Mesoscale Convective Complex. A large group of thunderstorms. Specifically what shows on the image is the large plume of very cold very high cloud tops, I guess.
Although, I guess the camera would only saturate for high heat, not low. So maybe what we're looking at is the thermal signature of lighting. But I really don't know.
Back in the 50s during Project Man High, the Air Force space equivalent environment, balloon flights launched from the Dakotas, it was first confirmed that storm tops could exceed 50,000 ft. During an anxiety filled night at altitude Major David Simons confirmed that thunderstorms that were expected to pass well below his capsule were reaching to nearly 70,000 ft.
how is that "even more correct"ly ? You originally said "the Dakotas" and us South Dakotans are pretty proud of NOT being part of North Dakota ... however, since I was born a Minnesotan, I'll click your link and smile, anyway! Uffda!