They can look like something out of a movie, an alien invasion on the horizon, but the bizarre shape in the sky is an arcus cloud.
Arcus cloud is the umbrella term for a low, horizontal cloud formation that usually accompany’s thunderstorms. You may know them as shelf clouds and roll clouds.
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We see both types of these arcus clouds in the Miami Valley. In northeast Ohio this week, a complex of thunderstorms produced some impressive shelf cloud photos.
