Multiple weather systems are significantly impacting Thanksgiving travel across the United States. A large, cross-country winter storm is bringing heavy snow, rain, and strong winds from the Pacific Northwest through the Midwest and into the East, with blizzard warnings issued for parts of Wisconsin and Michigan. The storm is expected to cause extensive travel disruptions, including delays at major airports such as Chicago O'Hare, Minneapolis-St. Paul, and New York City, with over 630 flights delayed early Wednesday. Severe lake-effect snow, with up to 3 feet possible in northern Wisconsin and Michigan, is creating dangerous travel conditions, especially in the Great Lakes snowbelts. Additionally, heavy rain and thunderstorms are forecasted in the South, including Texas and Louisiana, raising concerns about flash flooding. Temperatures are plunging, with Arctic air causing temperatures to drop into the single digits and below zero in some northern regions, marking the start of a colder winter period. Travelers are advised to plan ahead, with the best travel times before 11 a.m. or after 8 p.m. on peak days to avoid delays. Despite efforts by airlines to manage holiday traffic, volatile weather threatens to cause widespread delays and cancellations, affecting millions of travelers during the busiest travel weekend of the year.