Kansas ? Holiday travelers battled slick, icy roads and flight cancellations and delays on Wednesday as a major winter storm began to spread across much of the nation’s midsection — and the worst of the weather was still expected to come.

The slow-moving storm was likely to intensify today as it continued its trek north and east, bringing heavy snow, sleet and rain to a large swath of the Plains and the Midwest. A foot or two of snow was possible in some areas by Christmas Day.

“It’s an unusually large storm, even for the Plains,” said Scott Whitmore, a National Weather Service meteorologist in Topeka.

In northwest Kansas, snow started falling before sunrise Wednesday, after freezing rain had already iced up roads.

A stretch of Interstate 70 in western Kansas was snowpacked by mid-afternoon. The state Department of Transportation warned that travel would be almost impossible in northeast Kansas by this afternoon.

“It’s kind of hard to stay on the roads. You’ve got to go slow,” said Jason Juhan, a clerk at the Love’s truck stop in Goodland. “People are just trying to get through and get to where they need to as fast as they can.”

Still, he saw an upside: “It’s been a few years since we’ve actually had a white Christmas out this way.”