Heavy rain which prompted severe weather warnings for parts of southern England and Wales is moving north, bringing new flood risks, forecasters said.
The Met Office issued severe weather warnings for large parts of the country from south Wales to East Anglia.
Now forecasters say as much as 40mm of rain could fall in northern England and central and southern Scotland in the next 24 hours.
MeteoGroup forecaster Brendan Jones said: "It has been pretty wet across the UK but much of the heavy rain in the south is moving its way north. The focus of the heavy rain will be across northern England and central and southern Scotland, with another 20 to 40mm of rain expected to fall in those areas over the next 24 hours. Parts of the Midlands and Yorkshire may also see some lively thunderstorms."
Mr Jones said there was the possibility of snow falling in northern parts of Scotland. He added: "It's certainly going to feel chilly particularly in Scotland. There is a possibility in the Scottish mountains the heavy rain could fall as snow."
Although there is currently just one flood warning in place, the Environment Agency said on Wednesday there was a risk of localised flooding across the south and south-west of England, south Wales, the Midlands and parts of East Anglia.
The current flood warning is for the lower River Tone in Somerset, while six less serious alerts are also in place in East Anglia, the South East and South West.
Environment Agency flood manager Katharine Evans said: "Following an exceptionally wet April which led to some flooding last week, rivers are high and the ground is saturated, meaning that further rainfall brings with it an increased risk of flooding.
"We are continuing to closely monitor the forecast and rainfall, particularly for rivers in South Wales, Devon and Cornwall. And Environment Agency teams are out on the ground keeping a close watch on river levels, as well as checking defences and clearing any potential blockages to reduce the risk of flooding. If flooding does happen, we would urge people to keep away from swollen rivers and not to attempt to walk or drive through floodwater."
The continued unsettled weather comes after the wettest April on record, but much of England remains officially in a state of drought following two unusually dry winters in a row.