A snowstorm charging up the East Coast largely missed the Baltimore region, playing havoc with the predictions of meteorologists and plans of travelers as forecasts of up to a half-foot of snow amounted to little more than a dusting.

But as temperatures dipped after nightfall, state highway officials were watching for icy roads.

"You prepare for the worst and hope for the best," said Kellie Boulware of the State Highway Administration. "All in all, the fact that schools aren't in session, people are off for the holiday week, and we didn't have that many travelers on the highway gave our crews a chance to go out and throw down salt. We've got more on hand available to us."

Downed trees were also possible, with wind gusts expected to reach 40 mph overnight. Meanwhile, those returning home from destinations in the Northeast were expected to encounter trouble, with heavier snow and blizzard-like conditions in the mix.

In Ocean City, several inches of snow had accumulated by late afternoon. Mayor Rick Meehan said he thought the resort town could end up with a foot of snow.

"It's a bit of a pain, but it's beautiful out there right now," he said.

Meteorologists had anticipated 6 inches or more of snow in the Baltimore region before the system passed. With memories of this year's snowstorms still fresh, Gov. Martin O'Malley pre-emptively declared a state of emergency.

But the storm was downgraded before 3 p.m. by the National Weather Service when forecasters saw that the storm had lost momentum as it continued to move to the north, said Calvin Meadows of the National Weather Service.

Meteorologist Andy Woodcock, also with the National Weather Service, said the ultimate accumulation totals for the Baltimore area turned out to be minimal — which is what forecasters predicted before the storm showed signs of strengthening Saturday — in part because the storm tracked farther east.

The Baltimore region "dodged somewhat of a bullet," Woodcock said.

A Winter Weather Advisory was to stay in effect until 6 a.m. Monday.

Officials at Baltimore-Washington International Thurgood Marshall Airport urged passengers to check airline schedules tonight and Monday. Beginning Saturday night, airlines canceled a "significant number of flights," said Jonathan Dean, spokesman for BWI.

Dean said he did not know how many flights were canceled Sunday, but he said the airlines had communicated their cancellations to passengers, diminishing the number of travelers stranded at the airport.

The Northeast was receiving the brunt of the storm. Forecasters issued a blizzard warning for New York City for Sunday and Monday, with a forecast of 11 to 16 inches of snow and strong winds that will reduce visibility to near zero at times. A blizzard warning was in effect for Rhode Island and most of eastern Massachusetts, including Boston, with forecasters predicting 15 to 20 inches of snow. As much as 18 inches could fall on the New Jersey shore, with wind gusts topping 40 mph.

Fearful of the storm's impact, the NFL pushed back a Sunday night matchup between the Minnesota Vikings and Philadelphia Eagles to Tuesday.

A blizzard warning is issued when snow is accompanied by sustained winds or gusts over 35 mph.

"You don't want to go north," the weather service's Woodcock said.

Some flakes — part of a different weather system — fell Christmas morning, dusting cars and shrubs.

With the plans of untold numbers of holiday motorists hanging in the balance, transportation officials across the region prepared their crews.

Maryland's State Highway Administration began preparing for snow as early as Tuesday, when equipment was tested and stockpiles of gas and salt were evaluated.

As the storm moved through the South, airlines canceled hundreds of flights on Saturday, including many at the busy Hartsfield-Jackson Atlanta International Airport, a hub for Delta.

An airline spokesman said people with travel plans through Baltimore, Washington, Boston, New York and Newark, N.J., Sunday or Monday could change flights without a penalty as long as they travel by Dec. 29.

AirTran Airlines offered to waive ticket-change fees for some flights scheduled for this weekend and Monday in the Mid-Atlantic and South.

Amtrak canceled some of its Virginia routes into Monday morning, and Cliff Cole, an Amtrak spokesman, said the company would continue to monitor the snowfall to determine train schedules.

"I'm fairly certain there will be other adjustments we will have to make," Cole said. The Virginia cancellations were "the first round," he said.

The path of the storm has been unpredictable for the past week.

As recently as Friday, prognosticators were saying the Baltimore region would get no snow. Then, late Friday and into Saturday, the meteorological models began to shift. What had looked like a total miss suddenly morphed into a storm of several inches — conjuring memories of last year's major December storm, which was followed by historic twin blizzards in February.

But this time Baltimore was spared.

The storm started in California, blanketed sections of the Midwest and hampered motorists there on Friday before dipping south.

The Eastern Shore saw some of the heaviest snowfall in the region.

Sarah Crosby, assistant general manager at the Hilton Suites Ocean City, said Sunday that the hotel's guests had exhibited a gamut of reactions after about 6 inches of snow fell by midafternoon.

"We've had people who have checked out, who have extended their stay and [others who are] canceling their stays," Crosby said.

The 225-room hotel was about a quarter-full, she said, and many visitors adjusted plans to arrive later in the week — when the roads presumably will be clear.

Business was holding up because for every group that canceled or changed its plans, another group extended its stay, Crosby said.

Walter Eskiewicz, owner of Littleton's Bed and Breakfast in Pocomoke City, toward the southern end of Maryland's Eastern Shore, said the town had received at least 8 inches by early afternoon. He said the streets were deserted and impassable and his four guest rooms were empty.

Baltimore Sun reporters Michael Dresser, John-John Williams IV, Yeganeh June Torbati, Jessica K. Anderson, Justin Fenton and the Associated Press contributed to this article.