People across many parts of the country are bracing themselves for few days of travel disruption as snow, ice and bitterly cold temperatures grip the nation.

A series of yellow weather warnings for snow and ice from the Met Office came as a major incident was declared in Somerset due to the risk of flooding.

The warnings covering northern and south-west Scotland, Northern Ireland and Wales suggest there may be “further wintry showers bringing disruption from ice and snow” while an ice warning is also in place for the south west of England.

Met Office forecaster Alex Deakin said there is “a gradual change to slightly milder weather as we get towards the weekend but for now the cold weather persists with snow showers and the risk of ice into Thursday”.

It is set to be a cold and frosty start to many places on Thursday morning when temperatures could dip to -4C or -3C in towns and cities or even -8C in rural spots where snow may lie on the ground.

Many areas will go on to have a cold, dry, bright winter’s day with temperatures of around 3C but a “brisk cold wind” persists in northern Scotland.

A level three cold weather alert issued by the UK Health Security Agency, warning of conditions that “could increase the health risks to vulnerable patients and disrupt the delivery of services”, is in place until 9am on Friday.

The yellow weather warnings which are in place across western parts of the UK, Wales and the north of Scotland run until noon on Thursday while the ice warning for the south west of England lasts until 10am on Thursday.

The Met Office said: “As well as some low temperatures overnight, scattered showers will continue to affect northern and western areas. These showers are likely to be a combination of rain, sleet and snow, with some accumulations possible, especially over high ground.”

A major incident was declared in Somerset due to the risk of flooding across the county. Enhanced pumping began on Tuesday evening at Northmoor pumping station to reduce the amount of water being stored until river levels allow pumping to resume at Currymoor, which remains full.

On Wednesday afternoon the Environment Agency in the south west said that up to seven temporary pumps were working at Northmoor to help reduce the water levels in the area and “we are already seeing the benefits”.

The decision to declare a major incident is precautionary, public agencies say, so that they can be ready to take action if the situation worsens.

Somerset Council urged people to avoid walking in standing water or on ice as “both can be really dangerous”.

Members of the public have been warned to expect longer journey times by road, bus and train as well as some disruption due to the risk of ice and snow.

Heavy snowfall was reported across the north of Scotland and parts of Wales, and south-west England saw showers of rain, sleet, snow and hail on Wednesday morning, making driving conditions difficult.

Dozens of schools in Northern Ireland have remained closed as a result of heavy snow.

Met Office chief meteorologist Paul Gundersen said: “Cold air is continuing to push across the UK from the north and many areas have seen some snow, wintry conditions, and overnight frosts.

“National severe weather warnings have been issued across parts of western England, Wales, Northern Ireland and Scotland with more warnings likely to be issued over the coming days.”

David Renard, transport spokesman for the Local Government Association, said: “As temperatures start to plummet once again, councils are ready to work around the clock to grit roads and pavements to make sure that people are kept safe and local communities can get out and about.

“Councils have stockpiled 1.4 million tonnes of salt and are using new and innovative technologies where they can to ensure those areas that are most treacherous are kept clear and safe for use.

“During these cold spells, it is those who may be elderly or who have a respiratory disease who are at more at risk of ill health and are in need of more support.

“Some people may choose to limit their heating use due to the impact of rising energy bills and so councils are again asking people to check up on those who may need more help. It could help save lives.”

The cold spell is set to end later this week.

Mr Deakin said: “An extra hazard as we turn into Friday could be fog. It could turn quite dense in some places, particularly parts of northern Ireland, and it may be slow to clear.”

He added that temperatures are set to drop “well below freezing, particularly in rural areas”.