According to Wikipedia, a supercell is
. . . a thunderstorm that is characterized by the presence of a mesocyclone: a deep, persistently rotating updraft.For this reason, these storms are sometimes referred to as rotating thunderstorms. Of the four classifications of thunderstorms (supercell, squall line, multi-cell, and single-cell), supercells are the overall least common and have the potential to be the most severe. Supercells are often isolated from other thunderstorms, and can dominate the local climate up to 32 kilometres (20 mi) away.
And they can spawn tornadoes, though they often don’t.
From Mike Olbinski Photography comes a description and a stunning video of a “supercell” in Texas. His description:
It took four years but I finally got it. A rotating supercell. And not just a rotating supercell, but one with insane structure and amazing movement. I’ve been visiting the Central Plains since 2010. Usually it’s just for a day, or three, or two…but it took until the fourth attempt to actually find what I’d been looking for. And boy did we find it.
No, there was no tornado. But that’s not really what I was after. I’m from Arizona. We don’t get structure like this. Clouds that rotate and look like alien spacecraft hanging over the Earth.
We chased this storm from the wrong side (north) and it took us going through hail and torrential rains to burst through on the south side. And when we did…this monster cloud was hanging over Texas and rotating like something out of Close Encounters.
The timelapse was shot on a Canon 5D Mark II with a Rokinon 14mm 2.8 lens. It’s broken up into four parts. The first section ends because it started pouring on us. We should have been further south when we started filming but you never know how long these things will last, so I started the timelapse as soon as I could.
One thing to note early on in the first part is the way the rain is coming down on the right and actually being sucked back into the rotation. Amazing.
A few miles south is where part two picks up. And I didn’t realize how fast it was moving south, so part three is just me panning the camera to the left. During that third part you can see dust along the cornfield being pulled into the storm as well…part of the strong inflow. The final part is when the storm had started dying out and we shot lightning as it passed over us.
Here’s how supercells form (diagram from Wikipedia):
And an amazing photo, which Olbinski is selling as a print at his online gallery (click to enlarge):