A crazy mushroom cloud resembling something that Super Mario might pluck from the sky made the rounds on social media this past weekend. On June 12th, Alabama meteorologist Jane Dunne tweeted this photo of a mushroom cloud of near-perfect symmetrics shooting down rain off the state’s southeastern coast, which promptly went viral:

The photo was actually taken in July 2016 by Rick Geiss of Gulf Shores, Alabama, during an otherwise routine visit to a beach near his home. Why he waited nearly two years to send the photo to Dunne remains a mystery, but science can explain how this cloud, called a cumulus congestus, formed.

Clouds of this type come together with heat and moisture, a sort of one-off occurrence that isn’t part of wider weather patterns in the area such as hot or cold fronts. They form quickly, and often dissolve nearly as fast. “There is a large, central updraft (buoyant plume of air) that shapes the overall cloud,” Jeff Halverson, severe weather expert at the Capital Weather Gang, told The Washington Post. “The tapered appearance probably occurs because drier, cooler air is being pulled inward and upward along the margins of the updraft, evaporating some of the cloud edges and ‘sculpting’ its unique shape.”

The cloud formation itself looks peaceful when contrasted with the dark rain emanating from beneath it, but those enjoying a relaxing day on the beach didn’t appear to be phased by the nearby storm.

H/T: LiveScience