The south west of England and west Wales have been warned to brace themselves for heavy flooding on Monday evening after the Met Office forecast four or more inches of rainfall over the course of nine hours.
The Environment Agency currently has 16 flood alerts in place across England and Wales and expects to issue further flood warnings over the course of Monday evening.
Martin Weiler at Environment Agency said people in England should follow local and social media for updates.
“People in Cornwall and Devon should prepare for the possibility of flooding, by checking the latest situation on the Environment Agency’s website and by listening to local media," he said.
“The Environment Agency has been working around the clock to prepare for the forecast rainfall, by liaising with emergency services, clearing drains and checking flood defences."
In Wales Environment Agency spokesman Curig Jones told BBC Radio that they expected 100mm of rain to fall in western parts of Pembrokeshire.
"So what we could see are drainage systems not being able to cope with the rainfall," he said. "Also, we are monitoring river levels closely because we could see some flooding of low lying land," he said.
"We do ask that people take care when they're out and about - if they do see any flooding on the roads, not to walk or drive on them as they could be dangerous."