Wintry weather bedeviled Thanksgiving weekend travelers across the United States Saturday as a powerful and dangerous storm moved eastward, dumping heavy snow from parts of California to the northern Midwest and inundating other areas with rain.

A 5-year-old boy died and two other children were missing in central Arizona after a vehicle was swept away while attempting to cross a runoff-swollen creek. A storm-related death also was reported in South Dakota.

The National Weather Service said the storm was expected to drop 6 to 12 inches (15-30 centimeters) of snow from the northern Plains states into Minnesota, Wisconsin and Upper Michigan.

Blizzard conditions early Saturday were already buffeting the High Plains. The city of Duluth, Minnesota, issued a “no travel advisory” beginning at noon Saturday because of a major snow storm it termed “historic.”

Duluth officials asked the public to be patient as plows clear roadways and recommended that drivers stay off the roads to prevent accidents and let officers respond more quickly to emergencies.

Farther south, rain and thunderstorms were forecast along and ahead of the cold front, with heavy rainfall possible Saturday in parts of the Tennessee and Ohio Valleys.

Forecasters said a new storm is expected to bring California several feet of mountain snow, rain and gusty winds through the weekend. Another system is forecast to develop in the mid-Atlantic Sunday, moving as a nor’easter into Monday.

Authorities in the western states were still grappling Saturday with the aftermath of heavy rains and snow over the busiest travel weekend of the year.

In Arizona, officials continued searching for two children still missing after they found the young boy’s body about 3 miles (4.8 kilometers) downstream from where the vehicle they were riding in was swept away Friday, said Gila County sheriff’s Lt. Virgil Dodd.

The agency said Saturday two other children and two adults who were in the vehicle were rescued from a small island and the bank of the creek in Tonto National Forest northeast of Phoenix. Sheriff’s officials initially had said six people, including four children, were rescued Friday at locations along the creek.

High winds and ice were making travel almost impossible in some other places.

A 100-mile section of Interstate 80 in Nebraska and Wyoming closed Saturday morning because of high winds and blowing snow.

The Nebraska Department of Transportation said I-80 was closed in both directions and advised against travel in the state’s Panhandle region. Several other roads and highways also were closed.

Back-to-back snowstorms and strong winds combined to serious complicate travel by land across much of the rest of Wyoming, where roads were closed in the eastern and southern parts of the state because of whiteout conditions.

The National Weather Service in Wyoming reported 4 inches (10 centimeters) of snow fell in Cheyenne from 7 p.m. Friday through 10 a.m. Saturday “that has been blown all over kingdom come by our winds,” said meteorologist Andrew Lyons.

That was added to a foot (30 centimeters) of snow that fell before Thanksgiving.

Wind gusts up to 50 mph (80 kph) created ground blizzards and below-zero wind chill temperatures in some areas. A wind gust of 77 mph (124 kph) was reported in the mountains between Cheyenne and Laramie, Lyons said.

All roads in and out of Casper were closed Saturday morning, including the entire 300-mile stretch (483-kilometer) of Interstate 25 in Wyoming.

Travel was also difficult in Colorado Saturday as winds blew around snow that had fallen in previous days.

Northeastern Colorado roads were closed due to strong winds, blowing and drifting snow and poor visibility.

Interstate 25, U.S. Highway 85 and U.S. Highway 287 were closed north of Fort Collins, Colorado due to the poor conditions in Wyoming.

(AP)