king111807

  強烈熱帶風暴  
編號：04-20252026 ( 04 S )
名稱：Chenge

  基本資料  
擾動編號日期：2025 年 10 月 16 日 08 時
JTWC升格日期:2025 年 10 月 18 日 08 時
命名日期　　：2025 年 10 月 19 日 08 時
登陸地點　　：無

  巔峰時期資料  
近中心最大風速：
法國氣象局 ( MFR )：50 kts
聯合颱風警報中心 (JTWC)：60 kts ( TS )
海平面最低氣壓：978 百帕

  過去路徑圖   - 來源：維基百科

  擾動編號資料  
94S.INVEST.15kts-1009mb-6.0S-74.3E


以上資料來自：MFR、JTWC、颱風論壇整理製作

king111807

JTWC直接評級Medium

AN AREA OF CONVECTION (INVEST 94S) HAS PERSISTED NEAR 7.0S
77.0E, APPROXIMATELY 429 NM EAST-NORTHEAST OF DIEGO GARCIA. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN AREA OF CONVECTION THAT
HAS BEGUN SOME CONSOLIDATION SEEN VIA THE 170803Z GMI 89GHZ MICROWAVE
IMAGE WITH FORMATIVE CONVECTIVE BANDING ALONG THE SOUTHERN PERIPHERY. A
170442Z METOP-C ASCAT PASS REVEALS HIGHEST WIND SPEEDS (25-30KTS) BEING
ALONG THE AFOREMENTIONED CONVECTIVE BANDING. ENVIRONMENTAL FACTORS ARE
CURRENTLY ASSESSED TO BE MARGINALLY UNFAVORABLE WITH HIGH VERTICAL WIND
SHEAR (30-35KTS) AND RESTRICTED UPPER LEVEL OUTFLOW, OFFSET BY WARM SEA
SURFACE TEMPERATURES (29-30C). GLOBAL DETERMINISTIC MODELS ARE IN GOOD
AGREEMENT THAT THE AREA OF CONVECTION (94S) WILL BEGIN TO DEVELOP RATHER
QUICKLY AS ENVIRONMENTAL CONDITIONS IMPROVE OVER THE NEXT 36 HOURS, THEY
ALSO INDICATE 94S WILL MAINTAIN A SOUTH WESTERLY TRACK OVER THE NEXT 24-
48 HOURS.  MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1008 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN
THE NEXT 24 HOURS IS MEDIUM.

king111807

JTWC發布TCFA

WTXS21 PGTW 171800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 94S)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 150 NM
EITHER SIDE OF A LINE FROM 6.9S 75.9E TO 9.5S 68.8E WITHIN THE NEXT 12
TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED
TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED
TO BE 25 TO 30 KNOTS. METSAT IMAGERY AT 171730Z INDICATES THAT A
CIRCULATION CENTER IS LOCATED NEAR 7.0S 75.4E. THE SYSTEM IS MOVING
WEST-SOUTHWESTWARD AT 12 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 94S) PREVIOUSLY LOCATED NEAR
7.0S 77.0E IS NOW LOCATED NEAR 7.0S 75.4E, APPROXIMATELY 175 NM EAST OF
DIEGO GARCIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 171241Z
WSFM 37GHZ COLOR COMPOSITE MICROWAVE IMAGE DEPICT A CONSOLIDATING LOW-
LEVEL CIRCULATION CENTER (LLCC) WITH IMPROVED FRAGMENTED CONVECTIVE
BANDING. A 171632Z ASCAT-B IMAGE SHOWS AN ELONGATED CIRCULATION WITH 25-
30 KT WINDS OVER THE NORTHEASTERN QUADRANT, AND PATCHY 35 KT WINDS
DISPLACED 100 NM TO THE SOUTH. UPPER-LEVEL ANALYSIS INDICATES A
FAVORABLE ENVIRONMENT, CHARACTERIZED BY ENHANCED POLEWARD OUTFLOW INTO
THE WESTERLIES TO THE SOUTH AND IMPROVING EQUATORWARD OUTFLOW, WARM (27-
28 C) SEA SURFACE TEMPERATURES, LOW (10-15 KTS) VERTICAL WIND SHEAR.
GLOBAL DETERMINISTIC MODELS ARE IN GOOD AGREEMENT THAT 94S WILL CONTINUE
TO CONSOLIDATE AND INTENSIFY OVER THE NEXT 24-48 HOURS WITH A GENERALLY
WEST-SOUTHWESTWARD TRACK. THE SYSTEM IS EXPECTED TO TRACK SOUTH OF DIEGO
GARCIA BUT COULD PRODUCE 25-30 KT SUSTAINED WESTERLIES DURING THE
180000Z-190000Z TIMEFRAME. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED
AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR
1005 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL
CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
181800Z.//
NNNN

king111807

MFR編號第4號

WTIO30 FMEE 171337
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 1/4/20252026
1.A ZONE OF DISTURBED WEATHER 4

2.A POSITION 2025/10/17 AT 1200 UTC:
WITHIN 30 NM RADIUS OF POINT 6.8 S / 77.2 E
(SIX DECIMAL EIGHT DEGREES SOUTH AND
SEVENTY SEVEN DECIMAL TWO DEGREES EAST)
MOVEMENT: WEST-SOUTH-WEST 10 KT

3.A DVORAK ANALYSIS: NIL
4.A CENTRAL PRESSURE: 1003 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 30 KT
RADIUS OF MAXIMUM WINDS (RMW): 93 KM

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 0 SE: 350 SW: 315 NW: 0

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 700 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS (WINDS RADII IN KM):
12H: 2025/10/18 00 UTC: 7.5 S / 76.4 E, VENT MAX= 035 KT, MODERATE TROPICAL
STORM
28 KT NE: 150 SE: 350 SW: 285 NW: 150
34 KT NE: 20 SE: 230 SW: 195 NW: 0

24H: 2025/10/18 12 UTC: 8.6 S / 73.1 E, VENT MAX= 040 KT, MODERATE TROPICAL
STORM
28 KT NE: 30 SE: 415 SW: 415 NW: 0
34 KT NE: 20 SE: 230 SW: 195 NW: 0

36H: 2025/10/19 00 UTC: 9.1 S / 70.4 E, VENT MAX= 045 KT, MODERATE TROPICAL
STORM
28 KT NE: 30 SE: 415 SW: 415 NW: 0
34 KT NE: 20 SE: 230 SW: 195 NW: 0
48H: 2025/10/19 12 UTC: 9.5 S / 69.0 E, VENT MAX= 045 KT, MODERATE TROPICAL
STORM
28 KT NE: 30 SE: 415 SW: 415 NW: 0
34 KT NE: 20 SE: 230 SW: 195 NW: 0

60H: 2025/10/20 00 UTC: 9.9 S / 67.4 E, VENT MAX= 045 KT, MODERATE TROPICAL
STORM
28 KT NE: 30 SE: 415 SW: 415 NW: 0
34 KT NE: 20 SE: 230 SW: 195 NW: 0

72H: 2025/10/20 12 UTC: 10.3 S / 66.1 E, VENT MAX= 045 KT, MODERATE TROPICAL
STORM
28 KT NE: 215 SE: 530 SW: 435 NW: 230
34 KT NE: 140 SE: 295 SW: 230 NW: 75

2.B LONGER-RANGE OUTLOOK:
96H: 2025/10/21 12 UTC: 11.2 S / 63.5 E, VENT MAX= 045 KT, MODERATE TROPICAL
STORM
28 KT NE: 150 SE: 400 SW: 400 NW: 205
34 KT NE: 110 SE: 240 SW: 185 NW: 110

120H: 2025/10/22 12 UTC: 12.2 S / 60.7 E, VENT MAX= 045 KT, MODERATE TROPICAL
STORM
28 KT NE: 150 SE: 400 SW: 400 NW: 205
34 KT NE: 110 SE: 240 SW: 185 NW: 110

2.C ADDITIONAL INFORMATION:
A LOW-PRESSURE SYSTEM HAS FORMED OVER THE PAST FEW DAYS EAST OF DIEGO
GARCIA.

CONVECTION HAS GRADUALLY BECOME MORE ORGANIZED SINCE THIS MORNING
NEAR A CENTER THAT IS STILL ELONGATED ACCORDING TO THE LATEST ASCAT
PASS AT 0441Z. THIS OBSERVATION ALLOWS THE SYSTEM TO BE CHARACTERIZED AS
A DISTURBED AREA WITH AVERAGE WINDS OF 30KT. OVER THE LAST 6 HOURS,
CONVECTIVE ACTIVITY HAS CONTINUED TO BE MAINTAINED NEAR THE CENTER
WITH AN ACCENTUATION OF THE CURVATURE.

THE SYSTEM IS EXPECTED TO MOVE WEST-SOUTHWEST ALONG THE EDGE OF A
SUBTROPICAL RIDGE CENTERED TO THE SOUTH AND SOUTHEAST. THE CMRS
FORECAST IS BASED ON A COMPROMISE BETWEEN THE BEST AVAILABLE
GUIDANCE WITH GOOD CONFIDENCE FOR THE FIRST FEW DAYS.
THE SYSTEM IS EXPECTED TO INTENSIFY INTO A MODERATE TROPICAL STORM
OVER THE NEXT 24 TO 48 HOURS DUE TO DECREASING VERTICAL SHEAR AND GOOD
ALTITUDE DIVERGENCE.

NO SIGNIFICANT IMPACT IS EXPECTED FOR POPULATED AREAS OVER THE NEXT 72
HOURS.

king111807

JTWC升格04S

WTXS31 PGTW 180300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 04S (FOUR) WARNING NR 001//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/171752ZOCT2025//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL CYCLONE 04S (FOUR) WARNING NR 001   
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   180000Z --- NEAR 7.7S 74.2E
     MOVEMENT PAST SIX HOURS - 245 DEGREES AT 13 KTS
     POSITION ACCURATE TO WITHIN 045 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
     SATELLITE AND SYNOPTIC DATA
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            080 NM SOUTHEAST QUADRANT
                            090 NM SOUTHWEST QUADRANT
                            030 NM NORTHWEST QUADRANT
   REPEAT POSIT: 7.7S 74.2E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   181200Z --- 8.6S 72.0E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT
                            140 NM SOUTHEAST QUADRANT
                            110 NM SOUTHWEST QUADRANT
                            035 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 260 DEG/ 12 KTS
    ---
   24 HRS, VALID AT:
   190000Z --- 9.1S 69.6E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
                            150 NM SOUTHEAST QUADRANT
                            140 NM SOUTHWEST QUADRANT
                            070 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 265 DEG/ 08 KTS
    ---
   36 HRS, VALID AT:
   191200Z --- 9.2S 67.9E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
                            160 NM SOUTHEAST QUADRANT
                            150 NM SOUTHWEST QUADRANT
                            080 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 260 DEG/ 06 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   200000Z --- 9.4S 66.7E
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT
                            140 NM SOUTHEAST QUADRANT
                            140 NM SOUTHWEST QUADRANT
                            090 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 260 DEG/ 05 KTS
    ---
   72 HRS, VALID AT:
   210000Z --- 9.8S 64.7E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT
                            120 NM SOUTHEAST QUADRANT
                            140 NM SOUTHWEST QUADRANT
                            100 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 260 DEG/ 05 KTS
    ---
   LONG RANGE OUTLOOK:
    ---
   96 HRS, VALID AT:
   220000Z --- 10.1S 62.7E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
                            120 NM SOUTHEAST QUADRANT
                            140 NM SOUTHWEST QUADRANT
                            090 NM NORTHWEST QUADRANT
   VECTOR TO 120 HR POSIT: 265 DEG/ 06 KTS
    ---
   120 HRS, VALID AT:
   230000Z --- 10.2S 60.4E
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
                            120 NM SOUTHEAST QUADRANT
                            140 NM SOUTHWEST QUADRANT
                            080 NM NORTHWEST QUADRANT
    ---
REMARKS:
180300Z POSITION NEAR 7.9S 73.7E.
18OCT25. TROPICAL CYCLONE 04S (FOUR), LOCATED APPROXIMATELY 107
NM EAST-SOUTHEAST OF DIEGO GARCIA, HAS TRACKED WEST-SOUTHWESTWARD
AT 13 KNOTS OVER THE PAST SIX HOURS.
MINIMUM CENTRAL PRESSURE AT 180000Z IS 1004 MB. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 180000Z IS 12 FEET. NEXT WARNINGS AT
180900Z, 181500Z, 182100Z AND 190300Z.
2. THIS CANCELS AND SUPERSEDES REF A (WTXS21 PGTW 171800).//
NNNN

king111807

MFR升格TD

WTIO30 FMEE 180634
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 4/4/20252026
1.A TROPICAL DEPRESSION 4

2.A POSITION 2025/10/18 AT 0600 UTC:
WITHIN 30 NM RADIUS OF POINT 8.0 S / 74.2 E
(EIGHT    DECIMAL ZERO   DEGREES SOUTH AND
SEVENTY FOUR    DECIMAL TWO   DEGREES EAST)
MOVEMENT: WEST 12 KT

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

4.A CENTRAL PRESSURE: 1001 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 30 KT
RADIUS OF MAXIMUM WINDS (RMW): NIL

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 0 SE: 335 SW: 185 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: 2025/10/18 18 UTC: 8.9 S / 72.1 E, VENT MAX= 035 KT, MODERATE
TROPICAL STORM
28 KT NE: 0 SE: 335 SW: 285 NW: 95
34 KT NE: 0 SE: 110 SW: 165 NW: 65

24H: 2025/10/19 06 UTC: 9.4 S / 69.5 E, VENT MAX= 040 KT, MODERATE
TROPICAL STORM
28 KT NE: 95 SE: 325 SW: 285 NW: 95
34 KT NE: 65 SE: 120 SW: 165 NW: 65

36H: 2025/10/19 18 UTC: 9.4 S / 68.3 E, VENT MAX= 040 KT, MODERATE
TROPICAL STORM
28 KT NE: 95 SE: 325 SW: 285 NW: 95
34 KT NE: 65 SE: 120 SW: 165 NW: 65

48H: 2025/10/20 06 UTC: 9.4 S / 67.0 E, VENT MAX= 040 KT, MODERATE
TROPICAL STORM
28 KT NE: 100 SE: 325 SW: 285 NW: 100
34 KT NE: 75 SE: 130 SW: 165 NW: 75

60H: 2025/10/20 18 UTC: 9.6 S / 65.9 E, VENT MAX= 035 KT, MODERATE
TROPICAL STORM
28 KT NE: 110 SE: 305 SW: 285 NW: 100
34 KT NE: 85 SE: 130 SW: 165 NW: 75

72H: 2025/10/21 06 UTC: 10.0 S / 64.9 E, VENT MAX= 035 KT, MODERATE
TROPICAL STORM
28 KT NE: 120 SE: 295 SW: 285 NW: 100
34 KT NE: 95 SE: 130 SW: 165 NW: 75

2.B LONGER-RANGE OUTLOOK:
96H: 2025/10/22 06 UTC: 10.6 S / 62.6 E, VENT MAX= 035 KT, MODERATE
TROPICAL STORM
28 KT NE: 130 SE: 285 SW: 285 NW: 110
34 KT NE: 100 SE: 150 SW: 165 NW: 85

120H: 2025/10/23 06 UTC: 11.1 S / 59.2 E, VENT MAX= 030 KT, TROPICAL
DEPRESSION
28 KT NE: 140 SE: 280 SW: 285 NW: 110

2.C ADDITIONAL INFORMATION:
T=CI=2.5

OVER THE LAST 6 HOURS, CONVECTIVE ACTIVITY HAS WEAKENED SLIGHTLY AND
HAS TAKEN ON A SHEARED PATTERN. THE CURVATURE HAS IMPROVED IN THE
LOWER LAYERS AND, WITH THE ASCAT PASS, MAKES IT EASY TO LOCATE THE
CENTER 30 NM EAST OF THE CONVECTION. SUBJECTIVE ANALYSIS SUGGESTS A T
OF 2.5 WITH ESTIMATED WINDS OF AROUND 30KT IN LINE WITH THE LATEST
ASCAT DATA FROM 0334UTC. THE CIMSS OBJECTIVE ANALYSIS SUGGESTS
INTENSITIES BETWEEN 30 AND 35KT. THE MAXIMUM AVERAGE WIND INTENSITY
IS 30KT, SO STILL NO NAMING, BUT THE SYSTEM IS CLASSIFIED AS A
TROPICAL DEPRESSION.

THE SYSTEM'S TRACK REMAINS WEST-SOUTHWEST. LOCATED SOUTH OF THE
SYSTEM, THE SUBTROPICAL RIDGE IN THE MIDDLE AND LOWER TROPOSPHERE IS
CAUSING IT TO FLOW WEST-SOUTHWEST. ACCORDING TO THIS SCENARIO, THE
SYSTEM WILL PASS LESS THAN 150 KM FROM DIEGO GARCIA THIS SATURDAY.
SUBSEQUENTLY, THE RIDGE WILL SWELL SLIGHTLY OVER THE NEXT THREE DAYS
IN THE MIDDLE TROPOSPHERE, MORE SO IN ITS SOUTHWEST PART, ALLOWING
SYSTEM 04-20252026 TO MAINTAIN ITS WEST-SOUTHWEST MOVEMENT.
THEREAFTER, THE MID-TROPOSPHERE RIDGE IS EXPECTED TO CONTINUE
STRENGTHENING NOW ON THIS TRACK. THE RSMC FORECAST IS BASED ON A
COMPROMISE BETWEEN THE BEST AVAILABLE GUIDANCES, BUT IT SHOULD BE
NOTED THAT THE DISPERSION INCREASES QUITE RAPIDLY FROM 72 HOURS
ONWARDS, WITH SCENARIOS MOVING MORE NORTHWARD IN PARTICULAR.

LITTLE CHANGE IN INTENSITY FORECAST: THE SYSTEM IS EXPECTED TO
INTENSIFY INTO A MODERATE TROPICAL STORM OVER THE NEXT 06 TO 12 HOURS
DUE TO DECREASING VERTICAL SHEAR ABOVE THE SYSTEM AND GOOD ALTITUDE
DIVERGENCE. THE CONVERGENCE OF THE LOWER LAYERS WILL CONSOLIDATE
QUITE RAPIDLY, ALLOWING IT TO RESIST WIND SHEAR THAT IS STRENGTHENING
AGAIN AT ALTITUDE, WHILE IT IS MORE MODEST IN THE MIDDLE TROPOSPHERE.
IT SHOULD BE NOTED THAT THIS SHEAR IS MUCH MORE SIGNIFICANT NORTH OF
THE TRACK, LEAVING A HIGH DEGREE OF UNCERTAINTY IN THE INTENSITY
FORECAST DEPENDING ON THE TRACK FORECAST. HOWEVER, THE ENVIRONMENT
REMAINS FAVORABLE FOR MODERATE INTENSIFICATION OVER THE NEXT 24
HOURS, BEFORE REMAINING AT THE MODERATE TROPICAL STORM STAGE OVER THE
NEXT 5 DAYS.

EXCEPT FOR DIEGO GARCIA, NO SIGNIFICANT IMPACT IS EXPECTED FOR
INHABITED AREAS OVER THE NEXT 72 HOURS, OR EVEN THE NEXT 5 DAYS.=

king111807

MFR升格中度熱帶風暴，命名Chenge

WTIO30 FMEE 190050
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 7/4/20252026
1.A MODERATE TROPICAL STORM 4 (CHENGE)

2.A POSITION 2025/10/19 AT 0000 UTC:
WITHIN 30 NM RADIUS OF POINT 8.5 S / 70.8 E
(EIGHT DECIMAL FIVE DEGREES SOUTH AND
SEVENTY DECIMAL EIGHT DEGREES EAST)
MOVEMENT: WEST-SOUTH-WEST 13 KT

3.A DVORAK ANALYSIS: 3.0/3.0/D 0.5/18 H

4.A CENTRAL PRESSURE: 998 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 35 KT
RADIUS OF MAXIMUM WINDS (RMW): NIL

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 0 SE: 610 SW: 435 NW: 230
34 KT NE: 0 SE: 240 SW: 240 NW: 10

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1009 HPA / 800 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS (WINDS RADII IN KM):
12H: 2025/10/19 12 UTC: 8.8 S / 69.1 E, VENT MAX= 040 KT, MODERATE TROPICAL
STORM
28 KT NE: 0 SE: 520 SW: 490 NW: 100
34 KT NE: 0 SE: 350 SW: 285 NW: 0

24H: 2025/10/20 00 UTC: 8.9 S / 68.1 E, VENT MAX= 040 KT, MODERATE TROPICAL
STORM
28 KT NE: 240 SE: 715 SW: 610 NW: 285
34 KT NE: 0 SE: 360 SW: 325 NW: 0

36H: 2025/10/20 12 UTC: 9.0 S / 67.5 E, VENT MAX= 040 KT, MODERATE TROPICAL
STORM
28 KT NE: 260 SE: 520 SW: 520 NW: 250
34 KT NE: 10 SE: 175 SW: 305 NW: 0

48H: 2025/10/21 00 UTC: 9.2 S / 66.6 E, VENT MAX= 040 KT, MODERATE TROPICAL
STORM
28 KT NE: 195 SE: 465 SW: 465 NW: 325
34 KT NE: 0 SE: 0 SW: 195 NW: 205

60H: 2025/10/21 12 UTC: 9.3 S / 65.8 E, VENT MAX= 035 KT, MODERATE TROPICAL
STORM
28 KT NE: 195 SE: 335 SW: 555 NW: 405
34 KT NE: 0 SE: 35 SW: 220 NW: 195

72H: 2025/10/22 00 UTC: 9.4 S / 64.8 E, VENT MAX= 035 KT, MODERATE TROPICAL
STORM
28 KT NE: 155 SE: 155 SW: 215 NW: 155
34 KT NE: 0 SE: 0 SW: 155 NW: 0

2.B LONGER-RANGE OUTLOOK:
96H: 2025/10/23 00 UTC: 9.6 S / 63.1 E, VENT MAX= 035 KT, MODERATE TROPICAL
STORM
28 KT NE: 315 SE: 315 SW: 315 NW: 315
34 KT NE: 0 SE: 140 SW: 140 NW: 20

120H: 2025/10/24 00 UTC: 9.4 S / 60.3 E, VENT MAX= 030 KT, TROPICAL DEPRESSION
28 KT NE: 280 SE: 280 SW: 280 NW: 280

2.C ADDITIONAL INFORMATION:
T=CI=3

OVER THE PAST 6 HOURS, CONVECTIVE ACTIVITY HAS INCREASED SIGNIFICANTLY
AND THE SYSTEM HAS BEGUN TO TRANSITION TO A CURVED BAND
CONFIGURATION. DVORAK'S SUBJECTIVE ANALYSIS SUGGESTS AN UPGRADE TO T 3
WITH ESTIMATED WINDS OF AROUND 35KT. THE SYSTEM HAS BEEN RECLASSIFIED
AS A TROPICAL STORM AND WAS NAMED CHENGE AT 00UTC BY THE MAURITIUS
WEATHER SERVICE.

THE SYSTEM'S TRACK REMAINS WEST-SOUTHWEST, GUIDED BY THE SUBTROPICAL
RIDGE IN THE MIDDLE AND LOWER TROPOSPHERE SOUTH OF THE SYSTEM.
SUBSEQUENTLY, THE MID-TROPOSPHERE RIDGE IS EXPECTED TO CONTINUE TO
STRENGTHEN AND MAINTAIN THIS TRACK. THE CMRS FORECAST IS BASED ON A
COMPROMISE BETWEEN THE BEST GUIDANCES AVAILABLE, BUT IT SHOULD BE
NOTED THAT THE DISPERSION INCREASES QUITE RAPIDLY FROM 72 HOURS
ONWARDS, WITH SCENARIOS MOVING FURTHER NORTHWARD.

IN TERMS OF INTENSITY FORECAST, THE SYSTEM COULD INTENSIFY SLIGHTLY
OVER THE NEXT 24 HOURS. LOWER-LEVEL CONVERGENCE WILL CONSOLIDATE,
ALLOWING THE SYSTEM TO RESIST WIND SHEAR THAT IS STRENGTHENING AGAIN
AT ALTITUDE, WHILE REMAINING MORE MODEST IN THE MID-TROPOSPHERE. NOTE
THAT THIS SHEAR IS MUCH MORE SIGNIFICANT NORTH OF THE TRAJECTORY,
LEAVING A HIGH DEGREE OF UNCERTAINTY IN THE INTENSITY FORECAST
DEPENDING ON THE TRAJECTORY FORECAST. HOWEVER, THE ENVIRONMENT
REMAINS FAVORABLE FOR IT TO REMAIN A MODERATE TROPICAL STORM OVER THE
NEXT 3 TO 4 DAYS BEFORE WEAKENING DUE TO A SUPPLY OF DRYER AIR FROM THE
POLAR REGION.

NO SIGNIFICANT IMPACT IS EXPECTED FOR INHABITED AREAS OVER THE NEXT 72
HOURS.

king111807

MFR升格強烈熱帶風暴

WTIO30 FMEE 220043
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 19/4/20252026
1.A SEVERE TROPICAL STORM 4 (CHENGE)

2.A POSITION 2025/10/22 AT 0000 UTC:
WITHIN 30 NM RADIUS OF POINT 10.4 S / 63.4 E
(TEN    DECIMAL FOUR   DEGREES SOUTH AND
SIXTY THREE    DECIMAL FOUR   DEGREES EAST)
MOVEMENT: WEST-SOUTH-WEST 8 KT

3.A DVORAK ANALYSIS: 3.5/3.5/D 0.0/6 H

4.A CENTRAL PRESSURE: 987 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 50 KT
RADIUS OF MAXIMUM WINDS (RMW): 111 KM

6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 240 SE: 480 SW: 445 NW: 280
34 KT NE: 150 SE: 185 SW: 195 NW: 195
48 KT NE: 120 SE: 0 SW: 0 NW: 120

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 1000 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP

1.B FORECASTS (WINDS RADII IN KM):
12H: 2025/10/22 12 UTC: 10.8 S / 61.8 E, VENT MAX= 050 KT, SEVERE
TROPICAL STORM
28 KT NE: 230 SE: 400 SW: 295 NW: 220
34 KT NE: 140 SE: 195 SW: 165 NW: 155
48 KT NE: 85 SE: 65 SW: 55 NW: 35

24H: 2025/10/23 00 UTC: 11.2 S / 60.1 E, VENT MAX= 045 KT, MODERATE
TROPICAL STORM
28 KT NE: 175 SE: 390 SW: 325 NW: 175
34 KT NE: 100 SE: 195 SW: 175 NW: 120

36H: 2025/10/23 12 UTC: 11.2 S / 58.2 E, VENT MAX= 040 KT, MODERATE
TROPICAL STORM
28 KT NE: 175 SE: 350 SW: 315 NW: 155
34 KT NE: 100 SE: 165 SW: 165 NW: 110

48H: 2025/10/24 00 UTC: 10.8 S / 56.0 E, VENT MAX= 040 KT, MODERATE
TROPICAL STORM
28 KT NE: 95 SE: 405 SW: 400 NW: 150
34 KT NE: 0 SE: 215 SW: 215 NW: 95

60H: 2025/10/24 12 UTC: 10.2 S / 53.6 E, VENT MAX= 040 KT, MODERATE
TROPICAL STORM
28 KT NE: 95 SE: 370 SW: 325 NW: 95
34 KT NE: 0 SE: 195 SW: 175 NW: 65

72H: 2025/10/25 00 UTC: 9.7 S / 51.2 E, VENT MAX= 040 KT, MODERATE
TROPICAL STORM
28 KT NE: 130 SE: 445 SW: 435 NW: 150
34 KT NE: 75 SE: 240 SW: 230 NW: 100

2.B LONGER-RANGE OUTLOOK:
96H: 2025/10/26 00 UTC: 9.2 S / 46.1 E, VENT MAX= 035 KT, MODERATE
TROPICAL STORM
28 KT NE: 0 SE: 280 SW: 250 NW: 95
34 KT NE: 0 SE: 140 SW: 95 NW: 65

120H: 2025/10/27 00 UTC: 8.9 S / 40.2 E, VENT MAX= 025 KT, REMNANT
LOW

2.C ADDITIONAL INFORMATION:
PT=CI=3.5+

OVER THE LAST 6 HOURS, THE CLOUD PATTERN HAS CHANGED LITTLE,
REMAINING SHREDDED. HOWEVER, CONVECTIVE ACTIVITY HAS INCREASED
SLIGHTLY IN THE NORTHWESTERN PART OF THE SYSTEM. THE LATE RECEIPT OF
SAR-RCM2 DATA FROM 1402UTC ALLOWS US TO NOTE A CONTINUINGLY WIDE
LOW-LEVEL CIRCULATION (THE LOCATION OF THE CENTRE BY AUTOMATIC
POST-PROCESSING IS INCORRECT) AND WIND SPEEDS BARELY REACHING 48KT IN
THE NORTHERN PART OF THE SYSTEM. THIS REPRESENTATION IS ALSO
VALIDATED BY THE PARTIAL ASCAT PASS AT 1734UTC. IN THE ABSENCE OF
RECENT USABLE MICROWAVE DATA, WE CANNOT CONFIRM AN IMPROVEMENT IN THE
LOW-LEVEL CIRCULATION. HOWEVER, DUE TO THE SLIGHTLY IMPROVED CLOUD
CONFIGURATION SINCE 18UTC, A PT OF 3.5+ FROM SEVERAL ANALYSIS TIME
AND VALUES REACHING 48KT, CHENGE IS CLASSIFIED AS A STRONG TROPICAL
STORM AT 00UTC WITH ESTIMATED WINDS OF 50KT.

IN TERMS OF TRACK, LITTLE CHANGE WITH A DIRECTING FLOW IMPOSED BY THE
SUBTROPICAL RIDGE IN THE MIDDLE TROPOSPHERE, WHICH REMAINS CENTRED TO
THE SOUTHEAST OF THE SYSTEM, INDUCTING A WEST-SOUTHWEST MOVEMENT.
FROM THURSDAY ONWARDS, THE RIDGE WILL SWELL AGAIN SOUTH OF THE
SYSTEM, STRAIGHTENING THE TRACK TOWARDS THE WEST AND THEN
WEST-NORTHWEST, REINFORCED BY THE LIKELY WEAKENING OF CHENGE. THE
UNCERTAINTY ABOUT THE FORECAST TRACK IS DECREASING WITH THE SCENARIO
OF A SLIGHTLY NORTHERN TRACK IN THE MODELS THAT WERE STILL TOO
SOUTHERN. THIS CONFIRMS THE TRACK FORECAST BY THE RSMC WITH A
NARROWER CONE OF UNCERTAINTY. ON THIS TRACK, THE SYSTEM WILL PASS
NEAR AGALEGA DURING THE NIGHT FROM THURSDAY TO FRIDAY AND THE
FARQUHAR ISLANDS DURING THE NIGHT FROM FRIDAY TO SATURDAY.

HOWEVER, WITH THE INCREASE IN INTENSITY ANALYSED IN THE HEAVY
TROPICAL STORM, THE INTENSITY FORECAST HAS ALSO BEEN REVISED SLIGHTLY
UPWARDS, ALTHOUGH THE TIMELINE FOR THE UPCOMING WEAKENING REMAINS
UNCHANGED. IN FACT, THE SYSTEM REMAINS RESISTANT TO SHEARING, WHILE
THE WIDTH OF THE LOW-LEVEL CIRCULATION DOES NOT ALLOW FOR A
SIGNIFICANT INTENSIFICATION. FROM WEDNESDAY EVENING, THE NORTHEAST
SHEAR SHOULD GRADUALLY STRENGTHEN, ASSOCIATED WITH DRY INTRUSIONS.
CHENGE SHOULD THEN EXPERIENCE A SLOW AND PROGRESSIVE WEAKENING. THERE
IS STILL SIGNIFICANT DISPERSION ON THIS POINT, WITH SLIGHT INCREASES
IN INTENSITY AT DIFFERENT TIMES PROPOSED BY THE MODELS.

POSSIBLE WEATHER DETERIORATION EXPECTED IN THE NEXT 72 HOURS:
- AGALEGA: GALE-FORCE WINDS LIKELY AND HEAVY SHOWERSS BELOW 100 MM IN
24 HOURS BETWEEN THURSDAY AND FRIDAY. 4-METRE WAVES EXPECTED FROM
THURSDAY THROUGH FRIDAY MORNING.
- FARQUHAR: GALE-FORCE WINDS POSSIBLE AND HEAVY SHOWERS BELOW 100MM
IN 24 HOURS FROM FRIDAY EVENING. 4-METRE WAVES EXPECTED FROM FRIDAY
THROUGH SATURDAY.