Snow worked as a digital effects artist on Twister, he found himself hoping to have another go at crafting the violent air clouds that unleashed devastation across Oklahoma in the 1996 film.

The tool set was evolving so quickly back then that Id wished we could go back and do it over because technology advanced so quickly, Snow (yes, that is his real name) tells The Hollywood Reporter.

Nearly 30 years later, Snow got his chance as the visual effects supervisor for this years stand-alone sequel Twisters, starring Daisy Edgar-Jones and Glen Powell. The challenge this time was not technological limitations but rather viewer expectations. Ultimately, it does have to convince an audience that is much more visually aware of what tornadoes look like now than when they saw the original film, says Snow of the special effects. That was something we set out to do. Officially, six tornadoes were created for the film, though the simulation of the final storm, which catches fire after hitting an oil refinery, was so complex that it had to be broken down into smaller iterations, bringing the total to 10. Grounding the tornadoes in reality amid the heightened action of the movie and giving each its own individual character was the primary mandate from director Lee Isaac Chung, says Snow. The VFX team consulted with meteorologists to make sure their simulation tools were both scientifically accurate and powerful enough to capture the complexity of different types of storms, from wide wedge tornadoes to narrow cones. Using the 3D animation application Houdini, computational fluid dynamics software and a proprietary tool from VFX studio Industrial Light Magic, the team was able to mimic air movement, temperature, buoyancy, gravity, moisture density, vapor dissipation and other elements that determine a storms appearance.

Using the 3D application Houdini, computational fluid dynamics software and a proprietary tool from Industrial Light Magic, the VFX team was able to mimic the appearance of tornadoes. Courtesy of Universal (2) The VFX team also did research on the ground. We sent a team of storm chasers out with motion picture cameras to photograph storms. They actually got a couple of tornadoes on film. Unfortunately, nothings in the movie, but some of the storm clouds we were able to use as footage, says Snow. It was a great thing for our visual effects team because you could study the detail with high-quality, high-resolution material a lot better than what you might see on YouTube, for example. It allowed us to make [the tornadoes] very realistic. That was our watchword.

Shooting in Oklahoma, a state within the area known as Tornado Alley (and where the film takes place), was a mixed blessing, says Snow, recounting how the frequency of storms of all kinds often caused shooting to be shut down. At one point, we were filming a scene in a farmers market toward the end of the film, and a big storm came and demolished the set. The irony was we were going to demolish the set in the movie, so we had to rebuild this demolished set that the hailstorm had taken out and then demolish it again.

On the other hand, the location allowed for some meaningful practical effects. The good thing was that everyone got to feel what the weather was like, says Snow. The electricity in the air that you get in those severe storms it was good for the actors as well. Scott Fishers special effects team on set would have jet engines, rainmakers, hail-makers, everything imaginable [to replicate theenvironment].

Much like the unpredictability of the weather, even the best storm calculations couldnt guarantee an accurate result. Theres also the element of chance because youre simulating things with math and you dont really know how its going to turn out. So theres this crazy piece of magic when youre working with these tools to get that spark, says Snow. There are happy accidents just like there are when we film live action.

Scott Fishers special effects team used rain machines, hail-makers and jet engines to finesse the makeup of the storms. Courtesy of Universal (2) The need for the storms behavior to be guided in the same way as actors are in a film is why, even as technology continues to advance rapidly, Snow doesnt see a world where AI replaces the human touch in franchises like this one.

One thing that hasnt changed between the original film and this film is you need to be able to artistically direct things, says Snow. [The technology] has to serve the story, and what helps make things look real and beautiful and what makes it compelling to the audience is the artistry. And that aspect, I think, will be there even in another 30 years time. If its not, I dont know that you want to go and see the movie.

The final storm was so complex that it had to be broken down into smaller ones, bringing the total number of storms in the film up to 10. Courtesy of Universal This story first appeared in a January stand-alone issue of The Hollywood Reporter magazine. To receive the magazine, click here to subscribe.