A shelf cloud (or arcus cloud) making its way toward our office just a little before 9 PM this Tuesday evening, leading in the next narrow line of showers and gusty winds. https://cloudatlas.wmo.int/en/clouds-supplementary-features-arcus.html | US National Weather Service Spokane Washington

13K views · 244 reactions | A rare cloud formation awed onlookers at the Queensland and New South Wales border on July 4. Roll clouds – also known as Morning Glory or arcus clouds – are a low, horizontal formation that can signal microburst activities such as sudden downdraught or powerful air currents. They are considered rare by meteorologists and weather enthusiasts. This video was taken at Goondiwindi, Queensland. Credit: Jennifer Smith via Storyful | Courier Mail | Facebook