Continuity mistake: After leaving Aunt Meg's the first time, Jo and Bill are in the red truck. Bill says, "Ok, let's get you wired." When Jo looks over at him you can see that she already has the headphones around her neck. Then they cut to Bill and when he goes to put the headphones on her neck is bare.
Continuity mistake: When Jo's truck is lifted by the first tornado they encounter, it is dropped on the road in front of the red dodge driven by Bill's fiancée. When we see the truck drop, the drivers window is closed. As the dodge swerves to avoid hitting the other truck, the window is now opened. And finally, in the last shot where everyone is running to her aide, the window is closed again.
Continuity mistake: When Bill is going over the divorce papers, he comes to the page missing Jo's signature. It only has one red arrow near top right. When he hands it to Jo, she starts looking at it, then flips up page to look at others, and the missing signature page is a completely different page with two red arrows, one toward the top and another, on the right, toward the bottom.
Continuity mistake: Near the beginning, when Bill and Melissa have gone to get the divorce papers, Bill leaves Melissa talking to Dusty. When Dusty starts telling her about the "suck zone" there are a couple of black cows behind Dusty. Next, Jo comes over to meet Melissa and when the camera pans to the same area behind Dusty, there are no cows.