Conditions with temperatures at record or near-record warm levels on December 22 underwent a drastic change over a brief 24 hour period, as a sharp upper-level trough in westerly flow amplified while translating from the Pacific Northwest to the Plains.  Low pressure developed and deepened rapidly while moving from South Dakota around 0000CST December 23 to the northern Great Lakes by 0600CST December 24.
Very steep lower to mid-level lapse rates and lift focused within a 200-250hPa deep layer supportive of effective dendritic growth resulted in intense precipitation banding over a 5 to 8 hour period. Winds in the lower mixed layer reached 40 to 60 knots as Arctic air surged into the area behind the system, producing numerous hours of widespread whiteout conditions.

Blizzard in NOBLES, MINNESOTA
From 23-DEC-20 11:00:00 to 23-DEC-20 19:00:00 (CST-6)
Reported by: AWOS

Winds gusted as high as 60 mph near Rushmore and 55 mph at Worthington, and despite a lack of pre-storm snow cover, snowfall which accumulated to 4.0 inches at Worthington and 3.3 inches 4 miles south of Worthington resulted in widespread whiteout conditions for several hours.  As vehicles slowed for very poor visibility, several were rear-ended by faster moving vehicles which resulted in a multi-vehicle accident involving at least a dozen drivers which eventually blocked a bridge along Interstate 90 east of Worthington.  The very poor visibility also resulted in numerous stranded motorists, which were unable to be seen by rescue vehicles.  County shelters were opened in Ellsworth, Wilmont and Adrian. Minnesota Department of Transportation shut down all main roads during the blizzard across southwest MN due to poor visibility and numerous accidents.

Blizzard in LINCOLN, MINNESOTA
From 23-DEC-20 09:00:00 to 23-DEC-20 16:00:00 (CST-6)
Reported by: Department of Highways

Winds gusted as high as 70 mph 1 mile west of Lake Benton and 63 mph 5 miles south of Hendricks, and despite a lack of pre-storm snow cover, snowfall which accumulated to 2.0 inches 4 miles southwest of Ivanhoe resulted in widespread whiteout conditions for several hours. Minnesota Department of Transportation shut down all main roads during the blizzard across all of southwest MN due to poor visibility and numerous accidents.

Blizzard in LYON, MINNESOTA
From 23-DEC-20 10:00:00 to 23-DEC-20 19:00:00 (CST-6)
Reported by: AWOS

Winds gusted as high as 59 mph at Marshall and 58 mph at Tracy, and despite a lack of pre-storm snow cover, snowfall which accumulated to 3.0 inches at Marshall, 2.6 inches at Minneota and 2.0 inches at Tracy resulted in widespread whiteout conditions for several hours. Minnesota Department of Transportation shut down all main roads during the blizzard across all of southwest MN due to poor visibility and numerous accidents.

Blizzard in PIPESTONE, MINNESOTA
From 23-DEC-20 10:00:00 to 23-DEC-20 17:00:00 (CST-6)
Reported by: RAWS

Winds gusted as high as 50 mph at Pipestone, and despite a lack of pre-storm snow cover, snowfall which accumulated to 4.7 inches at Pipestone and 2.5 inches at Edgerton resulted in widespread whiteout conditions for several hours. Minnesota Department of Transportation shut down all main roads during the blizzard across all of southwest MN due to poor visibility and numerous accidents.

Blizzard in MURRAY, MINNESOTA
From 23-DEC-20 11:00:00 to 23-DEC-20 20:00:00 (CST-6)
Reported by: AWOS

Winds gusted as high as 65 mph 2 miles west of Dovray and 59 mph near Slayton, and despite a lack of pre-storm snow cover, snowfall which accumulated to 3.5 inches at Lake Wilson resulted in widespread whiteout conditions for several hours. Minnesota Department of Transportation shut down all main roads during the blizzard across all of southwest MN due to poor visibility and numerous accidents.

Blizzard in COTTONWOOD, MINNESOTA
From 23-DEC-20 12:00:00 to 23-DEC-20 21:00:00 (CST-6)
Reported by: AWOS

Winds gusted as high as 58 mph 4 miles east northeast of Jeffers and 55 mph 2 miles north of Windom, and despite a lack of pre-storm snow cover, snowfall which accumulated to 4.0 inches at Windom resulted in widespread whiteout conditions for several hours. Minnesota Department of Transportation shut down all main roads during the blizzard across all of southwest MN due to poor visibility and numerous accidents. Emergency management reported that there were numerous vehicles stranded with rescue parties unable to locate vehicles due to severely restricted visibility.

Blizzard in JACKSON, MINNESOTA
From 23-DEC-20 12:00:00 to 23-DEC-20 21:00:00 (CST-6)
Reported by: AWOS

Winds gusted as high as 59 mph at Jackson and 49 mph 4 miles southeast of Lakefield, and despite a lack of pre-storm snow cover, snowfall which accumulated to 3.7 inches 2 miles northeast of Lakefield resulted in widespread whiteout conditions for several hours. Minnesota Department of Transportation shut down all main roads during the blizzard across all of southwest MN due to poor visibility and numerous accidents.

Blizzard in ROCK, MINNESOTA
From 23-DEC-20 10:00:00 to 23-DEC-20 18:00:00 (CST-6)
Reported by: Department of Highways

Winds gusted as high as 59 mph near Beaver Creek and 49 mph at Luverne, and despite a lack of pre-storm snow cover, snowfall which accumulated to 2.5 inches at Hills resulted in widespread whiteout conditions for several hours. Minnesota Department of Transportation shut down all main roads during the blizzard across all of southwest MN due to poor visibility and numerous accidents. A two-vehicle accident occurred on U.S. Highway 75 north of Luverne around 1135CST when a vehicle which was travelling at a lower speed due to visibility was rear-ended, resulting in indirect injury to the driver of the vehicle which was hit from behind.