Weekend snow; Polar Vortex delivers sub-zero next week

The Siberian Express has left the station, and it's heading for Minnesota.

Snow arrives this weekend, the season's first bitterly cold air mass hits home next week. If NOAA's GFS model verifies, this could be the coldest air mass to hit the Twin Cities in nearly 3 years.

First, we start with snow this weekend. Here's the breakdown on Saturday night's inbound snowfall.

The system

A developing low pressure system tracks from eastern Colorado toward Chicago this weekend. The system is moderate in strength and moisture, and will produce bands of widespread light to moderate snow over the Upper Midwest this weekend.

Timing

Light snow develops in southern Minnesota Saturday. There are still model differences in timing of snow in the Twin Cities. The Euro brings snow into the metro by around 6pm. NOAA's models favor a later onset,  likely Saturday evening with a few models holding snow off until around midnight. Either way the bulk of the steady snow arrives Saturday night with the heaviest snow overnight into Sunday morning.

Snowfall totals

This looks like a longer duration, light to moderate snow event that will add up inches over 12-18 hours. The southerly storm track near Chicago favors laying out the heaviest snow band in southern Minnesota and northern Iowa.

The I-90 corridor and northern Iowa should pick up solid 3" to 6" totals by Sunday evening. The Twin Cities seems likely destined for a 2" to 5" range, with the heaviest totals favoring the south metro. Much of central and northern Minnesota will likely get 1" to 3" snowfall totals by the time snow winds down late Sunday. If you're heading to Madison or Chicago expect to run into 4" to 8" of fresh powder.

Here's the snowfall layout from NOAA's GFS model.

Polar Vortex arrives next week

The season's first true Arctic outbreak spins south from the Arctic Circle next week. We can trace the track of this upper level vortex all the way to the North Pole. Watch the deep blue blob spin southward toward the Great Lakes next week.

The Arctic front blasts through Minnesota Monday. Temps plunge into sub-zero territory for most of next week. The second Arctic wave late next week looks even colder. It should hit -30 up north, and the GFS is cranking out -16 for the Twin Cities a week from Saturday.

If temps hit -16 at MSP Airport it will be the coldest temp in nearly 3 years since we hit -23 on January 6, 2014. We managed -14 January 17th of 2016 last winter, and -15 March 2, 2014.

Stay warm and stay tuned.