Don’t be alarmed – they won’t beam anyone up
Otherworldly clouds have been spotted above the North Wales mountains glowing eerily in the low sun. Historically, the rare formations have been likened to flying saucers and have even been blamed for several UFO sightings.
Walkers in Eryri (Snowdonia) and the Llŷn Peninsula were struck by the clouds’ strange beauty. They twice appeared briefly earlier this week, with Anglesey’s southwest coast producing some of the most eye-catching displays.
During the festive period, the popular Newborough beach of Traeth Llanddwyn has been as busy as ever, with visitors facing long queues to exit the national nature reserve. For many, it was a price worth paying for the stunning views and the rare sight of “UFO clouds” drifting over from the Pen Llŷn mountains.
The quirky formations are also referred to as pancake clouds because they appear flat and stacked. But their formal name is lenticular clouds, a name originating from a Latin word meaning “lens-like”.
They’re not particularly common in the UK as they need the right weather patterns to make an appearance.
As hilly terrain is another prerequisite, Eryri’s mountains are as good a place any to find them. The North Wales Live Whatsapp community for top stories and breaking news is now live – here’s how to sign up
So too are high pressure systems like the kind we’ve seen this week – and which haves also been responsible for a series of spectacular cloud inversions in the national park.
Lenticular clouds drifting from the Llŷn Peninsula seen from Traeth Llanddwyn beach on Anglesey(Image: Emily Camp)
According to the Met Office, lenticular clouds form when wind blows across hills at different heights through the troposphere – the lowest layer of Earth’s atmosphere.
The forecaster explained: “When air blows across a mountain range, in certain circumstances, it can set up a train of large standing waves in the air downstream, rather like ripples forming in a river when water flows over an obstruction.
“If there is enough moisture in the air, the rising motion of the wave will cause water vapour to condense, forming the unique appearance of lenticular clouds.”
Sometimes you get several of ultra-flattened clouds stacked on top of one another – like a pile of pancakes.
UFO-like lenticular clouds seen above Eryri(Image: Dove Rosealinda)
Online, photos of the national park’s UFOs were shared from the Glyders in northern Eryri and from Blaenau Ffestiniog further south. In some cases they didn’t hang around for long – perhaps as little at 10 minutes.
UFO clouds may not beam anyone up into the sky – but do signify strong, gusty winds on the ground directly below. Sign up for the North Wales Live newsletter sent twice daily to your inbox
Pilots tend to avoid fling near them because they can cause significant turbulence, said the Met Office. On the other hand, skilled glider pilots like them because they provide a visual reference of where air is rising.
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