A rare example of a volutus or roll cloud was spotted stretching over the sky in Carlisle, Cumbria on Thursday.
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The clearly defined narrow cloud is believed to be cause by the Helm Wind, a strong north-easterly wind which blows down the south-west slope of the Cross Fell escarpment, and was seen by thousands of people as it drifted over Cumbria.
The Helm Wind is unique to Cumbria and the only named wind in Britain.
In April, meteorologists were left stumped by a swirling, corkscrew-shaped 'cloud' seen hovering over Greater Manchester.
The peculiar form sparked an online debate when members of the public began asking how the unusual cloud formed - and what caused its bizarre shape.
WessexWeather suggested it appeared to be a 'twisted contrail' – a trail left by aircraft engine exhausts when they zoom through the sky.
The meteorologist tweeted: "It's a twisted contrail I think. The perspective makes it look vertical, but it's actually horizontal."