Photographs of a cloud formation have confounded weather experts who say they have never seen anything like it.

Francesca Bregdan was standing in her garden in Bradwell, near Great Yarmouth, when the striking shape caught her eye.

But it wasn't until more than a year later that she realised its rarity.

Eastern Daily Press: It took hobby photographer Francesca Bregdan a year to realise quite what she had snapped.It took hobby photographer Francesca Bregdan a year to realise quite what she had snapped. (Image: Francesca Bregdan)

Her research revealed the formation to be a rare "double helix" last publicly reported in Russia in 2012.

The 31-year-old graphic designer, who has a passion for nature and photography, said she was keen to find out more about how it was formed.

Zoe Johnson, a forecaster at Weatherquest based at the University of East Anglia said: "I would say none of us have seen anything like it before - and between us we've looked at a lot of cloud pictures.

Eastern Daily Press: A twisted ciccus cloud spotted in Bradwell and photographed by nature enthusiast Francesca Bregdan.A twisted ciccus cloud spotted in Bradwell and photographed by nature enthusiast Francesca Bregdan. (Image: Francesca Bregdan)

"The consensus from us is that it’s cirrus cloud that has been twisted, perhaps by some upwind topography.

"A theory from one of my colleagues is that it could be cirrus spissatus, which often originates from the upper part of a cumulonimbus cloud.

"Cirrus clouds are the highest of the main cloud types, usually made up of patches or bands of ice crystals."

Eastern Daily Press: Francesca Bregdan knew it was unusual when she took this picture on October 7, 2020. But it wasn't until a year later that realised quite how rare it was.Francesca Bregdan knew it was unusual when she took this picture on October 7, 2020. But it wasn't until a year later that realised quite how rare it was. (Image: Francesca Bregdan)

She added that although a helix was not an official cloud type, the pictures could be said to show a helix composed of cirrus clouds.