What is a horseshoe cloud?
Clouds often captivate onlookers as they take on curious, billowing or ominous shapes, including those that look like flying saucers, ocean waves, mushrooms or giant cauliflower.
One cloud that has been specifically named after an object is the horseshoe cloud, one of the rarest documented cloud formations.
The unusual atmospheric sight was spotted most recently over Battle Mountain, Nevada, on March 8. As the photo went viral it generated a lot of buzz among cloud watchers and curious readers.
Some disagreed with the horseshoe name as they believe it looks more like a mustache or staple.
One of the rarest clouds ever. This was taken over Battle Mountain, Nevada, USA on 8 March 2018.
It's called a horseshoe cloud for obvious reasons. #nvwx
Credit goes to eagle-eye Christy Grimes. pic.twitter.com/XgQDY77ZzM — NWS Elko (@NWSElko) March 9, 2018
According to the National Weather Service in Elk, Nevada, this cloud formation occurs when rotating air or shearing horizontal winds create spin.
Wind shear, or changing wind speed and direction with altitude, can help to create spin. Gently rising air can then force part of the cloud upward.
AccuWeather Meteorologist Jesse Ferrell said he has been an avid weather photographer for 43 years but it wasn't until this past summer when he walked out his front door that he captured a photo of the rare sight in person.
AccuWeather Meteorologist Jesse Ferrell, an avid weather photographer, photographed his first horseshoe vortex cloud in State College, PA, on July 24, 2017.