A massive roll cloud blew over Timbercreek Canyon, Texas on Monday. A roll cloud is a horizontal cloud formation that glides relatively low to the ground, according to the National Oceanic and Atmospheric Association.

Usually these types of clouds occur alongside thunderstorms, sea breezes, and cold fronts.

This particular roll cloud wasn't caused by a thunderstorm. 

Huffington Post reports, roll clouds can occur at mysterious times, even during temperate weather. 

They are not dangerous, and can be caused by cold winds--perhaps that was the cause in this particular instance.

Truck driver Bonnie Mask who lives near Amarillo, Texas managed to capture the rare weather phenomenon on camera. 

Mask, who had the day off, looked out her window Monday morning to spot the tube-like roll cloud which tread on for about 20 to 30 minutes..

Yahoo News reported that She captured the video from in deck in Timbercreek Canyon so that she could show the footage to her husband, Todd.

Todd Mask later posted the video on his youtube channel. 

According to Livescience, 'Sinking cold air causes warm, moist air on the planet's surface to climb to higher altitudes, where the moisture condenses into cloud form.'

Kim Cunningham, a meteorologist for the Weather Channel, told Yahoo,' This is fairly rare, by the way, to have these things and see these things,especially when not associated with a thunderstorm. ... It's pretty cool though, and it probably freaked a lot of people out.'

Roll clouds are also extremely rare. Mask told Yahoo news, 'There was some cool air that blew over as the cloud blew over the house,' she said, adding that it was 'kind of strange.'

Todd Mask described the cloud in his wife's footage as, 'rolling like an ocean wave' and 'like a horizontal vortex.'

Sometimes roll clouds are mistaken for UFOs.

(dailymail.co.uk)

ANN.Az

ANN.Az