Some of these could cause “a danger to life” due to “fast flowing or deep floodwater”. On Friday the worst of the rain will be concentrated in northern and southern parts of the British Isles, though deteriorating conditions will move north during the evening.
However, many central parts of the country will see a much dryer day than on Thursday.
Over the weekend further weather fronts will bring in torrential rain which risk causing localised flooding.
Met Office meteorologist Alex Deakin forecast: “For many Friday will be a much dryer and much brighter day with some autumn sunshine around.
“However, across the south expect it to be another fairly cloudy day and there will be some rain here.
“It’s further north where we’ve seen the heaviest rain through Friday afternoon and evening.”
The southern band of rain is caused by a weather front which separates warm conditions in southern England from cooler ones further north.
During the day the weather front will take heavy rain from south west England and south Wales and drag it over the midlands, East Anglia and south east England.
Mr Deakin said: “That weather front and that area of rain is still around on Friday.
During the evening and overnight heavy rain will make its way northwards from south west England.
Western parts of Britain will be worst hit by the deluge whilst many eastern areas will remain dry.
Mr Deakin forecast: “A spell of wet and windy weather to swing across the country on Saturday.
“Then a brief rest bite before the next set of weather fronts come in during Sunday bringing another bout of wet weather.
“With that rain really building up there’s the real threat of further travel disruption or some flooding.”
A yellow Met Office warning for rain is in force for Wales and north-west England on Friday.
For Saturday and Sunday this remains in place and is extended into southern and central parts of Scotland.
On Saturday across Wales and north-west England the Met Office warns 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.”