Lots of complex things going on.

I think you're exactly right. That sounds right on with the warm air
from the south and the cold from the north underneathe. I thought it
was interesting how the briefer got it right on too with his warning. I
heard one controller tell someone up high that there was strange
jetstream pattern or something. They were all getting beat up. There
was a tornado reported a couple of hours before we arrived. The forty
mile an hour winds and rain had moved offshore about that time, a
couple of hours before. This gives me new respect for
windshear/downdrafts. My bro-in-law told me he has heard of trees being
flattened by downdrafts. If they can flatten a tree, they can take an
airplane and plant it, no doubt. I went down the ILS into Huntsville
one night when they were giving Low Level windshear alerts .. next time
that happens I'll have them vector me around some before attempting it,
having experienced it.