CHICAGO (STMW) –– The National Weather Service has issued a dense fog warning for Lake and Cook Counties Friday evening.

The advisory will remain in effect until 9 a.m. Saturday, and the weather service warns that the fog could reduce visibility to under a quarter mile. Though rain showers forecasted for Friday night could briefly clear the fog, it could “quickly return and persist through the night,” the weather service said.

And on the topic of showers, the weather service says thunderstorms are moving northeast toward the Chicago area and northwest Indiana, and that it could bring brief heavy downpours, funnel clouds, winds of more than 40 miles per hour, and hail that could reach the size of quarters.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2012. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)