The National Weather Service has issued a winter weather advisory until 6 p.m. today for portions of central and east central Missouri and south central and southwest Illinois. It will be the first snow of winter for those in the St. Louis area.

Forecasters expect up to an inch of snow with wind gusts as high as 30 miles an hour.

Road conditions are expected to be slippery and could impact the morning and evening commute. The rapid fall of temperatures into the 20s could result in a flash freeze of untreated roads and other surfaces, especially in areas north and west of St. Louis.

Drivers should plan for a slower than normal trip and should be especially alert when approaching bridges, overpasses and curves.

The counties expected to be affected include St. Louis County, St. Louis city, Jefferson, Madison, St. Charles, Lincoln, Franklin, Gasconade, Montgomery, Bond, Monroe, Osage, Calhoun, Macoupin, Jersey, Greene and Warren.

In Missouri, the latest road conditions can be obtained at  traveler.modot.org/map/ or by calling 1-888-275-6636. In Illinois, the latest road conditions can be obtained at www.gettingaroundillinois.com.