An area of warm, very humid air is expected to move northwards from France into southern Britain late on Thursday and into Friday.
Temperatures are expected to peak in the low to mid 20s°C on Friday before isolated severe thunderstorms develop.
This will be succeeded by a band of more widespread heavy rain and occasional thunderstorms.
These will move gradually north later in the day, affecting much of the eastern region until around 7am on Saturday morning.
The Met Office is warning the public to be aware of the chance of, in particular, surface water flooding causing localised disruption along with lightning and hail.
See the latest Met Office weather warnings at metoffice.gov.uk.
Following last week’s Met Office warning, the predicted thunderstorms failed to materialise for most of Sussex with heavy rain falling mainly in the west of the country.
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