Chicago - Storms packing ice, sleet and rain could upend Thanksgiving holiday plans for millions of Americans taking to the roads, skies and rails on Wednesday, likely the busiest travel day of the year.So far, the deadly storms barrelling into the mid-Atlantic and Northeast have not resulted in many flight delays or cancellations.But forecasters are expecting the weather to worsen throughout Wednesday, just as many Americans are setting out to join far-flung family members in time for Thanksgiving on Thursday. More than 43 million people are to travel over the long holiday weekend, according to the AAA, a federation of motor clubs in the US and Canada."The timing of the storm couldn't be worse," said Chris Vaccaro, spokesperson for the National Weather Service headquarters in Maryland. "We are seeing numerous threats as the storm is beginning to develop and intensify."Heavy rain and breezy conditions were to strike the East Coast from the Carolinas to the Northeast on Wednesday, with ice and snow a possibility in the Appalachians, western Pennsylvania and western New York. Snow totals from the Ohio Valley to the interior of the Northeast were expected to be less than 25.4cm, the weather service said. ‘Worst time ever’The storm system, which developed in the West, has been blamed for at least 11 deaths, half of them in Texas. It limped across Arkansas with a smattering of snow, sleet and freezing rain that didn't meet expectations.But even a weaker than expected storm system is potentially bad news the day before Thanksgiving.The overwhelming majority of travellers - about 39 million people - will be on the roads during the long weekend. But more than 3 million people are expected to filter through airports, and the weather could snarl takeoffs and landings at some of the busiest hubs on the East Coast, including New York and Washington, DC.Weather woes aside, there were some things for travellers to be happy about this year. The Federal Aviation Administration last month lifted restrictions on the use of most personal electronic devices during takeoffs and landings, and some airlines, including American, have already begun allowing passengers to stay powered up from gate to gate.On the ground, gas prices are a little cheaper than a year earlier.Jeff Smidt hoped to travel from his home in Toronto on Wednesday to visit his family near Boston. He planned to drive if he could not fly because of the weather."My understanding is that I'm travelling at like the worst time ever," Smidt said. He tried to change his JetBlue reservation to get on an earlier flight but was told the airline wasn't waiving any change fees yet."Worst comes to worst, it will be an eight-hour trek down Interstate 90," he said.