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Storm · Forecast to formLow in the South Pacific · L-2026-0059

A new low is likely to form on Sunday afternoon

Forecast to form Sun afternoon, in the South Pacific; nearly all forecasts show it.

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

Forecast to form Sun afternoon, in the South Pacific; nearly all forecasts show it.

Quick answers

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

Where will the low in the South Pacific form?
Forecasts that develop it have the centre forming in the South Pacific on Sunday afternoon. The most likely path takes it in the South Pacific by Wednesday afternoon.
How sure is the forecast?
High confidence. 102 of 103 show the storm, and they broadly on its early path (agreement 74 out of 100).
Do the AI and physics models agree?
Broadly, with some differences. By Tuesday afternoon the AI ensembles’ middle track is about 170 kilometres northwest of the physics ensembles’. At its deepest, the AI ensembles take it to about 978 and the physics ensembles to about 975 hPa.
Will the low in the South Pacific become a bomb cyclone?
21% of forecasts (2 in 10) 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 forms. The forecasts that show it have the centre taking shape in the South Pacific on Sunday afternoon, at about 991 .

How sure. 102 of 103 show the storm, and they broadly on its early path.1

How strong. It is still strengthening: forecasts deepen it to about 977 by Monday afternoon. Two in 10 forecasts make it a , deepening about 24 hectopascals or more in a day.

What’s uncertain

Whether it forms. 102 of 103 develop it; the rest do not. Storms that exist only in the forecast can change a lot from run to run.

Later on. The forecasts fan out after Tuesday. By Thursday morning, the is about 1,750 kilometres across.2

When it arrives

No town we track is within reach of this storm; it stays in the South Pacific.

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
30 of 3112Z
ECMWF
51 of 5112Z
Environment Canada
21 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 9 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
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