The UK has been battered by heavy rain causing severe flooding with people trapped in their cars and the outlook is for further downpours and fog with “atrocious” driving conditions.
Motorists are being warned to stay off the roads with cars having been caught in flood water and there are expected to be "miserable conditions" over the next two days.
The Met Office issued weather alerts as a band of rain, which arrived in Cornwall on Wednesday afternoon, travels across the country before passing over Scotland's east coast on Friday.
Conditions may be "atrocious" for much of the UK, while the Scottish Highlands could see some snow, the forecaster said as it put out a yellow warning for rain.
In West Sussex carriageways of the M23 and A27 are both closed.
National Highways stated in one alert: "The M23 in West Sussex is closed southbound between J10 (Crawley) and J11 (Pease Pottage) due to flooding following heavy rainfall in the area.
And in another it said: "The A27 in West Sussex is closed eastbound between the A259 west (Emsworth) and A259 east (Fishbourne) due to extensive flooding following heavy rainfall in the area."
For both it added: "National Highways Traffic Officers are currently in attendance along with specialist service providers working to clear the carriageways."
National Highways also said diversions are in place, and urged people to allow extra time for journeys or find an alternative route.
Police in Winchester, Hampshire, also advised of a large tree coming down and blocking a road in Swanmore.
Meanwhile, the Environment Agency in England has issued 25 flood warnings and 98\ flood alerts mostly across the south and Midlands, while in Scotland there are three flood warnings and eight alerts.
The Met Office's first weather warning kicked in at 5pm, covering a southeast area stretching from Southampton and the Isle of Wight in Hampshire to the coast in Kent, until 6am on Thursday.
Forecasters warned roads, homes and businesses could be flooded and transport services disrupted.
Another yellow rain warning then came into force across a large area of the UK for the whole of Thursday, from 12am until 11.59pm.
This covers an area stretching from Birmingham, Lincoln and Hull to North Wales, Liverpool and Manchester, as well as the east coast up to the Scottish border.
The rain brings a small chance of homes and businesses flooding, communities being temporarily cut off by flooded roads and disruptions to transport, the Met Office warns.
A third warning will come into force at 3pm on Thursday until 6pm on Friday for the east coast of Scotland, stretching from the English border up past Aberdeen with similar risks of flooding, and transport disruptions.
And the latest warning is for fog in Northern Ireland which runs from 4.40am until 10am with the Met Office stating: "Areas of thick fog probably causing some tricky travel conditions or delays this morning."
Met Office spokesperson Craig Snell said: "The warning areas are where we are most concerned about the risk of flooding but it doesn't mean that the areas outside them are not going to see some pretty atrocious conditions."
Mr Snell said a warning is in place for the southeast because "it has been quite wet there since the beginning of November with many places already seeing more than their month's share of rain".
The Midlands and the north of England will have a "pretty miserable day" on Thursday after the rain sweeps in overnight, Mr Snell continued.
"The rain will be accompanied by a brisk wind so it's not going to feel feel good."
He added Scotland could see "two days of persistent rain" and this may result in snow falling in the Highlands.
"If you want to take a walk in the hills in Scotland tomorrow you may come across snow but for the lower levels it is just going to be rain," he said.
RAC breakdown spokesman Rod Dennis warned motorists to "exercise great care" during the wet weather.
"The chances of being involved in a collision rise dramatically in wet weather, and even more so if there's snow, so it's vital drivers slow down, leave plenty of space behind the vehicle in front and use their lights to make sure they're easily seen by other road users," he said.
"The risk of aquaplaning where a vehicle's wheels lose contact with the road as they skim across standing water will be high, particularly for those who don't slow down to appropriate speeds for the conditions."
UK 5 day weather forecast
Today:
Persistent rain affecting many central, northern and eastern areas, heaviest across parts of northeast England, with possible flooding. Some western and southern parts brighter after early fog and frost in Northern Ireland, but scattered showers in southwest. Windy, feeling cool.
Tonight:
Rain continues across some northern and northeastern areas, heavy and persistent in places, especially across hills in eastern Scotland. Clearer in parts of south and west. Windy for many.
Friday:
Rain should ease across northern England but continues across eastern Scotland, with possible flooding. Brighter in Northern Ireland and some southern areas, with scattered showers. Rather chilly, gales in northeast.
Outlook for Saturday to Monday:
Some rain in the north and perhaps east on Saturday, otherwise bright after an early frost. Showers or longer spells of rain from Saturday night onwards, with some strong winds.
