Other mistake: When the blue van rolls over, and they turn around to go pick them up, they park like 20-30 feet from the van for no reason, instead of right by it, seemingly just to have a tree block their path, then decide to run into a church with really big stained glass window and wood pews while a FIRE tornado is just outside. Rolling the van back upright, all the TVs and equipment inside the van seem to be working just fine.
Factual error: What kind of small American town has an airport that has 6 jumbo jets sitting on the runway? I mean, I think Dallas is the closest airport in the region that would have 4 engine 747s at the ready. Topeka, Oklahoma city, etc. commercial airports could barely handle one 747, let alone 5-6.
Continuity mistake: In the scene near the end when they are taking cover in the storm drain, the manhole cover is stripped away by a combination of the wind and a flying semi truck. As the tornado reaches its strongest winds, the manhole cover, which is mysteriously back somehow, flies off again, this time by wind alone.