Two scientists are hunting for information on tornadoes and Tornado Alley. They have developed a system to launch lots of sensors that can be sucked up into a tornado and give them valuable data. The downside is that they have to get awfully close to the tornado to position the sensor carrier in the right place.
This is pretty much the classic tornado movie and the ones others are compared to. The story opens in 1969 with a tornado in a rural area which results in a father being killed. The daughter grows up to be an expert in weather, especially tornadoes.
She was married to a guy who was also involved in tornado study but they separated and now the guy has a new potential wife. He also invented a way to disperse data-gathering devices into a tornado, and the rest of the film deals with he and his still-present-wife pursing that and nearly getting killed by a tornado while the woman he was going to marry is totally out of her depth and can't handle the life style he follows.
The special effects are some of the best done in any of the related films, the storyline is good, and the tornado aspect of the film is good.