Suburban counties across the Chicago area are being advised to brace for thunderstorms Tuesday.

The weather service issued a severe thunderstorm watch about 6:15 a.m. for several counties in the southern, western and southwestern suburbs. The thunderstorm watch is in effect until 3 p.m., the weather service said.

Heavy rains and quarter-sized hail could rain down on the area, the weather service said, with winds reaching up to gusts of up to 70 mph. An “isolated tornado” is also a possibility.

Temperatures in the Chicago area are expected to peak at about 85 degrees Tuesday before dropping to a low of about 67 degrees at night, the weather service said. The rains could continue into Wednesday, but are expected to taper off by the following day.