HUNTSVILLE, Ala. (WHNT)– When the sky grows dark and stormy, it’s easy to be on edge. Seeing the wicked types of cloud formations we had with Thursday’s storms may have you thinking the worst is happening.
Many WHNT News 19 viewers shared pictures with us of what they claimed to be a tornado north of Athens and a few more over in northeast Alabama. Very low-hanging, rugged– even cone-shaped– clouds could be seen underneath and just ahead of the strong storms. So what were these clouds? Tornadoes? Something completely harmless?
Most of the clouds we saw yesterday were totally harmless shelf clouds.
Shelf clouds are often confused with wall clouds due to their appearance. None of the clouds we received pictures of Thursday showed wall clouds. Shelf clouds form as the rain-cooled thunderstorm air rushes out ahead of the storm and meets up with warm air. The colder, more dense air lifts the warm air, causing it to cool and form the shelf cloud. You may have noticed yesterday feeling the cool wind before the rain began.
UAH has a vertical profiling radar that took this imagery as the storm passed over the campus around 6 p.m. Thursday.
— Simon Brewer (@SimonStormRider) May 13, 2016
You can see the upward and downward moving air (Simon’s mark-up), and you can practically see why shelf clouds look the way they do: rain-cooled air in the thunderstorm downdraft races out in front of the rain while warm, humid air rises over top of it. That creates the low-hanging cloud on the leading edge of the storm.
A few other photos were a bit more suspicious; Paul Taylor shared a picture of this cloud formation just north of Athens as an intense storm blew through. More than likely, this was just a scud cloud. The National Weather Service in Huntsville found some minor tree damage and damage to a few barns in Limestone County, but had no evidence that a small tornado touched down in this area.
Scud clouds form as warm, moist air rushes up into thunderstorms, and they are generally harmless despite their turbulent look.
We also saw several of these same type of clouds from our Jack’s camera network as storms ascended Lookout Mountain in Fort Payne.
Do you have a picture of yesterday’s storms? Email it to firstname.lastname@example.org.