noaa weather radar error

i was flipping channels bored not just about 30 minutes ago and saw on the national radar broadcasting channel, the one with automated voices. The animated radar of the last 3 hours or so.

well in one of the frames was a giant storm, over minnesota. A large swath, i believe it was angeled downwards towards the south east, but the red areas was huge.

It was only 1 frame and am curious to find out if any meteoroligists could tell me what those errors are?

A thought went through my head when i saw it, "could that be another dimension and the satellite somehow anomalously picked up a frame?
but that was just to entertain my sci-fi part of my brain.

Might have been fog but I don't know. I am in MN and it was very foggy here this morning but it's turned out to be a beautiful day now.