This is the start of Severe Weather Awareness Week and that means the storm experts are preparing for the worst ? the next big tornado outbreak.
Here's a first-hand look at the storm lab in Colorado where their research may help keep you safe this spring.
We have seen violent tornadoes hit the Chicago area before: Oak Lawn in 1967, Plainfield in 1990 and Utica in 2004.
Storm experts to in Colorado are using the latest technology to see just what would happen if a major tornado struck the Chicago area again.
Eventually one of these killer twisters will strike and experts say the destruction could be unprecedented.
Inside this unassuming airport hangar in Boulder, CO leading scientists are gearing up for tornado season.
This is where we found Dr. Josh Wurman. He's tracked hundreds of tornadoes including some of the strongest ever recorded. His concern, although rare, an especially powerful tornado in Chicago would be catastrophic.
"We dragged 10 hypothetical tornadoes through Chicago and in some of those cases tens of thousands up to a hundred thousand homes would be destroyed," Wurman said. "And we don't know how many people would be killed or injured but probably it would be in the thousands."
It's happened before, Oklahoma City, Birmingham, Alabama and Joplin, Missouri are just a few of the cities that have been decimated by twisters.
Wurman knows first-hand what can happen when one rips through an urban area.
"We intercepted a tornado near Oklahoma City. It was an F-5 tornado killed over three dozen people, and we were about a mile away from the center of that tornado and about a half a mile from the edge," he said.
That's just one of the many twisters Wurman and his team have tracked using these DOWS, a Doppler radar on wheels that he invented to help scientists learn more about the most powerful tornadoes.
"I have intercepted over 170 tornadoes with the DOWS, and so I have seen weak one and really, really strong ones," he said. "The strongest one I ever saw was in the Guiness Book of World Records as the stronger wind speed ever measured we measured winds over 300 miles per hour."
At the National Center for Atmospheric Research in Boulder, Colorado they're looking into ways of improving severe weather forecasting.
George Bryan is one of the leading weather computer modelers in the country. He has analyzed the data collected by Wurman and his team. That information helped develop models that meteorologists everywhere now use to better forecast where tornadoes might form.
"Including these more complex, what we call micro physics, ice and rain physics, helps us produce more realistic tornadoes and better forecasts and predictions of severe thunderstorms," Bryan said.
With better understanding of the dynamics involved in tornadoes more advanced warning is now possible which has been proven to save lives.
"When severe weather threatens, they need to be at a higher state of alertness so they are not caught out in the open, they have a plan to get into a basement or community shelter, and they can just make the tornado more survivable," Wurman said.
Tips for being safe in a tornado:
-Get to a basement and under a sturdy object
-In a high rise, go to a windowless area in the center of the building
-If trapped in a car, park and keep your head down and seat belt on.
For more tips visit: Ready.Illinois.gov