The Met Office has extended yellow thunderstorm warnings across England and Wales, with fears that "severe" flash flooding could cut off some communities as heavy, slow-moving showers bring roughly a month's worth of rain to ground already parched by a prolonged dry spell and widespread drought. Two consecutive warnings cover today and tomorrow, with forecasters and officials, including London Mayor Sir Sadiq Khan, urging people to check flood insurance and prepare for possible travel disruption, road closures and lightning strikes.

The first warning runs from 3am to 10pm today, covering much of England and northern and eastern Wales, with up to 30mm of rain possible in under an hour and up to 50mm over two to three hours. A second warning, from 6am to 10pm tomorrow, covers all of Wales and a similar swathe of England (excluding London and the South West), with up to 30mm expected in three hours widely and over 75mm possible on high ground over 12 hours; hail up to 2cm and frequent lightning are also forecast. The Met Office's Steve Willington warned of a "growing risk" of localised flooding and disruption, while the RAC cautioned that rain mixing with built-up oil and rubber residue on roads increases skidding risk after the dry spell, which had left drought declared across nearly three-quarters of England and the whole of Wales.