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StormSouthern Ocean low in the southern Indian Ocean · L-2026-0054

The Southern Ocean low in the southern Indian Ocean is near its strongest and will slowly weaken as it heads southeast

Very deep low bottoming out near 948 hPa Sun morning, about 1,050 km W of Casey Station; 9 in 10 forecasts show it.

Updated Sat., Sept. 26, 9:58 p.m. UTC · 103 from NOAA, ECMWF and Environment CanadaMedium confidence

Very deep low bottoming out near 948 hPa Sun morning, about 1,050 km W of Casey Station; 9 in 10 forecasts show it.

Quick answers

As of the Sat 26 Sep 12Z model run · updated Sat., Sept. 26, 9:58 p.m. UTC

Where is the Southern Ocean low in the southern Indian Ocean going?
The centre is about 1,300 kilometres east of Mawson Station, moving southeast at about 45 km/h. The most likely path takes it about 650 kilometres west of Casey Station by Tuesday morning.
How sure is the forecast?
Medium confidence. 94 of 103 show the storm, and they on where it goes (agreement 54 out of 100).
Do the AI and physics models agree?
Broadly, with some differences. By Monday night the AI ensembles’ middle track is about 300 kilometres west of the physics ensembles’. Both take it to about 949 at its deepest.
Will the Southern Ocean low in the southern Indian Ocean become a bomb cyclone?
Unlikely. None of the 103 deepen it fast enough to count as a (a pressure fall of roughly 24 in 24 hours, adjusted for latitude).

What we know

Where it is. At 10 p.m. Saturday, the centre was about 1,300 kilometres east of Mawson Station, with a central pressure near 950 .

How sure. 94 of 103 show the storm, and they on where it goes.1

How strong. It is near its strongest now. Forecasts have it filling steadily, to about 967 by Monday. None of them turn it into a rapidly deepening .

What’s uncertain

Later on. The forecasts fan out after Monday. By Tuesday morning, the is about 900 kilometres across.2

When it arrives

No town we track is within reach of this storm; it stays about 1,300 kilometres east of Mawson Station.

DetailsStrength, sources and the fine print

How strong it gets

Central pressure over time. The line is the middle forecast; the band holds 8 in 10 of them.

(lower is stronger)

Times are shown in

Where the forecasts come from

ModelTracks
NOAA
31 of 3112Z
ECMWF
45 of 5112Z
Environment Canada
18 of 2112Z

Also tracking

  1. Bering Sea lowLikely to pass 20–320 km from Kodiak Sun evening; 7 in 10 forecasts bring it within 160 kmL-2026-0002
  2. September Nor’easterLikely to pass 20–140 km S of New York Sun afternoon; nearly all forecasts bring it within 160 kmNE-2026-01
  3. Ross Sea lowVery deep low bottoming out near 943 hPa Sat afternoon, in the Southern Hemisphere; all 103 forecasts show itL-2026-0057
  4. Bellingshausen Sea lowVery deep low in the Southern Hemisphere, near 958 hPa now and filling; nearly all forecasts show itL-2026-0064
  5. East Pacific tropical system off MexicoTropical system over the North Pacific, near 978 hPa now and filling; nearly all forecasts show itL-2026-0061
  6. See all 55 storms →

Notes

  1. Forecast tracks from the 12Z model run: GEFS (31), AIFS ENS (51), GEPS (21). A single run is one high-resolution forecast; ensemble forecasts are the same model run many times with small changes.
  2. The cone encloses where the centre is expected to be about two times in three at each hour, from the spread of the forecasts, widened by 20 percent; not yet calibrated against past storms. It shows uncertainty in the track, not the size of the storm.
  3. Shading shows the share of forecasts that bring the centre within 160 kilometres of a spot at any time in the next 6 days. Rain, wind and surge can reach much farther.
  4. Times are in your time zone. Arrival windows run from the earliest to the latest closest approach across forecasts that bring the centre within about 300 miles (500 km).
  5. NOAA/NCEP.
  6. Data Source: Environment and Climate Change Canada.
  7. This service is based on data and products of the European Centre for Medium-Range Weather Forecasts (ECMWF). Source: www.ecmwf.int. Licence: CC BY 4.0.
  8. Cyclone tracks computed by WeatherNick from the model fields.
  9. Not an official forecast. For warnings and decisions, follow your national weather service.

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Stormlines Tracks: NOAA, ECMWF, Environment Canada · 12Z run

Full forecast
Through Tue 6 a.m. UTC