This is a clipper like system but not a real clipper as its not going up around the ridge and the sfc low diving southeast pretty quickly like a typical clipper des. Its more of the 850mb low and the track of that with the sfc low being further south moving southeast to ESE across the central plains and into MO and then KY with band of snow on the northside closer to where the 850mb low is.
sfc low track
As this sytem is getting its act together warm air advection will be taking place and running up and over the cold air causing snow to break out in a northwest to southeast oriented band streaking to the southeast along the 850mb low track and into our area by late tomorrow night with the heaviest snow falling from about 10pm to the late morning hours on saturday with possible lake enhanced/lake effect snowfall after that in the afternoon and evening.
There are things working for this system and things not working to help create a good snowfall. Its going to be a quick hitter, probably a good 12 hour period of moderate snow but the snow ratios will be around 13/14:1 which will be a powdery type. There will also be good snow growth given the depth of the DGZ. There is also could be some nice fronto banding which would aid in heavier snowfall rates.
here is an image showing the amount of lift going on in our snow system
this is a map showing the probability of the depth of the DGZ being greater than 100mb allowing for good snow growth
Another thing to watch for is a possible meso low forming out over lake michigan and even coming onshore which could enhance snowfall amounts near the lake saturday afternoon and evening. meso lows are more favorable in weak synoptic flow environments, which is what we will have on the north and northeast side of the 850mb low. The flow from surface to 800mb is weak easterly to northeasterly flow, with no significant flow above that until you get up to about 600mb.
here you can see the LSX WRF picking op on a possible meso low moving down the lake and actually comes onshore in northeast IL
as for amounts, Im still riding my 3-6" call from yesterday for area wide with heaviest near the lake due to lake enhancement/lake effect snow and guess LOT will go with a winter weather advisory for tomorrow night into saturday afternoon. here is an image of total QPF run off a hi res WRF
