It will be the week that Minnesotans remember this winter.

A major polar vortex outbreak will likely hit Minnesota and much of the eastern U.S. next week. The massive upper-air low-pressure system is forecast to drive bitterly cold arctic air deep into the continent next week.

NOAA GFS model 500-millibar height anomalies January 29-30 via tropical tidbits.

Extreme cold

Yes, it's cold out there now. But this will feel like a walk in the park compared to next week. Temperatures next Tuesday through Thursday could run 20 to 50 degrees colder than average across the Midwest and Great Lakes.

20s below for MSP?

Models from the National Oceanic and Atmospheric Administration Global Forecast System and the European Centre for Medium-Range Weather Forecasts are cranking out temperatures colder than 20 below for the Twin Cities next Wednesday and Thursday morning.

Some models suggest temperatures will not rise above zero Monday night until Friday afternoon.

It's getting harder to get to 20 below at Minneapolis−Saint Paul International Airport. But the magnitude of this inbound air mass seems to have the capability to make a serious run at 20 below for the Twin Cities.

NOAA via Weather Bell.

Sunday night snow

A low-pressure system Sunday into Monday favors heavy snow from southwestern Minnesota into northern Iowa. Current forecast models storm tracks keep the Twin Cities on the northeast edge of the snow shield.

NOAA GFS model Sunday into Monday via tropical tidbits.

With plenty of arctic air in place, this looks like a very efficient snow maker. Snow to water ratios could go to 15:1 or even 20:1 in some areas.

That means snow could pile up quickly in southern Minnesota. Snowfall totals from 6 inches to a foot or more seem quite possible in southern Minnesota and northern Iowa.

NOAA GFS snowfall output via pivotal weather.

Stay tuned for possible track changes.