Chicago severe weather could produce ‘very large hail, strong tornadoes’

The Chicago area will face multiple chances of severe weather this week, with all manner of hazards in play including ‘very large hail’ and ‘strong tornadoes.’

According to the Storm Prediction Center, the entire Chicago area is at risk of severe weather on Monday, Tuesday and Wednesday, with dangerous wind gusts and even localized flooding possible across the region.

While the biggest threat of severe weather won’t arrive until Tuesday, there is still a chance of strong-to-severe thunderstorms on Monday. According to the SPC, the entire Chicago area is at a ‘marginal’ risk of severe weather, the second of five levels the agency uses to determine the likelihood of storms developing.

The main risk with storms that form will be hail, though there is also a non-zero chance of dangerous wind gusts or even isolated tornadoes.

The expectation is that storms will be isolated in nature during the afternoon and become more widespread into the evening, with another line of storms potentially sweeping through overnight and moving across the city and northern suburbs.

The main areas under the gun of severe weather on Monday will be up in Minnesota and Wisconsin, including the Twin Cities, where a wide swath of the region is at an “enhanced risk” of severe weather, the third of five levels of risk used by the SPC.

That “enhanced risk” area will move Tuesday to cover a large part of the Chicago area, especially north of Interstate 80. The rest of the area is still at a “slight risk,” and the main event will likely unfold in the afternoon and then again into the evening, according to the NBC 5 Storm Team.

Warm temperatures in the low-to-mid-80s and elevated humidity, with dewpoints in the 60s, will lead to the formation of supercell thunderstorms, which could cause the formation of hail of up to two inches or more in diameter, the SPC warns.

What’s more, those supercells could lead to the formation of tornadoes, some of which could be “strong,” according to forecast models.

As the evening continues, some storms could begin to form into lines, and those could produce dangerous wind gusts or even flash flooding due to heavy rain, with widespread impacts expected late into the night.

Even as that threat passes, the Chicago area won’t be done with severe weather, as the entire area is at a “marginal” risk of severe storms, according to the SPC.

Again, the main threats will be gusty winds and large hail, though a tornado cannot be ruled out amid several rounds of showers and thunderstorms.

Things will finally start to calm down a bit on Thursday, with highs in the 70s and partly-to-mostly sunny skies, according to forecast models.

Friday could see highs in the low-80s, though there is another chance of showers and thunderstorms headed into the weekend.

Stay tuned to the NBC 5 Storm Team for all the latest weather news and information, and be sure to download the NBC Chicago app for real-time weather alerts sent directly to your phone in the event of severe weather.