Met Office forecasters have updated their weather warning and state "rain will be the main hazard."
Large swathes of the South West and UK have been braced for thunderstorms which were due to kick in from 12pm.
And while thunderstorms still remain a threat during the 10-hour alert period, it's heavy rain which will pose the greatests risks.
READ MORE: UK weather charts show intense rainfall amid 10-hour Met Office thunderstorm warning
The Met Office said this morning: "The warning has been changed to focus on rain rather than thunderstorms as this will be the main hazard, though some thunderstorms are likely. The end time has also been extended until the end of Saturday."
Weather maps reveal a huge band of rain started moving west towards the south of England at around 3am, before spreading across the rest of the country.
Forecasters say driving conditions could worsen and flooding and lightning strikes are "possible."
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Met Office on what to expect
- There is a good chance driving conditions will be affected by spray, standing water and/or hail, leading to longer journey times by car and bus
- Delays to train services are possible
- Flooding of a few homes and businesses could occur.
- Some short term loss of power and other services is possible, with possible damage due to lightning strikes, in a few places
