Twisters director Lee Isaac Chung can’t help but suspect Mother Nature had a grudge against his stormy sequel.

The movie, starring Daisy Edgar-Jones, Glen Powell, and Anthony Ramos as a new generation of storm chasers, was frequently stalled by lightning strikes, wrecked by high winds, and pummeled with powerful rains when it filmed in the fields of Oklahoma in late spring of last year. There were clear skies overhead when the film had its gala premiere in Oklahoma City this past Monday—but just a few states away, at least 11 tornadoes tore through the Chicago area, knocking out power for tens of thousands of people.

Even before that, the filmmaker was feeling superstitious. “I would wonder sometimes if the weather knew what it was doing, you know what I mean?” Chung tells Vanity Fair.

Chung thought he knew what he was doing too. It was Chung’s choice to film in rural Oklahoma during the peak of storm season in order to capture the darkest and most ominous skies. The 45-year-old filmmaker grew up on a farm in neighboring Arkansas (as chronicled in his Oscar-winning drama Minari), where tornadoes are also commonplace; he was used to living and working under tempestuous circumstances.

“It just ended up being a fact of life for me, and I think for everybody I knew growing up there. When we first moved to that farm in Arkansas, I was four years old, and we moved into a trailer home, which was just in the middle of this field,” Chung says. “And a few weeks into that, a tornado came into the area. The storm was really picking up outside, and our whole mobile home just felt like it was rocking. We jumped into my dad’s pickup truck because he said, ‘We ought to go and look for a place that’s low.’ So we went down the hill and went into this ravine in case the tornado came.”

He remembers falling asleep in the truck waiting for the winds to pass. “Then I woke up and I was safe in my bed and it was sunny,” Chung says. “That was quite jarring, and it stuck in my mind. As I got older, it just became like background noise. You just have storm season, you do the tornado drills, and every now and then there’s a tornado and it rips apart a town nearby. It just becomes part of reality. It’s like forest fires here in California. We freak out about it a little bit, but for most of us, we just accept it as something that happens.”

The original Twister, which starred Helen Hunt and Bill Paxton as scientists trying to document the physical properties of tornadoes, had been a touchstone for him as a young man. “All of us had dealt with tornadoes in the area, so it felt like a hometown film in many ways,” says Chung, who was a 17-year-old high school junior when that movie debuted in 1996. He went to see the movie with his immigrant farmer parents, who knew the risks powerful storms posed to their way of life. One bad tornado could ruin them, or their neighbors, or everyone in the vicinity. For working-class people in these areas, rebuilding isn’t always an option. “You really feel as though there’s nothing left, there’s nothing to build from,” Chung says.

That gave Twister a kind of subversive thrill for Chung and his parents. “It was a complete surprise to me as a kid that it was about a bunch of scientists who were actually going towards these things and trying to study them,” he says. “My concept of tornadoes was always that you’re just always going to run away from it and find a place to hide. So when I saw that, I remember it being really compelling.”

Chung might have seemed like an unlikely choice to direct the sequel, shifting gears to a massive summer blockbuster after having made his name with an intimate family drama like Minari. But all those experiences made the film more than a level-up payday for him. Chung was determined to add a personal touch to the story—and finally race toward the tornadoes himself.

Although most of the whirlwinds in Twisters would be generated through visual effects, Chung wanted to capture the feel of the land and towns that are so frequently ravaged by the weather in the Midwest’s so-called Tornado Alley. “I remember talking to people who had worked on the first Twister,” Chung says, including Twisters production designer Patrick Sullivan, who had been a set designer on the original movie. “I heard they had quite a long stretch of sunny weather when they really needed clouds and a sense of storminess. So I felt this deep conviction that we should be filming during tornado season.”

He takes a breath: “I was very naive with that decision.”

The film captured plenty of genuine cloudbursts, gales, and skies that resemble deep and painful bruises—but they came at a cost. “I didn’t fully know what the consequences of that would be,” Chung says. “I wasn’t fully thinking about how much we would be shut down by weather. It was just a constant thing for us. I could not pinpoint a specific story about lightning because I felt like our entire shooting schedule was lightning delay after lightning delay. It was just constantly happening. I’d arrive on set, and first thing, we’d have a lightning delay.”

It got so bad that the crew was forbidden from saying certain words—like the wizards who refuse to speak the name “Voldemort” in Harry Potter. “By the end, our assistant director, David Venghaus, banned the word lightning on set. No one was allowed to say lightning because it was some kind of bad omen,” Chung says.

Twisters was especially susceptible to storms, since light towers and camera rigs are almost literal lightning rods. “We do have to be safe. And we’re in fields very far away from the city, 200 of us out there who suddenly have to find a place to shelter. It’s very difficult. So we have to anticipate what the weather is going to do,” Chung says.

The production turned to two experts—one to get them within safe range of the storms, the other to help them evacuate if the weather defied prediction. “We had this full-time meteorologist, and their sole role was to figure out what was going to happen for us each day,” Chung says. “He worked in conjunction with this woman who was an emergency planner. So they did all kinds of things, like having temporary shelters in place.”

Trouble started even before the cameras started to roll. On Anthony Ramos’s first day in Oklahoma, he and Chung were going over the script when a storm walloped them and they learned of a tornado in the neighboring town of Cole. “It ended up being a couple of vortexes that came together and formed this EF-3 tornado, which was similar to something that happens in our movie,” Chung says. (The EF scale is used by the National Weather Service to rank a storm’s destructive aftermath, with 0 being the lowest and 5 being the most catastrophic.) “We just had to shelter there and wait it out for a couple of hours. This sort of thing would happen quite often.”

As a result, the makers of Twisters—a big-budget studio tentpole with a price tag of around $155 million—began to operate like indie guerrilla filmmakers. They’d race out to capture footage when conditions were relatively clear, then scurry to safety when the winds and rains got a little too dramatic for comfort.

“We were filming the sequence where Daisy and her friends from college run to an overpass, and the skies looked incredible that day. I was very happy, but I heard that a storm was coming in. First it was just a few rumbles, and finally the [assistant director] says, ‘We’ve got to kill it after one more setup.’ The winds are picking up, and we’re filming these guys running up into the overpass [to hide from a tornado], and we have to shut down: That storm ended up producing a tornado. All of us had to find shelter and get out of there.”

This happened over and over again. There’s a scene where Powell and Edgar-Jones unleash one of her experiments into a whirlwind; a real tornado forced them to wrap early and flee. “We were finding constantly that we would film wonderful skies, but then we’d get shut down as a result, maybe 30 minutes into it,” Chung says. “The compromise was always just that we’d had a lot less time to do things.”

They got to be good at this dash-and-shoot approach despite all the weather delays, which became a point of pride for the indie director turned blockbuster filmmaker. “On my end, I did not want to go over budget or over schedule,” Chung says. “I was already dealing with the fact that I am the Minari guy making Twisters. I just wanted to show that we’re going to be all right. I would just incorporate that fast speed that we were filming into the language of the film. So that was the negotiation, and we finished on schedule actually.”

The harrowing weather also bonded the cast and crew. “It definitely forced all of us to come close together with each other and to work together really well. I felt like the storms actually helped us a lot in that regard,” Chung says. “We’d spend so much time together during lightning delays where we’re just quietly listening to the rain, and then talking about life. That would happen quite a lot.”

None of the crew or actors on Twisters were harmed in any of the storms, but the sets did take some heavy hits. “One day we were filming the El Reno farmer’s market that we had built. We had set it up to destroy it, and then this massive storm came through with 50 mile-per-hour winds, and it destroyed the set while we were hiding away,” Chung says.

The only problem was that they hadn’t yet filmed the before scenes, when the merchants and customers see the storm approaching and everything is still intact. But nature’s wrath had given the production designers some good reference imagery. “We had to come out and rebuild that set—then destroy it again,” Chung says. “But we took pictures of the destruction so we’d know how to make the destruction look based on reality.”

Knowing what he knows now, would he have still dared to shoot in Tornado Alley in the springtime?

“Our weather adviser said to me this year, ‘You know, last year was actually quite a boring storm season,” Chung says. “This year was bad, and we could not possibly have filmed there because it was a record outbreak. But I wouldn’t take the gamble and say, ‘Let’s film there next tornado season.’ You never know what’s going to happen.”