ST. LOUIS (AP) -- Holiday travelers in the Midwest and parts East and South were keeping a leery eye Friday on a band of foul weather stretching across the nation's midsection that was threatening to mar the opening weekend of one of the year's busiest travel periods.
Forecasters were predicting a stew of foul weekend weather, from freezing rain and snow in the north to torrential rain in the Ohio Valley and Appalachia and possibly even tornadoes in the South.
The worst of the storm wasn't expected to hit Midwest population centers until Saturday, and although few flights had been canceled as of midday Friday, the weather was already taking a toll on air travel: FlightStats.com reported more than 1,900 U.S. delays, with the most at Chicago's O'Hare, Denver International, and the three big New York-area airports.
The foul weather could cause headaches for the estimated 94.5 million Americans planning to travel by road or air during this holiday season, which runs from Saturday through New Year's Day. Concerns were similar a month ago, when a winter storm hit just as people were traveling for Thanksgiving.
Dennis Richmond, 72, said Friday that he was worried that snow could delay his son's Saturday flight from Washington, D.C., to Madison, Wis., which could get up to 8 inches of snow. He said he didn't tell his son to change his itinerary, though, because there were few alternatives, and that he still planned to drive the roughly 140 miles from La Crosse to pick him up.
"The thing is, trying to book another flight at this time of year is next to impossible," he said. "I just want to alert him to the fact he might be delayed."
While much of the East awoke to unusually warm temperatures on Friday, the storm was causing pre-Christmas travel worries from Chicago and Detroit to Boston and New York. In New England, communities were planning for a bit of everything — snow, sleet and rain — but were most concerned about the threat of freezing rain.
The National Weather Service predicted that parts of Maine could get more than a half-inch coating of ice, which would make roads treacherous and cause widespread power outages.
"The best advice for everyone is just to really pay attention. With every few hours, we're going to get better information," Maine Emergency Management Agency spokeswoman Lynnette Miller said Friday.
Freezing rain snarled traffic and forced some school closures in Michigan and Wisconsin on Friday. The Wisconsin Department of Transportation said Interstate 90/94 was ice-covered from Tomah and Mauston. The state was bracing for significant snow, sleet and ice.
The weather service issued a flash flood watch from Arkansas northeastward through parts of Missouri, Illinois, Indiana and Ohio, with up to 4 inches of rain projected. With falling temperatures, some of that could be freezing rain by Saturday night in the St. Louis area, weather service meteorologist Jon Carney said.
While the Midwest and Plains were preparing for ice and snow, residents down South were concerned about tornadoes, which forecasters said were possible this weekend even though they are uncommon this time of year. The area most threatened stretched from central and northeastern Texas through Louisiana, Mississippi, Arkansas and southeast Missouri, where 80 mph wind gusts and flash flooding were possible.
Tom Kines, an AccuWeather meteorologist, said a northern cold front clashing with warm, humid air from the South is causing the unsettled weather.
"I think there's a high likelihood there will be severe storms with hail and damaging wind" in parts of the South, Kines said. "Whether or not there's tornadoes, that's tough to say, but I will say the conditions are right."
Weekend temperatures could surpass 70 degrees in Nashville this weekend and approach that in New York City, as well, Kines said. But by Sunday night, the storm will be hammering the Northeast, where residents could be treated to a rare winter thunderstorm.
Kansas City, Mo., was bracing for freezing rain this weekend followed by 6 inches of snow.
In Vinita, Okla., on Friday, customers lined for gas at the Diamond Rio convenience store in preparation for the snow and ice the region was expecting. The state gets more than its share of nasty weather, and local resident James Allen was taking the latest batch in stride.
"Right now I don't think it's gonna be that bad," he said. "Might be a little bit of ice and snow but I think it'll melt off in a couple of days."
If there is a silver lining, it's that Christmas happens mid-week this year, said AAA spokeswoman Heather Hunter.
"When a holiday falls on a Wednesday it gives travelers more flexibility of either leaving the weekend before, or traveling right before the holiday and extending the trip through the following weekend," Hunter said.
Associated Press writers Kelly P. Kissel in Little Rock, Ark., David Sharp in Portland, Maine, Dinesh Ramde in Milwaukee, Joshua Freed in Minneapolis and Ken Miller in Oklahoma City contributed to this report.