Waves of wintry weather

“Waves” should make you think of balmy ocean water lapping at beaches in Hawaii or the Caribbean, but in this case we are talking waves of wintry weather from the northwest.

It seems like we just keep getting one Alberta Clipper after another.  The routine of a light blanket of snow pushed southeastward by an Arctic front and followed by frigid air from the Yukon  seems to happen every several days.  It might be boringly repetitious if it were not so face-and finger-numbing, not to mention downright dangerous.

Saturday treated most of us to cold sunshine before clouds began to build in the northwest.

Most of Minnesota and Wisconsin are cloud-free but snow-covered. Credit:NOAA

Now there is a new clipper system approaching by way of the Dakotas.  This one will lay down a swath of snow from the northwest to southeast beginning tonight and tapering off on Sunday.  Here’s the way it is likely to play out.

Credit:NWS Chanhassen

Most snowfall amounts are likely to be in the tw0- to three-inch range .  Some amounts around four or five inches could occur near the center of the swath and in southeastern Minnesota.  And it will be a fluffy, easily-windblown snow.

As the snow tapers off on Sunday, the wind will increase again.  Whiteout, blizzard conditions are likely to make travel difficult or impossible in much of western and the southern Minnesota as Sunday progresses.  Blizzard Watches have been posted for western and south central Minnesota for Sunday.  Expect them to be upgraded to Warnings later today.

Conditions are likely to deteriorate first in the open areas and Buffalo Ridge of southwestern Minnesota.  The map below indicates the forecast steady wind at 6 a.m. CST Sunday.  Each full barb represents 10 knots (1.15 mph) and each half barb is 5 knots.  Arrows fly in the direction the wind will be moving.  Gusts will be higher.

Travel conditions could deteriorate first in southwestern Minnesota early Sunday. Credit:NOAA

As Sunday goes, on the wind will continue to crank up, blow more snow around and advance farther east.  By 3 p.m. much of the western and southern Minnesota will be affected.  Open areas are likely to experience steady winds of 30 to 40 mph with gusts to as much as 55 mph.  Visibilities in open areas and along highways including I-90 in southern Minnesota will drop to near zero.  Even right in the metro area the wind will gust over 30 mph Sunday afternoon and evening.

Strong northwest winds will the Twin Cities by early Sunday afternoon. Credit:NOAA

In addition to the drifting snow and limited visibilities for travelers, wind and falling temperatures will create frigid conditions for anyone caught outdoors unprepared.   Expect widespread very dangerous windchills from Sunday night into Tuesday.

Dangerous windchills are on their way. Credit:NWS La Crosse

Monday morning will be very cold with some lingering wind.  Forecast low temperatures range from 30 below in northeastern Minnesota to 15 below in the southwest.  Windchills will give create “feels like” temperatures of -30 to -50 over a large area.

Tuesday morning might be even a few degrees colder than Monday in eastern Minnesota, but less breezy.