(CNN) -- As if the heavy snow, ice and high winds from a major winter storm weren't enough, temperatures plummeted in the upper Midwest and elsewhere Wednesday, the National Weather Service said.





The storm brought blizzard conditions to some areas as gusty winds and blowing snow created whiteout conditions across much of the upper Midwest and Great Lakes regions. Winds of at least 35 mph and rain to the east caused hundreds of flights to be delayed or canceled, leaving travelers stranded. Parts of the Southeast received more than 6 inches of rain, causing flash flooding.





A 28-year-old woman was killed in Omaha, Nebraska, Tuesday night when a truck plowing snow in a parking lot backed into her, police spokesman Jacob Bettin said. She was pronounced dead at the scene.





In Nashville, Tennessee, early morning winds -- possibly up to 50 mph -- toppled the Christmas tree at the Tennessee State Capital, said CNN affiliate WKRN-TV. A facilities supervisor said the tree had been secured with hooks in concrete.





An Arctic high pressure system or air mass began moving southward from Canada on Wednesday, bringing with it frigid temperatures.





The temperature in Portland, Oregon, was 12 degrees, breaking the previous record of 15 degrees, set in 1972, said Jonathan Wolfe, meteorologist with the weather service's Portland bureau.





By Wednesday afternoon the temperature in Minneapolis, Minnesota, was 9 degrees. It was minus 2 degrees in Denver, Colorado; and 11 in Kansas City, Missouri.





Forecasters warned that places such as North Dakota and Minnesota could get dangerous wind chill readings of 25 to 35 degrees below zero.





Madison, Wisconsin, received more than 17 inches of snow, prompting the University of Wisconsin to cancel classes for the first time since 1990. The campus police department estimated 3,000 students descended onto the school's Bascom Hill Wednesday afternoon for a snowball fight, with a few minor injuries reported, according to the university's Web site.





Watch snow blow outside a hotel in Wisconsin





Early Wednesday morning, students began forming a giant snowball about six blocks from the campus and rolled it to an intersection near the university, former student Chad Krueger told CNN's iReport.





How is the weather where you are? Send an iReport





The storm prodded Nicole Stec of Janesville, Wisconsin, to finally buy those new tires her car had been needing.





"I'm a procrastinator, so I put it off for a while. But now it's time because there's snow on the ground," Stec told WISC-TV at a Janesville tire shop. "It's my Christmas present from Santa, apparently."





Elsewhere, Des Moines, Iowa, received more than a foot of snow, with more to come, and Freeport, Illinois, had 11 inches.





Schools were also closed across Iowa and parts of Minnesota.





Passengers heading to cities in snow-bound states were left waiting. High winds in the Northeast were creating flight delays of more than an hour Wednesday night.





New England also was expected to get dangerously low temperatures as snowfall was tapering off by Wednesday evening. Areas in Maine were expected to get an additional 4-8 inches of snow overnight after as much as 10 inches fell earlier in the day, the weather service said.





Connecticut's Department of Transportation deployed all of its 632 trucks to clear roads of snow that prompted numerous school closings Wednesday morning, CNN affiliate WFSB-TV reported.





Watch iReporters' shots of the storm





Flash floods struck north-central Alabama where rescuers ended up in a tree early Wednesday when their boat overturned as they tried to help a motorist whose car was swept into a rain-swollen creek, said the administrative assistant for Morgan County's Emergency Management Agency.





"The people were all right," said Rita Weeks. "They waited in the tree until people could come get them."





Earlier Wednesday, in the same county, a man hung on to a bridge over a creek after his vehicle was swept away by floodwaters, Weeks said.





Forecasters said the area got more than 3 inches of rain
how many students descend on field for snowball fight? How many came for the snowball fight? What were closed in Iowa? Where was the snowball fight? How many students participated? What did the campus police say? Which region has heavy snow?
3,000 3,000 Schools Madison, Wisconsin, 3,000 estimated 3,000 students descended onto the school's Bascom Hill Wednesday afternoon for a snowball fight, upper Midwest
question: how many students descend on field for snowball fight?, answer: 3,000 | question: How many came for the snowball fight?, answer: 3,000 | question: What were closed in Iowa?, answer: Schools | question: Where was the snowball fight?, answer: Madison, Wisconsin, | question: How many students participated?, answer: 3,000 | question: What did the campus police say?, answer: estimated 3,000 students descended onto the school's Bascom Hill Wednesday afternoon for a snowball fight, | question: Which region has heavy snow?, answer: upper Midwest