Storm Center 7 McCall Vrydaghs said these holes appear in cirrocumulus or altocumulus clouds.
Super cooled water droplets within the cloud are disturbed by something in the sky — often the passing of a plane — which triggers the freezing of these droplets.
Vrydaghs said that can have a domino effect of freezing molecules surrounding one another. Those freezing droplets then become heavier and can’t remain suspended in the cloud.
They begin to fall creating this “fallstreak” or “hole punch” effect, Vrydaghs said.
In the instances where the fallstreak hole appears long in shape, it’s then referred to as a “canal cloud,” and likely the result of a plane cruising through the cloud at the same altitude or climbing at a very slow rate.
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