Friday Night Snow in Southern Wisconsin

Deer hunters must be absolutely giddy about this.  When gun season opens Saturday morning, they'll be greeted by a fresh blanket of snow with which to track deer and keep their Busch Light cold.  

We're still a good 36 hours away from it, but there's some agreement in some computer models about southern Wisconsin's first snow event of the season.

There is significantly less agreement among forecasters about how much snow we'll get.  Forecasts still range from completely non-committal, to "light accumulations" to AccuWeather's aggressive 6-10" forecast.  Here's that map:

Officially, the National Weather Service has issued a Winter Storm Watch from 6pm Friday to 3pm Saturday.  That watch calls for snow ranging from 4 to 7 inches in extreme southern Wisconsin (Madison and Milwaukee included) and Northern Illinois.

Here's what's pretty certain:

• Low pressure will approach from the west late Friday
• It'll be a pretty fast-moving system
• Temperatures will support mainly snow, as a cold pocket sets up today and tonight
• It'll drop the heaviest snow in a narrow, elongated band
• Temperatures Saturday night will be the coldest of the season (mid-teens with single digit wind chills)

What's less certain:

• Exact track of the low, although most models show the Wisconsin/Illinois border as a primary focal point
• System strength (how low the pressure gets)
• The potential for brief lake-effect snow midday Saturday along Lake Michigan (from Sheboygan to Kenosha)

Storm track is always a key ingredient in predicting how much snow will fall in any one place, but in this case, the track is particularly important.  That's because the storm is very compact.  A nudge to the north or south changes snow totals dramatically.  If it does nudge, I think it nudges south.  Here's how Mateo Earth sees it at 4:00am Saturday morning...

Here are my early projections for snow fall, starting 6pm Friday and ending Noon Saturday:

Wisconsin Dells:  1-2"
Madison:  5"
New Glarus:  6-7"
Milwaukee:  7" (possibly more at the lakeshore)

Updates to come, especially if the track fluctuates!