The storm, caused by a low-pressure system moving east from the Pacific Ocean, dropped temperatures by up to 50 degrees in places like Denver, where it was sunny and in the mid-70s Tuesday but reached the mid-20s by Wednesday night.
The low-pressure system was affecting areas from Colorado to Michigan, with heavy snow and thunderstorms, and even down into Texas, where dry conditions and high winds have led to wildfire warnings.
While the whipsawing forecasts drew groans, they did not come as much of a surprise to those familiar with springtime in the Plains and the Rockies.
“In Colorado, that’s not uncommon at all,” said Natalie Sullivan, a meteorologist with the National Weather Service in Boulder, Colorado, noting that April is historically the state’s second-snowiest month of the year, behind March.
Ahead of the storm Wednesday, Gov. Jared Polis activated the Colorado National Guard, and about 50 soldiers were prepared to respond to stranded drivers. State officials also shut down a highway in the eastern part of the state and part of a highway that cuts through the mountains, citing numerous accidents.
Even before the low-pressure system reached the Rockies, it wreaked havoc on the West Coast, knocking out power in Los Angeles and kicking up dust storms in Nevada, according to AccuWeather.
Officials in states across the Midwest watched anxiously for weather dangers.
Much of the region is still reeling from severe flooding brought on by storms and rising rivers last month. The floods inundated small towns and created a humanitarian crisis on the Pine Ridge Native American reservation.
Officials in Hamburg, Iowa, worked quickly to add a temporary 5-feet-tall levee to the town’s current levee system before the Missouri River crests by Sunday or Monday, as they expect. Floodwaters inundated much of the town of 1,100 people last month after heavy rain accumulated on frozen ground in the region.
More pressing than Hamburg’s weather, said CathyCrain, Hamburg’s mayor, was the snow and rain in cities to the north, such as Yankton, South Dakota. When precipitation hits those areas hard, it swells the Missouri River and flows down into Hamburg.
Meteorologists predicted as much as 2 1/2 feet of snow in parts of eastern South Dakota.
This article originally appeared in The New York Times.