CHICAGO (CBS) — A flash flood watch is in effect through Thursday morning for southern counties in the area, including Kankakee County in Illinois and Lake and Porter counties in Indiana.

Counties shown in green are in a flash flood watch through Thursday morning.

Rainfall rates of 1.5 inches to 2 inches per hour are possible as rain moves in from the south.

Localized flash flooding is possible in the watch area.

Warm and humid air south of the front will continue to creep closer.

At the same time, high pressure to the north is feeding in a northeasterly wind, pulling in cool, stable air.

Expect rain to increase through the night and fog to linger near the lakeside.

Forecast:

Wednesday night: Fog lakeside, rain increases through the night, heaviest south of I-80

Thursday: Morning leftover showers. High 74

Friday: Partly cloudy, rain at night. High 79

Saturday: Scattered storms. High 84

Sunday: Scattered storms. High 83

Mary Kay Kleist