A powerful winter storm is set to blast portions of the U.S. with accumulating snow, cold temperatures, strong winds and rain just as millions of people across the country prepare to travel early for Thanksgiving.The first widespread winter storm of the season is the second in a pair of storms set to sweep across the U.S. this week.The first storm system already produced severe weather on Monday across the southern Plains and lower Mississippi Valley, including several Severe Thunderstorm Warnings and Tornado Warnings in portions of Texas, Oklahoma and Louisiana.THANKSGIVING TRAVEL COULD BREAK RECORDS THIS YEAR BUT EXTREME WEATHER COULD SNARL PRE-HOLIDAY TRAVELAccording to the Denton County Office of Emergency Management in Texas, strong winds knocked over at least two tractor-trailers on Interstate 35, including one that fell onto a pickup truck, in the city of Denton.Emergency officials said the southbound side of the interstate was closed while first responders investigated the incident.HOW TO WATCH FOX WEATHERA video recorded in the community of Weatherford, Oklahoma, showed strong winds blowing and torrential rain falling across the region when the severe weather blew through early Monday morning.And a photo posted by the Somervell County, Texas, Fire Department, showed a trailer that was blown over onto its side when strong winds moved through that area.As the storm system moves off to the north this week, arctic air will collide with the storm, setting the stage for widespread snow across the Dakotas and potentially into portions of Minnesota and Wisconsin.Strong winds are expected to develop on the western side of the system on Tuesday, with wind gusts reaching 50-60 mph in the Dakotas.DRIVING ON THE ICE AND DRIVING IN THE SNOW: WEATHER DRIVING TIPS FOR DRIVING IN INCLEMENT WEATHERThe FOX Forecast Center said that travel along Interstate 29 from Fargo, North Dakota, to Sioux Falls, South Dakota, and Interstate 94 from Fargo to Bismarck, North Dakota, could be hazardous as the rain transitions to snow.On Wednesday, cities such as Minneapolis, as well as Green Bay and Milwaukee in Wisconsin, will be on alert for the potential of snow showers throughout the day as colder air wraps around the storm system.DOWNLOAD THE FREE FOX WEATHER APPAccording to the FOX Forecast Center, the second storm could have a more widespread impact, especially as people plan on traveling ahead of Thanksgiving.A powerful low-pressure system is expected to form in the Ohio River Valley and Great Lakes region and will rapidly develop. This new low will significantly intensify as it spins over the Great Lakes later this week, bringing the threat of high winds across the region into the eastern U.S.As the storm drifts off into the mid-Atlantic and Northeast toward the end of the week, trailing winds are expected to bring in enough cold air to support a large band of snow somewhere in the Ohio River Valley.WHEN CAN YOU EXPECT THE FIRST SNOW OF THE SEASON?The coldest air will be on the southern side of the system and blow into the Appalachian Mountains.It’s that area, according to the FOX Forecast Center, where snowfall is possible across portions of the Ohio Valley, the northern mid-Atlantic and the interior Northeast from the end of the week into the weekend. However, forecasters said there is still substantial uncertainty about the amount of cold air available for snow.For now, the National Weather Service has issued Winter Storm Watches for the mountains of eastern West Virginia and the western Maryland Panhandle from Thursday afternoon through Saturday evening.There’s also the threat of lake-effect snow, but it will be hit-or-miss depending on how the low-pressure system tracks, according to the FOX Forecast Center. As it stands now, the air may be too warm to support lake-effect snow.Be sure to download the free FOX Weather app and enable notifications to be alerted to any changes in the forecast.HOW MUCH SNOW WILL AN INCH OF RAIN PRODUCE?The inclement weather at the end of the week and into the weekend across the Northeast does have the potential to snarl air and road travel just as the Thanksgiving travel week gets underway.Rain in the Northeast could be heavy at times, but as of now the FOX Forecast Center doesn’t expect there to be flash flooding in the region due to the recent record-dry conditions.However, it does bring much-needed rain to the region, which will help with the ongoing wildfire threat.Out West, a powerful bomb cyclone associated with a major atmospheric river is expected to soak the region from California to Washington this week, and that could lead to flooding.The term “bomb cyclone” comes from the meteorological term “bombogenesis” or “explosive cyclogenesis.” This happens when a storm system’s central pressure drops at least 24 millibars within 24 hours.A big stream of moisture is set to arrive on Tuesday night and is likely to stick around through late in the week, possibly into the weekend, the FOX Forecast Center said.