Overview
- The Met Office said on Friday that a highly unusual disruption of the stratospheric polar vortex is underway and that it could become the earliest major sudden stratospheric warming on record.
- A sudden stratospheric warming is a rapid rise in polar stratosphere temperatures that can weaken the polar vortex and, if that change reaches the lower atmosphere, shift the jet stream and encourage blocking highs that alter UK weather.
- Forecasters say any surface effects usually take one to three weeks to appear and can take up to six weeks, though short-range guidance already flags a chance of colder air and brief wintry showers spreading from the north toward the end of next week.
- Experts note that a record-strong El Niño may be helping to trigger the early disruption while also making it harder to predict how the stratospheric change will translate into local weather at ground level.
- If the disturbance propagates downward it could raise the odds of cold snaps and localized snow in eastern areas or produce a drier winter that worsens drought and increases heating demand, but concrete local impacts remain uncertain.