Blizzard conditions possible as powerful storm sweeps the region

From dense fog to blizzard conditions in less than 24 hours, the Upper Midwest is about to experience a sharp turn toward winter.

Powerful storm system takes shape Sunday

Attention now turns to a potent winter storm set to impact the Upper Midwest on Sunday. A system over the northern Rockies will merge with another emerging from the Southwest, phasing over the northern Plains. At the surface, low pressure will rapidly strengthen across the Central Plains before tracking northeast toward Michigan.

Snow will begin very late Saturday night or early Sunday morning across western Minnesota. Farther east, precipitation may start as rain or a rain/snow mix before a strong cold front sweeps through early Sunday.

Once the cold front passes, temperatures will fall rapidly and any rain will quickly change over to snow. This raises increasing concern for a flash freeze, particularly in areas that see rain early on. Temperatures will begin relatively mild, in the 20s and 30s across eastern Minnesota, before plunging through the day, with single digits and teens settling in farther west.

As the storm slows over Michigan, snow will continue across central and eastern Minnesota and Wisconsin through Sunday night. Steady snowfall is expected Sunday afternoon into the night, with the heaviest totals east of the Mississippi River into western Wisconsin, where 6 to 8 inches or more are forecast. Farther west, snowfall amounts will drop off to a couple of inches across western Minnesota.

Dangerous winds and blizzard conditions

Behind the cold front, winds will strengthen significantly. As the storm reaches peak intensity, sustained winds of 30 to 35 mph are expected across western and southern Minnesota, with gusts of 50 to 55 mph. Combined with falling snow, these conditions will make travel hazardous.

A blizzard warning is in effect from 9 a.m. Sunday to 6 a.m. Monday for a corridor from Alexandria and Long Prairie south through Hutchinson, the southwestern Twin Cities metro area, and into Mankato and Albert Lea, where strong winds will coincide with heavier snowfall.

Farther east, snowfall is expected to be heavier but winds slightly weaker, prompting a winter storm warning. Western Minnesota remains under a winter storm watch, where blizzard conditions are less likely due to lighter snow accumulations. Snow will taper off late Sunday night, though blowing snow may continue into Monday.

Travel conditions will be hazardous Sunday, starting in western Minnesota in the early morning and reaching central and eastern Minnesota by early afternoon, continuing through Sunday night. If possible, it is best to travel Saturday night or wait until Monday.

Looking ahead, high pressure will move in early next week. A weak clipper may bring light snow north of I-94 Tuesday, followed by a stronger system Wednesday capable of producing accumulating snow. High pressure builds in late week, bringing a shot of Arctic air for New Year’s Day.