A Red Flag Warning means that critical fire weather conditions are either occurring now, or will shortly. A combination of strong winds, low relative humidity, and warm temperatures can contribute to extreme fire behavior.

The National Weather Service in Chicago has issued a Red Flag Warning, which is in effect from noon today to 6 PM CST this evening. * Affected Area...Boone, McHenry, Kane, DuPage, Kendall, Grundy, Will, Kankakee, Iroquois and Ford. * Timing...This afternoon. * Winds...South 15 to 20 mph with gusts up to 35 mph. * Relative Humidity...As low as 18 TO 25 percent. * Impacts...Dry fuels, low relative humidity, and strong winds will create conditions favorable for the rapid spread of wildfires.