Watch the skies: June is top month for tornadoes in suburbs

It was with trepidation that Frank and Char Kozak of Schaumburg returned to Oklahoma last month for the first time since they survived a violent EF5 tornado there three years ago.

The journey, Frank Kozak said, was for a happy occasion: Char's mother's 95th birthday. But still, the couple remained glued to the Weather Channel for much of the visit.

“It's changed our lifestyle,” Kozak, a Schaumburg village trustee, said of the storm that injured both of them. A vigilant watch over the weather has become an important part of the couple's routine back home in Schaumburg.

“It's one of those things you don't wish on your worst enemy,” Frank Kozak said. “It's one of those things we can say we survived but we don't like to brag about.”

In the Chicago area, June stands out as the month with the most tornadoes, though April and August have claim to some of the deadliest.

Forty-seven of the 194 tornadoes to hit the six-county area since 1950 have been in June, including a tornado 50 years ago on Thursday that damaged homes in Arlington Heights and flattened a hangar at what was then Palwaukee Airport in Wheeling.

A look at 65 years of data from Cook, DuPage, Kane, Lake, McHenry and Will counties shows 10 tornadoes hit the area in 2015, the most since 2008.

An EF4 tornado last year in Fairdale, in DeKalb County, killed two people and was the most severe tornado in the area since the deadly EF5 tornado that struck Plainfield in August 1990, killing 29 people.

Locally, “the overall trend has been fewer violent tornadoes in recent years,” ABC 7 Meteorologist Phil Schwarz said.

In fact, less powerful EF0 or EF1 tornadoes account for 135 of the 194 tornadoes that have hit the Chicago area since 1950. The EF scale rates tornadoes on a scale of 0 to 5, with EF5 tornadoes having winds over 200 mph and causing severe damage.

After June, April had the most tornadoes, with 41 striking the area between 1950 and 2015. August had 31 and May had 27. The Chicago area hasn't seen any tornadoes in February or December, but one on Jan. 7, 2008, in Boone and McHenry counties destroyed buildings near Poplar Grove.

A tornado, or twister, is a violently rotating column of air that extends between the Earth's surface and a cloud.

The most intense tornadoes emerge from what are called supercell thunderstorms, said Danny Neal, of Plainfield, who founded the Illinois Storm Chasers with friend Adam Lucio in 2014. Those ingredients include warm moisture near the surface and relatively cold, dry air above, paired with drastic changes of wind direction and speed. Neal's team analyzes weather data several days out and heads out to areas where storms are likely, providing the National Weather Service with on-the-ground data to help give people early warnings about severe weather.

In the Chicago area, Will County has had the most tornadoes since 1950, with 60. That's followed by Cook County with 46 tornadoes, compared to DuPage County's 26, McHenry County's 23, Kane County's 22 and Lake County's 12.

Neal — whose early memories include surveying the wreckage of the Plainfield tornado with his grandfather — believes the tornadoes in Will County have to do with its distance from Lake Michigan.

“My main belief is that many tornadoes are due to the cool air from the lake moving about 40 or 50 miles away,” he says. “On that boundary between the hot and the cold air is where those storms like to form.”

The 1960s were the deadliest decade, accounting for seven of the 15 fatal tornadoes in the Chicago area.

A Palm Sunday tornado ripped through McHenry and Lake counties on April 11, 1965, killing six and injuring 75. An EF2 tornado that hit Arlington Heights on June 9, 1966, wreaked havoc on homes, as well as on Palwaukee Airport.

The Chicago area's worst tornado outbreak was on April 21, 1967. A series of tornadoes raked northeastern Illinois, three of which were EF4s.

One struck near Belvidere, wrecked hundreds of cars at the Chrysler plant, destroyed 127 homes and rolled over 12 buses loaded with students at Belvidere High School, where 13 of the 24 victims died. That tornado petered out near Woodstock.

Another hit Fox River Grove, North Barrington and Lake Zurich, killing one person and destroying about 75 homes and Seth Paine School in Lake Zurich.

The worst storm of the day formed near Route 53 and Naperville Road and bore east toward Oak Lawn, throwing 25 to 40 cars in all directions near 95th Street and Southwest Highway, hitting the high school and leveling a mobile home park.

Thirty-three people were killed, including 16 stuck in traffic and several children at a roller skating rink.

Technology has improved warnings in recent years, Schwarz says, with the development of Doppler radar allowing meteorologists to track storms as they are developing and give more advance warning.

The Kozaks' harrowing experience left them impressed with the quick response of rescuers.

“People were there in three or four minutes digging us out,” Frank Kozak said.

Upon returning to Schaumburg, Kozak said, he scrutinized the village's disaster preparedness and found “we are pretty well prepared for this type of thing, in terms of communication with residents and schools, and recovery.”

Experts say if there's a tornado warning, head for a basement and take shelter under something like a heavy table. In a building without a basement, go to the lowest floor and stay away from windows, preferably in a small room or under a stairwell. If you're outside, do your best to get away from vehicles and trees, lie face down and protect the back of your head.

Still, Schwarz said, when tornadoes hit a densely populated area, such as the one that devastated Joplin, Missouri, in 2011, “you can do everything right and it can still kill you.”

“Some of it's dumb luck ... Eventually, it will happen again.”