The National Weather Service has expanded the Winter Weather Advisory that includes the Tri-Cities and Thumb southward into Genesee, Shiawasse, and Lapeer counties.
The precipitation will likely start as light snow along the I-69 corridor after 9pm, then quickly change to freezing rain.
Although temperatures south of I-69 may briefly be warm enough to support plain rain at times during the overnight, colder air will move back into the area by sunrise causing a change-over to freezing rain.
If you can avoid travel tomorrow morning, that's probably the best option.
If you must hit the roadways, allow plenty of extra time to get to your destination and drive with extreme caution.
For more information on the updated advisory, click here.