Severe weather warnings are also in force for Wales, the north west, north east, south west and south east of England as well as London.
South-west England and south Wales have been battered since the early hours of Friday morning, with the rain set to head north east throughout the day, hitting Northern Ireland and the south of Scotland by mid-afternoon.
Paul Mott of MeteoGroup, the weather division of the Press Association, warned that up to 50mm of rain was expected in the next 24 hours, as much as would be typically seen in a fortnight in September.
Experts warn that after an unusually-wet August the ground is saturated the risk of flooding is increased across the UK.
Copyright © PA Business 2008