The Met Office has warned of disturbances to the stratospheric polar vortex as snow showers are expected to hit parts of northern Scotland and the Northern Isles in the early hours of Thursday.
Ten regions could experience snowfall on Thursday as chilly conditions start to spread across the UK, according to the Met Office. The weather service said snow showers may appear in parts of northern Scotland and the Northern Isles during the early hours.
Sudden Stratospheric Warming Developing
This follows the Met Office's warning last week regarding disturbances to the stratospheric polar vortex high above the Arctic. Experts indicated there are signs that a sudden stratospheric warming (SSW) - which can increase the chances of an extended dry, cold period of weather in Britain - is "developing".
In a forecast issued on Monday, Met Office Chief Meteorologist Jason Kelly said: "Snow showers could briefly fall on lower ground in northern Scotland and the Northern Isles, mainly Shetland, overnight on Wednesday and into Thursday." He noted that snow may only settle on higher ground, adding this is "relatively normal for the time of year".
Cold Temperatures and Frost
The mercury reached 14C on the Isles of Scilly on Monday, but a "risk to life" cold weather alert has now been issued for the UK. Netweather forecast maps suggest temperatures at 6am on Friday could be around 0C or below freezing across much of the UK, with some parts of the West Midlands seeing temperatures as low as -4C.
Met Office weather maps appear to support the broader outlook, although they suggest temperatures in some areas, particularly along the coast, could be slightly higher, at around 1C to 2C. Chillier and progressively frostier conditions are anticipated to move southwards as the week progresses, following a damp and foggy beginning for many areas.
Full List of Areas Facing Snow
The Met Office said colder air is expected to move further south across the UK through Thursday and Friday. Most locations will turn dry with some clear or sunny intervals, the forecaster said. Showers may still occur in northern and eastern areas, with some wintry showers over elevated ground in Scotland.
Temperatures are set to fall below average widely by Thursday, and "particularly" by Friday, the Met Office has warned, as frost becomes increasingly widespread. The forecaster noted that the north-east is likely to bear the brunt of the chill during "stronger winds".
Come the weekend, temperatures are expected to creep back towards seasonal norms, with the possibility of some rainfall as high pressure shifts towards mainland Europe. The Met Office's forecast for Thursday to Saturday reads: "Feeling markedly colder with frosty nights ahead. Largely dry with plenty of autumnal sunshine, though showers around the coasts and wintry showers in the far north with strong winds."
The full list of areas facing snow on Thursday includes: Caithness, Sutherland, Ross-shire, Cromartyshire, Inverness-shire, Nairnshire, Moray, Banffshire, Orkney Islands, and Shetland Islands.
