The National Weather Service's flood watch for Cook, DuPage and Kane counties, and virtually the entire Chicago area, is scheduled to expire at 4 a.m. Wednesday, Jan. 30.
Showers and thunderstorms spread across Northern Illinois and Northwest Indiana Tuesday afternoon, with rain persisting through the evening. Precipitation of 1.5 to 2 inches was predicted, with some areas receiving more.
"Much of the area continues to have frozen ground, with only the top few inches of soil having thawed," according to the weather service. "(This) could lead to a majority of the rainfall becoming runoff and resulting in a rapid rise to area streams and rivers."
DuPage County issued the following statement Tuesday afternoon:
"DuPage County Stormwater Management is anticipating activation of the County’s flood control facilities early Wednesday morning based on forecasted precipitation.
The National Weather Service estimates rainfall totals could reach up to 1.75 inches throughout the area late Tuesday into early Wednesday. If rainfall meets or exceeds forecasted amounts, the County projects the precipitation would trigger operation of the DuPage County flood control facilities.
DuPage County Stormwater Management operates 15 flood control facilities throughout the County with a total floodwater storage capacity of nearly 4 billion gallons. Areas protected by the facilities should not expect flooding. Elsewhere, based on current forecasts, the County expects overbank flooding to be minor and contained to low-lying areas.
During storm events, Stormwater Management staff monitors real-time stream and rain gage information, which is available to the public at ec.dupageco.org/dec/stormwater/watershed/index.html.
Temperatures will begin dropping in the early morning hours Wednesday, reaching the mid-30s by noon. The rain is then expected to turn to snow for the rest of the day, tapering off around midnight.
On Thursday, expect a high 18 degrees under mostly cloudy skies; overnight low 5 degrees.
On Friday, temperatures are expected to hold steady at about 18 degrees day and night.
A slight warmup is coming Saturday, with a high of 29 and a low of 23 degrees, accompanied by a 30 percent chance of snow. Sunday could reach 39, with no chance of precipitation.
Expect dry, cloudy and cold conditions next week.