The Met Office has issued this warning for thunder on Sunday.
The warning is in place from 1 pm on Sunday 17 September until 6 am on Monday 18 September.
The warning states:
Heavy showers and thunderstorms are likely to arrive across southern England during Sunday and move northeastwards through the afternoon.
From late afternoon through Sunday night there is a small chance of thunderstorms becoming severe, with large hail, frequent lightning, gusty winds, and torrential rain producing 30 to 40 mm in an hour.
The most likely scenario is that impacts are more limited and isolated, but should these more severe storms develop, flooding and disruption could occur.