A video of a monster shelf cloud passing through the Illinois sky Tuesday went viral across the internet.
The video shows a giant cloud shelf appear over a Walmart in Illinois.
The video, which called the storm a "monster apocalyptic shelf cloud," was shared multiple times across social media.
Live Storm Chasers shared the video as well:
You walk out of @Walmart & see this... What do you do?— Live Storm Chasers (@Livestormchaser) August 9, 2018
Monster apocalyptic shelf cloud structure passing through Anna, IL on Aug 7, 2018!#ILwx #StormHour @StormHour #Breakingweather
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Licensed By: Maranda Benefield pic.twitter.com/hRgi9RLqJ1
FOX-2 meteorologist Glenn Zimmerman said the footage captured the beginning of a thunderstorm cloud. Sometimes these storm clouds can build from the ground and rise up toward the sky in what weather experts call shelf clouds.
Shelf clouds are often seen at the beginning of thunderstorms. The shelf clouds aren’t tornadoes or wall clouds.
“What you're seeing in a shelf cloud is the boundary between a downdraft and updraft of a thunderstorm or line of thunderstorms,”according to The Weather Channel.
The shelf cloud will cause “an abrupt shift in wind direction and increased wind speed, followed within minutes by heavy rain or hail,” according to The Weather Channel.
The shelf clouds could cause downed trees, fallen tree limbs and power outages.