The National Weather Service says there is uncertainty about Tuesday’s storms, which could produce severe weather including large hail and tornadoes in Illinois.
The National Weather Service (NWS) said showers will increase in coverage Monday evening with a few thunderstorms possible.
A few of the storms may be strong enough to produce small hail. A warm front will move across the area Tuesday.
Temperatures will warm well into the 70s south of the front with cooler temperatures in the 50s north of the front, the NWS said.
Temperatures may hold in the 40s all day near Lake Michigan.
Scattered thunderstorms are possible Tuesday afternoon through Wednesday morning. “Any storms that occur may become severe,” the weather service said, adding that “all modes of severe weather are possible.”
A hazardous weather outlook was activated Monday afternoon for the Chicago area, including Lake and McHenry counties.
The NWS said there is a “considerable amount of uncertainty” that exists in whether storms will even develop Tuesday.
“If storms do form, a few would have the potential to produce destructive hail and tornadoes, some of which could cause extensive damage,” the NWS said.
If severe weather materializes, it could occur between 4-10 p.m.
“While the atmosphere will be supportive of severe storms, the presence of a layer of warm air aloft, known as a cap, may prevent storms from developing in our area altogether,” the NWS said.
Southerly winds may gust to 40 mph Tuesday evening and westerly winds may gust as high as 50 mph on Wednesday.
A cold front will then move across the area Wednesday morning.
Dry and cooler weather is expected Wednesday evening through Friday.