Deputy First Minister John Swinney has renewed advice to the public not to travel in areas covered by an amber warning for snow which has now been extended into Friday morning.

It covers much of the country until 10:00 tomorrow and is expected to cause extensive disruption.

“Conditions continue to be treacherous across much of Scotland, which has led to the decision by the Met Office to extend the amber warning for snow overnight and through the Friday morning rush hour, signalling the potentially life-threatening nature of the extreme weather," he said.

“Throughout today and into tomorrow morning, the clear and unequivocal advice for people in affected areas is not to travel unless it is absolutely necessary to do so."

A skier jumps over two people on Arthur's Seat in Edinburgh.

Buchanan Bus Station in Glasgow played host to more 60 stranded passengers overnight as buses to Edinbugh, Oban, Campbeltown and London were all cancelled.

Many passengers were travelling in family groups with young children.

Staff at the bus station provided them with foil blankets, hot drinks and food from the cafeteria and ensured there was formula milk for babies.

Customer services and security manager Michael Ferrie said: “Staff were, as always, absolutely brilliant and immediately stepped up to the challenge when it became obvious that no buses with any operator were able to go anywhere."

"There were far more HGVs on the M80 than there should have been when a red warning was in place," First Minister Nicola Sturgeon told MSPs in Holyrood.

At its peak more than 1,000 vehicles were stuck on the motorway between Glasgow and Stirling in freezing conditions. About 300 were stranded in their vehicles overnight.

Ms Sturgeon told first minister's questions: "We have to be very clear in the message we are sending to companies who deliver goods with HGVs that during a red weather warning an HGV should not be on one of our trunk roads unless it is absolutely unavoidable.

"I saw some branded HGVs on the motorway yesterday and given the branding I would struggle to see how their journey was unavoidable."

Due to the continued weather situation, all outpatient appointments and non-urgent elective procedures scheduled for today and tomorrow at the Borders General Hospital have been postponed.

NHS Borders said they would be rearranged "as soon as possible".

A door holds up the snow in Westerwood in Cumbernauld, North Lanarkshire.

Image source, Sandy Young

First minister Nicola Sturgeon told MSPs in Holyrood a "high-impact" amber warning remained in place for most of the country.

She said "That means the advice today for the general public remains 'do not travel' unless it is unavoidable."

The first minister said everything possible would be done to keep roads open but "if you do travel during this period, you do face significant risks of encountering blocked roads and possibly becoming stranded".

Ms Sturgeon urged employers to be flexible and put the safety of their staff first.

Wintery scene in Chapelhall next to Airdrie in Scotland on Thursday.

Image source, Garry Henderson

Helpline NHS 24 has been affected by the extreme weather, with many staff unable to get to work.

It has been operating on 50% capacity but overnight answered 1,730 calls.

NHS 24 Medical Director Dr Laura Ryan said staff had battled the elements.

She said: “This will inevitably have an impact on the access to the service, while the extreme weather continues over the coming days and we would ask the public to only call if they absolutely need support.

"Many GP surgeries are experiencing difficulty opening and while we will do what we can to help, we would advise the public only to call if they cannot wait until their surgery opens.

"If you do need to call us, please be patient as it may take longer to have your call answered."

A cold pigeon at St Margaret's Loch in Holyrood Park in Edinburgh.....

... and at Rouken Glen Park in East Renfrewshire this plastic duck was nestled on the ice while its real feathered friends were in hiding.

Jamie McIvor
BBC Scotland education correspondent

Thousands of children are facing the prospect of a THIRD day off school because of the weather.

Most schools in Scotland are closed today and some councils have already said they will be shut tomorrow as well.

There are no state schools open today from Greenock and Dunoon in the west to Dunbar in the east.

The closures are even more widespread than yesterday.

Scottish Borders, Glasgow, Edinburgh, Midlothian, South Lanarkshire and Falkirk councils have already confirmed schools will stay shut tomorrow - many other councils are likely to confirm their plans as soon as possible to help make sure parents can make adequate arrangements.

Although the disruption to education is significant, secondary school closures have less of a practical impact on students at this time of year than they might have in December or January when prelim exams take place - although the loss of teaching time as formal exams come near can be a worry.

Glasgow-based colorectal surgeon, Andy Renwick, has been speaking to the BBC about getting to work in the snowy conditions.

He told of an unnamed colleague who walked from Anniesland to Paisley - just under eight miles - to operate on a cancer patient.

Mr Renwick told the BBC Radio Scotland's John Beattie Show: "I won't give her name because she would be genuinely upset with me."

"She is operating today on someone who has bowel cancer, she knew that had to be done and so she has made extra effort to get in here to make sure that was actually delivered."

Asked about getting to work in the current conditions, Mr Renwick said: "Last night we had foundation year one doctors stay in hospital overnight without having bought anything with them.

"They have remained overnight and remained in the hospital waiting for colleagues to turn up.

"We have had phone calls from their colleagues assuring us that they are trying to get in and they are waiting for transport to try and get in so they can actually relieve them. Hopefully we will be able to take the ones who can get home today home later on.

"One of my colleagues had a 4x4 and thankfully she picked me up this morning, I didn't have to walk the two hours 50 minutes."

A Lothian Buses spokesman said: "We have reviewed our service position for the rest of the day, assessing current road conditions with the predicted weather reports.

"The safety of all of staff and customers is of paramount importance and as a result we have made the decision that no services will run today.

"This includes any night services due to run this evening.

"Service provision for Friday 2 March will be reviewed at 04:00 on Friday.

"In any case no services will operate before at least 06:00 on Friday.

"Airlink 100 will continue to run on a 15 minute frequency pending further reviews on weather and customer loadings."