MEDIUM - 马达加斯加东北扰动天气区第12号(94S) - 逐渐南下

红豆棒冰冰

编扰资讯

94S INVEST 260311 1200 8.7S 54.6E SHEM 15 0

Ragasa

ABIO10 PGTW 111800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN/111800Z-
121800ZMAR2026//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY: NONE.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) AN AREA OF CONVECTION (INVEST 94S) HAS PERSISTED NEAR 9.3S
54.9E, APPROXIMATELY 273 NM SOUTH OF SEYCHELLES. ENHANCED INFRARED
SATELLITE IMAGERY DEPICTS FLARING CONVECTION ALONG AN ANALYZED SURFACE
TROUGH. ENVIRONMENTAL ANALYSIS REVEALS FAVORABLE CONDITIONS FOR
DEVELOPMENT OF A TROPICAL CYCLONE, WITH LOW VERTICAL WIND SHEAR (10 TO
15KTS), WARM SEA SURFACE TEMPERATURES (29 TO 30 C), AND MODERATE
EQUATORWARD OUTFLOW. GLOBAL DETERMINISTIC AND ENSEMBLE MODELS ARE IN
GOOD AGREEANCE ON THE STEADY DEVELOPMENT OF 94S OVER THE NEXT 48 HOURS
AS IT TRACKS GENERALLY EASTWARD AND ENVIRONMENTAL CONDITIONS REMAIN
FAVORABLE. GFS IS THE MOST AGGRESSIVE MODEL. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1010 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.
      (2) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.//
NNNN

Ragasa

AWIO20 FMEE 111128
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE

BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN

DATE: 2026/03/11 A 1200 UTC

PART 1: WARNING SUMMARY

NIL.

PART 2 : TROPICAL WEATHER DISCUSSION:

The basin is in a monsoon trough (MT) configuration east of 50E. Convective activity is moderate on both sides of the MT and in the Mozambique Channel.

The dry phase of the MJO is expected to gradually move away towards the east of the basin and the maritime continent by mid-March, enabling the return of more conducive conditions for convective activity over the western part of the basin. In the next few days the passage of a low-amplitude Kelvin wave could contribute to the strengthening the monsoon flow. In addition, a Rossby wave is expected to gradually enhance the monsoon flow and vorticity within the MT over the center and west of the basin between the end of the week and the beginning of next week.

Near Agalega :
The strengthening of the monsoon flow and the arrival of a new subtropical ridge south of Madagascar should gradually enhance convergence on both sides of the MT over the western part of the basin, especially near Farquhar or Agalega. Moreover, this area could benefit from good upper divergence on the northwestern edge of an upper trough located over the east of the Mascarenes. These favorable conditions should enable the formation of a low-pressure area from Thursday 12th near Agalega. The deterministic GFS model suggests a tropical storm development from Friday 13th or over the weekend. On the other hand, the deterministic IFS model injects a little more dry air into the western edge of the system due to a larger trough, meaning that the system fails to reach tropical storm status. A significant number of ensemble and AI models also forecast significant cyclogenesis potential by Saturday.

The risk of tropical storm development near Agalega is low from Friday 13th then becomes moderate from Saturday, March 14th.

Off the south/south-west of the Chagos archipelago :
Due to a lack of convergence in the lower layers, cyclogenesis is no longer considered for this suspect area.

For the next 5 days, there is no potential for this suspect area to develop into a moderate tropical storm.

In the Mozambique Channel :
A weak northerly monsoon flow is expected to settle along the African coast from Wednesday 11th, becoming moderate on Thursday 12th, feeding a weak low-pressure area currently located near the northeast coast of Mozambique (near the province of Nampula). At the same time, a surge of trade winds is underway over the southern Mozambique Channel. According to most models, the convergence between these flows does not seem optimal at the moment, occurring a little too close to the coast of Mozambique or even slightly inland, which reduces the potential for cyclogenesis. Nevertheless, some models suggest that the convergence will remain a little further out to sea. In this case, with a favorable large-scale context (low shear, good upper divergence, warm surface waters), cyclogenesis is possible, as suggested in particular by several successive runs of the GEFS ensemble. Chances of cyclogenesis will therefore depend mainly on how efficient the low-level convergence is and on the proximity of the low-pressure area to land.

The risk of tropical storm formation in the Mozambique Channel, near the coast of Mozambique, is expected to become very low from Friday 13th, then low on Saturday 14th.

Over the far east of the basin :
Due to a lack of convergence in the lower layers and an increase in deep shear, cyclogenesis is no longer considered for this suspect area.

For the next 5 days, there is no potential for this suspect area to develop into a moderate tropical storm.



10-day outlook:
During the following week (March 16th to 22nd), the risk of cyclogenesis regarding the suspect area in the Mozambique Channel could increase.

NOTA BENE: The likelihood is an estimate of the chance of genesis of a moderate tropical storm over the basin within the next five days:

Very low: less than 10%      Moderate: 30% to 60%      Very high: over 90%
Low: 10% to 30%              High: 60% to 90%

The Southwestern Indian ocean basin extends from the Equator to 40S and from the african coastlines to 90E.

Ragasa

AWIO20 FMEE 121209
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE

BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN

DATE: 2026/03/12 A 1200 UTC

PART 1: WARNING SUMMARY

NIL.

PART 2 : TROPICAL WEATHER DISCUSSION:

The basin is in a monsoon trough (MT) configuration east of 50E. Convective activity is moderate on both sides of the MT and in the Mozambique Channel along a convergence zone wrapping around a low-pressure system located off the Mozambican coast.

The dry phase of the MJO is located over the eastern basin and will continue toward the maritime continent through the end of the week, allowing for the return of conditions more favorable to convective activity over the western basin. Currently, the intersection of a weak Kelvin wave with a Rossby wave boosted by an MRG is slightly strengthening the monsoon flow and vorticity in the western part of the MT. However, the Kelvin wave is too weak to improve vorticity within the MT further east. Over the disturbed area to the west of the MT, equatorial convergence will remain good over the next five days thanks to the slow movement of the equatorial Rossby wave and the westward thrust of the MJO.

Between Agalega and Farquhar :
The strengthening of the monsoon flow and the arrival of a new subtropical ridge south of Madagascar should gradually reinforce convergence on either side of the TM over the western part of the basin, particularly near the Farquhars and Agalega. In addition, altitude divergence should be good over the area, on the northwestern edge of a trough centered over the eastern Mascarenes. These conditions are conducive to the formation of an elongated and ill-defined low-pressure system. The surrounding convection has no sustained effect and no convincing curvature.
The window of intensification will continue until the end of the week, with symmetrization likely to occur between tomorrow and Saturday. It should be noted that shear conditions could deteriorate from Sunday onwards, making cyclogenesis difficult south of 13oS or, alternatively, during the passage of the Mascarene Islands at the beginning of next week.
The latest runs of the American GFS and European IFS models suggest sluggish cyclogenesis with a lack of convergence on the polar side, preventing the system from symmetrizing. This pattern is consistent across their respective ensembles. The AI ensembles are in line with this. Only the fine scale AROME model and its ensemble suggest clear and rapid cyclogenesis, but this does not appear to be the most relevant to the analysis.

The risk of tropical storm development near Agalega is low from Friday 13th then becomes moderate from Saturday, March 14th.

In the Mozambique Channel :
The tropical low-pressure system over the northern Mozambican coast is struggling to deepen and is moving further inland, making it difficult for it to move out to sea in the next five days. At this stage, only a few outliers of the American ensemble forecast cyclogenesis early next week.

For the next 5 days, there is no longe  potential for this suspect area to develop into a moderate tropical storm.



10-day outlook:


NOTA BENE: The likelihood is an estimate of the chance of genesis of a moderate tropical storm over the basin within the next five days:

Very low: less than 10%      Moderate: 30% to 60%      Very high: over 90%
Low: 10% to 30%              High: 60% to 90%

The Southwestern Indian ocean basin extends from the Equator to 40S and from the african coastlines to 90E.

Ragasa

ABIO10 PGTW 121800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN/121800Z-
131800ZMAR2026//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY: NONE.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 94S) PREVIOUSLY LOCATED NEAR
9.3S 54.9E IS NOW LOCATED NEAR 9.9S 54.7E, APPROXIMATELY 320 NM SOUTH OF
SEYCHELLES. ENHANCED INFRARED IMAGERY DEPICTS A DEVELOPING BUT ELONGATED
LOW-LEVEL CIRCULATION EMBEDDED IN THE MONSOON TROUGH, OBSCURED BY
FLARING CONVECTION. A 121416Z WSF-M MICROWAVE PASS REVEALED A MOSTLY
LINEAR CONVECTIVE STRUCTURE ALONG THE NORTHERN PERIPHERY OF THE TROUGH
AXIS. ENVIRONMENTAL ANALYSIS REVEALS MODERATELY FAVORABLE CONDITIONS FOR
DEVELOPMENT OF A TROPICAL CYCLONE WITH MODERATE VERTICAL WIND SHEAR (15
TO 20 KTS), WARM SEA SURFACE TEMPERATURES (28 TO 29 DEGREES CELSIUS),
AND GOOD EQUATORWARD OUTFLOW. GLOBAL DETERMINISTIC MODELS HAVE
DECREASED THE PROJECTED PEAK INTENSITY COMPARED TO 24 HOURS AGO, WITH
THE EXCEPTION OF NAVGEM. HOWEVER, GLOBAL MODELS GENERALLY AGREE ON SOME
DEVELOPMENT OVER THE NEXT 48 HOURS PRIOR TO THE ENCROACHMENT OF A DRY
AIR MASS FROM THE SOUTH AND WEST. THE ECMWF, GFS, AND GOOGLE DEEPMIND
ENSEMBLE SYSTEMS CONTINUE TO AGREE ON A MODEST CHANCE OF TROPICAL
CYCLONE DEVELOPMENT. MODELS ALSO AGREE ON A GENERALLY SOUTHEASTERLY
TRACK OF 94S OVER THE NEXT 24 TO 48 HOURS. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 18 TO 23 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 UPGRADED TO
MEDIUM.
      (2) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.//
NNNN

pocketbox

WTIO30 FMEE 130645
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)

0.A WARNING NUMBER: 1/12/20252026
1.A ZONE OF DISTURBED WEATHER 12

2.A POSITION 2026/03/13 AT 0600 UTC:
WITHIN 40 NM RADIUS OF POINT 8.7 S / 54.6 E
(EIGHT DECIMAL SEVEN DEGREES SOUTH AND
FIFTY FOUR DECIMAL SIX DEGREES EAST)
MOVEMENT: EAST-NORTH-EAST 4 KT

3.A DVORAK ANALYSIS: 1.5/1.5/D 1.0/24 H

4.A CENTRAL PRESSURE: 1003 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: 130 SE: 0 SW: 0 NW: 0

7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 400 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM

1.B FORECASTS (WINDS RADII IN KM):
12H: 2026/03/13 18 UTC: 9.6 S / 56.5 E, VENT MAX= 030 KT, ZONE OF DISTURBED
WEATHER
28 KT NE: 140 SE: 0 SW: 0 NW: 140

24H: 2026/03/14 06 UTC: 10.8 S / 58.3 E, VENT MAX= 035 KT, MODERATE TROPICAL
STORM
28 KT NE: 150 SE: 150 SW: 0 NW: 150
34 KT NE: 85 SE: 0 SW: 0 NW: 0

36H: 2026/03/14 18 UTC: 12.7 S / 59.8 E, VENT MAX= 030 KT, TROPICAL DEPRESSION
28 KT NE: 155 SE: 155 SW: 0 NW: 0

48H: 2026/03/15 06 UTC: 14.7 S / 60.5 E, VENT MAX= 025 KT, TROPICAL DISTURBANCE

60H: 2026/03/15 18 UTC: 16.2 S / 60.5 E, VENT MAX= 025 KT, REMNANT LOW

72H: 2026/03/16 06 UTC: 17.8 S / 60.1 E, VENT MAX= 025 KT, REMNANT LOW

2.B LONGER-RANGE OUTLOOK:
NIL

2.C ADDITIONAL INFORMATION:
T=CI=1.5

IN THE LAST 24 HOURS, CONVECTIVE ACTIVITY HAS BEGUN TO ORGANIZE AROUND
A LARGE LOW-LEVEL CIRCULATION PRESENT SOUTH OF THE MAIN CONVECTION.
SCATTEROMETRIC DATA DOES NOT SUGGEST THE PRESENCE OF SIGNIFICANT NEAR
GALE FORCE WINDS LAST NIGHT. SINCE 00Z, THERE HAS BEEN A NOTABLE
IMPROVEMENT IN THE CLOUD PATTERN, WITH MARKED SIGNS OF CURVATURE.
HOWEVER, THE LATE-NIGHT MICROWAVE PASSES (0004Z F18 AND 0235Z F17),
ALTHOUGH SHOWING AN IMPROVEMENT, DID NOT ALLOW WITH CERTAINTY TO
LOCATE THE CENTER IN THE AREA OF VORTICITY VISIBLE ON THE SATELLITE
IMAGE. IN THE ABSENCE OF MORE RELIABLE DATA, SYSTEM 12 IS CURRENTLY
ANALYSED AS A ZONE OF DISTURBED WEATHER WITH MAXIMUM WINDS NEAR
30KT.

OVER THE NEXT 24 HOURS, SYSTEM 12 IS EXPECTED TO MOVE SOUTHEASTWARD
UNDER THE INFLUENCE OF THE NORTHWESTERLY MONSOON FLOW. FROM SUNDAY
ONWARDS, IT SHOULD GRADUALLY MOVE SOUTHWARD ALONG THE WESTERN
EDGE OF A RIDGE. AT LONGER RANGE, THE TRACK WILL DEPEND ON THE
INTENSITY OF THE SYSTEM. ACCORDING TO THE MOST LIKELY SCENARIO, IT
COULD WEAKEN SIGNIFICANTLY AND EVOLVE INTO A SURFACE TROUGH ON THE
NORTHWESTERN SIDE OF THE SUBTROPICAL SURFACE RIDGE. IF IT REMAINS MORE
INTENSE, IT COULD BE CARRIED TOWARDS THE MIDDLE LATITUDES IN LINE WITH A
HIGHER STEERING FLOW. THE FORECAST THEREFORE REMAINS QUITE UNCERTAIN
BEYOND 48 HOURS.

IN TERMS OF INTENSITY, THE SYSTEM IS BENEFITING FROM RATHER FAVORABLE
CONDITIONS IN THE SHORT TERM, WITH RELATIVELY LOW SHEAR, GOOD
DIVERGENCE, AND VERY GOOD CONVERGENCE ON THE EQUATORIAL SIDE. THE
WEAK CONVERGENCE ON THE POLAR SIDE REMAINS THE LIMITING FACTOR AT
FIRST FOR THIS POSSIBLE CYCLOGENESIS. FROM SUNDAY ONWARDS, THE
NORTHWESTERLY DEEP SHEAR SHOULD STRONGLY INCREASE, LEADING TO A
PROBABLE WEAKENING OF THE SYSTEM.

POSSIBLE TC HAZARDS :
- AGALEGA
HEAVY RAINS 50-100MM POSSIBLE IN THE NEXT 24H. IMPROVEMENT ON SATURDAY
EVENENING
- SEYCHELLES (ALPHONSE AND COETIVY)
HEAVY SHOWERS POSSIBLE TODAY, IMPROVEMENT ON SATURDAY MORNING
- SAINT BRANDON
HEAVY SHOWERS AND ROUGH TO VERY ROUGH SEAS 4M POSSIBLE FROM SUNDAY
AFTERNOON.

pocketbox