A tornado warning was issued for parts of Kane and DuPage counties, including the Elgin, St. Charles, Wheaton, Carol Stream and Glendale Heights areas, and tornadoes were reported in DeKalb, Kane, Lee an Bureau counties earlier Monday, the National Weather Service said.
Tornadoes were reported near the towns of Esmond, Kirkland and Sycamore in DeKalb County. Tornadoes were also reported near Maple Park and Burlington in Kane County, in Paw Paw, about 20 miles south of Rochelle in Lee County and near Arlington in Bureau County.
A line of storms from Waukegan in the northeastern part of the state down to the border of Lee and LaSalle counties was moving southeast Monday evening, Brian Leatherwood, a meteorologist with the National Weather Service, said.
He and four other meteorologists had received several reports of rotating wall clouds, funnel clouds and tornadoes as of 6:30 p.m. Monday, Leatherwood said.
“These tornadoes are really low and very small in nature so that’s making it a little bit difficult,” Leatherwood said. “But they seem to be pretty widespread with all the reports that are occurring at this moment.”
The warnings came after a tornado watch was issued earlier Monday afternoon through 10 p.m. for Cook County and several other counties in northeastern and north-central Illinois and parts of northwest Indiana.
The Illinois counties included Boone, Bureau, Cook, DeKalb, DuPage, Grundy, Kane, Kankakee, Kendall, Lake, LaSalle, Lee, McHenry, Ogle, Putnam, Will and Winnebago.
The Indiana counties included Jasper, Lake, Newton and Porter.
A severe thunderstorm warning was later issued for the Rockford area and east to the McHenry County line.
The tornado watch came on the eve of the one-year anniversary of a rare derecho that spawned a tornado in Chicago’s Rogers Park neighborhood, and before the watch was issued, the day had already been eventful weatherwise.
“At this moment it’s certainly not like the derecho that we had almost a year ago, but there could be some severe weather with it throughout this evening,” Leatherwood said Monday afternoon.
Some 4 to 5 inches of rain fell in Chicago’s far northwest suburbs Monday, causing “minor flooding” in ditches and low-lying areas in McHenry and Boone counties, forecasters said.
Initially the National Weather Service issued a severe thunderstorm warning for areas near Rockford and southeast toward Kirkland, which was in effect until 4:15 p.m. Wind gusts around Rockford reached 35 miles per hour, Leatherwood said. Some of those storms could “produce a tornado or two,” Leatherwood said, although the main concern was “straight line winds” that could gust up to 60 or 70 miles per hour.
“We can’t rule out a tornado in this kind of scenario so we’re just trying to keep an eye on that,” Leatherwood said.
Hail was another concern as the storms moved away from the Rockford area and toward the east and south, Leatherwood said. The hail was expected to be small, but people were advised to seek cover if necessary.
“You certainly wouldn’t want to be out in it if you’re unprotected, but I don’t think it’s going to be too dangerous,” Leatherwood said. “We’re not talking softball (size) or anything to that effect.”
Closer to the city, rain and thunderstorms were expected to mix in with heat and humidity in the Chicago area later this week, forecasters said.
Monday had a forecast high of 83 degrees, and Chicagoans were warned of muggy weather in between morning and late afternoon thunderstorms, according to Kevin Donofrio, a meteorologist with the weather service.
A high of 91 degrees Tuesday may end up feeling more like 102 with the heat index, according to the weather service’s forecast. There is also a 20% chance of rain and thunderstorms after 1 p.m. and a 60% chance of precipitation at night, according to meteorologists.
Wednesday also is expected to be hot and potentially wet, with a high of 90 degrees and a 40% chance of rain and thunderstorms during the day and a 30% chance at night. Much of the same was expected Thursday, when there’s a 40% chance of thunderstorms after 1 p.m. The day should otherwise be sunny, with a high of 90 degrees, according to the weather service.
“For people outdoors, we’re kind of in this pattern when we’re going to have breaks, then we’re going to have storms at times, so it’s good … to have your eye to the sky. Our motto here is: ‘When thunder roars, go indoors,’” Donofrio said.
The heat, humidity and rain are expected to break Friday, making for a dry weekend, with projected high temperatures below 80 degrees.
Meteorologists also planned to host a talk Tuesday to commemorate and discuss the Aug. 10, 2020, derecho that spurred dayslong power outages throughout the area and a confirmed 11 tornadoes in northern Illinois. Forecasters said the talk, which would be live on social media, may be postponed, depending on the availability of meteorologists.
For more on the forecast, visit the Tribune’s weather page.