By Brendan O'Brien
CHICAGO (Reuters) - A powerful winter storm was barreling through the eastern half of the United States on Thursday, bringing a variety of weather threats to the area that included heavy snow, damaging thunderstorms and the potential of isolated tornadoes.
The National Weather Service (NWS) issued winter storm, strong wind and thunderstorm warnings and watches for the wide swath of the nation stretching 1,500 miles (2,400 km) from western Oklahoma to northern Maine from Thursday afternoon into Friday.
The system was expected to dump a quick burst of snow on an area from Oklahoma to Michigan and into the Northeast while threatening Mississippi and Tennessee up through Ohio and into the Northeast with severe thunderstorms, the NWS said.
"It's a pretty potent large-scale storm system that's got a lot of different hazards associated with it depending on where folks," are said NWS meteorologist in Matt Beitscher, who is based in St. Louis. "In our area, the road conditions are pretty treacherous."
Snowfall exceeding 2 inches (5 cm) per hour and winds reaching 40 miles per hour (64 kph) could severely reduce visibility on roadways, with the heaviest snowfall of up to 8 inches in the region that stretched from western Oklahoma to northern Maine, the weather service said.
Some 200 flights were canceled in and out of Chicago's O'Hare International Airport while another 270 were canceled from and to Detroit Metropolitan Wayne County Airport. In all, about 1,000 flights had been canceled in the United States on Thursday, Flightaware.com reported.
The storm was forecast to also spark potentially strong thunderstorms in the Mississippi, Tennessee, Alabama and Arkansas where it could produce damaging wind gusts, large hail, and isolated tornadoes.
Rainfall of up to 2 inches was expected in this region, with locally higher amounts, causing the threat of flash flooding.
The storm was also packing strong southerly winds reaching 50 mph could which could down power lines and cause hazardous travel conditions from the South and into the Ohio Valley. Wind gusts could reach as high as 65 mph on Thursday night in parts of southern New England, the weather service said.
(The story refiles to add dropped word 'and' to headline.)