南半球各类图像自动更新暨非扰动云团专帖（2024年7月－2025年6月）

红豆棒冰冰

AWIO20 FMEE 181048
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 18/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin remains in a Near Equatorial Trough (NET) configuration to the east of 60°E, undulating between 2 and 9°S.
The NET is poorly defined and devoid of any significant convective activity in its western part. On the other hand,
convection has intensified east of 80°E in the vicinity of an area of enhanced vorticity associated with a moister
environment. A vast and very much elongated clockwise circulation is present around 9°S/90°E.
The weak wet phase of the MJO over the east of the Indian Ocean is currently overlapping with an equatorial Rossby
wave, thus maintaining some vorticity over the eastern part of our basin. Nevertheless, convergence is likely to remain
very insufficient over the next few days : on its equatorward side, the westerly flow is increasingly attracted towards a
north-hemispheric vortex, to the detriment of the vortex in our basin; on the poleward side, the passage of a subtropical
trough is likely to divert the trade winds. Moreover, an increasingly strong east-northeast wind shear will also contribute
to prevent the formation of a significant tropical low.
Development of a tropical storm is not expected over the next 5 days.

红豆棒冰冰

AWIO20 FMEE 190955
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 19/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin remains in a Near Equatorial Talweg (NET) configuration east of 60°E, undulating between 2 and 10°S. The
NET is poorly defined and convection is moderate on its eastern side. A vast and very much elongated clockwise
circulation is present around 9°S/90°E.
A Rossby wave is maintaining vorticity over the eastern end of our basin, behind the westerly thrust of a passing MJO.
Nevertheless, convergence should remain very weak over the next few days, and increasingly strong east-northeast
shear will also help prevent the formation of a tropical low-pressure system.
Development of a tropical storm is not expected over the next 5 days.

红豆棒冰冰

AWIO20 FMEE 201109
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 20/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin remains in a Near Equatorial Talweg (NET) configuration between 73°E and 82°E, undulating between 4 and
6°S. The NET is poorly defined and convection is moderate on its southeastern side. An elongated clockwise circulation
is present around 9°S/90°E.
The crossing of a Rossby wave with a Kelvin wave is maintaining vorticity over the eastern end of our basin, behind the
westerly thrust of a passing MJO. Nevertheless, convergence should remain very weak over the next few days, and
increasingly strong east-northeast shear also helps prevent the formation of a tropical low-pressure system.
Development of a tropical storm is not expected over the next 5 days.

红豆棒冰冰

AWIO20 FMEE 211008
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 21/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin features a short branch of the Near Equatorial Trough (NET) between 70°E and 85°E, undulating around 7S.
Convective activity is concentrated around a weak, ill-defined low-pressure area centered around 8S/80.4E. Convective
activity is also occurring within a low-level trough southeast of the coast of South Africa, sustained by purely baroclinic
mechanisms.
The crossing of a Rossby wave with a Kelvin wave is maintaining vorticity over the eastern end of our basin, behind the
westerly thrust of a passing MJO. Nevertheless, convergence should remain very weak over the next few days, and
increasingly strong east-northeast shear also helps prevent the formation of a tropical low-pressure system.
Development of a tropical storm is not expected over the next 5 days.

红豆棒冰冰

AWIO20 FMEE 221115
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 22/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin features a short branch of the Near Equatorial Trough (NET) between 70°E and 85°E, undulating around 5S.
Convective activity is concentrated around a weak, ill-defined low-pressure area centered around 8S/80.4E. Convective
activity is weak.
The crossing of a Rossby wave with a Kelvin wave during the weekend is maintaining vorticity over our basin.
Nevertheless, convergence should remain very weak over the next few days : the return of a negative phase of the MJO
and increasingly strong east-northeast shear also helps prevent the formation of a tropical low-pressure system.
Development of a tropical storm is not expected over the next 5 days.

红豆棒冰冰

AWIO20 FMEE 230931
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 23/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin is in a Near Equatorial Trough (NET) configuration between 60°E and 85°E, undulating around 6S. Convective
activity in the basin is low to non-existent.
The crossing of a Rossby wave with a Kelvin wave during the weekend is maintaining vorticity over our basin.
Nevertheless, the wave context remains inhibiting to allow a more significant implementation of vorticity, within the NET.
Development of a tropical storm is not expected over the next 5 days.
No significant signal for conditions more conducive to cyclogenesis up to 10 days.

红豆棒冰冰

AWIO20 FMEE 240955
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 24/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin is now in a winter pattern, with trade winds crossing the equator and feeding the north-hemispheric monsoon.
Convective activity remains weak, with a few isolated thunderstorm clusters in the slowing trade wind areas.
Current equatorial wave activity (Rossby and Kelvin waves, MJO over Indonesia) mainly has an influence on
cyclogenesis potential over the North Indian ocean or near Indonesia, but has no effect on our basin due to the
persistently unfavorable winter basin configuration.
Development of a tropical storm is not expected over the next 5 days.

红豆棒冰冰

AWIO20 FMEE 251004
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 25/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin is now in a winter pattern, with trade winds crossing the equator and feeding the north-hemispheric monsoon.
Convective activity remains weak, with a few isolated thunderstorm clusters in the slowing trade wind areas.
Current equatorial wave activity (Rossby and Kelvin waves, MJO over Indonesia) mainly has an influence on
cyclogenesis potential over the North Indian ocean or near Indonesia, but has no effect on our basin due to the
persistently unfavorable winter basin configuration.
Development of a tropical storm is not expected over the next 5 days.

红豆棒冰冰

AWIO20 FMEE 260957
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 26/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin is now in a winter pattern, with trade winds crossing the equator and feeding the north-hemispheric monsoon.
Convective activity remains weak, with a few isolated thunderstorm clusters in the slowing trade wind areas.
Current equatorial wave activity (Rossby and Kelvin waves, MJO over the Maritime Continent) mainly has an influence
on cyclogenesis potential over the northern hemisphere tropics but has no effect on our basin due to the unfavorable
winter basin configuration.
Development of a tropical storm is not expected over the next 5 days.

红豆棒冰冰

AWIO20 FMEE 271137
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 27/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin is a buffer zone, with the trade winds crossing the equator and feeding the north-hemispheric monsoon.
Convective activity remains low, with a few storm clusters present in the slowing trade winds north of a Diego-Garcia /
Coetivy line, west of 65E.
Current equatorial wave activity (Rossby and Kelvin waves, MJO over the Maritime Continent) mainly has an influence
on cyclogenesis potential over the northern hemisphere tropics but has no effect on our basin due to the unfavorable
winter basin configuration.
Development of a tropical storm is not expected over the next 5 days.