Snow showers will become heavier and more frequent early on Friday and will continue on and off through the day. One or two spells of more persistent, heavy snow seem quite likely, although amounts will vary from place to place. A gradual improvement seems likely during the late evening. Travel delays on roads are likely, as are public transport cancellations. In some places vehicles may become stranded. There is a chance of power cuts, while services such as mobile phone coverage may be affected. Some rural communities may be cut off.
A further 10-15 cm is likely to build up above 150 m with 20-30 cm possible over the highest routes - although (as is the nature with showers) some areas will see less. At low levels, 2-6 cm, perhaps locally 10 cm, would be more likely. Showers may well be accompanied by hail and lightning at times, increasing the potential for disruption to power supplies. Winds will strengthen at times, bringing the potential for temporary blizzard conditions and drifting over hills.
Snow showers will affect the northwest of the UK during Thursday and Friday, although often falling as sleet and hail near windward coasts. Ice will also form in some areas overnight. Travel delays on roads are likely, as are public transport cancellations. In a few places, mainly upland areas, vehicles may become stranded. 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.
Snow showers will be heaviest and most frequent across western Scotland where a further 10-20 cm is likely to build up above 200-300 m with 30 cm possible over the very highest routes. The high ground of Northern Ireland and northern England will also see 10-15 cm building up. At low levels, parts of the warning area will see 3-7 cm of snow but some places near the west coast will see 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. Winds will strengthen at times, particularly from later Thursday, bringing the potential for temporary blizzard conditions and drifting on hills and mountains.
Ice is likely to form through Friday night and last into Saturday morning with some sleet and snow showers continuing in places. There will probably be ice on some untreated roads, pavements and cycle paths, potentially resulting in some injuries from slips and falls.
Sleet and snow showers will eventually become confined to areas exposed to the westerly winds overnight, but following the showers of Friday, ice will then be the main hazard, particularly on untreated surfaces. The snow showers may give an additional 1-3 cm of snow in places.
Spells of heavy rain are likely on Sunday, which combined with thawing of lying snow, may lead to localised surface water flooding, especially in northern and western counties. Spray and localised flooding on roads probably making journey times longer Bus and train services may be affected with journey times taking longer.
An active weather system will introduce milder air from the west across Northern Ireland. 10-20 mm of rain is likely quite widely with locally 25 mm possible. This is likely to assist thawing of lying snow, increasing the risk of impacts from localised surface water flooding. This is most likely in northern and western counties where there is most snow lying.
An area of snow is likely to move eastwards across parts of Scotland and northern England on Sunday. The snow is more likely to affect higher routes with lower levels only affected more locally. In addition, rain may fall onto frozen surfaces for a time, particularly across Scotland, following a very cold night. Some roads and railways likely to be affected, with longer journey times by road, bus and train services. Some injuries from slips and falls on icy surfaces. Probably some icy patches on some untreated roads, pavements and cycle paths. The snow is expected to become confined to northeast Scotland later in the day as it progressively turns to rain from the southwest.
Amounts of fresh snow will vary considerably across the warning area. Most of the snow is expected on higher ground with 3-6 cm likely above around 200 m and perhaps 10-15 cm locally on ground above 300 m. At lower levels 1-3 cm looks more likely, with some spots escaping altogether.