The UK is preparing for a sharp drop in temperatures as an Arctic air mass sweeps southwards, prompting the UK Health Security Agency (UKHSA) to issue its first cold health alerts of the season. The alerts, which are yellow, cover the West Midlands and the north west of England and will be in effect from 09:00 GMT on Thursday until 12:00 GMT on Saturday.

Widespread Frost and Sub-Zero Temperatures

Forecasters warn that from midweek onward, overnight temperatures in many towns and cities will fall below zero, bringing the most widespread frost of the season so far. Some rural spots could see overnight temperatures plummet to minus 5C or even lower. Sleet and snow are possible in some far northern locations, with strong wind gusts creating bitter conditions.

The UKHSA cautioned that the upcoming cold snap is likely to have minor impacts on health and social care services and poses a greater risk to the lives of vulnerable people. Cold health alerts are typically issued between 1 November and 30 March.

Weather Shift After Foggy Days

After the thick fog of recent days, visibility will improve on Wednesday, with crisp sunshine forecast for many parts of the UK. Low pressure and a weather front will graze southern parts of Britain, bringing outbreaks of rain and slightly milder air with highs reaching 10 to 14C.

However, late on Wednesday, cloud will clear ahead of the Arctic air surging southwards across the country. By Wednesday night, a strong to gale force northerly wind will develop over northern and eastern parts of Scotland, making it feel especially bitter with gusts exceeding 50mph.

Snow and Strong Winds

Showers are expected to stream in, with sleet and snow possible in Shetland and Orkney as well as northern Scotland. Over higher ground, snow may settle into Wednesday night, which is not unusual for early November. Winds will also strengthen along the North Sea coast all the way down to the coast of Norfolk, making it feel very cold.

The 'feels like' temperature, which takes into account expected air temperature, relative humidity and wind strength, shows single figure temperatures on Thursday. Winds will remain strong on Thursday across the far north of the UK. However, inland it will be calm as a ridge of high pressure builds.

Frosty Nights Ahead

Widespread frost is expected across the northern half of the UK while the southern half holds on to somewhat milder morning conditions for a little while longer. Thursday afternoon is expected to be sunny across much of the country though showers, some of which could be wintry, may still continue in the far north.

While Thursday morning may feel cold across much of the country, daytime highs will still typically reach 7C. The northerly breeze will make it feel colder in some places. Thursday night will bring freezing temperatures to most of the UK.

On Thursday evening, the weather will be clear and calm across much of the country as temperatures fall rapidly. Winds will have eased somewhat across Northern Scotland and along the North Sea coast.

Friday will bring frost on grass, pavements and cars in many parts as the air temperature falls below zero from Scotland to Southern England. Most towns and cities will experience temperatures around zero or just below, while rural spots in Scotland and even southern England chill to minus 5C.

Counties along western and southern western coasts of the UK will not be quite as cold, as the warmer sea and an onshore breeze will prevent frost from forming. Inland, after a frosty morning, daytime highs will peak at 6 or 7C for most.

Saturday and Sunday night will be cold and frosty in some southern and eastern parts of the country. By the weekend though, milder weather will already be spreading in from the Atlantic making the cold snap rather brief for most.