Good travel through Christmas; major winter storm beginning on Wednesday

Snowfall has been light for much of Minnesota so far this winter. MSP Airport has measured just 7.6 inches for the Twin Cities.

These quiet conditions will continue from Christmas Eve through Christmas night. Weak disturbances will kick out just some patchy light snow Monday night and Tuesday, so over-the-roaders around the state should be able to get where they are going with little fuss and bother.

Look for high temperatures Christmas afternoon from the single digits around Hallock in the northwest corner of the state to the low 30s in the Twin Cities area and across southern Minnesota.

Pacific storm

A strong Pacific storm came ashore with rain and snow for Oregon, California and Nevada on Monday. That storm will track toward the Four Corners area of the Southwest and then turn our way. Winter storm watches have been posted for the Central Plains.

High impact winter storm Wednesday-Friday

Snow should beginning arriving in western Minnesota Wednesday morning and spread east across the state during the day.

Warm air arriving from the south will change the snow over to rain Wednesday night, most likely from the Twin Cities to much of southern Minnesota. Periods of freezing rain are possible along the rain-snow boundary. Any change to rain will diminish snowfall totals.

Return to snow on Thursday

As the low pressure center tracks off to the east on Thursday, colder air from Canada will change the rain back to snow for the Twin Cities and then points farther southeast.

Increasing wind will generate blowing and drifting snow to limit visibilities later on Thursday and into Friday.

Snowfall should end from west to east on Friday.

So, how much snow?

That's a difficult question to answer when the storm is still so far away and part of it will be rain when it arrives. My forecast as of early Monday evening is for a large area of at least around 8 to 12 or more inches of snow from parts of southwest and west central Minnesota through central Minnesota to the Arrowhead and northwestern Wisconsin. Less should fall in the Twin Cities and to the south.

Any change in the track or speed of the storm will change these amounts and locations, so check current forecasts before traveling.

The following graphic from the Twin Cities National Weather Service indicates that our greatest uncertainty is along that southwest-to-northeast band where the precipitation type could be either rain or snow, or it might go back and forth. All snow is likely north of that band while all rain is likely to its south.

Arctic chill

Cold air blowing from Canada will bring us a very chilly last weekend of 2018. Temperatures should begin to fall on Friday. Saturday's highs could be just single digits in northern Minnesota and teens in the Twin Cities and the south.

Biggest storms of record

The Minnesota State Climatology Office has posted a list of the top 20 snowfalls for the Twin Cities since 1891. It is not an absolute list as now can be difficult to measure. Also, measurement locations, techniques and frequencies have changed at times. But here is the list, and it does include that awful blizzard we endured last April (number 12).