AUSTIN (KXAN) – What was with the weird clouds on Thursday? It’s a question a few viewers asked the KXAN First Warning Weather team after seeing what looked like a bizarre hole in the clouds, shown below.
The answer: It’s a fallstreak hole.
As defined by the National Weather Service, fallstreak holes are large circular or elliptical gaps that can appear in cirrocumulus or altocumulus clouds. Often times, you’ll hear meteorologists refer to fallstreak holes as “hole punch clouds”.
How do they form?
Fallstreak clouds form in mid- to high level clouds composed of tiny water droplets that are much colder than freezing, but have not yet frozen. Why? These “supercooled” water droplets look for something to freeze onto, which at those level of the atmosphere tend to be ice crystals.
Often times, planes passing through this cloud layer can provide these ice crystals…