Thunderstorm alerts could be issued this week, the Met Office warned as it forecast "intense rainfall" across parts of the UK.The deluge is expected to hit on Wednesday evening - after a drier and widely sunny Tuesday - during which time some western areas could see 20-40mm of rain over just a few hours.

Thunderstorm alerts could be issued this week, the Met Office warned as it forecast "intense rainfall" across parts of the UK.The deluge is expected to hit on Wednesday evening - after a drier and widely sunny Tuesday - during which time some western areas could see 20-40mm of rain over just a few hours.