Disaster movies based on weather events often stretch the science nearly to a breaking point. In "Into the Storm," a flick about a massive attack of giant tornadoes, the filmmakers definitely took more than a few liberties with their portrayal of funnel clouds.
The story centers on an exceedingly unlucky Oklahoma town that is battered by four tornadoes in only 12 hours. It's not entirely impossible for four twisters to strike the same area in a short time, but it isn't likely.
History has seen multiple large-scale tornado outbreaks when the weather conditions are ripe. In those cases the twisters are generally spread over a wide area, such as the 1999 outbreak that sent around 50 funnel clouds spinning over Oklahoma and Kansas.
The movie also shows tornadoes with multiple funnel clouds in one small area. In reality, funnel clouds do occasionally have multiple vertices surrounding a primary focal point. These are rare, though, and in situations where they merge they don't actually form ever-larger and more destructive storms, as in the movie.
Finally, destruction in the film is sometimes silly and sometimes way, way over the top. One of the most dangerous aspects of tornadoes is flying debris, but somehow no one onscreen ever suffers any real injuries from airborne lumber or metal. Yet the same storms grab entire plane fleets and launches them into the stratosphere.
Then again, for all of the hokey science of "Into the Storm," that aspect may have been least worrying part of the movie. The acting was more artificial than the weather.