A cross-country storm, a blast of Arctic air and an outbreak of showers and thunderstorms are threatening to snarl traffic and pile up delays at airports over the Thanksgiving holiday weekend, one of the nation's busiest travel periods.

Mother Nature is about to serve up some unappetizing conditions for the millions of Thanksgiving travelers: sloppy weather, snow, the coldest temperatures since February and a potentially disruptive storm are on the way through the holiday weekend. Here’s a day-by-day look at what to expect this week.

Don't worry about making space in your freezer for leftovers this year if you live in any of the states expected to have a chilly holiday weekend.

"Heavy coastal and mountain rain may lead to instances of flash flooding, particularly over the windward foothills of the southern Sierra Nevada below 8,000 feet, where excessive rainfall may cause land/rock/mudslides," the NWS said in a forecast Tuesday morning.

With Thanksgiving holiday travel well underway, many have reached their destinations — but for everyone else, a storm tracking from the Rockies to the Midwest and Northeast into Thursday will bring rain and snow,

One of the strongest storms we've seen in Massachusetts in quite a while will bring rain and snow on Thanksgiving.The holiday will essentially be a washout with rain expected from mid-morning until late in the evening Thursday.

Some people save their Thanksgiving travel for the day-of, and those in the eastern half of the U.S. could experience disruptions.

Snow and rain are in the forecast for some parts of the U.S. as travelers hit the road and head to the airport for Thanksgiving. Here's your weather forecast for the holiday week: Wednesday Heavy snow is hitting the Colorado Rocky Mountains on Wednesday.