UpdateJanuary 22nd, 2013 at 1:43 pm by Chad Evans under Chad's WLFI Weather Blog
Weak clipper is passing to our southwest right now. A quick snowfall of up to 1.5″ in a narrow band will occur from eastern Missouri to western Kentucky.
As for us, weak clipper to our northwest will pass tonight with few flurries & snow showers. A light dusting is possible in a few places.
Another weak clipper looks to pass tomorrow. 1″ or less of accumulation is possible late morning-afternoon in the viewing area.
Accumulating snowfall still looks likely late, late Thursday to Thursday night & Friday morning. I still like 3-6″, but I cannot tell you who’s getting 3″, who’s getting 3.5″, 4″, 5″ or even 6″ of snowfall. Those details are unclear. However, right now it still looks like the heaviest snowfall from the event would be east of here. I am thinking of taking out any mention of mix, as 0C line at 850 mb (about 5,000′) is generally setting up south of here.
Below is suggested model guidance with some numbers I pasted based on my thinking of the snow being 18:1 ratio, good dynamics, frontagenic forcing & baroclinically-induced low-level jet taking hold. The second graphic is actually the NAM model, showing where it thinks the heaviest snowfall will be. Its performance is better now & pretty much in line with GFS, European & NOGAPS.
Given forcing, 18:1 ratio looks good given efficient dendrite (flake) production likely.