A blizzard that paralysed parts of Colorado and Wyoming has barrelled into the US Midwest, bringing white-out conditions to western Nebraska and dumping heavy rain that prompted evacuations in communities father east.
South Dakota's governor closed all state offices on Thursday as blizzard conditions moved in, while wind, blowing snow and snow-packed roadways made travel treacherous in western Nebraska.
Heavy rain caused flooding in eastern parts of both states, as well as in Iowa.
Several cities in the region have been hit by heavy rain this week, with records set in Sioux Falls, South Dakota, and Sioux City, Iowa.
The flooding forced evacuations in both states, though no injuries have been reported.
The massive late-winter storm hit Colorado on Wednesday, causing widespread power outages, forcing the cancellation of hundreds of flights and wreaking havoc on roadways as drivers became overwhelmed by blinding snow.
A wind gust clocked in at 156 kph in Colorado Springs.
In the Texas Panhandle, a utility worker was killed while working to restore power amid strong winds pushed in by the storm.
Wind gusts in the area exceeded 128.74 kph. And in New Mexico, 36 miners at a nuclear waste repository were trapped underground in an elevator for about three hours because of a power outage caused by the extreme weather.
The storm also contributed to the death of Daniel Groves, a Colorado State Patrol officer who was hit and killed by a car as he helped another driver who had slid off Interstate 76 near Denver.
"This is a very epic cyclone," said Greg Carbin, chief of forecast operations for the National Oceanic and Atmospheric Administration's Weather Prediction Center.
"We're looking at something that will go down in the history books."
Meteorologists call the rapid change in pressure a "bomb cyclone" or "bombogenesis."
Australian Associated Press