A winter preview is still on track to reach the Sauk Valley by the end of the work week and we'll already begin to feel those colder temperatures by this afternoon as brisk westerly winds continue. Under a partly cloudy sky temperatures will only reach the lower 40s for highs.
An area of low pressure will be moving south of the area for Thursday bringing more clouds to the area. Light rain possibly mixing with snow before ending Thursday night will become likely by the afternoon hours. Temperatures will again remain cold with highs near 40. No snow accumulation is expected with this first round.
Once this initial system departs by Friday morning, a fast-moving Alberta clipper style system will quickly work down from Iowa and bring a round of light to perhaps moderate snow by Friday evening. Some minor accumulations will be possible, especially on grassy and elevated surfaces. Pavement temperatures are expected to remain above freezing. A moderate band of snow will likely develop near the Quad Cities metro areas and quickly progress southeast. This area has the best chance at picking up a bit of accumulation, mostly under an inch. The rest of the area will likely pick up a dusting and perhaps some slushy accumulation on some less-traveled roads.
Behind this system, another reinforcing shot of cold air arrives sending temperatures plummeting into the lower 30s for the weekend with another push of cold air by early next week. With some wind around temperatures will easily only feel like the 20s during the day.