(CNN) -- Snowstorms and icy conditions on Sunday delayed flights across the northern United States, caused havoc on roads and left thousands without electricity.



A worker shovels snow as the storm hits Chicago, Illinois.



At least one death has been attributed to storms that hit all over the country in the past week. A 44-year-old Massachusetts man died Friday when a tree limb weighed down by snow fell on him, authorities said.



Forecasters say there's more cold weather to come.



Authorities urged motorists in north-central and northeast Iowa to stay off roads because of poor visibility caused by blowing snow. Authorities prohibited tow trucks from operating on U.S. Highway 20, near the border with Minnesota, because of concerns the tow trucks would get stuck.



Forecasters said wind chills of 20 below and 30 below zero were possible in much of the rest of the Midwest, prompting wind chill advisories and warnings for the region into Monday morning.



Blizzard warnings also were expected to be in effect into Monday for parts of Maine and western parts of Michigan's lower peninsula.



In much of Maine, between 10 and 18 inches of snow was expected to fall Sunday and Monday, the weather service said. Whiteout conditions were expected at night, with wind gusts of up to 45 mph, the weather service said.



The Minnesota Department of Transportation ordered snowplow drivers off the road until Sunday morning in 13 southwest counties, because of poor visibility, blowing snow and wind gusts up to 40 mph, an agency spokeswoman said Saturday.



The western U.S. has also been hit with the cold blast. Parts of Washington saw 2 to 3 feet of snow last week. On Friday, two buses carrying 80 people collided on a road in Seattle and crashed through a metal railing, where they hung over a freeway for several hours before two trucks rescued them.



Many roads in Walla Walla, Washington, had yet to be plowed by Saturday, and the only practical way to drive on them was to have chains on tires, iReporter Aaron Cloward said.  Watch how driving has been difficult in Walla Walla »



Cloward, a native of Salt Lake City, Utah, said he had "never seen roads this bad or snow this bad." He also said he's been unable to free his car.



"Everything is sold out -- snow shovels, ice melt, salt, chains ... so I don't know how to get out," he said.



The storm system is expected to move eastward, where people are already dealing with air traffic delays and power outages brought on by snowfall earlier this week.



"This is essentially the reincarnation of the same storm that brought the heavy snow to parts of California, southern Nevada and northern Arizona," Steve Corfidi, lead forecaster with the weather service's Storm Prediction Center in Norman, Oklahoma, told CNNRadio.
What kind of warning was there in Michigan? Where have motorists been urged to stay off roads? What kind of warning is there for Maine, Michigan? Who has issued a blizzard warning? How many deaths are from the storms? Who is urging motorists to stay off roads? How many people died because of the storms in total? Who urged motorists in north-central to stay off the roads? Who has issued a blizzard warning for parts of Maine? What was attributed to one death? How many deaths have been caused by the storm?
Blizzard north-central and northeast Iowa Blizzard Forecasters At least one Authorities one Authorities Forecasters storms one
question: What kind of warning was there in Michigan?, answer: Blizzard | question: Where have motorists been urged to stay off roads?, answer: north-central and northeast Iowa | question: What kind of warning is there for Maine, Michigan?, answer: Blizzard | question: Who has issued a blizzard warning?, answer: Forecasters | question: How many deaths are from the storms?, answer: At least one | question: Who is urging motorists to stay off roads?, answer: Authorities | question: How many people died because of the storms in total?, answer: one | question: Who urged motorists in north-central to stay off the roads?, answer: Authorities | question: Who has issued a blizzard warning for parts of Maine?, answer: Forecasters | question: What was attributed to one death?, answer: storms | question: How many deaths have been caused by the storm?, answer: one