UK snow: Schools and transport hit by disruption
More than 3,000 schools have been closed in England and Wales as a band of heavy snow affects most of the UK.
Transport is disrupted with flights at Heathrow, Bristol and Southampton airports cancelled and hazardous conditions reported on many roads.
Heavy snow is falling in Wales, where a rare Met Office red warning for severe disruption has been issued.
There is an amber warning for Northern Ireland and most of England, with snow also due in parts of Scotland.
There have been widespread school closures in England with over 500 in Hampshire and the Isle of Wight, and 300 in Norfolk, while 300 schools and colleges have been closed in Gloucestershire. In Wales, 1,200 schools have been closed.
In other developments:
- Many major roads are being affected by snow, with parts of the M4 and M50 closed for a time. There are hazardous conditions on the M5, the BBC travel centre reports
- 10,000 households in parts of south Wales are being affected by power cuts
- Around 179 flights have been cancelled at London's Heathrow Airport and its northern runway was closed for 45 minutes for snow to be cleared. Birmingham Airport is closed until 14:45 GMT, while there are also delays and cancellations at London City and Leeds/Bradford airports
- British Airways has cancelled over 60 flights. It has offered those travelling on Friday and over the weekend the chance to change their flights free of charge to a later date
- Eurostar cancelled four journeys between London and Brussels
- The East Coast train company has lifted ticket restrictions for all journeys on its trains which arrive in, or depart from, King's Cross station in London after 10:00 GMT on Friday
- Rail services have also been affected with some operators running altered timetables. South West Trains has published a revised timetable, while Southern Railways said it planned to operate a "less frequent service" between London and the south coast
- In London, contingency plans for Tube services have been put in place
The Met Office's red warning for snow, which is unusual and means all non-essential travel should be avoided, applies to the south-eastern side of the Brecon Beacons and Black Mountains until 21:00 GMT on Friday.
Red warning areas could see up to 30cm (12 ins) of snow and blizzards.
Amber severe weather warnings, which mean be prepared for disruption and only travel if necessary, are also in place until at least 21:00 GMT across large parts of central, western and southern England and Wales, as well as Northern Ireland.
BBC Weather said Northern Ireland would experience rain early on Friday, which would turn to snow during the course of the day, with between 10cm and 15cm expected in most areas and about 20cm over hills.
BBC weather forecaster Mike Silverstone said much of England and Wales would experience between 5cm and 15cm of snow on Friday, whereas Northern Ireland could see up to 20cm (8 ins) by Saturday morning.
The snow is expected to ease off later on Friday, although it is set to remain in eastern areas, forecasters said.
He added it was likely to stay very cold over the weekend, with snow likely to be confined to Scotland, north-eastern England and Northern Ireland on Saturday.
The Highways Agency has put road ploughs and snow blowers on stand-by to clear major routes.
Steve Crosthwaite, who heads the agency's National Traffic Operations Centre, urged drivers to allow more time for travel.
He added: "During periods of severe weather we also suggest people consider whether their journey is essential."
RAC spokesman Simon Williams said reaching stranded motorists was now a "real challenge".
"In order to deal with an expected increase in calls for assistance later in the day, we have also put every technically qualified engineer normally based in the office back out on the road again in patrol vehicles," he said.