Continuity mistake: When the cow blows by the truck, the truck is driving down an empty dirt road with water on both sides. During the shots of the occupants, the road behind the truck is paved and dry. Also in one of these rear shots a truck (Red Chevrolet Blazer) drives by in the opposite direction.
Factual error: In the begining when Jo's dad is bringing the family downstairs and say's "TV says it's big, might be an F-5" That scene was set in 1969. In reality he would not have known anything about an F-5 or any tornado with an F rating because the Fujita scale was not developed until 1971.
Continuity mistake: When the telephone pole falls on the truck, you see Dorothy get thrown off the bed and the tailgate gets broken off along with it. A couple of scenes later, the tailgate is back and hanging there like it was untouched, and the pole is no longer there.
Continuity mistake: After Bill Paxton and Helen Hunt chase the first tornado they switch to Bill's new truck. They look at the speedometer once then they look at again about 3 seconds later and the odometer is hundreds of miles different than it was only 3 seconds before. Furthermore, the truck has gained a quarter gas tank in a blink and has the airbag warning light turned on.
Visible crew/equipment: When they are trapped in the garage and the tornado is whipping through, if you look real close when the debris is falling on them you can see (very quickly) a crew member throwing trash in the background.
Continuity mistake: When Bill and Jo are going through the house, the house is on its side horizontally. When they are crashing through the rooms though, the rooms are vertical. Also, in the same scene, you can clearly see them going up the stairs to the second floor. When they burst out, they are magically back down on the first floor. Right after that, the windshield is all cracked. A second later, it's perfectly fine.
Visible crew/equipment: Near the beginning of the movie when Bill and Mellisa are on their way to get the divorce papers signed, you can see the reflection on the passenger side window of the helicopter and the cameraman. A few shots later when the camera angle is in front of the Dodge, you can see a brief reflection of the brake lights from the camera truck in the rear window of the Dodge.
Continuity mistake: When the good group is chasing the tornado, the bad group is following them (watching for skid marks on turns, etc.) anyway, the bad guys see skid marks at a turn about 10ft in front of them. They would have to turn immediately and they would still barely make the turn. The camera goes off the road and shows the driver's "what do I do?" expression for about 3 seconds, then the camera goes back on the road and the turn is the same distance away. In reality they would have passed the turn and been about 20 ft past it by then.
Plot hole: Throughout the entire movie, barns, houses, cars, 18-wheelers, etc. are demolished and lifted into the air like they were made of paper. And yet Jo and Bill pass through one tornado after another with nothing more than their hair getting messed up (a little.) You'd think just the debris flying into their faces at 100 miles an hour would be enough to give them a few injuries.
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.
Revealing mistake: They wouldn't be able to walk or run nearly so easily when near a tornado. In ametuer video footage of real tornados, the people could only move quite slowly, and were walking on an angle of 30 degrees from upright.
Continuity mistake: When Jo's crew is having their little steak snack at Aunt Meg's, we see Preacher watching TV. There's a good shot of the top of the television set and there are NO walkie-talkies on top. Yet when they hear about another tornado, they all jumped up and grab their walkie-talkies off the top of the TV.
Visible crew/equipment: There's a shot late in the movie at Helen Hunt's Aunt's house - the camera shows all of her home made "wind chimes" blowing in the wind. As the camera pans in and shows a little man sawing or axing something, you see a human hand appear near the bottom of the screen as the camera leaves the scene.
Continuity mistake: During the first tornado, Beltzer says the twister is about three miles away. You later see Bill turn the truck off the road directly onto that dirt path, not ten yards away. The tornado then arrives and sucks Jo's truck into the air. After the tornado, Melissa is driving along and says, "Oh my God" as the tornado disappears, back to about three miles away.
Revealing mistake: When Bill and Jo are driving towards the first tornado together (arguing), it's clear there's no windshield in the red truck. There's no rear view mirror and it's perfectly clear. During the next few scenes, a rear view mirror appears and there is mud on the windshield around the wiper tracks.