Two rounds of snow on the way followed by a return of arctic air this weekend

The first of two snow events arrives later tonight, I guess you could call it a one-two punch!

Winter Weather Advisory (purple area on map) in effect late tonight through Thursday morning for all of northwest Wisconsin and for parts of east-central Minnesota.

Some cities included in the advisory: Duluth, Cloquet, Hill City, Aitkin, Brainerd, Moose Lake, Hinckley, Superior, Bayfield, Ashland, Grantsburg, Minong, Shell Lake, Spooner and Hayward.

Plan on slippery road conditions and reduced visibilities due to snow. The hazardous conditions could impact the Thursday morning commute.

Source: https://www.weather.gov/dlh/

Here’s the 18z NAM-WRF model radar forecast valid from 8 PM this evening to Midnight Thursday night.

-Snow develops this evening while it spreads east-northeast into portions of the Northland (blue colors on map)

-Snow tapers off from west to east late Thursday morning into Thursday afternoon.

-As the system snow moves away, ENE winds blowing across Lake Superior may cause lake effect snow showers to develop near Lake Superior, and these lake effect snow showers could impact the city of Duluth late Thursday afternoon into Thursday evening.

Source: https://weathermodels.com/

There is a lot of cold/dry air in place so it will take a while for the atmosphere to saturate enough before it starts to snow tonight, and with so much cold/dry air, it’s possible will see the main snow band (4-6″ zone) setup a little farther south from where I have it on my forecast map, with that said snow to liquid ratios should be rather high with tonight’s event meaning it won’t take much QPF to fluff up to a few inches of snow with ratios forecast to be around 18:1 to 22:1 per model guidance.

Here’s my snowfall forecast for event number 1 – Snow totals listed below are through 1 PM Thursday.

18z NAM model showing the two snow systems nicely on the vorticity forecast valid through 6 AM Saturday. Source: https://www.tropicaltidbits.com/

Note the dips in the solid black lines as they cross Minnesota, as those dips move overhead it creates lift in the atmosphere which results in some snow.

Here are the storm track forecasts for Thursday and Friday.

System one takes more of a southerly track with system two tracking farther north.

Source: https://www.wpc.ncep.noaa.gov/

Low temperature forecast for Thursday morning, December 12. Source: https://graphical.weather.gov/

High temperature forecast for Thursday, December 12.

There is one hell of a pool of frigid arctic air which is forecast to spill south/east out of northern Canada next week, but how far south this airmass spreads is very uncertain right now.

Model mayhem for next week. The area outlined in black indicates where the greatest uncertainty is regarding the temperature forecast for next week.

The Euro ensemble model keeps the brunt of the frigid air north of Minnesota next week.

European ensemble forecast for next week. Source: https://weathermodels.com/

GFS ensemble model has at least some of the frigid air spilling south into the Northern Plains, upper Midwest and Great Lakes next week.

GFS ensemble forecast for next week. Source: https://www.tropicaltidbits.com/

Note: On Tuesday, high temperatures at Hibbing and Brainerd, Minnesota ranked in the top 5 coldest maximum temperature on record for December 10th.

Forecast for Duluth and Superior

*Winter Weather Advisory 10 PM this evening to Noon Thursday*

.Tonight… Increasing cloudiness. Snow developing between 11 PM and 1 AM. Low 0 to 5 below. Wind west around 10 mph becoming east late.

.Thursday… Occasional snow. Accumulations of 2 to 4 inches possible. High 17 to 22. Wind east to northeast 10 to 15 mph.

.Friday… Snow possible. Mostly cloudy. High 20 to 25. Wind southeast 10 to 15 mph.

Thanks for reading!

Tim