Trees are at risk of being toppled by wind because they kept their “sail-like” leaves over a mild autumn, the Met Office has warned.

A warmer autumn season with relatively little wind means many deciduous trees have still not shed their leaves, meaning they could be more easily damaged or uprooted during upcoming bad weather, the weather service said.

Britain is set to be hit by gales of up to 80mph towards the end of the week, with yellow-level weather warnings for wind issued for Friday and Saturday.

Unusually, there have been no named storms or severe periods of wind during the autumn, meaning branches have been left intact. Normally, one of two storms would have hit the UK during this period.

Grahame Madge, a spokesman for the Met Office, said: “These will be very strong winds, severe gales in places, gusts of potentially up to 80mph in some exposed coastal locations, more likely 55mph to 60mph elsewhere, but even so that’s still very strong winds.

“It is likely to have local impacts, particularly as you’ve got things like trees still in pretty full leaf because it’s been a mild autumn.

“When you got bare branches, the wind is more able to go through. But when the tree is in full leaf, it’s more like a sail, it catches more of the wind.”

‘Very windy weather’ expected

The “very windy weather” could cause delays to transport, damage buildings, lead to bridge and road closures and cause power cuts, as well as uproot trees.

“Prolonged periods” of snowfall are also possible at higher elevations in parts of Scotland and northern England and Wales at the end of the week.

Areas above 200m in Scotland have the highest chance of snow from Friday. Hilly areas in the North such as the Pennines, are also more likely to see this type of weather. However, it is unlikely to be heavy enough to settle, the Met Office said.

Mr Madge said there was “no sign” of snow in lower areas in England and Wales, but added: “Never say never.”

It will come after “several shots” of Arctic air move into the UK later this week, as the jet stream dips southwards, bringing much colder and wetter weather.

The mercury could dip as low as -2C in parts of London and the South East overnight on Thursday and drop to freezing on Friday night, reaching around 6C during the day on Saturday.

The temperatures are below average for November but not exceptionally low, the Met Office added.