Large swathes of the UK are bracing for violent thunderstorms and heavy downpours, with parts of Wales, Southwest England, and Northern Ireland expected to be worst affected. Up to 20mm of rain could fall in a matter of hours, disrupting what had been a relatively calm spell of autumn weather.
The Met Office and meteorological analysts at MetDesk are tracking a band of Atlantic low pressure that is due to sweep across the country on Sunday, bringing sudden weather shifts and possible travel disruption. Rainfall is expected to begin in the southwest before spreading northeastwards across the rest of the country.
Regions at Risk of Severe Downpours and Strong Winds
According to The Mirror, the latest forecast data shows that rural parts of south Wales, particularly Carmarthenshire, could see more than 20mm of rain over just a few hours. This heavy rain is predicted to begin around 4pm on Sunday, as a low-pressure system moves in from the Atlantic, bringing unstable atmospheric conditions.
Wind speeds are also expected to increase sharply, particularly along the west Wales coast, where gusts may reach 50mph. As the system tracks slowly northeastwards through the afternoon and evening, much of England, Wales, and Northern Ireland will be affected. The rainfall will not be uniformly distributed, with the heaviest evening showers expected to shift towards North Yorkshire by 10pm.
Southwest England, including Devon and Dorset, may also experience isolated thunderstorms in the evening, while Wiltshire, Gloucestershire, and Worcestershire could see localised storm activity. According to MetDesk, although lightning and thunder were originally forecast to be widespread, new modelling suggests storm coverage will be more scattered than initially predicted.
Colder Temperatures Expected as High Pressure Breaks Down
The incoming weather system marks a clear departure from the mild and settled conditions experienced earlier this week. Temperatures in Plymouth and Aberystwyth had reached 17.1°C and 18.6°C respectively, but Sunday’s rain is likely to coincide with a significant drop in temperature, with daytime highs possibly falling to 10°C in some areas.
According to the Met Office, “a transition to more unsettled conditions than of late is expected” as the Atlantic low pressure spreads across the UK. The forecast also warns of lingering showers into Monday morning, particularly along the south coast, as the system proves slow to clear. While the exact impact remains uncertain, localised flooding, difficult driving conditions, and delays to transport are possible if forecasts materialise.
