The warning is for a combination of widespread heavy snow and very strong easterly winds bringing blizzard conditions and drifting. It is valid between 15:00 Thursday 1 March and 02:00 Friday 2 March 2018

Red warnings are issued when it is highly likely that the weather will cause a high level of impact. This is the second red snow warning issued this week but only the third the Met Office has issued since the current warning system came into force in 2011.

Other Yellow and Amber Warnings remain in place across the UK for today (Friday) and into the weekend.

Storm Emma, named by the Portuguese met service, will push up from the south through the day bringing heavy snow and strong winds. Gusts of over 60 mph will lead to blizzard conditions with severe drifting snow a significant risk.

Paul Gundersen, chief meteorologist at the Met Office said: “Whilst initially the snow will be patchy in nature, will turn heavier and more persistent through the afternoon and evening and it will become very windy. 10-20 cm of snow is to settle widely across the red warning area with 30-50 cm possible over the hills and moors.“

“Parts of southwest England and Wales could also see freezing rain and for a time on Thursday night – a relatively rare weather phenomena in the UK. This may lead to widespread icy stretches, especially on untreated surfaces, leading to difficult conditions for vehicles and pedestrians.

“The combination of the snow, very strong winds and resultant drifting will lead to long delays and cancellations of public transport and some roads are likely to become blocked by deep snow, stranding vehicles and passengers..

“We advise people to avoid travel, keep up to date with the forecast and warnings and follow the advice of the emergency services and local authorities.”.

Freezing rain starts as snow, ice, or hail, which melts as it falls through a layer of relatively warmer air before encountering  a layer of colder air near the ground. The rain droplets become 'supercooled' and are below freezing on impact on surfaces such as roads, pavements and power cables. Long interruptions to power supplies and other utilities are very likely to occur, along with damage to trees and other structures due to heavy snow or ice. Some remote communities may become cut off.

As well the red warning in southwest England and South Wales, almost the whole of the UK is covered by yellow or amber warnings as the intense snow showers continue to feed in from the east, merging into more persistent bands.

The Met Office has been working extremely closely with our partners in road, rail, air transport and emergency services to ensure they have the latest forecast information and to help minimise the impacts on members of the public.

Dr Thomas Waite, a Consultant in Health Protection at Public Health England, said: “Weather like this is extremely rare in this country – and it brings very real risks to health. Those with heart and lung conditions, the over 65s and young children may struggle to cope in conditions like these and even the fit and well may feel the ill effects of this exceptional weather. Although the weather will vary from place to place staying warm will help keep you well. Our advice is heat homes to at least 18C, to keep a close eye on weather forecasts and plan your day around them and think if there are people that you’re able to check up on, please do.”Highways England’s Head of Road Safety, Richard Leonard, said: “Gritters are out treating our routes around the clock but it is still important to drive to the conditions when snow is forecast.

“If you need to travel in the morning, make sure you keep your distance and reduce your speed because, even in conditions that seem normal and when the snow is not settling, it can be slippery if ice patches have formed, or where fresh salt has not been worked into the carriageway.

“Drivers should plan their journeys, monitor weather reports and pack a snow kit of blankets, food, water and a shovel if they really need to travel.”

Looking ahead through the weekend and into the following week, the cold weather is expected to remain over northern and central parts bringing further snow showers for some. In the far south it should turn less cold, with a slow thaw of lying snow.

You can find out the current forecast in your area using our forecast pages and by following us on Twitter and Facebook, as well as using our mobile app which is available for iPhone from the App store and for Android from the Google Play store.