Large parts of the UK are likely to be closed this week due to heavy rain and some flood warnings.
Up to 70 mm of rain is expected in the worst affected areas for more than 48 hours.
It comes after a weekend of eight centimeters of snow in some parts of the east of England.
There is an amber warning for rain covering a circular area including Sheffield, Manchester, Blackburn and Leeds from 6am on Tuesday until the end of Wednesday.
The Met Office has warned of heavy rains, which could cause snow to melt across the mountains and cause some flooding.
Buildings can be damaged, floodwaters can be “life threatening” and travel can be difficult.
Yellow, less severe, warning for rain on Tuesday, covering much of the region, including Wales, and the upper half of the UK. On Wednesdays and Thursdays, the warning covered the whole of England and Wales.
Rainfall of up to 200 mm is possible in some parts of Wales.
Meteorological Office forecaster John Griffiths said: “Part of the low pressure area will move late Monday and it will rain heavily over the next three days.
“Between Tuesday and Wednesday, about 40-70 mm of rain is expected in the northwest of the UK, which is 100-120 mm in hilly areas.
“On Thursday more deep low pressure will begin to travel south to other parts of the UK, with heavy rain and thunderstorms from the north.”
The Environment Agency had 14 flood warnings across the UK on Sunday evening, extending from the southeast to the northeast, meaning “immediate action” is needed.
Natural resources said Wales had the lowest flood risk on Monday and the lowest risk on Tuesday, Wednesday and Thursday.