Chris Fawkes
Lead Weather Presenter
The Met Office has issued snow and ice warnings for parts of Scotland and England as much colder weather is set to arrive across the UK from Sunday.
Frost and plunging temperatures will be widespread with heavy snow forecast for higher ground in southern Scotland and northern England.
A cold front will push southwards over the weekend, with the air turning progressively colder into next week as an Arctic air mass becomes established.
This change in weather fortunes comes about thanks to a blocking area of high pressure building across Greenland with cold Arctic air emptying out across the UK and bitter northerly winds developing.
The fact that this pattern established itself in late November means we are in for some cold weather for the time of year but temperatures would have been much lower had this system set up in the heart of winter when the Arctic is far colder.
Will it snow?
Northerly winds will bring frequent showers to northern Scotland, probably falling as sleet and rain near to coastal areas.
The hills of northern Scotland will see regular snow showers with 5-10cm (2-4in) building up over hills and a few centimetres in some lower areas by Monday, with the potential for some localised disruption where it settles.
The ground in November is not as cold as it would be in midwinter so some of the snow hitting the roads will probably melt, though larger accumulations could gather on colder grassy surfaces.
Many inland areas of the UK are likely to see quite a lot of dry weather with morning frosts and sunny skies.
Showers will be frequent in Northern Ireland along with coastal areas of England and Wales – these will probably be mixed with some rain, sleet and hail.
Low pressure moves across the UK on Monday and Tuesday, bringing wet and windy weather on the south side of the low pressure.
There will be some heavy snow in the colder air on the north side of the system, especially over high ground with Met Office warnings of 15-20cm (6-8in) of snow above 400m (1,300ft) elevation in parts of northern England and southern Scotland.
Towns and cities at lower elevations also have a risk of seeing some disruptive snow, perhaps 2-10cm (1-4in) in places, but much will depend on the precise track of the low pressure, the heaviness of the precipitation and the elevation of the land.
These factors make forecasting this zone of potentially disruptive snow very tricky – and this uncertainty is likely to stay in weather forecasts for the next day or two.
When will the cold spell end?
There is a small chance that a second low pressure towards the end of next week could bring some snow to the south of the UK. It is very uncertain this far ahead but is something we will be monitoring closely over the next week.
The cold spell looks set to last for about a week for many, before milder Atlantic air returns in time for the start of winter.
Read our thoughts on the forecast further ahead with our monthly outlook.