Chicago - With airports across the country recovering from a blast of snow and ice storms, some unlucky holiday travelers stranded for the second night in a row prepared to wake up Christmas morning at the nation's second busiest airport.

Newlyweds Tommy and Siobhan Costello were at O'Hare International Airport on Wednesday for the second night en route to their honeymoon in San Diego.

About 500 flights were canceled at O'Hare on Tuesday, the day the Costellos arrived from their native Ireland. The weather disruptions meant the earliest flight out they could get was Thursday. Since the couple packed for California, they didn't have clothes to venture out into the city where the weather was expected to dip into the single digits Wednesday evening.

"This was supposed to be a pit stop," said 30-year-old Siobhan Costello, who wandered the terminal hallways with her husband. "But there's nothing you can do."

Airline officials said the Costellos were among a dwindling group of stranded passengers. About 100 flights were canceled early Wednesday, but as the day progressed and the weather improved, the cancellations dropped off and delays shortened to between 30 and 45 minutes.

City of Chicago Aviation Department spokesman Greg Cunningham said airlines at O'Hare requested 75 cots for passengers Wednesday night.

Complicating matters at O'Hare, an American Airlines plane hit an icy patch while turning onto a runway and slid sideways into the grass. There were no injuries in the Wednesday evening incident, and 54 passengers were to be put on other flights leaving the same night.

Airports across the country recovered from a barrage of snow and ice storms Wednesday, with some conditions improving, but highways remained dangerously slippery in some areas.

At least 30 people were killed in crashes on rain- and ice-slickened roads across the nation's midsection Tuesday and Wednesday.

Newark Liberty International Airport was experiencing delays of more than four hours, the Federal Aviation Administration reported. Kennedy International Airport had been experiencing three-hour delays, but those were down to 15 to 30 minutes by Wednesday night.

"The airlines are dealing with nothing but unhappy customers," said Mike Conway, spokesman for Detroit's Metropolitan Airport, where delays were reported because of conditions elsewhere in the country.

The weather service posted winter storm warnings and advisories for large parts of the West, plus parts of the Midwest and the Northeast.

Driving conditions were still tough in Oregon's Portland metro area, where many side streets were clogged with snow and motorists were required to have tire chains, unless they had four-wheel drive and tires designed for hazardous weather. More snow fell in the region Wednesday, followed by rain that would likely freeze overnight.

Oregon's largest utility, PGE, said it had restored service to 265,000 customers since the storm arrived Friday, but 47,000 were still blacked out Wednesday.

Washington Gov. Chris Gregoire declared a winter storm emergency Wednesday as city and county officials struggled to keep up with record levels of snowfall.

Temperatures rose and light rain was falling across the western part of the state Wednesday, melting some of the ice on streets and roads, but the National Weather Service forecast 2 more inches of snow for the Seattle area on Christmas.

Motorists in Michigan had to cope with drifting snow in places in addition to ice-covered pavement.

"It looks like all areas should see a white Christmas," meteorologist Dave Kook said from the weather service office in Oakland County's White Lake Township. "There's enough snow on the ground that it won't all melt away with the rain."

Amtrak also reported improvement Wednesday. Trains out of Chicago and elsewhere were leaving on time - or relatively close to it - unlike Tuesday when several trains were canceled and some 600 furious travelers waited for as much as 22 hours for delayed trains at Chicago's Union Station, spokesman Marc Magliari said.

Also Wednesday, an avalanche in the Rocky Mountains killed two snowmobilers in northern Utah. The Utah Avalanche Center warned people not to venture into the backcountry.