FORECASTERS have added an 'amber' - more serious - weather warning for the south west as thunderstorms are set to strike.

The Met Office has issued a further weather warning for much of the south, including Somerset, which says 'flooding of homes and businesses could happen quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds', amid the forecasts.

The amber warning, which is in place for between 4pm today (Thursday) and 6am tomorrow, comes after a yellow warning was issued for between 11am today and 6am on Friday.

"Fast flowing or deep floodwater is possible, causing a danger to life," a forecaster added.

"Spray and sudden flooding could lead to difficult driving conditions and some road closures and where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services.

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"Power cuts might occur and other services to some homes and businesses could be lost."

Sunny spells are forecast, with thundery showers set to start in southern coastal areas before spreading northeast.

Showers are set to continue through the afternoon with some torrential downpours likely especially in the west, the forecaster added, with temperatures reaching as high as 24C.

Tonight, showers may merge to give some more general thundery rain this evening, this then clearing away east overnight to leave most parts dry with mist and fog patches by morning.