[H]eavy, squally showers will turn to sleet, hail and snow for many areas of Scotland later on Monday, then parts of Northern Ireland and the far north of England Monday night.
Snow showers will continue through Tuesday and Tuesday night, although perhaps more of sleet and hail near some coasts.
Over the hills, snow will drift in the strong to gale force winds.
Delays on roads are possible, as are public transport cancellations.
There is a chance of power cuts, while services such as mobile phone coverage may be affected.
A few rural communities may become cut off. In addition some roads and pavements will turn icy, increasing the chances of accidents or injuries.
A spokesman for the Met Office said: “Snow showers will be heaviest and most frequent across western Scotland, where high ground is likely to see 10-20 cm building up above 200-300 metres.
“There may also be more than 15cm over the hills of Northern Ireland, especially in the north.
“At low levels throughout the warning area, 2-8 cm will be more typical, with some places seeing very little.
“Showers will be accompanied by hail and lightning at times, particularly across western Scotland. Here, in particular, there is potential for disruption to power supplies from lightning strikes.
“Strong winds bring the potential for temporary blizzard conditions and drifting of lying snow, mainly over high ground.”