Watching the weekend

We've been focused on what's going to happen with the weather the week of Christmas, but there are a few things we need to look at for the weekend.  The southern branch of the jet stream stays pretty active keeping the majority of storms along the Gulf and out east.

Further north, though, weak subtle low pressure systems will move through the northern branch of the jet stream and could bring us a little wintry weather through Sunday.  Moisture remains limited, but as we've seen in the past few days even the weakest lift in the atmosphere can produce some very light precipitation.  The first of those waves was north in Minnesota and Wisconsin Friday morning and did bring very light drizzle/flurries to the Stateline between 3am and 5:30am.  The next wave that swings through will be early Saturday and then again Saturday night.  Flurries are possible under cloudy skies Saturday morning, but as temperatures begin to warm Saturday night freezing drizzle will be possible.  Temperatures at the surface will remain below freezing, but aloft we'll be warming.  While it's not going to be much, it could be just enough to cause some slick spots.  Throughout the day Sunday, warm air will continue to be pumped into northern Illinois and southern Wisconsin.  Temperatures will warm, but again, we could be dealing with drizzle or even freezing drizzle through Sunday night.  By Monday, there will be enough warm air in place to keep the majority of precipitation all rain before a changeover to light snow late Tuesday and Wednesday.