Twister

Twister is the original "Twisters" movie made in 1996. This move is based on two rival teams trying to collect data from within a tornado's funnel using the new Dorothy probe. Surprisingly, this movie shares many similarities with Twisters. The two main protagonists are Dr. Jo Harding, and Bill Harding. This movie was released on the exact date of May, 10, 1996. Me personally, I would recommend watching this movie first before watching Twisters. This movie starts off with a young girl, which is the protagonist, witnessing her dads death due to him trying to close the storm cellar and being blown away by the F5 winds. Then the movie goes on as the protagonists use the newly made Dorothy to capture data. 

Then after that, the rival team copies Dorothy and makes a new version to compete with. During the deployment process of Dorothy, they fail to load Dorothy in the path of the tornado. During the climax, or the end of the movie, a new F5 tornado forms forcing them to flee. Both of them find out theres no outrining this F5 tornado. They jump out of the truck, and let Dorothy intercept the tornado. This causes the success in collecting the data for the tornado, showing the windspeeds and shape of the lardeg wedge tornado. However both of the protagonists runn into a shed and strap themselves to an underground pipe using a belt. They intercept the tornado and witness the large eye of the funnel.