Up to 50mm of rain will lash parts of the UK within 18 hours as the Met Office issues a yellow weather warning covering large swathes of England, Scotland and Wales, with flooding and travel chaos expected.
The warning takes effect from late afternoon on Thursday through to Friday morning, with forecasters warning residents to brace for challenging conditions as heavy downpours sweep across the country.
Northern England and parts of Scotland will bear the brunt of the deluge, with 20-30mm of rain expected widely and up to 50mm possible over higher ground. The volume of water poses serious flooding risks, particularly in urban areas and on already saturated ground.
Regions from the Midlands northwards face the heaviest impact, including the North West, North East, Yorkshire and Humber. Scotland's southern and central belts, plus parts of the Highlands, are also under warning, whilst northern and central Wales will see the worst conditions. Northern Ireland expects scattered showers but escapes the most severe warning areas.
Motorists face treacherous conditions with standing water, reduced visibility and longer journey times inevitable. Bus and train services are likely to suffer delays or cancellations, with passengers urged to check travel updates before setting off.
A small number of homes and businesses could flood, whilst power cuts remain possible. Temperatures will stay mild at 8-12°C, with winds of 10-20mph and stronger gusts accompanying heavy showers.
Residents should secure loose outdoor items, clear drains where safe, and never attempt to walk or drive through floodwater. The Environment Agency will monitor river levels closely, issuing flood alerts as needed.