Mild start to the week; then snow; then c-c-c-cold

This week is going to kick off with a couple mild days.

Southerly flow and a warm front set to cross the state today will warm our temperatures well above average. Highs this afternoon should range from the low 30s in the far north to the low and maybe mid 40s in southwestern Minnesota behind the warm front.

The Twin Cities should reach about 40 Monday afternoon.

Dec 18 - Mon fcst map
Forecast surface weather map for Monday. NOAA Weather Prediction Center

As shown on the forecast map, some snow is likely in northern Minnesota today. Accumulations of a couple inches are likely near Canada and in the higher ground inland from Lake Superior.

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This morning the National Weather Service has added a winter weather advisory from North Dakota into Kittson, Rosseau and Marshall Counties in the northwestern corner of Minnesota. A mixture of sleet and freezing rain is moving into that area this morning and will change to snow for this afternoon.

Dec 18 adv
Winter weather advisory until 3 p.m. Monday for sleet and freezing rain changing to snow. Grand Forks National Weather Service

Sunshine Tuesday!

After all the recent overcast skies, some sunshine will be welcome Tuesday. Expect high temperatures in the 20s across the north, 30s in the middle and low 40s in southern Minnesota.

Let's melt some ice

Two days of mild temperatures and a bit of sun should clear up some of the ice lingering in parking lots.

A weak weather system for Wednesday

Light to possibly moderate snow should spread across about the northern half of Minnesota on Wednesday and Wednesday night. The Twin Cities could be near the southern edge of accumulating snow.

An actual storm?

This winter has brought most of us little snow so far. The weather disturbances that have crossed the state have been weak Alberta clippers from the northwest with unimpressive dynamics. Real winter storms have been absent.

That pattern will change later this week as a stronger system approaches from the west. This storm should affect mainly the southern half of Minnesota with shovelable and plowable snowfalls. Heaviest amounts of several inches or more are likely for southern Minnesota north to about the Twin Cities area.

Lesser amounts should fall farther north across central Minnesota and north to Duluth and northwestern Wisconsin. As always, this is just a preliminary forecast. The track probably will need to be adjusted before the storm arrives.

Dec 18 - mpx wx story
Snow outlook from Wednesday through early Friday. Twin Cities National Weather Service

Arctic outlook

A very lengthy period of very cold weather will arrive from Canada after the snow departs. The thermal downturn will bring us a very chilly weekend. On Sunday, Christmas Eve, the Twin Cities could easily have a high temperature just in the single digits.

Then the really cold air will arrive. Parts of Minnesota are likely to remain below zero, night and day, all of next week and into January.

One forecast for next Tuesday, December 26, hints at widespread cold daytime temperatures:

Dec 18 - GFS fcst temps 3P Tue 26
GFS model forecast temperatures and winds for 3 p.m. Tuesday, December 26. NOAA/College of DuPage

Note the 3 p.m. forecasts of temperatures of 14 below in the Twin Cities and 26 below in northwestern Minnesota.

In actuality, we probably will not be nearly that cold. A prominent aspect of climate change is that winter temperatures in the northern plains are tending to be milder than they were in the last century, especially during winter nights. And, if the nights do not get as cold, then the days have a head start on warming. Regardless of the details, next week will be uncommonly frigid.