DeKALB – If the April 9 tornado happened about 15 miles southeast, it could have been disastrous for DeKalb and Northern Illinois University.

About 20,000 people would have been affected, and it would have caused serious damage to the area, according to Stephen Strader, a doctoral student in meteorology at NIU.

“The two that I think would have been most scary is both NIU and DeKalb police stations would have been impacted,” he said Thursday.

Representatives from the meteorology department at NIU and the National Weather Service in Chicago spoke to a crowded room during a symposium titled “Gone with the Wind: Providing Perspective on the April 9th Tornado.”

It looked at how the tornado that destroyed Fairdale and killed two women happened, what could have happened, and safety precautions for the next disastrous storm.

“This is the most significant tornado event I’ve worked since 2003, when I first became a forecaster in the Springfield office,” said Geno Izzi, an NWS meteorologist.

NIU meteorology professor Walker Ashley gave an overview of the tornado using food recipe comparisons and photos of food in his slide show presentation. He said moisture, instability, shear and lift are the perfect ingredients for a devastating tornado. He showed a diagram of all four of them overlapping directly over the region.

“It’s the shear that’s so critical for creating what we call organized thunderstorms, and the storm that we got in Fairdale,” Ashley said.

He said that while the tornado is widely known as EF 4, that scale is based on damage – a tornado that hits open soil would generally be ranked EF0.

“We knew several days out this would have potential,” Ashley said. “We’re always looking at how these ingredients are shifting into models. Then the day of, we’re looking at observations.”

NIU meteorologist Gilbert Sebenste gave some uplifting news – “the survival rates from these tornadoes are very high,” he said.

He outlined a plan that should be implemented before the next severe tornado event: Identify a shelter, make sure you can be properly warned, and get ready to go when you have to, or before you have to if possible.

Sebenste said outdoor tornado sirens are pretty useless to people inside and should “be thrown in the trash,” which elicited audience applause.

NIU emergency management coordinator Kyle Ullmark also spoke at the symposium, addressing NIU’s protocols and response before and after severe weather.

Izzi broke down the order of events on April 9: A tornado watch had been issued early that afternoon, then the warning was issued at 6:35 p.m. with a confirmed touchdown just a few minutes later, when the warning announced “complete destruction is possible.”

Debris, including a Fairdale street sign, was found about 30 miles away, Izzi said. He said talk of the area being protected by lakes, valleys and Chicago skyscrapers are all myth.

“This is a wake-up call for the entire region,” Izzi said, “that we are tornado-vulnerable.”