This is so cool can someone explain the scientific phenomena behind this?

Just checked, this is a shelf cloud, a type of arcus cloud that usually signals the coming of severe weather. This is actually fairly normal behavior for shelf clouds, I think it’s just that the video is really close to the squall so it looks extremely ominous.

Here are a few more examples of shelf clouds.

Umm

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You’re saying that like the photos ain’t spooky and ominous

you all talk about illinois as if it isn’t already ‘the mist’.