What Are Cold Air Funnels And How Do They Form?

It's a cold and rainy spring day in South Dakota, not typically the type of weather day where you're expecting tornadoes. I usually associate tornado weather with a hot and humid day, not a day that feels like it could be straight out of October.

But you look up and see some rotation in the clouds, and maybe even a little rope-like thing descending from the clouds! What is that? Is it a tornado?

MORE: Debunking 5 Common Tornado Myths in South Dakota

Get our free mobile app

What is a Cold Air Funnel?

Chances are, what you're seeing is a Cold Air Funnel. They are slender, rope-like funnel clouds. They rarely make it all the way to the ground.

According to the National Weather Service, Cold Air Funnels form under rain showers or weak thunderstorms when the air high in the atmosphere is frigid and the air near the ground is warm

Canva

"The funnels are most common in the fall and spring when the sun is able to heat up the lower levels of the atmosphere, causing convection to bubble up and form showers, but temperatures around 15,000 to 20,000 feet above the ground are quite cold."- National Weather Service

FLASHBACK: May 30, 1998: The Tornado That Changed Spencer, South Dakota Forever

Is a Cold Air Funnel a Tornado?

It's rare for a Cold Air Funnel to reach the ground, so Tornado Warnings aren't usually issued. They are also difficult to see on radar. If the funnel does reach the ground, then it's considered a tornado, and a warning would be issued.

On the rare occasion that one does touch down, it could cause some damage with winds around 80 miles per hour. It'd likely be classified as an EF-0 tornado then.

Cold Air Funnels are also a quick weather phenomenon. They rotate in the cloud, then drop the rope for a few minutes. So, if you see one, take a picture!