BBC Weather Watchers/StargazerThe Met Office warned that yellow weather warnings for snow and ice could affect travel in Scotland and northern England later.
Scattered rain, sleet and snow are expected, with a snow warning in place for most of mainland Scotland north of Perth until 6pm.
A yellow ice warning covers most of the central belt, southern Scotland and northern England from 4pm on Tuesday until 11am on Wednesday.
Subsequently, a snow and ice warning comes into force for all of northern Scotland, including Orkney, Shetland and the Western Isles, from 6pm on Tuesday until 9pm on Thursday.
BBC Time Watchers/FreddyThe Met Office said 2 to 5 cm (0.8 to 2 inches) of snow is possible at lower levels and up to 10 cm (4 inches) at higher ground.
There is a snow and ice warning for Northern Ireland overnight, as well as an ice warning for Wales and much of the Midlands in England.
Also in England, a snow and ice warning covers some eastern coastal areas and western coastal areas on Wednesday and Thursday.
The UK Health Security Agency (UKHSA) has also issued amber and yellow cold health alerts for the north of England and the Midlands, which are valid until Saturday.
It will be less cold at the end of the week and temperatures will rise slightly to return to average by the weekend.
Meteorological OfficeBear Scotland, which maintains Scotland’s main roads, has reported “snowy conditions” on several routes in north-west Scotland, with snow plows clearing the A82 and A9.
Some Calmac ferry services have been affected by weather conditions, with some cancellations and delays on West Coast and Western Islands routes.
ScotRail urged people to take care when traveling and check the status of their entire journey before setting off.
Sand sellers have been out overnight pre-treating and patrolling roads across the country.
Stagecoach said customers would be informed of any changes to its app or social media channels.
The Met Office warned there was a possibility of power cuts and road closures.
“Conditions are getting colder”
A yellow warning means the weather is likely to have some impact for some people, but others will be able to continue as normal.
People are advised to monitor the latest forecasts to determine the extent to which they may be affected, especially if the weather worsens.
The coldest night since March was recorded on Saturday when temperatures dropped to -7C at Tulloch Bridge in the Highlands.
Kirsty McCabe, of the Royal Meteorological Society, told BBC Radio’s Good Morning Scotland program that people would notice the “sudden change” to cold weather.
“So far November has been well above average, it feels very soft,” he said. “This is the first proper cold snap of the season. It really feels quite wintry. Plus, we have snow and ice warnings.
“Yes, most of the snow will be over higher ground, in parts of northern Scotland, but a fairly wintry mix could fall tonight, even in the central belt towards lower levels. So we could see a few flakes of snow tonight.”
BBC Weather Watchers/Kaiser_MuldoonFor those traveling to Hampden to watch Scotland play Denmark in the World Cup qualifier, McCabe said there could be a bit of sleet in places and “maybe the odd rumble of thunder”.
He said while the snow was not likely to settle at lower levels, it could be enough to cause disruption.
“It could make roads more slippery in some places and could affect travel and trains,” he said.
He added that the cold wave will last until the end of the week and that on Friday morning temperatures could drop to -10°C in some areas.
However, he said temperatures would return to average over the weekend.

Police Scotland said drivers should make sure their cars are roadworthy before heading out.
Last week, Scottish transport operators outlined their winter resilience plans.
This included storing 497,000 tonnes of salt, more than was used throughout last winter, and preparing 240 salt spreaders to carry out salt spreading and snow plowing patrols on the national highway network.
So far, November has been considerably milder than previous years.
Typical night temperatures at this time of year range from 2C in Scotland to 5C in the south of England, but they rarely fell into single figures during the first week of November this year.
Temperatures below -10C were recorded in some parts of northern Scotland last November, including Braemar in Aberdeenshire, which hit a low of -11.2C.
Temperatures to drop
This week’s weather will give us an early taste of winter, writes BBC Scotland Weather’s Christopher Blanchett.
The forecast is for 1 to 2 inches (2 to 5 cm) of snow on terrain above 500 feet (150 m) in inland areas north of the central belt.
On higher terrain and on higher road routes, the snow will be heavier, with a greater potential for some disruption.
Some disruption is likely due to ice, sleet and snow, causing travel issues throughout Tuesday morning, before easing into the afternoon.
BBC/C Bee Weather WatchersThere is a small pocket of less cold air within the system, meaning that in much of the central belt and south, snow is likely on higher ground.
But as temperatures drop Tuesday night, the snow may drop back to lower levels for a while.
Strong northerly winds will blow across the country on Wednesday and Thursday, with frequent snow showers at sea level in the north of Scotland and some eastern and western coasts.
On Thursday night the coldest spots in the country could drop to -10°C.





























