Do green skies mean a tornado is coming? Busting the most common storm myths

Yahoo

02-04-2025

Storms are starting to ramp up in Illinois, with threats of hail, strong winds and even tornadoes forecast throughout the week.
The Weather Company, a global climate forecaster, warns Illinois residents about believing everything they read online as they prepare for incoming storms. One of the company's meteorologists, Jonathan Belles, debunked some of the most common falsehoods surrounding severe storms, recommending tips on how to best prepare for them.
Here's what he said.
Belles said the commonly referred to "tornado season" is a misnomer, as tornadoes can occur at any point throughout the year.
"Many states can have tornadoes in all months," Belles explained. "We obviously have a bigger peak in May ... generally from March through June. But parts of the South have tornadoes in the middle of winter as well."
He said you should be prepared year round, without waiting for March, April or May. He also said tornadoes are moving North as temperatures rise worldwide, crossing through places like North Dakota in the winter.
Though Illinois' tornado season is thought to primarily take place between April and June, the state has historically been hit by tornadoes outside of this range. For example, Illinois experienced numerous tornadoes between February and August in 2024, with one hitting as late as October 30, according to National Oceanic and Atmospheric Administration data collected by the Marion Star.
Belles said green skies do not indicate an incoming tornado, but rather show that the clouds overhead are full of moisture. Such clouds have the potential to produce rain, hail or severe storms but do not directly correlate with tornadoes.
Belles warned against hiding under overpasses during severe storms, saying it can cause more harm than good during hail storms, tornadoes or strong winds.
"Basically all you're doing is taking up space for people behind you," he said. "A lot of it becomes a traffic jam, and people get stuck behind you, out into the hail and out into the storm. So it might help a dozen people, but you may have hundreds behind you that are getting smashed with hail, and that (can lead) to some injuries."
He also warned that those hiding under an overpass can get sucked out from under it by a tornado or strong winds.
Others are reading: What to know about tornado sirens, alerts and terminology ahead of Illinois storm season
Though many Chicagoans may believe they're safe amidst the large mass of skyscrapers and highrises, Belles said the notion that tornadoes don't strike cities is "completely false."
"Here in Atlanta, we had a tornado run right through downtown a number of years back," he said. "And there's been several instances where Nashville or Memphis — I could probably name any bigger city of the last 50 to 100 years — has had some interaction with a tornado. And there in Chicago, a lot of times they'll be coming west through the city and run into the lake."
The National Weather Service found that 92 significant tornadoes (meaning tornadoes that caused fatalities, injured at least 10 people or were rated F2/EF2 or greater) struck the Chicago metro area between 1855 and 2008.
Belles said lightning does not shy away from striking the same spots twice — especially when it comes to metal objects and tall buildings.
"They're going to strike the closest object to the sky most times, which is generally a skyscraper, but could be farm equipment, could be a tree, just whatever the highest object is in the vicinity," he said. "So it'll be kind of the easiest spot for lightning to hit once or twice or three times. And you'll often see the Statue of Liberty will get hit several times during a thunderstorm."
Belles said this also applies to humans.
"If you are the tallest object, say, in the field or whatnot, it can also be you," he explained. "Where people get struck seems to be more males, often playing golf or some other sport outside, once or in very rare cases, a couple times."
Story continues after photo gallery.
Belles said mountains can tear up tornadoes or storm clouds but will not stop them.
"Especially as we go into the summer, you'll often see small lines go from the plane all the way to the east coast without really batting an eye as they're going over mountains," he explained. "We've definitely had tornadoes on top of mountains before."
As for bodies of water, such as Lake Michigan or the Gulf of America, Belles said the storm simply changes its name from "tornado" to "water spout" as it moves from land. These storms are typically stronger on land due to the increased heat, but can be dangerous regardless of location, according to Belles.
"Don't let your guard down if you're near a body of water or a mountain," he said. "Tornadoes are definitely possible just about anywhere."
Belles said this claim is also "completely false."
"Tornadoes often train," he said. "And by that, I mean they kind of act like a train car, where one after the next, they'll come through a community, usually a mile or two to the left or right. But it's definitely possible to get tornadoes to hit the same place twice."
For example, the same spot in Mississippi was hit by two tornadoes within 41 minutes of each other on March 15, according to the Weather Channel.
Belles said the best thing to do to prepare for a severe storm is to figure out a plan with your family and friends, coming up with a safe room located in the most interior part of your home. He recommended choosing a secondary room located higher up if you're aware of frequent flooding in your area.
"Also, have a storm kit in there, something with power," he said. "Have a helmet or two or one for each member of your family, and make sure there's an extra pair of shoes in there. ... If the power does go out, make sure you have some non-electronic entertainment for you and the kids. Those outages go on for days or weeks sometimes."
He also recommended rehearsing your plan several times with your family so that you can be best prepared when the moment comes.
Belles warned against filming tornadoes, saying that if a twister is close enough to capture on your phone's camera, you should find shelter immediately.
The National Weather Service offers additional tips for tornado preparedness on its website.
This story has been updated to add new information.
This article originally appeared on Journal Star: Are cities safe from tornadoes? What to know about most common storm myths