A severe thunderstorm warning and flood watch remains in effect for northwestern Cook, northwestern, south-central McHenry and Kane counties.
Trained spotters reported baseball sized hail and damaging winds near Huntley originating from these isolated but strong storm cells.
The storm could cause people and animals in the outdoors to be severely injured; the storm may shatter windows and cause damage to roof, siding and vehicles according to the National Weather Service.
Runoff from excessive rainfall could flooding in northern Kane county and northwestern Cook county.
Authorities recommend moving to to a shelter, inside a building and to stay away from windows.
For the latest radar, forecasts and conditions contact the Chicago Weather Center.