Polar Vortex Disruption Could Set Record for Earliest Ever, Met Office Says

A disruption of the stratospheric polar vortex, the ring of cold winds high above the Arctic, is under way earlier than any on record, forecasters say. The Met Office told The Independent that if it develops into a major Sudden Stratospheric Warming (SSW), it will be the earliest such event ever recorded. The agency stressed that it is still unclear whether it will affect weather at ground level.

The Met Office described the disruption as "highly unusual" and said the current large El Niño may be contributing to it. Some forecast maps already show wintry weather for parts of Britain, but the official long-range outlook does not point to a deep freeze.

What is happening high above the Arctic

The polar vortex acts like a spinning wall of wind that keeps the coldest air near the North Pole. When it is strong, the cold stays contained. When it weakens, Arctic air can spill south into North America and Europe, The Independent reported.

Severe Weather Europe, a forecasting site, said stratospheric winds are dropping to near zero and are expected to reverse direction in the coming days, with the reversal first forecast for Friday. It said all ECMWF and GEFS ensemble forecast members show a reversal at some point, and that the event looks brief, with winds recovering by mid-November. The site put the timing about three weeks earlier than any previous such event, and said temperatures in the stratosphere are forecast to run more than +27°C (49°F) above normal for the time of year.

How El Niño fits in

The Met Office said El Niño is known to raise the likelihood of SSWs. The Independent reported that this El Niño has exceeded earlier benchmarks to become the strongest on record and has helped drive record summer heat. The Met Office also said El Niño is associated with an increased risk of cold snaps.

The agency noted that an SSW in November 2025 did not directly lead to substantial cold weather in the UK.

What it means for winter weather

For UK readers, the Met Office said SSWs often raise the chances of cold weather, but at this stage the influence on surface weather is uncertain. When a warming event makes the jet stream snake more, it can create a large area of high pressure over the North Atlantic and Scandinavia. That tends to bring a long, dry, cold spell to northern Europe, including the UK, while southern Europe sees milder, wetter and windier conditions. Cold easterly winds can develop along the boundary and sometimes bring snow, as happened in early 2018, according to The Independent.

Any effect is not immediate. The Independent reported that an SSW usually takes a few weeks to influence UK weather, and that forecasters can reliably predict individual events only about a week ahead.

For North America, Severe Weather Europe said it searched climate model simulations and found 21 winters in which the vortex collapsed in the same window during a strong El Niño and westerly tropical stratospheric winds. Those cases showed a cold signal stretching from western Canada into the United States in December. The author stressed this is not a forecast for this winter. He said the signal runs against the pattern a strong El Niño tends to push.

What the forecasts show for now

AOL, citing maps from WXCharts, reported that up to 12 counties in parts of Scotland and northern England could see snow by next Thursday, Nov. 12. Such long-range charts are uncertain.

The Met Office long-range forecast expects temperatures a little below average in early to mid-November, then near or slightly above average. For Nov. 18 to Dec. 2, it sees an increasing chance of changeable, more unsettled conditions, with rain and at times strong winds. It said confidence in the overall pattern is very low. It added that Atlantic low-pressure tracks may shift farther south toward the end of November, and that colder interludes remain possible, perhaps especially later in the period.

Around Prague, based on reporting by The Independent, Severe Weather Europe, AOL.co.uk