Heavy rain could bring flooding and travel disruption across much of the UK on Wednesday and Thursday with an amber warning issued for part of the country.
The Met Office has issued the warning for parts of north Wales and north-west England, including Liverpool and Manchester, for 24 hours from noon on Wednesday.
The warning for the region says flooding and disruption are likely, with rain becoming heavy and persistent.
A yellow warning for rain is in place for the north of England, the Midlands and north and mid-Wales until 6am on Thursday, with the southern edges of the affected area extended to run roughly from around Norwich to Bath.
A yellow rain warning comes into place at noon on Wednesday for Scotland, covering the south and east of the country, which runs until 6pm on Thursday.
A further yellow warning for thunderstorms has been added for much of the south coast of England from 8am to 7pm on Wednesday.
The Met Office meteorologist Alex Burkill said: “Some areas are really going to see a lot of heavy, persistent rain through a big chunk of Wednesday. It is going to be a pretty wet picture as we go through the rest of the week for many places.
“There is some uncertainty as to exactly where we are going to see the heaviest rain and where is most likely to be impacted.”
The forecast says heavy and, in places, prolonged rainfall is expected from an area of low pressure arriving from the east, which has brought downpours to parts of central Europe.
Many places could see 30-40mm of rain, while a few areas may receive 60-80mm as heavy rain moves northwards throughout Wednesday. The Met Office said there was a small chance a few upland areas could have up to 150mm.
In addition to the thunderstorm warning, which also includes scattered showers and the threat of spray on the roads and sudden flooding, there may be heavy, thundery showers in the south of England that could bring 30-40mm within three hours.
A Met Office spokesperson said: “The precise track of the low pressure that would determine where the rainfall comes is still uncertain and is something we are keeping an eye on.
“We would encourage people to keep an eye on the forecast over the next couple of days to see how that evolves.”
The chief meteorologist, Andy Page, said areas exposed to the strengthening northerly winds were most likely to have the highest rainfall.
Northern areas are expected to remain cloudy and wet on Thursday but drier further south with brighter conditions becoming more widespread by the end of the week.
Bank Holiday Monday is expected to be dry and fine for much of the country, feeling warm in the sunshine, although there remains the threat of showers ahead of more settled conditions.