Unusual warmth with a week of temperatures mainly in the 70s (even 50s and 60s on November 9 less than a day before this storm) was brought to an abrupt end as a deep trough of low pressure moved out of Rockies and into the Plains.  An intense lower- to mid-level frontal zone oozed eastward as a strong jet lifted out across the Plains on November 10, initiating widespread precipitation.  More rapid shallow cooling occurred across northwest Iowa and led to a swath of freezing rain which accumulated from a tenth to a half inch during the overnight and morning hours, before changing to snow in the afternoon.  Heavier and more persistent snowfall occurred with the deeper cooling to the northwest across southeast South Dakota, far northwest Iowa and southwest Minnesota, where amounts ranged from 3 to 7 inches.

Winter Weather in DICKINSON, IOWA
From 09-NOV-20 23:00:00 to 10-NOV-20 19:00:00 (CST-6)
Reported by: COOP Observer

Freezing rain and freezing drizzle overnight and much of the morning accumulated to one to two tenths of an inch, especially on elevated surfaces, including powerlines which resulted in brief power outages.  Precipitation changed to snow during the midday and afternoon, and totaled 3.7 inches in Lake Park and 3.1 inches 4 miles northwest of Milford.

Winter Storm in SIOUX, IOWA
From 10-NOV-20 03:00:00 to 10-NOV-20 18:00:00 (CST-6)
Property damage: 20.00K
Reported by: COOP Observer

Snowfall, briefly mixed with sleet or freezing drizzle during the morning, became heavy at times between 1300-1600CST. Slick roads caused a school bus carrying 12 students to slide off the road and roll in the ditch 5 miles west of Sioux Center, however, no injuries occurred. Accumulations reached 6.5 inches at Orange City and 6.0 inches at Rock Valley. Property damage costs are rough estimates.

Winter Storm in LYON, IOWA
From 10-NOV-20 08:00:00 to 10-NOV-20 18:00:00 (CST-6)
Property damage: 4.00K
Reported by: CoCoRaHS

Snowfall, briefly mixed with sleet or freezing drizzle during the morning, became heavy at times between 1300-1600CST.  Accumulations reached 6.5 inches near Larchwood.  Hazardous travel resulted in several accidents, with one resulting in an (indirect) injury to a driver that lost control, left the roadway and rolled once in the north ditch along County Highway A34 near George. Property damage costs are rough estimates.

Ice Storm in WOODBURY, IOWA
From 09-NOV-20 21:00:00 to 10-NOV-20 17:00:00 (CST-6)
Property damage: 6.00K
Reported by: Emergency Manager

Freezing rain overnight and through the morning resulted in ice accumulation of a quarter to half inch, especially on elevated surfaces, including powerlines.  Brief power outages were reported.  Snowfall developed later morning and through the afternoon, and accumulated to 3.0 inches at Sioux City.  Slick roadways resulted in several accidents. An (indirect) fatality occurred on eastbound U.S. Highway 20 west of Moville shortly after 1200CST, when the driver and sole occupant of the vehicle left the road and rolled several times.  Around the onset time of the freezing rain during the evening of November 9, more than 200 ducks were killed when they confused wet and ice-covered Highway 20 for wetlands and were hit by passing vehicles. Property damage costs are rough estimates.

Ice Storm in CHEROKEE, IOWA
From 09-NOV-20 22:00:00 to 10-NOV-20 17:00:00 (CST-6)
Reported by: Emergency Manager

Freezing rain fell during the overnight and morning hours, accumulating to one-quarter inch on mainly elevated surfaces, including powerlines.  Brief power outages were reported.  Snowfall in the afternoon accumulated to 3.0 inches at Cherokee and 4 miles north of Cleghorn.

Ice Storm in IDA, IOWA
From 09-NOV-20 22:00:00 to 10-NOV-20 17:00:00 (CST-6)
Reported by: Emergency Manager

Freezing rain during the overnight and morning hours produced an ice accumulation of around a half inch on mainly elevated surfaces, including powerlines.  Brief power outages were reported.  Light snowfall in the afternoon accumulated to 1.2 inches 5 miles north northwest of Holstein.

Winter Weather in PLYMOUTH, IOWA
From 09-NOV-20 22:00:00 to 10-NOV-20 17:00:00 (CST-6)
Property damage: 10.00K
Reported by: COOP Observer

A mix of sleet, freezing rain and freezing drizzle overnight and much of the morning accumulated ice to around a tenth of an inch, especially on elevated surfaces.  Slick roadways resulted in an rollover accident along U.S. Highway 75 northwest of Le Mars, causing a pair of (indirect) injuries to the driver and one passenger, and (indirect) fatality to a backseat passenger.  Precipitation changed to snow late morning, briefly heavy between 1200-1500CST. Snowfall totaled 5.3 inches at Arkon, 3.7 inches at Remsen, and 3.3 inches at Le Mars. Property damage costs are rough estimates.

Winter Weather in O'BRIEN, IOWA
From 09-NOV-20 22:30:00 to 10-NOV-20 18:00:00 (CST-6)
Reported by: COOP Observer

A mix of sleet, freezing rain and freezing drizzle overnight and much of the morning accumulated ice to around a tenth of an inch, especially on elevated surfaces. Precipitation changed to snow during the afternoon, briefly heavy between 1300-1600CST. Snowfall totaled 5.6 inches at Sanborn, 4.8 inches at Sheldon, and 3.6 inches at Primghar.

Ice Storm in BUENA VISTA, IOWA
From 09-NOV-20 23:00:00 to 10-NOV-20 17:00:00 (CST-6)
Reported by: Law Enforcement

Periods of freezing rain during the overnight and morning hours accumulated to a quarter inch on elevated surfaces, including powerlines. Brief power outages were reported. Light snowfall in the afternoon resulted in snowfall of 1.0 inch at Sioux Rapids and 0.5 inch at Storm Lake.

Winter Weather in CLAY, IOWA
From 09-NOV-20 23:00:00 to 10-NOV-20 18:00:00 (CST-6)
Reported by: COOP Observer

Freezing rain and freezing drizzle overnight and much of the morning accumulated to one to two tenths of an inch, especially on elevated surfaces, including powerlines which resulted in brief power outages.  Precipitation changed to snow during the midday and afternoon, and totaled 2.5 inches 4 miles west northwest of Everly and 1.7 inches at Spencer.

Winter Storm in OSCEOLA, IOWA
From 10-NOV-20 00:30:00 to 10-NOV-20 18:00:00 (CST-6)
Reported by: COOP Observer

Snow was intermittently mixed with light freezing rain during the morning with up to a tenth of an inch ice accumulation. Snow continued through afternoon, and was briefly heavy between 1300-1600CST. Snowfall totaled 6.5 inches at Sibley.