As much as 10 inches (25 centimeters) of snow may fall in Chicago from a storm that has scrubbed more than 1,200 flights into and out of the city for today and hundreds more in Washington for tomorrow.
The snow’s intensity will build through the day and may reach rates of 1 to 2 inches per hour, the National Weather Service said. In some areas as much as 12 inches are possible, according to a winter storm warning issued by the agency.
“It’s been snowing for several hours,” Amy Seeley, a weather service meteorologist in Romeoville, Illinois, said at midday. “The heaviest snow is probably going to happen early this afternoon through this evening through the rush hour.”
The storm, the third in the Midwest in three weeks, tied up air travel as it moved east. As of 12:45 p.m. New York time, 805 arrivals and departures had been scrubbed at Chicago’s O’Hare International Airport, which United Continental Holdings Inc. and AMR Corp.’s American Airlines use as a hub.
At Midway International, where Southwest Airlines Co. dominates flights, 239 were scratched, according to FlightAware, a Houston-based tracking service. Across the U.S., 1,239 trips were dropped.
Almost 600 flights have been canceled for tomorrow, 365 of them into or out of Washington’s Dulles International and 171 at Reagan National, FlightAware said.
Rain is expected to start falling in the mid-Atlantic region, including Washington, later today before changing to snow after dark, said Rob Carolan, founder and meteorologist at Hometown Forecast Services Inc. in Nashua, New Hampshire.
“I think the Washington area has a pretty good chance at 3 to 6 inches and Philadelphia may get 3 to 6 inches,” Carolan said.
Winter storm warnings and weather advisories stretch from South Dakota to Maryland and as far south as Georgia, according to the weather service. A winter storm watch extends from Virginia into southern New Jersey and coastal flood watches have been issued from Delaware to Connecticut, including all of New York’s Long Island.
Yesterday, at least 24 inches of snow fell in Rocky Boy, Montana, and 12 inches in Warwick, North Dakota, the U.S. Weather Prediction Center in College Park, Maryland, said yesterday. Kelliher, Minnesota, reported 10 inches today and 15 inches were measured at Landon, North Dakota.
Gusts of 61 miles (98 kilometers) per hour were clocked at Buffalo, South Dakota, and 60 mph in Rapid City, according to the agency, which officially changed its name today from Hydrometeorological Prediction Center.
Parts of northern Illinois and Indiana have at least a 60 percent chance of receiving 6 inches or more in the next 24 hours, while in sections of West Virginia, Maryland and Virginia the odds are greater than 90 percent, the center said.
New York City may get 2 inches of snow through the day tomorrow, said Mike Layer, a weather service meteorologist in Upton, New York. The biggest threat to the area will be high wind and coastal flooding, he said.
“The precipitation will start just before rush hour and increase during the day,” Layer said.
Winds are expected to gust as strongly as 37 mph tomorrow in Manhattan and higher on Long Island, the agency said.
Boston and southern New England are the most difficult areas to forecast because what happens there depends on the track the storm takes as it moves into the Atlantic, said Alan Dunham, a weather service meteorologist in Taunton, Massachusetts.
“This is a very fluid situation,” Dunham said. “There are still a lot of discrepancies among the various forecast models. Yes, we are going to have a winter event, but there are a lot of unknowns, whether it will be mainly rain, whether it will be mainly snow.”
The only certainty is that the storm will push heavy seas into the coast, raising the possibility of beach erosion and flooding, he said.
Massachusetts and Rhode Island will probably have good weather through tomorrow.
“Then it’s what happens Wednesday night, Thursday and into Friday,” Dunham said. “That’s very much up in the air.”