With showers and thunderstorms moving into the Chicago area from two different directions, forecasters are warning that heavy downpours and dangerous lightning are possible throughout the region.
A severe thunderstorm warning issued for parts of Cook County in Illinois and Lake County in northwest Indiana until 5:15 p.m. has been allowed to expire.
An earlier severe thunderstorm warning issued for parts of McHenry, Lake, Kane and Cook counties until 3:45 p.m. was also allowed to expire.
The storms were packing wind gusts of up to 60 miles per hour and quarter-sized hail, according to the National Weather Service, but have since weakened.
Lines of thunderstorms are moving into northern Illinois from Wisconsin, traveling toward the southeast at just 10 miles per hour, and more storms are firing up in central Illinois and moving toward the northeast, according to doppler radar.
The storms are expected to persist throughout the afternoon, with lightning, heavy downpours, gusty winds and small hail possible with the converging weather systems.
The weather pattern is conducive to heavy rains and thunderstorms due to the instability of the atmosphere. High dew points, coupled with high temperatures, are leading to heat indices in the mid-to-upper 90s in some locations, providing plenty of fuel for slow-moving thunderstorms to dump large amounts of rain on some already-saturated areas.
High temperatures, and the chance of rain, are still in the forecast for the remainder of the work week, with highs expected to stay in the mid-to-upper 80s.