DES MOINES — The first widespread snowstorm of the season crawled across the Midwest on Thursday, with whiteout conditions stranding holiday travelers and sending drivers sliding across slick roads — including into a fatal 25-vehicle pileup in Iowa.
The storm, which dumped a foot of snow in parts of Iowa and Wisconsin, was part of a system that began in the Rockies this week before trekking into the Midwest. It was expected to move across the Great Lakes overnight before moving into Canada.
The storm led airlines to cancel about 1,000 flights ahead of the Christmas holiday — relatively few compared to past big storms, though the number was rising.
On the southern edge of the system, twisters destroyed some homes in Arkansas and peeled the roofs off buildings, toppled trucks, and blew down oak trees in Alabama.
In Iowa, drivers were blinded by blowing snow and did not see vehicles that had slowed on Interstate 35 about 60 miles north of Des Moines, State Police said. A chain of crashes involving semitrailers and cars shut a section of the highway. Officials said two people were killed and seven injured.
‘‘It’s time to listen to warnings and get off the road,’’ said Colonel David Garrison of the Iowa State Patrol.
Thomas Shubert, a store clerk in Gretna near Omaha, said his brother drove him to work in his truck, but some of his neighbors were not so fortunate.
‘‘I saw some people in my neighborhood trying to get out. They made it a few feet, and that was about it,’’ Shubert said.
Along with Thursday’s fatal accident in Iowa, the storm was blamed for traffic deaths in Nebraska, Kansas, and Wisconsin. In southeastern Utah, a woman who tried to walk for help after her car became stuck in snow died Tuesday night.
The heavy, wet snow made some unplowed streets in Des Moines nearly impossible to navigate in anything other than a four-wheel drive vehicle. Even streets that had been plowed were snow-packed and slippery.
The storm made travel difficult from Kansas to Wisconsin, forcing road closures, including a 120-mile stretch of I-35 from Ames, Iowa, through Albert Lea, Minn. Parts of Interstate 80 in Nebraska and Interstate 29 in Missouri that had been closed were reopened Thursday afternoon. Iowa and Wisconsin activated National Guard troops to help rescue stranded drivers.
Those who planned to fly before the Christmas holiday did not fare much better.
Shanna Tinsley, 17, and Nicole Latimer, 20, were both going to the Kansas City area to see their families when their flight Thursday morning from Milwaukee’s General Mitchell International Airport was canceled. Neither cared about a white Christmas, and hoped to get on another flight later in the day.
‘‘It would be cool I guess, but I’d rather be there than stuck without family with a white Christmas,’’ Latimer said. Added Tinsley, ‘‘Wisconsin is full of snow, you see it all the time.’’
In Chicago, commuters began Thursday with heavy fog and cold, driving rain, and forecasters said snow would hit by midafternoon.
Airlines delayed and canceled hundreds of flights from Chicago’s O’Hare and Midway airports. Southwest Airlines canceled all of its flights at its Midway hub that were scheduled for after 4:30 p.m., and American Airlines said it was shutting down its O’Hare operations after 8 p.m.
Airlines were waiving fees for customers affected by the storm who wanted to change their flights. They were monitoring the storm during the night to determine whether more cancellations would be necessary Friday.
The cancellations got a lot of attention because the storm came days before Christmas. Daniel Baker, chief executive of flight tracking at Flight- Aware.com called it ‘‘a relatively minor event.’’
By comparison, airlines canceled more than 13,000 flights over a two-day period during a February 2011 snowstorm that hit the Midwest. And more than 20,000 flights were canceled during Hurricane Sandy.
Before the snowstorm, several Midwest cities had broken records for the number of consecutive days without measurable snow.
In the Des Moines suburb of Urbandale, Kristin Isenhart, 38, said her three children, ages 9, 5, and 3, were asking about going outside to play after school was canceled for the day.
‘‘They are thrilled,’’ she said.
As far as the region’s drought, meteorologists said the storm would not make much of a dent. It takes a foot or more of snow to equal an inch of water, said Brian Fuchs, a climatologist at the National Drought Mitigation Center.
Tens of thousands of people lost power in Arkansas, Iowa, and Nebraska as heavy snow and strong winds pulled down lines.