Minor accumulating snowfall Friday night - Little snowfall Sunday

The closer we've gotten to the weekend the weather picture has become a little more clear.  Unfortunately for all you snow lovers you'll have to take a trip up north this weekend if you want to get any big snow.

Before we get into the weekend I do want to talk about the weather for this evening and overnight.  A fairly strong upper level low is currently producing light to moderate snowfall in eastern South Dakota.  By midnight tonight that low will be near the Iowa/Minnesota border and by Saturday morning shifting towards southwest Wisconsin.  As night falls temperatures will drop as colder air moves in aloft.  At the same time this occurs another weak surface low looks to develop in central Illinois and quickly race northeast by Saturday morning.  While a rain/snow mix is expected to occur late this evening and overnight I truly wouldn't be surprised if there was accumulating snowfall by Saturday morning, maybe an inch or two across southern Wisconsin and northwest Illinois.  If this does occur roads late tonight and Saturday morning will be slick.  So be careful!  After that system moves out Saturday afternoon we should remain quiet until Saturday night.

Going into this weekend is a perfect example of why we don't put all our eggs in one basket, or weather model for that matter.  As I talked about in previous posts warm air feeding into the system initially could cut back snowfall totals significantly and it looks like that may be the case here.  I'm not even 100% sure we'll see substantial rainfall from this either.  The morning model runs haven't really changed from last night as they still bring warm air into northern Illinois by Sunday morning.  There are two branches of the jet stream at work going into the weekend:  the northern branch and the southern branch.  If these two branches were to come together this would mean a bigger storm system rather.  Right now, it doesn't look like that is going to occur and there will be two seperate lows forming in each branch.  This will keep any significant snowfall in Wisconsin back through Minnesota where half a foot of snow, or more, may fall by Sunday night.  Winter Storm Watches have been issued for parts of the Midwest in anticipation of heavy snowfall this weekend.  For us, depending on when and how quickly the cold air moves in Sunday afternoon/evening will determine just how much, if any, snowfall we receive.  I'm not completely ready to throw in the towel just yet on any snow for Sunday because I want to wait to see how well the evening runs come in.  These will have had a whole days worth to sample the storm system in question.  But as of right now it looks like the bulk of precipitation will fall as rain with maybe a couple slushy inches on the backside.