DeKalb County weather alert: Flash flood warning, severe thunderstorm watch issued

10:10 p.m. Update:

Parts of northeastern DeKalb County are under a flash flood warning effective until 3 a.m. Wednesday, according to the National Weather Service. The alert was issued around 10 p.m.

The flash flood warning is for parts of central Boone, central Winnebago, McHenry, Kane and northeastern DeKalb counties. According to the alert, doppler radar indicated another round of thunderstorms was headed to the area and had already dropped between two to five inches of rain.

Area residents and motorists should be on alert for rapid onset of flooding in small creeks and streams, urban areas with poor drainage, highways, streets and underpasses and low-lying areas.

Some locations that will experience flash flooding include Rockford, Elgin, Crystal Lake, Carpentersville, Algonquin, Lake in the Hills, McHenry, Belvidere, Woodstock, Huntley, Loves Park, Machesney Park, Roscoe, Harvard, Rockton, Marengo, Poplar Grove, Genoa, Cary and Pingree Grove.

9:15 p.m.

DeKalb County is under an areal flood advisory and a severe thunderstorm watch until early Wednesday morning, according to the National Weather Service.

The flood advisory is in effect until 12:45 a.m. Wednesday, according to the alert, while the severe thunderstorm warning remains in place until midnight.

A special alert for Kingston, Genoa and Sycamore was issued effective until 9:30 p.m. Tuesday, urging residents to seek shelter if able and be on alert for 40 mph wind and possible penny-sized hail.

Severe weather is expected to continue into the night across much of northern Illinois Tuesday. The stormy night follows a day of intense temperatures reaching nearly 100 degrees, where heat indexes were expected to reach nearly 110.

Temperatures dropped significantly Tuesday night, however, with mid-70 degree weather bringing with it high winds and rain.

Much of northern Illinois is included in the severe thunderstorm watch, including DeKalb, Kendall, McHenry, Will, Bureau, Ogle, Carroll, Kane, Lee and Whiteside counties.

The flood advisory is also expected to impact DeKalb and Kane counties, caused by excessive rainfall. Minor flooding is predicted in low-lying and poor drainage areas. Flooding is expected in the northeast side of the county, including in Sycamore and Genoa, into Kane County.