Thunderstorms may develop bringing torrential rain, hail and lightning to a few places, with potential disruption to travel and flooding.
The weather front is expected between 6pm Tuesday and 9pm Wednesday.
There is a chance that homes and businesses could be flooded quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds
Where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services
Spray and sudden flooding could lead to difficult driving conditions and some road closures
There is a slight chance that power cuts could occur and other services to some homes and businesses could be lost
Through Tuesday evening there is potential for thunderstorms to break out, initially across parts of southern England, before developing more widely overnight and then clearing through Wednesday morning. The thunderstorms may merge into areas of more prolonged and widespread rain for a time on Tuesday night and at first on Wednesday. Widely 15-30 mm of rain may fall, with up to 50 mm in a few locations. After a drier interlude, further thunderstorms may develop in a few places during Wednesday afternoon, mainly southeastern parts of England. Whilst rain and flooding is likely to be the largest impact, hail, lightning and gusty winds will be additional hazards.