What was that hole in the clouds?
On Monday, our amazing viewers began sending us pictures of a cloud formation (or lack of clouds) they saw around 4 p.m. over northeast Oklahoma. Social media lit up with these strange and awe-inspiring images. This rare phenomenon is called fallstreak hole or hole-punch cloud.
Here’s what happened: Last evening, behind the strong cold front we had a layer of cirrocumulus clouds over our area. That’s common.
The fallstreak hole appeared when water in this section of the cloud is below 32 degrees but has not frozen yet. Water molecules need something to attach themselves to. They need a condensation nuclei. Without this the water vapor can have a temperature well below 32 degrees but not frozen. This is called supercooled.
Once the subfreezing water droplets begin to form ice, the chain reaction begins. An odd looking void forms in the clouds. The hole is created as these ice crystals fall (in a streak) from the center and begin to evaporate. Thus the name fallstreak.
In my 30-plus years in meteorology I have seen about a dozen of these. Interesting, last night I was inside watching storms over SE Oklahoma and did not go outside to see this. Sorry I missed the show, but thanks to our viewers I was able to see some amazing images. Thank you!
If you want to learn more about these and about how aircraft contribute to fallstreaks and skypunch formations, check out the Cloud Appreciation Society. In 2011 they published an interesting article on fallstreak holes and this link will take you there.
You can always share your pictures and video with us at burst.com/ktul. You might even end up on TV!