: 15.8S 67.3E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   021200Z --- 15.5S 66.4E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 020 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 280 DEG/ 06 KTS
    ---
   24 HRS, VALID AT:
   030000Z --- 15.3S 65.2E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 265 DEG/ 09 KTS
    ---
   36 HRS, VALID AT:
   031200Z --- 15.5S 63.4E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            070 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            070 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 260 DEG/ 10 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   040000Z --- 15.8S 61.4E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
                            080 NM SOUTHEAST QUADRANT
                            070 NM SOUTHWEST QUADRANT
                            060 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 260 DEG/ 10 KTS
    ---
   72 HRS, VALID AT:
   050000Z --- 16.4S 57.1E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
                            080 NM SOUTHEAST QUADRANT
                            080 NM SOUTHWEST QUADRANT
                            080 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 260 DEG/ 10 KTS
    ---
   LONG RANGE OUTLOOK:
    ---
   96 HRS, VALID AT:
   060000Z --- 17.0S 53.0E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            020 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            050 NM SOUTHWEST QUADRANT
                            100 NM NORTHWEST QUADRANT
   VECTOR TO 120 HR POSIT: 245 DEG/ 08 KTS
    ---
   120 HRS, VALID AT:
   070000Z --- 18.4S 49.8E
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
REMARKS:
020300Z POSITION NEAR 15.7S 67.1E.
02JAN26. TROPICAL CYCLONE 09S (GRANT), LOCATED APPROXIMATELY 605
NM SOUTH-SOUTHWEST OF DIEGO GARCIA, HAS TRACKED WEST-
NORTHWESTWARD AT 04 KNOTS OVER THE PAST SIX HOURS.
MINIMUM CENTRAL PRESSURE AT 020000Z IS 994 MB.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 020000Z IS 16 FEET.
NEXT WARNINGS AT 021500Z AND 030300Z.
REFER TO TROPICAL CYCLONE 11S (IGGY) WARNINGS (WTXS31 PGTW)
FOR SIX-HOURLY UPDATES.//
NNNN

1. WDXS32 PGTW 020300
   
2. MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
   
3. SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 09S (GRANT) WARNING NR
   
4. 032//
   
5. RMKS/
   
6. 1. FOR METEOROLOGISTS.
   
7. 2. 6 HOUR SUMMARY AND ANALYSIS.
   
8. 
   
9. SUMMARY:
   
10.    INITIAL POSITION: 15.8S 67.3E
    
11.    INITIAL INTENSITY: 35 KTS
    
12.    GEOGRAPHIC REFERENCE: 605 NM SOUTH-SOUTHWEST OF DIEGO GARCIA
    
13.    MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 04 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 (TC) 09S (GRANT) WITH A PARTIALLY EXPOSED LOW-LEVEL
    
19. CIRCULATION CENTER (LLCC) AS ASSOCIATED CONVECTION CONTINUES TO
    
20. BECOME SHEARED TO THE SOUTHWEST QUADRANT. ALONG WITH SUSTAINED
    
21. VERTICAL WIND SHEAR ABOVE 10 KTS, DRY AIR HAS BEEN PREVALENT
    
22. THROUGH THE EASTERN AND NORTHERN SEMICIRCLES, VOIDING MUCH OF THE
    
23. REGION OF ANY SIGNIFICANT CONVECTION. ALTHOUGH MUCH OF THE NORTHERN
    
24. AND EASTERN SIDES OF THE SYSTEM APPEAR CONVECTION FREE, THIS HAS
    
25. REVEALED CURVED LOW-LEVEL CLOUD LINES WRAPPING CYCLONICALLY JUST
    
26. BENEATH THE SHORT-LIVED FLARING CONVECTION AS THE SYSTEM TRACKS
    
27. WESTWARD. ALOFT, TC 09S IS SUPPORTED BY AN EQUATORWARD OUTFLOW
    
28. CHANNEL, OBSERVED ON ANIMATED WATER VAPOR IMAGERY. THE ENVIRONMENT
    
29. REMAINS MARGINAL FOR THE SYSTEM, AS DRY AIR CONTINUES TO SUFFOCATE
    
30. THE CYCLONES PERIPHERY. THE INITIAL POSITION IS ASSESSED WITH HIGH
    
31. CONFIDENCE BASED ON THE AFOREMENTIONED FULLY EXPOSED LLCC OBSERVED
    
32. ON ANIMATED MSI. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM
    
33. CONFIDENCE BASED SUBJECTIVE AGENCY DVORAK ESTIMATES AS LOW AS 30
    
34. KTS AND CIMSS OBJECTIVE INTENSITY ESTIMATES RANGING FROM 32-39 KTS.
    
35. 
    
36. INITIAL WIND RADII BASIS: PERSISTENCE
    
37. 
    
38. CURRENT STEERING MECHANISM: NORTHWESTERN EXTENT OF A SUBTROPICAL
    
39. RIDGE (STR) LOCATED TO THE SOUTHEAST
    
40. 
    
41. AGENCY DVORAK AND AUTOMATED FIXES:
    
42.    PGTW: T2.0 - 30 KTS
    
43.    DEMS: T5.0 - 90 KTS
    
44.    CIMSS SATCON: 43 KTS AT 012052Z
    
45.    CIMSS ADT: 41 KTS AT 020000Z
    
46.    CIMSS D-MINT: 38 KTS AT 012101Z
    
47.    CIMSS D-PRINT: 30 KTS AT 020000Z
    
48. 
    
49. FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
    
50.    VWS: 10-15 KTS
    
51.    SST: 27-28 CELSIUS
    
52.    OUTFLOW: MODERATE EQUATORWARD
    
53. 
    
54. ANALYSIS CONFIDENCE:
    
55.    INITIAL POSITION: HIGH
    
56.    INITIAL INTENSITY: MEDIUM
    
57.    INITIAL WIND RADII: MEDIUM
    
58. 
    
59. 3. FORECAST REASONING.
    
60. 
    
61. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
    
62. THE FORECAST FROM THE PREVIOUS WARNING.
    
63. 
    
64. FORECAST DISCUSSION: TC 09S IS FORECASTED TO TRACK
    
65. WEST-NORTHWESTWARD OVER THE NEXT 12-18 HOURS ALONG THE NORTHWESTERN
    
66. PERIPHERY OF THE STR LOCATED TO THE SOUTHEAST. FOLLOWING TAU 18, TC
    
67. 09S IS EXPECTED TO BEGIN A SOUTH-SOUTHWESTWARD TRACK THROUGH TAU 96
    
68. AS THE DEEP-LAYER STR TO THE SOUTH BUILDS WESTWARD AND THE NEAR
    
69. EQUATORIAL RIDGE TO THE NORTH EXTENDS WESTWARD OVER NORTHERN
    
70. MADAGASCAR. AFTER TAU 96, THE CYCLONE WILL TAKE ON A SOUTHWESTWARD
    
71. TRACK AND BEGIN TO ROUND THE WESTERN PERIPHERY OF THE STR TO THE
    
72. SOUTH UNTIL THE END OF THE FORECAST PERIOD. REGARDING INTENSITY, TC
    
73. GRANT IS FORECASTED TO MAINTAIN STEADY INTENSITIES NEAR 35 KTS INTO
    
74. TAU 48 AS DRY AIR REMAINS PREVALENT, COMPETING WITH WARM SEA
    
75. SURFACE TEMPERATURES (ABOVE 26 C) AND SUPPORTIVE UPPER-LEVEL
    
76. OUTFLOW. FOLLOWING TAU 48, THE SYSTEM IS FORECASTED TO REGAIN ITS
    
77. MOIST CHARACTERISTICS WITH A DECREASE IN DRY AIR AS TC 09S
    
78. APPROACHES MOZAMBIQUE. AS THE CYCLONES CORE RE-MOISTENS, SURFACE
    
79. INTENSITIES ARE EXPECTED TO INCREASE TO 50 KTS BY TAU 96. FOLLOWING
    
80. TAU 96, DECREASING INTENSITIES TO 30 KTS ARE FORECASTED WITH THE
    
81. RE-INTRODUCTION OF DRY AIR ALONG THE SYSTEMS EASTERN SEMICIRCLE
    
82. THROUGH THE END OF THE FORECAST PERIOD.
    
83. 
    
84. MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE AND ARTIFICIAL
    
85. INTELLIGENCE (AI) MODELS CONTINUE TO BE IN GOOD AGREEMENT INTO TAU
    
86. 72, WITH A CROSS-TRACK SPREAD OF 117 NM. FOLLOWING TAU 72, MODEL
    
87. SOLUTIONS BEGIN TO DIVERGE, WITH NAVGEM TAKING ON A NORTHWESTWARD
    
88. TRACK. THE REMAINDER OF JTWC NUMERICAL MODEL SOLUTIONS AND AI
    
89. SOLUTIONS ILLUSTRATE A SOUTHWESTWARD TRACK BUT VARY IN
    
90. ALONG-TRACK SPREAD (391 NM) AS STEERING INFLUENCES FROM THE STR TO
    
91. THE SOUTHWEST DIFFER. THE TIGHT GROUPING OF JTWC CONSENSUS
    
92. SOLUTIONS LEND HIGH CONFIDENCE TO THE 72 HOUR FORECAST, WHILE THE
    
93. DIFFERENCE IN ALONG-TRACK SPREAD LEND MEDIUM CONFIDENCE THEREAFTER.
    
94. INTENSITY GUIDANCE IS IN FAIR AGREEMENT, MAINTAINING A 10 KTS
    
95. SPREAD BETWEEN 25-40 KTS UNTIL TAU 48 BETWEEN ALL SOLUTIONS.
    
96. FOLLOWING TAU 48, UNCERTAINTY INCREASES AS THE GFS DETERMINISTIC
    
97. AND COAMPS-TC SOLUTIONS CHARACTERIZE STEADY INTENSITIES OF 35 KTS
    
98. UNTIL TAU 120. HAFS-A IS THE ONLY OUTLIER, INCREASING INTENSITIES
    
99. TO 75 KTS BY TAU 108. DUE TO THE SPREAD IN EXPECTED INTENSITIES IN
    
100. THE LONG-TERM FORECAST, THE JTWC INTENSITY FORECAST IS ASSESSED
     
101. WITH MEDIUM CONFIDENCE THROUGH THE 120 HOUR PERIOD.
     
102. 
     
103. FORECAST CONFIDENCE:
     
104.    TRACK 00-72 HR: HIGH
     
105.    TRACK 72-120 HR: MEDIUM
     
106.    INTENSITY 00-72 HR: MEDIUM
     
107.    INTENSITY 72-120 HR: MEDIUM//
     
108. NNNN

复制代码

pocketbox

全球热带气旋监测公报
预报：徐润杰、张增海  签发：王海平  2026 年 01 月 02 日 10 时
“格兰特”向偏西方向移动

时  间: 2日08时（北京时，下同）

海  域: 西南印度洋

命  名: “格兰特”，GRANT

中心位置: 南纬15.9度，东经67.6度

强度等级: 热带风暴

最大风力: 8级，18米/秒，相当于我国的热带风暴级

中心气压: 999百帕

参考位置: 距离毛里求斯东北方向约1150公里

变化过程: 过去24小时，“格兰特”强度由12级减弱为8级

预报结论: “格兰特”将以每小时6公里左右的速度向偏西方向移动，强度逐渐减弱



图1  卫星红外监测图像（北京时间2026年1月2日08时00分）

“伊格吉”向东南方向移动

时  间: 2日08时

海  域: 澳大利亚附近海域

命  名: “伊格吉”，IGGY

中心位置:  南纬15.2度，东经109.5度

强度等级:  一级热带气旋

最大风力: 8级，20米/秒，相当于我国的热带风暴级

中心气压: 998百帕

参考位置: 距离圣诞岛东南方向670公里

变化过程: 过去12小时，“伊格吉”强度维持8级

预报结论: “伊格吉”将以每小时13公里左右的速度向东南方向移动，强度逐渐减弱



图2  卫星红外监测图像（北京时间2026年1月2日08时00分）

ygsj24

WTIO30 FMEE 020647
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 25/5/20252026
1.A MODERATE TROPICAL STORM 5 (GRANT)

2.A POSITION 2026/01/02 AT 0600 UTC:
WITHIN 20 NM RADIUS OF POINT 15.7 S / 67.0 E
(FIFTEEN    DECIMAL SEVEN   DEGREES SOUTH AND
SIXTY SEVEN    DECIMAL ZERO   DEGREES EAST)
MOVEMENT: WEST 5 KT

3.A DVORAK ANALYSIS: 2.5/2.5/S 0.0/6 H

4.A CENTRAL PRESSURE: 999 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 35 KT
RADIUS OF MAXIMUM WINDS (RMW): 65 KM

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 0 SE: 0 SW: 140 NW: 140
34 KT NE: 0 SE: 0 SW: 0 NW: 95
48 KT NE: 0 SE: 0 SW: 0 NW: 0
64 KT NE: 0 SE: 0 SW: 0 NW: 0

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1009 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM

1.B FORECASTS (WINDS RADII IN KM):
12H: 2026/01/02 18 UTC: 15.2 S / 66.2 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 0 SE: 165 SW: 215 NW: 0

24H: 2026/01/03 06 UTC: 15.4 S / 64.7 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 0 SE: 165 SW: 215 NW: 0

36H: 2026/01/03 18 UTC: 15.7 S / 62.7 E, VENT MAX= 025 KT, TROPICAL
DISTURBANCE

48H: 2026/01/04 06 UTC: 15.9 S / 60.6 E, VENT MAX= 025 KT, TROPICAL
DISTURBANCE

60H: 2026/01/04 18 UTC: 16.2 S / 58.5 E, VENT MAX= 025 KT, TROPICAL
DISTURBANCE

72H: 2026/01/05 06 UTC: 16.6 S / 56.3 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 140 SE: 175 SW: 150 NW: 0

2.B LONGER-RANGE OUTLOOK:
96H: 2026/01/06 06 UTC: 17.7 S / 52.3 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 100 SE: 250 SW: 215 NW: 0


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

OVER THE LAST 6 HOURS, THE CLOUD PATTERN HAS HARDLY CHANGED, WITH
CONVECTIVE ACTIVITY LIMITED TO THE WESTERN SEMICIRCLE AND A PARTIALLY
EXPOSED CENTER. THIS IS CONFIRMED BY THE LATEST MICROWAVE DATA (
2345Z SSMIS AND 0452Z AMSU). IN THE ABSENCE OF ASCAT PASSES, THE
ANALYSED INTENSITY REMAINS UNCERTAIN. THE 0109Z SAR RCM2 PASS GAVE A
MAXIMUM INTENSITY CLOSE TO 35KT. THE ANALYSED INTENSITY WAS THEREFORE
MAINTAINED AT 35KT.

REGARDING THE TRAJECTORY, NO CHANGE IN THE FORECAST. UNDER THE EFFECT
OF THE TRANSITORY SWELLING OF A RIDGE IN THE SOUTHWEST, GRANT SHOULD
CONTINUE TO MOVE WEST-NORTHWESTWARDS OVER THE NEXT 24 HOURS. FROM
SATURDAY, WITH THE SHIFT OF THE RIDGE TO THE SOUTH-SOUTHEAST, THE
TRACK IS EXPECTED TO TURN WEST THEN WEST-SOUTHWESTWARDS AS THE SYSTEM
IS CAUGHT IN THE TRADE WINDS. SPREAD AMONG THE MODELS IS THEN
INCREASING, PARTICULARLY IN RELATION TO THE DIFFERENT INTENSITY
SCENARIOS.

IN TERMS OF INTENSITY, ENVIRONMENTAL CONDITIONS ARE UNFAVORABLE IN
THE SHORT TERM, WITH A FAIRLY STRONG EAST- NORTH-EASTERLY SHEAR THAT
WILL HAVE A GREATER IMPACT AS THE SYSTEM SLOWS DOWN. THIS IS LEADING
TO DRY AIR INTRUSIONS AND A WEAKENING TO THE TROPICAL DEPRESSION OR
DISTURBANCE STAGE. CONVECTIVE ACTIVITY MAY NOT BE SUSTAINED NEAR THE
CENTER. IN THE LONGER TERM, CONDITIONS COULD IMPROVE SLIGHTLY, WITH
TEMPORARILY LESS SHEAR, MORE MOISTURE IN THE MID-TROPOSPHERE, AND
VERY WARM UNDERLYING WATERS. HOWEVER, THE DEVELOPMENT OF A MODERATE
EAST TO SOUTHEASTERLY SHEAR AND THE LACK OF SURFACE CONVERGENCE COULD
LIMIT THE CHANCES OF REINTENSIFICATION. THE AMERICAN MODELS (GFS,
HWRF, HAFS) CONTINUE TO SUGGEST AN INTENSIFICATION, WHILE AT THE SAME
TIME, IFS AND AIFS SUGGEST THAT THE SYSTEM WILL DISAPPEAR OFF THE
COAST OF MADAGASCAR. THE CURRENT FORECAST FAVORS THE SECOND SCENARIO
FOR THE MOMENT.

SIGNIFICANT IMPACT EXPECTED ON INHABITED LAND OVER THE NEXT 72 HOURS
:
IN SAINT BRANDON, AS THE SYSTEM IS FORECAST TO PASS CLOSE SUNDAY, AT
A WEAK STAGE, HEAVY THUNDERY SHOWERS ARE POSSIBLE. THE PROBABILITY OF
GALE-FORCE WINDS IS ESTIMATED TO BE VERY LOW.=