Merseyside is set to be hit with heavy downpours over a 60 hour period this week.
A yellow rain alert is also in place for the region from Tuesday to Wednesday, before most of the UK falls into the warning on Thursday.
The Met Office said this was because of an area of "low pressure" set to move in on Monday evening.
Receive newsletters with the latest news, sport and what's on updates from the Liverpool ECHO by signing up here
It comes after a mixed bag of weekend weather, which saw between four and eight centimetres of snow in some parts of England on Saturday, before a sunnier and milder day on Sunday.
What to expect:
- Homes and businesses could be flooded, causing damage to some buildings
- Fast flowing or deep floodwater is possible, causing a danger to life
- Delays or cancellations to train and bus services are possible
- Spray and flooding could lead to difficult driving conditions and some road closures
- Some communities may be cut off by flooded roads
- Possible power cuts and loss of other services to some homes and businesses
John Griffiths, a Met Office forecaster, said: "An area of low pressure will move in late on Monday, bringing with it quite a lot of rain over the following three days.
"Between Tuesday and Wednesday around 40-70 mm of rainfall is expected to fall in the north-west of England, potentially rising to 100-120mm in the hilly areas.
Check the weather forecast in your area by entering your postcode:
"On Thursday more deep low pressure will start travelling south to the rest of England, with strong downpours and heavy gales coming in from the North Sea."
Mr Griffiths said the flooding would come as the rainfall combines with snowmelt.
