The storm dumped at least 33 inches of snow in a part of South Dakota's scenic Black Hills, National Weather Service meteorologist Eric Helgeson said Friday afternoon. Later in the day, thunderstorms rolled across the Plains, and witnesses reported seeing tornadoes in Nebraska, Iowa and South Dakota.
Storms packing powerful winds destroyed homes in the northeast Nebraska town of Wayne, where witnesses said a tornado appeared to be 2 miles wide, according to the National Weather Service. The weather service said witnesses also reported at least two tornadoes near Sioux City, Iowa, causing some damage in Jefferson, S.D., and Moville, Iowa. The extent of the damage wasn't immediately clear because the storms hit as night fell; it also wasn't immediately clear if anyone was injured.
Earlier in the day, snow was blamed for the deaths of three people who were killed in a traffic accident on snow-slicked U.S. 20 in northeast Nebraska.
Forecasters said the cold front would eventually combine with other storms to make for a wild, and probably very wet, weekend for much of the central U.S. and Southeast.
Julie Lee said she and fellow members of her White Rose Band were accustomed to snow, just "not for the fourth of October." They had barely unloaded their instruments in South Dakota's Old West casino town of Deadwood before the wet, heavy snow started falling and closed part of Interstate 90, the area's only interstate.
"Our car is like an igloo," said Lee, who sings and plays the clarinet and saxophone for her North Dakota-based polka band. "I'm glad we got everything out."
The snow prompted Deadwood officials to postpone their annual Octoberfest, including Friday night's dancing-and-singing pub crawl and Saturday's Wiener Dog Races and Beer Barrel Games. But Lee said she and her accordion-playing husband, who had planned to set up in a casino bar, would entertain stranded guests because "you can only gamble for so long."
Officials were warning drivers to stay off the roads in the Black Hills and in eastern Wyoming, where reports of 5 to 10 inches of snow were common. Forecasters urged travelers to carry survival kits and to stay in their vehicles if stranded.
"I've lived in Wyoming my whole life and I've never seen it like this this early," Patricia Whitman, shift manager at the Flying J truck stop in Gillette, said in a telephone interview. She said her truck stop's parking lot was full of travelers waiting out the storm.
"I know several of the businesses nearby are completely closed because they can't even get workers into work - it's pretty nasty," she said.
The snow also snapped tree limbs that knocked out power lines in parts of the state, causing thousands of people to lose power.
By Friday night, South Dakota officials had closed I-90 from the Wyoming border to Murdo. And no travel was advised in Rapid City, where first responders were overwhelmed with calls for stuck vehicles and downed trees and power lines making some roads impassable. Police spokeswoman Tarah Heupel said snow and ice was accumulating on traffic signals, making the lights difficult to see.
Although early October snowfalls aren't unusual for the region, a storm of such magnitude happens only once every decade or two on the Plains, National Weather Service meteorologist Steve Trimarchi said.
"I couldn't say when the last time we've had one like this. It's been quite a while," Trimarchi said.
The cold front is moving slowly east and expanding south and will meet up with the remnants of Tropical Storm Karen on Saturday or Sunday, after that storm makes landfall along the Gulf Coast.
Though much of the Midwest and Southeast may get soaked, it won't be as devastating as past combination storms, such as Superstorm Sandy, said William Bunting, operations chief at the Storm Prediction Center in Norman, Okla. Sandy resulted from the merging of cold fronts and a tropical storm.
The Midwest, especially Kansas, Nebraska and Iowa, are at most risk for large thunderstorms, tornadoes and hail, "perhaps baseball-sized hail," Bunting said.
In Nebraska, the National Weather Service said a possible tornado caused severe damage to an area south of Wayne.
Large hail and powerful winds were forecast for northwest Oklahoma later Friday, while heavy rain settled in parts of Iowa and was expected to swoop northeast across the region into Wisconsin.
Snow also was still falling across northern Colorado on Friday, though no major problems were being reported.