A yellow weather warning has been brought forward, with Hertfordshire braced for possible thunderstorms this week.

Initially, the Met Office had issued the warning for 12pm until 11.59pm on Thursday (August 1), which stretched to the east coast, into Wales in the west, and as far north as Middlesborough.

An updated warning has now been issued for large parts of London and the East of England for tomorrow (Wednesday, July 31) between 12pm and 11.59pm.

St Albans and Watford are the most likely areas to be affected.

The warning reads: "Some isolated flooding and disruption from thunderstorms is possible on Wednesday.

"Whilst many places will stay dry, a few thunderstorms are likely to break out on Wednesday.

"These are possible at any time, but become more likely during the afternoon and evening."

"These are possible at any time, but become more likely during the afternoon and evening. Where these occur, 20 to 30mm of rain is possible within an hour, and perhaps as much as 50mm in two hours."

However, the risk of thunderstorms remains low, with the Met Office saying: "This warning has a very low likelihood and a medium impact."