More images have emerged of a spectacular cloud formation that resembled a huge UFO hovering above North Wales. Keen walker and photographer Allyson Jones grabbed these stunning pictures as she hiked across a quarry in Snowdonia.

The lens-shaped clouds were spotted in Gwynedd and Anglesey late last week. But Allyson wasn’t expecting to see them when she got up early to capture the sunrise over Dinorwic quarry, Llanberis, at the weekend.

“I was about to go back to the car but turned round one last time and saw them forming above Snowdon,” she said. “I ran back along the quarry viewpoint, set up my tripod and caught the clouds at their biggest and most spectacular.”

Known as lenticular clouds, their rare appearance in North Wales caused quite a stir on the Somerset-based Cloud Appreciation Society. More were reported over Portmeirion and photos of twin lenticular clouds above Anglesey were shared on Facebook’s North Wales Storm Watch.

According to the Met Office, the clouds form downwind of hills or mountains, and are “quite unusual” in the UK. It added: “They look a lot like the traditional shape of flying saucers in science fiction, and real lenticular clouds are believed to be one of the most common explanations for UFO sightings across the world.”

Look at more pictures of the unusual cloud formation in our gallery below

Allyson was thrilled to have seen the bizarre cloud formation. In February she was caught up in freak weather that hit Cwmorthin quarry, Tanygrisiau, during Storm Franklin. It had been preceded by a local tornado warning.

“But it was nothing as amazing as this. They were amazing. It was an awesome birthday surprise!” she said.

Lenticular clouds form when air blows across a mountain range, like ripples forming in a river. “On the ground, they can result in very strong gusty winds in one place, with still air only a few hundred metres away,” added the Met Office.

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This content was originally published here.