The Met Office has issued a statement - Colder weather on the way
Following the occasional colder snap so far this winter, there are now signs that cold winter weather resulting from a sudden stratospheric warming is on the way for the UK. Deputy Chief Meteorologist, Martin Young said: “The latest forecast suggests the highest risk of any severe wintry weather is from late January and into February. Whether cold spells will be brought about by Arctic air arriving from the north or easterly flows arriving from the continent remains uncertain. “However, before this happens we expect a rather changeable and relatively mild spell over the weekend and early next week, with some rain for most of us. “From the middle of next week, and especially during the last week of January and into early February, there is an increased likelihood of cold weather becoming established across all of the UK. This would bring an enhanced risk of snow and widespread frost almost anywhere across the UK, but particularly across northern parts. However, the cold weather may not affect the whole of the UK and it is still possible that some milder and wetter interludes will intersperse this generally cold period, especially in the south.
More information : https://www.metoffice.gov.uk/news/releases/2019/colder-weather-coming