Chicago weather remains unsettled heading into the weekend, with the possibility of more severe storms Friday that could produce flash flooding and even a brief tornado.

A tornado watch has been issued until 11 p.m. Friday for Cook County and most of northern Illinois. Strong storms are expected to hit the Chicago area between 8 p.m. and midnight, the National Weather Service said.

Potentially dangerous storms accompanied by damaging winds and hail were possible in the Chicago area on Friday night.