WHAT A DIFFERENCE A WEEK MAKES...
We've seen some big changes in the weather around the Midwest recently featuring the addition of both cold and snow. Here's the U.S. snow cover Dec 1st. Only 9% of the country was covered with the average depth 0.7"
As of December 26th snow cover nationally had increased to 46%, most of it coming during the past week. The average snow depth is 2.8".
Temperatures for most of December have averaged well above normal.
However, the MJO (Madden Julien Oscillation) is now in phase 8 allowing cold air to plunge into the country.
Notice the difference in the temperature departures the past 7 days.
The cold deepens over the next week. 5 day temperature departures through December 31st look like this.
5-10 day departures over the Midwest are really brutal Dec 31st through January 5th
As far as snow goes, there will be some of that between now and the new year but there is little consistency between models on track, intensity, and amounts. The first disturbance to bring snow is set to arrive in my area late Wednesday night departing Thursday morning. The latest trends have been to push the heavier amounts north and that seems correct. Even where the snow is heaviest most amounts should come in around 2 to maybe 3" up in Minnesota and Wisconsin.
This will be a fluffy snow with minimal moisture content. Snow ratios will be up around 20:1 meaning 0.10" moisture would bring 2" of snow. In my area the heaviest amounts of 1-2" will occur along and north of HWY 20. South of that line amounts will taper off to an inch near HWY 30 and not much more than a dusting south of 1-80. We'll do some fine tuning later Wednesday. For now here is the latest snow forecast from the GFS. This is not looking like much more than a nuisance for most of my area.
Here's the GFS regional perspective of the Midwest.
Another disturbance is possible late Friday or Saturday but it appears the brunt of that system will stay just southwest of my area. Here's the total snowfall from both systems. I don't know what it is about me and snow but as you can see it always goes around me. I know I'm whining but I just can't catch a break when it comes to the white gold. Someday!
That's all I've got for now. Stay warm and stay positive. Roll weather...TS