Continuity mistake: In the scene where they're leaving the school, there are a ton of cars behind them on the highway and then all the cars just disappear.
Suggested correction: Our heroes are in the last bus. There are a few cars exiting behind them, but you see at least one of the cars pass the bus and get ahead of it. In the first aerial shot of the highway, you can only see two cars behind the last bus. When the tower falls, it lands just behind the second-last bus, cutting off 3 cars, then our heroes' bus, then the Titus and another 2 cars. At no time is there a line of cars behind the last bus that disappears.
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.
Continuity mistake: When the blue van is blown over, Titus turns around and the road is wet with puddles but as he drives on the grass/dirt it's dry. (00:51:29)
Continuity mistake: After Donk has successfully jumped into the flaming pool on an ATV, he takes off the goggles he was wearing and puts them onto his helmet. He hugs his friend, Reevis, and after a cut the goggles are back over his eyes, only to be put back up once again.
Continuity mistake: School security cameras have 3 separate time stamps. 18:19 then 13:53 then 20:07.