Storm Alex will bring heavy rain and up to 65mph winds with two yellow weather warnings in place for the weekend.
Homes and businesses are at risk of flooding as a deluge of rain and gales are set to batter the southern coast from 3am to 8pm on Friday.
Storm Alex, named by the French meteorological service, is to move across northern France and into the Channel overnight.
The wet weather will then continue on into the weekend, with up to two inches of rain due to fall in 12 to 18 hours.
On Saturday, a yellow warning is in place for western, southern and central England, western Scotland and all of Wales until 6pm on Sunday evening.
There is a "small chance" homes could be flooded, while the amount of rain could cause travel disruptions and road closures.
The Met Office states there is also a slight chance of building damage and powercuts in some areas.
Met Office forecaster Oli Claydon said: "By Friday this will become a lot more unsettled, as low pressure moves in from France along with Storm Alex, bringing with it wet and windy weather, particularly along the south coast.
"This will start to calm down by around 8pm, though Saturday will remain fairly breezy with downpours continuing throughout the day."
Parts of London, the south east and south west will see maximum temperatures of around 14C until the weekend.
Large parts of Scotland will remain around the 11C mark, dropping to lows of 6C during the evenings.