Shelf clouds occur at the leading edge of thunderstorms. A form of arcus cloud (along with wall clouds), these striking formations look like a long bar or shelf of cloud below a storm cloud. Shelf clouds are accompanied by gusts of wind, and often followed by precipitation – rain, hail, or both.
View at EarthSky Community Photos. | Jim Saudade captured this early afternoon shelf cloud formed over Boston Harbor, Massachusetts, on June 28, 2020. He said: “Shelf cloud quickly followed by pea sized hail and a deluge of rain.”
View at EarthSky Community Photos. | Sarah Iler of Birch Run, Michigan, captured this image on August 2, 2020, at 8:39 p.m. She wrote: “Thunderstorms all afternoon and then this shelf cloud formed in the evening. It was amazing.”
View at EarthSky Community Photos. | Jay Banfield caught this shelf cloud from Centerton, Indiana, at 11:56 a.m. on August 17, 2019. Jay described it as: “Well defined shelf cloud ahead of a 15-20 degree temperature drop.”
Shelf cloud photographed by Rita Addison at Osmond Beach, Florida, on June 3, 2018.
A shelf cloud moving over the Fire Island Inlet Bridge, on Long Island, NY, May 15, 2018, by James Trezza. Nikon D750 & Nikon 20mm.
Josh Blash caught this shelf cloud from Rye, New Hampshire, on July 23, 2016. Josh said: “Everything got very still when I took this, just moments before the fury of the storm began.”
Simon Toogood in Tasmania captured this impressive shelf cloud in 2014. He said: “Stormy weather – and shelf clouds like these – are common at this time of year.”
Bottom line: Photos of stunning examples of shelf clouds, from the EarthSky community.
Source:
https://earthsky.org/earth/photos-shelf-clouds-arcus