By Basant El-Faramawy
Forecasters warn that a disruption of the stratospheric polar vortex, potentially amplified by a record-strength El Niño, could bring freezing Arctic air to the UK this winter. The Met Office said the current El Niño event is the strongest on record and is already disturbing the high-altitude ring of cold winds above the Arctic.
Polar Vortex Disruption Underway
A "highly unusual disruption" of the stratospheric polar vortex is now underway, according to the Met Office. If it develops into a major Sudden Stratospheric Warming (SSW), it would be the earliest such event on record. SSWs can weaken the jet stream, allowing severe cold to plunge southward into Europe and North America.
El Niño's Role
The Met Office noted that the large El Niño may be contributing to the disturbance, as El Niño increases the likelihood of SSWs. While SSWs often raise the chances of cold UK weather, the influence on surface conditions remains uncertain. A similar SSW in November 2025 did not lead to substantial cold weather for the UK.
Potential Weather Patterns
If a sudden stratospheric warming occurs, the jet stream may "snake" more, creating a blocking high-pressure area over the North Atlantic and Scandinavia. This pattern typically brings prolonged dry, cold weather to northern Europe, including the UK, while southern Europe becomes milder, wetter, and windier. Cold easterly winds on the boundary of these zones can produce snow, as seen in early 2018.
Forecast Limitations
Forecasters can reliably predict individual SSWs only about a week in advance, and the effects on UK weather usually take a few weeks to materialize. The long-range forecast suggests below-average temperatures in November before a return to slightly above average later in the month, with more unsettled conditions but no guarantee of freezing weather.
