October 2013 North American storm complex

A massive blizzard and tornado outbreak that affected the Northwest, Rockies, and much of the Midwest in early-October 2013. A total of 22 tornadoes were confirmed as the system moved eastward across the eastern half of the United States, including two that were rated EF4. The storm was unofficially named Winter Storm Atlas by The Weather Channel.

Summary of events
On October 3, 2013, the National Weather Service issued a blizzard warning for Rapid City and the Black Hills in advance of the storm urging people to delay or cancel travel plans.

Heavy snowfall trapped over six dozen people inside of their automobiles and tornadoes injured 17 people in Iowa and Nebraska. Rapid City, the second largest city in South Dakota, was engulfed in close to two feet of snow, which exceeds the amount of snow that the city has ever recorded during any whole month of October. Furthermore, on October 4, 2013, the city received over 19 in of snow, which exceeded the previous one day record in October by more than 6 in. Over 20,000 people lost electricity in Black Hills, where more than a meter of watered down, dense snow had fallen. The storm system also included thunderstorms that brought iced precipitation, significant rain and over half a dozen tornadoes to Nebraska and Iowa. Two of these tornadoes were violent enough to be rated EF4 on the Enhanced Fujita scale. Over 200 mi of Interstate 90 was shut down from South Dakota to Wyoming.

The storm affected about 5,000 ranches in western South Dakota producing snow totals as high as 5 ft and 70 mph winds that scattered herds for miles and resulted in the deaths of many cattle due to exhaustion and hypothermia. In a storm South Dakotans called the Cattleman's Blizzard, at least 14,000 cattle, 1300 sheep, 300 horses, and 40 bison were killed with South Dakota ranchers reporting losses of 20 to 50 percent of their herds. Thousands of people were without power. Three people died in a motor vehicle accident on US 20.

The storm coincided with the United States federal government shutdown of 2013, which limited timely federal response to the disaster.