After a spell of rain and cooler weather, high temperatures will roll across Chicago and the suburbs later this week.
Dangerously high heat and humidity are forecast for Wednesday and Thursday, with the National Weather Service issuing a extreme heat watch early Monday morning. A heat watch indicates that the weather is right for high heat to effect the Chicago area, but is not yet occurring.
This pattern of cold weather followed by warmer temperatures is a common occurrence in the Midwest at this point of summer, National Weather Service senior meteorologist Brett Borchardt said. The potential combination of high heat and humidity along with warm overnight temperatures creates concern about heat-related illnesses, he said.
“Even though we get heat waves every year, and we’ve already had a heat wave this year, it’s good not to let your guard down, just to practice those safety tips (of) limiting time outdoors, staying hydrated, even if you don’t think you need water, just continuously drinking water and fluids and checking in on neighbors and loved ones, especially those who may be vulnerable without air conditioning,” Borchardt said.
Wednesday night into Thursday morning may be the most dangerous time of the heat wave because it is harder to stay cool during the higher temperatures.
“A lot of people focus on the highest temperature or the heat index during the day, but it’s those warm overnight, low temperatures that can be really dangerous, because their bodies can’t cool off,” Borchardt said.
A cold front is expected to return at the end of the week, which could aid in creating the right conditions for thunderstorms. While the radar currently shows the bad weather staying north in Wisconsin, Borchardt said the possibility of potential rain and thunderstorms still exists.
The amount of humidity in the atmosphere could make the potential thunderstorms strong or severe throughout the entirety of the week as well, creating a “pick your poison” scenario between a continued heat wave and storms, he added.
“Temperatures should let up just a little bit, and that is when we are expecting at least a higher chance of thunderstorms once we get toward the end of the week,” Borchardt said. “Now, if for whatever reason those storms don’t materialize, the dangerous heat could very well extend into Friday, but we see a better signal for storms by then, which should suppress the heat.”
The National Weather Service will update the heat watch to a heat advisory or a extreme heat warning should the high temperatures and humidity occur.
