Polar Vortex Weakening at Record-Early Date: Could the UK See Snow This Winter?

The polar vortex — a giant ring of freezing winds spinning high above the Arctic — is weakening far earlier than ever recorded, and forecasters say it could raise the chances of cold weather and snow in the UK later this winter. But experts are clear about one thing: snow is not guaranteed, and nobody should expect it next week.

The weakening is already under way. In recent days the vortex has stretched out of shape and briefly split into two smaller circulations around the Arctic. Weather models now show its winds could reverse by the middle of November. If that happens, scientists will call it a major sudden stratospheric warming — and it would be the earliest one ever recorded.

That is why this story matters. It is not a snow forecast. It is a warning that the winter ahead may not follow the usual script, and that a familiar pattern — one that brought the “Beast from the East” to Britain in 2018 — may be starting to form weeks ahead of schedule.

What is happening high above the Arctic?

About 30 kilometres above the North Pole, powerful winds blow from west to east around the Arctic. They form a vast circle known as the stratospheric polar vortex. In a normal winter, these winds stay strong and keep the coldest air locked up around the pole.

That is changing. The winds have weakened sharply in recent days, and the vortex has stretched and briefly split into two smaller circulations. Forecast models from the European Centre for Medium-Range Weather Forecasts (ECMWF) and NASA now show the winds reversing — blowing from east to west — in the first half of November.

If the winds do reverse, meteorologists will declare a major sudden stratospheric warming, or SSW. That is the technical name for what happens when the polar vortex breaks down and the air high above the Arctic warms rapidly.

NASA’s own data shows how weak the winds have already become. On 29 October, the average west-to-east wind at the height scientists use to measure the vortex had fallen to 13.5 metres per second, against an average of 23.3 for that date over 1979 to 2026. NASA’s forecast turns the wind easterly on 5 November.

The Met Office, Britain’s national weather service, said on 30 October that it expects a sudden stratospheric warming to start next week, and that it “may also lead to some dry weather deeper into November”. On 4 November, the Met Office told The Independent: “A highly unusual disruption of the stratospheric polar vortex is now underway. If it becomes a major SSW, it will be the earliest such event on record.”

What is the polar vortex, in simple terms?

Think of the polar vortex as a fence made of wind. Every autumn, as temperatures fall in the Arctic, a ring of strong winds forms high above the North Pole, between 10 and 50 kilometres up. It spins around the Arctic like a wall, keeping the bitterly cold air inside.

When the vortex is strong, the cold air stays put and the weather further south stays relatively mild and changeable. When the vortex weakens or breaks down, the fence collapses. The jet stream — the fast-moving river of air that steers our weather — can buckle and wobble, letting cold Arctic air spill south into Europe and North America.

A sudden stratospheric warming is one of the main ways the vortex breaks down. Warm air surges up into the stratosphere, the winds slow, stop, and then reverse. The effects do not reach the ground straight away. It usually takes anywhere from two to six weeks for the disruption high above the Arctic to change the weather where we live.

That delay is important. Even if the vortex breaks down in mid-November, any cold weather it causes would most likely arrive in late November or December, not next week.

Why is this event so unusual?

The timing is what makes this event stand out. Most sudden stratospheric warmings happen in the middle of winter — January or February. An event in early November is almost unheard of.

Jeff Knight, lead climate scientist at the Met Office, told the BBC: “It would appear to be the earliest on record looking back over the 75 years we’ve been observing… with most experts agreeing this is a very unusual event.”

The current earliest major sudden stratospheric warming on record happened on 28 November — in both 1969 and 2025. If the winds reverse in the first half of November this year, it would beat that record by about three weeks.

Dr Judah Cohen, an atmospheric scientist at the Massachusetts Institute of Technology (MIT), told reporters it would almost certainly be the largest and earliest polar vortex disruption on record. He stressed, though, that the timing, strength and effects on the weather are still highly uncertain.

It is also unusual because there is so little to compare it with. Scientists have good records of sudden stratospheric warmings going back to 1958, and detailed satellite records since 1979. In all that time, they have never seen one start this early. That means there is no past example to show exactly what will happen next — and forecasters are honest about that uncertainty.

What happened the last time the vortex broke down?

The most famous example in Britain is the “Beast from the East” in late February and early March 2018. A sudden stratospheric warming broke down the polar vortex, and a blast of freezing air from Siberia swept across the UK. Snow fell heavily, thousands of schools closed, and transport networks ground to a halt in many areas. It was one of the coldest spells Britain had seen in years, and it arrived after a mild winter that had given little warning.

The photograph with this article was taken during that cold spell — snow-covered fields in the UK on 3 March 2018, at the height of the Beast from the East.

Researchers have checked what happened after the 32 major warmings since 1979. Central England was colder than normal in the 30 days after 19 of them. That is a lean towards cold — but it is far from a rule. In 13 of those 32 cases, temperatures were normal or warmer than usual.

Will the UK see snow?

This is the question everyone is asking, and the honest answer is: maybe, but not soon, and not certainly.

Professor Andrew Perez-Charlton, a meteorologist at the University of Reading, told the BBC: “The typical response to a SSW is for colder and drier conditions over Europe and the UK.” A weaker vortex can also boost the chance of snow, especially in eastern parts of the UK, where cold air from the east and north-east has the shortest journey over land.

But several things stand in the way of snow in the near future. First, the air is not yet at mid-winter temperatures. Even if Arctic air reaches Britain in late November, it may not be cold enough for widespread snow. Second, there is no precedent for an event this early, so forecasters cannot be sure the usual pattern will follow. Third, the Met Office’s long-range forecast to 29 November does not mention snow at all. It expects high pressure, fog and frost first, then more unsettled weather with temperatures near or a little above normal.

The Met Office’s outlook for November to January still makes a cold three months less likely than normal overall, while saying cold spells remain possible. In other words, the winter as a whole is still expected to be milder than average — but the polar vortex disruption adds a real chance of a sharp cold spell somewhere along the way.

For now, the message from forecasters is simple: the next few weeks look mild and wet, and London rarely sees lying snow before December in any case. Any cold effect from the vortex would most likely come from late November into December. Snow in the coming weeks is not likely.

What about the rest of Europe and North America?

The effects of a sudden stratospheric warming are not limited to Britain. When the jet stream buckles, cold air can spill south across northern Europe and into North America too. At the same time, other regions can turn unusually mild — the pattern is not the same everywhere.

Northern Europe, including Scandinavia and Germany, often feels the cold first, while southern Europe may stay mild or even warm. In North America, the eastern United States and Canada are the places most likely to see cold air push south, although that depends on exactly how the jet stream bends.

Why is it happening now?

Scientists do not yet know exactly why the vortex is weakening so early. It could simply be part of the natural variability of our weather patterns. But one suspect is El Niño — the natural warming of the Pacific Ocean that is currently at record strength.

In a normal El Niño year, the polar vortex typically weakens towards the end of winter, not the beginning. With the current El Niño taking the world’s weather into uncharted territory, Jeff Knight suggested it could have “helped load the dice” for this early warming event. He added, however, that “because this is so rare, there’s not enough evidence” — and that a link between a strong El Niño and an early sudden stratospheric warming is unclear and will need further research.

That El Niño is already making headlines of its own. It has broken the previous record set in 2015, and forecasters have warned of a historic peak and major effects on weather around the world, including Pakistan’s monsoon and winter.

What happens next?

The next few days will tell scientists a lot. If the winds above the Arctic reverse as forecast, the sudden stratospheric warming will be confirmed — and the record books will be rewritten. Forecasters will then watch for the effects to work their way down to the surface over the following two to six weeks.

The Met Office will update its long-range forecasts as the picture becomes clearer. Its forecast to 29 November currently shows no snow, and its November-to-January outlook still leans mild overall. If a cold spell does develop, the first signs will appear in the forecasts for late November and early December.

And for the rest of the world, this is a reminder of how connected the weather is. A ring of wind 30 kilometres above the North Pole, weakening a few weeks early, can change the odds of snow in London, cold in Berlin, or a freeze in New York. The atmosphere does not respect borders, and neither do its surprises.

Frequently asked questions

What is the polar vortex?

The polar vortex is a ring of strong winds that spins high above the Arctic, between 10 and 50 kilometres up. It forms every autumn and normally keeps the coldest air locked around the North Pole. When it weakens or breaks down, cold Arctic air can spill south into Europe and North America.

What is a sudden stratospheric warming?

A sudden stratospheric warming, or SSW, happens when the polar vortex breaks down and the air high above the Arctic warms rapidly. The winds slow, stop, and then reverse direction. It is the main way the polar vortex collapses, and it can change weather patterns at the surface for weeks afterwards.

Why is this polar vortex event a record?

If the winds reverse in the first half of November, it will be the earliest major sudden stratospheric warming ever recorded. The current earliest happened on 28 November, in 1969 and 2025. The Met Office’s lead climate scientist, Jeff Knight, said it would appear to be the earliest on record looking back over 75 years of observations.

Will it snow in the UK?

Snow is possible later in the winter, especially in eastern parts of the UK, but it is far from guaranteed. The Met Office’s forecast to 29 November does not mention snow, and the air is not yet at mid-winter temperatures. Any cold effect would most likely arrive from late November into December, and it would take two to six weeks for the vortex disruption to affect weather at the ground.

What was the Beast from the East?

The Beast from the East was a severe cold spell that hit the UK in late February and early March 2018. It was caused by a sudden stratospheric warming that broke down the polar vortex, letting freezing air from Siberia sweep across Britain. Heavy snow fell, thousands of schools closed, and transport networks were badly disrupted.

Is El Niño causing this?

It is not clear. The current El Niño is at record strength and may have “loaded the dice” for an early warming event, according to the Met Office’s Jeff Knight. But scientists say there is not enough evidence yet, and the link between a strong El Niño and an early sudden stratospheric warming needs further research.

Does a cold winter mean global warming has stopped?

No. A single cold spell, even a snowy one, is a short-term weather event. The long-term trend is still warming — October 2026 is on track to be the hottest October ever recorded. Cold snaps can still happen in a warming climate. What matters is the average over years and decades, not one cold week.

Conclusion

The polar vortex is weakening at a time of year when it should be at its strongest, and if its winds reverse in the coming days, it will be the earliest breakdown on record. That is a remarkable event, and it raises the odds of a cold, possibly snowy spell in the UK and northern Europe later this winter.

But it is not a snow forecast. The effects, if they come, will take weeks to arrive, and the history of past events shows that cold weather follows a sudden stratospheric warming more often than not — but not always. The Met Office’s near-term forecast is mild and wet, with no snow in sight before the end of November.

So the sensible response is to watch, not worry. Keep an eye on the forecast as December approaches, especially if you live in eastern Britain. And remember that this early vortex disruption is one more sign of a climate system that is behaving in ways scientists have not seen before — from a record El Niño to the first snow on Pakistan’s northern mountains arriving while much of the country stays dry.

Sources

• BBC Weather (via BytesEU), “Could the earliest weakening of the polar vortex on record bring UK snow?”, 6 November 2026 — https://www.byteseu.com/2501087/
• BBC Weather (via Newsmint mirror), “Could the earliest weakening of the polar vortex on record bring UK snow?”, 6 November 2026 — https://read.newsmint.io/article/article-1a0d914dd3f0410b?category=top-stories&country=us
• The Independent (via Europe Says), “What is Sudden Stratospheric Warming — and how could it impact London’s winter weather?”, 4 November 2026 — https://www.europesays.com/britain/159152/
• Energy Radio, “Will it snow in London? Polar vortex collapse explained”, 2 November 2026 — https://energyradio.uk/london-snow-polar-vortex/
• Prepared Britain, “Earliest polar vortex breakdown on record forecast for November: what it means for the UK”, 2 November 2026 — https://www.preparedbritain.co.uk/guides/polar-vortex-uk-winter

This article is for general information and education only. It is not legal or financial advice.