The Met Office has issued a yellow weather warning for heavy showers and thunderstorms that will hit much of England and Wales - including Greater Manchester.
The storms are expected to hit between 9am on Tuesday, July 27, and 6am on Wednesday, July 28.
The thunderstorms and heavy rain may lead to flooding and transport disruption.
The Met Office has warned that sudden flooding could lead to difficult driving conditions and possibly some road closures.
It has warned that where lightning and flooding occurs there is a chance of delays and some cancellations to train and bus services.
There is also a 'small chance' that homes and business could be flooded quickly, with damage to some buildings from floodwater or lightning strikes.
The Met Office has said that 20 to 30mm of rain is possible in around one or two hours, and a few places could see around 60mm in three to six hours.
