Bizarre cylindrical clouds appear over Sydney

A rare cloud formation, stretching for hundreds of kilometres and spanning the entire length of Sydney, has baffled NSW residents.

A rare cylindrical cloud formation, stretching for hundreds of kilometres and spanning the entire length of Sydney, baffled New South Wales residents on Tuesday.

Images of the strange weather phenomenon flooded social media, showing the uniquely shaped clouds over different parts of the city.

At its peak, the formation was about 300 kilometres long.

“These are what we call altocumulus volutus – that’s the Latin name,” Christie Johnson, a senior meteorologist at the Bureau of Meteorology, explained to Channel 9.

“They’re clouds that form high up in the atmosphere.

“They are a rare phenomenon, you need to get the right mix of ingredients.

“It’s not 100 per cent clear what’s kicked off these particular clouds.

“It takes sort of quite specific conditions to get these clouds, which is why they are rare.”

The rare cloud phenomenon wowed Sydney residents. Picture: Twitter

The clouds stretched for 300km. Picture: Twitter

The cylindrical formation. Picture: Twitter

Many residents were baffled. Picture: Twitter

But the formation made for great photos. Picture: Twitter

“The roll clouds were produced by atmospheric gravity waves that formed over eastern NSW on Tuesday morning,” meteorologist Ben Domensino said on Weatherzone.

“These invisible waves in the atmosphere caused elongated areas of rising air that cooled enough to produce parallel bands of cloud.

“These roll clouds then drifted towards the east and passed over Sydney, Newcastle and surrounding areas of New South Wales.”