Climatology

Flooding events becoming a dangerous trend in the Midwest

PEORIA (Heart of Illinois ABC) – Many residents around St. Louis continues to clean up after 7 to 12 inches of rain fell earlier this week. The daily rainfall record in St. Louis was broken in just 6 hours. If it can happen there, it can happen here.

Ed Shimon, National Weather Service Warning Coordination Meteorologist, said “Flash flood events are going to occur across central Illinois in the future, and some of them could be as bad as what happened in St. Louis.”

Typically, two air masses collide and where that occurs is called a front. When the front barely moves and is stuck in one area, it is called a stationary front. Along this front, thunderstorms form, and when this front is oriented west to east, storms can form along the boundary over and over again.

They’re called training thunderstorms, and they can lead to excessive rainfall like we saw in St. Louis and in Gibson City in August 2021.

Trent Ford, Illinois State Climatologist, said “You’ve got one storm that’s raining an inch an hour that moves over you in 15 20 minutes. But the next one comes right after, and the next one, and the next one. And we get this set up called training.”

Forecasting the exact location for the heavy band of rain is difficult. Shimon added, “Usually the Weather Prediction Center quantitative precipitation forecast will highlight an area with excessive rainfall potential. And usually it’s a larger area just because of the variability that you could see in an event like this, and it can set up anywhere within a 100-200 mile area north to south.”

If that band shifted north 160 miles, it would’ve hit central Illinois, but we have already seen plenty of heavy rain events.

Ford listed, “Last year in Gibson City, 11 inches in 6 hours. Last year in June 2021, Bloomington-Normal especially south between Bloomington and Heyworth got 10 inches in 3 days. Peoria, the city of, got 6 inches in 6 hours in July of 2020. The summer of 2020 is when you all got half your rain in about a 6 hour period of time.”

The frequency and intensity of these heavy rain events are increasing, and all communities in Illinois are vulnerable. For climatological records, a heavy rain event is categorized when 2+ inches of rain fall within a 24 hour period. Over the past 50-70 years, there has been a 30-50% increase in heavy rain events in the Midwest and the Northeast.

Because heavy rain events commonly lead to flash flooding, it is important to be prepared and plan ahead for a sudden flash flooding event. You can have a safety kit and non-perishable food stored in a waterproof bag. You can also store extra water in your cars and homes, and be sure to turn on emergency alerts on your devices.

There has been one fatality so far in central Illinois (NWS Lincoln forecast area) due to weather, and it was from a flash flooding event in Shelbyville. Remember to never drive through flooded roadways or walk through flooded areas.

If a Flash Flood Emergency alert comes on your phone, you should treat it similarly to a tornado warning. This alert is reserved for extremely dangerous and life-threatening situations related to flash flooding.

Copyright 2022 Heart of Illinois ABC. All rights reserved.

.

Related Articles

Leave a Reply

Your email address will not be published.

Back to top button