The national weather service has put Oxfordshire on alert as intense electrical storms and rapid-onset flooding threaten the area.
Drivers are being told to expect significant problems on the roads as conditions deteriorate across the region.
The warning covers most of England starting at 3am on Wednesday, August 26 and continuing until 10pm on Thursday, August 27.
A wall of torrential rain and thunderstorms is expected to sweep northwards from just below Oxfordshire’s southern boundary towards the Midlands and northern areas.
Forecasters indicate the precipitation could be severe, with 20 to 30 millimetres descending within a single hour and totals reaching 40 to 50 millimetres over a two-to-three-hour period in certain locations, resulting in flooding on roads.
An additional yellow alert for electrical storms runs from 6am to 10pm on Thursday, with officials noting potential for widespread disruption.
Senior meteorologist Steve Willington explained that Wednesday brings an escalating threat of downpours and thundery conditions, with the warm and muggy atmosphere serving as fuel for powerful showers and storms.
Some locations could receive substantial rainfall in a very short timeframe, creating conditions for flash flooding, traffic problems, and regular lightning strikes.
Surface spray and unexpected flooding may create hazardous road conditions and temporary closures, while large hailstones and repeated lightning are also possibilities.
The RAC has highlighted that dangerous driving conditions from wet roads are amplified at present due to the extended period without rain.
Residents are urged to ready themselves and their homes, verify road conditions prior to setting out, and monitor official weather alerts for the latest information.
