Weirdest Cloud (Or Lack Of Cloud?) We‘ve Ever Seen!

This is a fallstreak cloud, sometimes also called a punch cloud. They are, we think, the mythical thing that pilots describe when they talk about finding that “hole” to descend through. This one would be a piece of cake. And if you were above these clouds in an airplane that wasn’t equipped with FIKI, you’d definitely want to not spend much time in those altocumulus clouds—they’re almost certainly packing a lot of ice, including the worst kind—supercooled droplets. Supercooled droplets are essentially big drops of water that are very cold but haven’t solidified. It needs a trigger to do that, and an airplane passing through such clouds can do the trick. Under such conditions, clear thick ice can build very quickly and can take planes out of the sky.

What does this have to do with punch clouds, though? Everything. The clouds form in a spectacular way, according to meteorologists. The place where they begin to form are composed largely of supercooled droplets, and when they finally start to crystalize, they grow and fall, hence the “fallstreak” term. But before they fall, their crystalizing has a radiating effect, as their neighbors go through the same process. Hence, you get a hole that grows, sometimes until it’s very large, like this one.

 

Thanks to our contributors for the awesome video and images!