Here We Go...

Let's get right to this.

The computer models have now nudged the track of the low north again, right over Chicago, where they had it tracking early yesterday.

 

There's good news and bad news if you live in the Madison/New Glarus area.

Good: heavy snow stays to our north.  The Green Bay/Fox Valley area should get the brunt, and the heaviest totals will extend back toward Tomah.  Confidence level here is about 80%.

Bad: as temperatures fall to and below the freezing mark, there's a better chance now that we will see freezing rain and/or sleet in our area.  That mixed pre-slopitation will change to all snow as the low moves away Thursday morning.  Confidence level here is about 60%.

So, the question becomes: when will our temperatures fall to freezing, and will the ice stick?  Let's walk through the day tomorrow....

We'll have periods of rain throughout the day tomorrow (possibly even some rumbles of thunder).  Temperatures will struggle to get out of the 30s.  Wind will pick up throughout the day as the low gets closer.  Persistent northeast wind will lower temperatures slowly, until we finally hit the freezing mark sometime between midnight and 3am tomorrow night/Thursday morning.  Rain will continue fall, but will freeze on some surfaces on contact.  How much ice accumulations will depend on: 1) how quickly surfaces cool after a warm day today; 2) how heavy the rain gets, and 3) whether trucks get out and apply salt. 

Here's how the models see temperatures in our area at midnight:

The low will start to pull away mid-morning on Thursday, and at that time, precipitation should change to all snow.  I'm thinking about a 6-hour period of snow, falling at an average rate of a half inch an hour, giving us about 3 inches of total snow.

That's not much, unless it's falling on top of ice.  Personally, I think the roads will take some time to cool, so I'm not expecting much ice accumulation, if any.  But it's worth watching.

For my friends to the north, I think the highest totals will be in the 10-14" range, with the highest amounts WSW of Green Bay.  Slightly closer to home, areas about 50-70 miles north of Madison could see some brief thunder snow, which could cause locally higher amounts.

The fresh model runs look like this.  The highest totals are overstated, but the locations of the heaviest snow seem to be spot-on.

The main concern in south-central Wisconsin will be road conditions on Thursday morning.  Let's all take the responsibility to share what we're seeing/hearing via social media.

I'll update forecasts tomorrow if anything changes!