Overview
- The Met Office has issued an outlook for an unsettled spell from Wednesday to Friday (Aug 26–28) as a low‑pressure system moves in from the southwest, with deputy chief forecaster Mark Sidaway saying some places could see 20 to 30 mm of rain in just a few hours.
- Independent model guidance and analyst WxMacca report higher short‑period totals are possible, with UKV signals suggesting 50–100 mm in about 12 hours for some locations and Thursday night currently flagged as the most concerning window.
- Rain and thunderstorms are expected to develop first in southern England and Wales before spreading north and west, putting the South, the Midlands, the North West (including Greater Manchester) and parts of Scotland at risk of heavy bursts.
- Forecasters warn of practical hazards including frequent lightning, large hail, strong gusts and rapid surface water flooding, and emergency agencies advise people to monitor updates, avoid driving through floodwater and follow local warnings.
- The change follows a record warm, dry summer and drought in parts of the UK, so while the rain could help reservoirs it may also run off dry soils and increase flash‑flood risk, and the Met Office says the changeable, wetter pattern could persist into early September.