Dec 29 (Reuters) - A storm system that triggered deadly tornadoes and flooding in the U.S. Midwest and Southwest was pushing north on Tuesday, bringing snow and ice to a swath of the country from Iowa to Massachusetts and threatening another day of air travel delays.
More than 40 people were killed in wild weather in the United States during the Christmas holidays last week, including 11 in the Dallas area who died in a series of twisters that reduced buildings and homes to splinters.
The severe weather also has stranded tens of thousands of air travelers during one of busiest travel periods of the year.
By early Tuesday, 931 flights had been canceled in the United States and 2,441 were delayed. About 2,900 flights were canceled on Monday and nearly 5,000 others delayed according to FlightAware.com.
Travelers - whether on the roads or at airports - could expect a new round of delays, the weather forecasting site AccuWeather said. On its official Twitter account, United Airlines tried to reassure passengers that they would be rebooked as soon as possible.
Parts of eastern Oklahoma, Arkansas, Missouri and Illinois were under flood warnings and flood watches early Tuesday, while up to a foot (30 cm) of snow was forecast for Iowa and the Great Lakes region, the National Weather Service (NWS) said.
The Northeast, which basked under unusually warm temperatures over the Christmas holiday, was getting its first major snow and ice of the season, with significant snowfall in upstate New York and New England. The busy corridor from New York City to Washington, D.C., could expect sleet and rain through midday Tuesday, according to the NWS.
In Chicago, which was pelted by sleet and strong winds, 245 flights were canceled on Tuesday at O'Hare International Airport, the country's second busiest airport and a hub for both United and American Airlines.
The weather also created treacherous road conditions. Two women were killed on Monday when their car got stuck on icy tracks and was hit by a commuter train, according to local media reports.
The low-pressure storm system pummeled the Missouri Valley and Texas during the weekend, and created blizzard conditions in New Mexico and western Texas.
Days of heavy rain triggered flooding in Missouri, where state officials said the death toll could reach 13. At least three people were still missing in flooded areas late on Monday, the St. Louis Post-Dispatch reported.
(Reporting by Victoria Cavaliere in Los Angeles and Mary Wisniewski in Chicago; Editing by Dominic Evans and Bill Trott)