Chicago weather today includes flash flooding possibility as strong storms with heavy rain move through

CBS News

3 days ago

A Flood Watch has been issued for the Chicago area as a line of thunderstorm races east, bringing heavy lightning and torrential rainfall.
There is a threat of flash flooding with these storms that originated to the west and are moving east-northeast at about 25 miles per hour. This round of thunderstorms will be followed by another round of less severe, but equally rainy, storms Wednesday afternoon, with rain continuing overnight and into Thursday morning.
A Flood Watch is in effect for Boone, Cook, DeKalb, DuPage, Will, Grundy, Kane, Kendall, Kankakee, La Salle, Lake, Livingston and McHenry counties in Illinois and Benton, Jasper, Lake, Newton and Porter counties in Indiana until 1 p.m. Thursday.
A Flood Advisory is in effect for Grundy, Kankakee, Livingston and Will counties until 3:45 p.m.
The first line of storms, that developed to the west around 11 a.m., have brought torrential rainfall and a huge amount of lightning, with over 300 strikes recorded around noon in one cell alone. Lightning frequency is measured in 10 minute increments, so that means that cell is producing around 30 strikes per minute or one lightning strike every other second. The storms also have the potential for wind gusts over 40 miles per hour.
See the latest 7-day forecast from our First Alert Weather team
The path of the first round of storms has changed slightly, riding a boundary of higher atmospheric energy from Channahon to Park Forest, so the worst of the storm is now excepted to stay south of the city of Chicago.
After these storms have left the area, another round of storms is expected to develop. They are not expected to be severe in a widespread way, but could be stronger along the I-80 corridor into Northwest Indiana. These storms are expected between 5 p.m. and 6 p.m., and will also bring heavy rain.
That rain continues overnight and into Thursday morning as a cold front arrives, breaking the oppressive heat and humidity and gives way to a much cooler and nicer weekend. Temperatures will start falling into the 70s by mid-afternoon Wednesday.
There is also a Beach Hazards Statement in place for all beaches along Lake Michigan from 1 p.m. Wednesday through 4 p.m. Friday. High waves and dangerous rip currents make the lake a hazard for boaters and swimmers alike, so it is advised to stay out of the water.
While rain will end by Thursday morning and is not forecast over the weekend for Lollapalooza, festivalgoers should plan on getting muddy if they're going to be there tomorrow.
Once the storms have passed, highs in the 70s or low 80s and sunny skies are forecast through Monday.