A winter storm could wreak havoc on holiday travel as more than 6 inches of snow could fall here.

Lee Hendricks, a meteorologist with the National Weather Service in Pittsburgh, said this morning that the track of the storm could change, but that he still expects significant snowfall to hit the area on Tuesday.

Snow will start late tonight and will spread from south to north by Tuesday morning, Hendricks said. The most intense snow will be Tuesday night into early Wednesday, while the storm will likely taper off by midday Wednesday.

The storm could easily delay holiday travelers who plan to hit the road on Wednesday, which is typically one of the busiest travel days of the year.

“Frankly, if people delay leaving a little on Wednesday, it shouldn’t be as much of an issue,” Hendricks said. “There is still a degree of uncertainty with the forecast, though. A shift 80 miles east or west can really change it.”

The National Weather Service has issued a winter storm watch that begins Tuesday morning and ends Wednesday afternoon for southwestern Pennsylvania.

Nationally, an icy storm that started in the West and is blamed in at least 10 fatal accidents was bringing a mix of snow, sleet and freezing rain to parts of Arkansas, Oklahoma and Texas today as it trudged eastward.

The storm dropped more than 10 inches of snow on parts of southwest Oklahoma overnight, and a winter weather advisory remained in place for much of the southeast of the state with freezing rain and sleet in the cards.

The National Weather Service issued a winter weather warning for southwestern Arkansas. The region was preparing for the worst of the storm to hit through this afternoon, with forecasters warning of ice accumulations on slick roads.

It downgraded the forecast for North Texas to a winter weather advisory, saying the area would experience light freezing rain and sleet but not temperatures as cold as originally forecast.

Nearly 300 flights of American Airlines and American Eagle were canceled in and out of Dallas-Fort Worth International Airport today due to the weather, spokesman Laura Masvidal said, mirroring disruptions at the air hub a day earlier.

Early today, the weather service said southwestern Oklahoma had experienced some snow late Sunday, with 10 inches reported in Granite and 13 inches of snow reported in Vinson.

Around dawn in Dallas, where a mix of rain and sleet hit around midday Sunday, temperatures edged above freezing but rain continued to make roads treacherous.

The storm last week hit California, New Mexico, Nevada and Arizona.

Portions of New Mexico had several inches of snow — especially at higher elevations — and near white-out conditions were reported near Albuquerque. Flagstaff in Arizona had 11 inches of snow early Sunday, while metro Phoenix and other parts of central Arizona were drenched with several inches of rain, causing the cancellation of sporting events and parades.

The weather was blamed in at least 10 deaths in traffic accidents. The storm also caused hundreds of rollover accidents, including one that injured three members of singer Willie Nelson’s band when their bus hit a pillar on Interstate 30 near Sulphur Springs, about 75 miles northeast of Dallas.

Early today, the Texas Department of Public Safety said two people died in separate wrecks Saturday night on snow-covered roads near Amarillo and Dumas.

Nonetheless, some were excited when they awoke to several inches of snow in southwestern Oklahoma on Sunday.

“It looks great. I love the snow,” said Damaris Machabo, a receptionist at a Holiday Inn motel in Altus.

Eagle staff writer Jared Stonesifer contributed to this report.