People are being urged not to travel “unless absolutely necessary” as Storm Bert causes travel disruption across the country.
Major roads have been closed following several crashes, while trains and ferries have been cancelled amid strong winds, heavy rain, snow and ice – and flights have been pulled.
Forecasters have predicted as much as 40cm of snow on high grounds and winds of up to 70mph.
Nearly all of Scotland is under a Met Office weather warning, including an amber snow and ice alert for parts of the Highlands, Aberdeenshire, Perth and Kinross and Angus.
In England, an amber warning was in place all Saturday morning and flights were cancelled at Newcastle Airport and Leeds Bradford Airport.
Frequent travellers Tim Harding, 53, and his wife, Chona, 58, were due to fly at 9.15am with Dutch airline KLM to Amsterdam from Newcastle before flying with Delta airlines to Orlando, Florida, to meet their family in the US for Thanksgiving.
The couple, who arrived at the airport at around 6am on Saturday morning, said the weather was “unprecedented” as the snow fell “really quick” over a two-hour period.
Mr Harding told the PA news agency: “Going to the airport… it was sleeting all the way through then all of a sudden it started coming down.
“There were about four or five snow ploughs on the runway and they just couldn’t clear it. It was windy and it was literally coming down really quick, so hard. In the space of two hours, it went from nothing to decimated.
“The gritters were out continuously, the ploughs were out continuously, but it just wasn’t having an impact unfortunately.
“I was surprised how quickly it came down and how much came down in a two-hour period. I haven’t seen that for a long time.”
Roads became impassible in parts of North Yorkshire as snow made travel difficult.
TransPennine Express “strongly” urged customers not to travel north of Carlisle on Saturday while Avanti West Coast advised passengers not to travel north of Preston – including Lancaster, Oxenholme, Penrith, Carlisle, Glasgow and Edinburgh.
Leeds Bradford Airport said its runway was fully open again just after 10am on Saturday following work to clear snow.
Manchester Airport and Edinburgh Airport said they did not anticipate disruption due to Storm Bert.
A spokesperson for Manchester Airport said: “If there are strong gusts when planes come in to land they might do a go around but we are not anticipating any disruption.”
Travellers are suffering major disruption on Saturday, with warnings that more is to come especially in Scotland.
Emergency services closed junctions 13 and 14 of the M74 following a crash at around 7am.
Traffic Scotland warned of “extremely poor driving conditions” in the area.
Police Scotland urged people not to travel on the country’s roads “unless absolutely necessary”.
The A68 between St Boswells and Ancrum in the Scottish Borders has also been closed following a five-car crash in the area.
The Queensferry Crossing is also closed in both directions due to the risk of falling ice. Traffic on the M90 is now being diverted over the Forth Road Bridge.
Meanwhile, ScotRail has cancelled services from Inverness to Elgin, Aberdeen to Inverurie as well as Glasgow Queen Street to Oban.
The transport operator said trains from Glasgow Central to Carlisle will terminate at Dumfries.
The Met Office said the bad weather means there is a risk that some rural communities could be cut off, while an amber warning means there is a potential risk to life.
The forecaster said: “Heavy snow will spread north-eastwards on Saturday morning, giving significant accumulations in many areas.
“Accumulations of 10-20cm are likely on ground typically above 200m, with potentially as much as 20-40 cm on hills above 400m.
“Snow will eventually revert to rain during Saturday afternoon but may be preceded by a short spell of freezing rain in places adding to the ice risk.
“Strengthening winds will lead to drifting of lying snow, with difficult travelling conditions likely on higher level routes, and the risk of interruptions to power supplies.
“A fairly rapid thaw of lying snow is then likely on Saturday night as milder air moves in.”
On Sunday, some of the more severe weather will ease in the east but the vast majority of the country will remain under a yellow rain and snow warning, while the Western Isles will also fall under a yellow wind warning.
Further travel disruption is expected then.