The Met Office issued the warning which will last from Saturday, January 4 until Sunday, January 5.
“Heavy snow, and some freezing rain in places, may cause some disruption over the weekend,” the Met Office said.
It said there could be power cuts and services, such as mobile phone coverage, may be affected and some rural communities could be cut off.
There is a small chance of injuries from slips and falls on icy surfaces, and a risk of travel delays on roads with some stranded vehicles and passengers, along with delayed or cancelled rail and air travel.
The forecast until Sunday:
“Outbreaks of rain spreading progressively northeastwards later on Saturday and overnight into Sunday will likely be preceded by a spell of snow on its northern flank. Whilst there is some uncertainty, any snow in southern and eastern parts of England, especially at low levels, will probably be rather transient before turning back to rain.
“However, some significant accumulations of snow are possible across parts of Wales, the Midlands and northern England in particular, at least for a time, where 5cm or more could accumulate fairly widely, with perhaps as much as 20-30cm over high ground of mid and north Wales and potentially 30-40cm over parts of the Pennines. This, accompanied by strengthening winds, may lead to drifting of lying snow.
“In addition, as milder air moves northwards, snow may turn to a spell of freezing rain for a time, again more especially across parts of Wales, the Midlands and northern England, adding to the risk of ice and leading to some treacherous conditions in places. A fairly rapid thaw of lying snow is possible later on Sunday, although exactly how far north the rapid thaw will reach remains uncertain at this stage.”