Those saving their Thanksgiving trip for the day may encounter snags when it comes to roads in the eastern half of the country.

An updated forecast from AccuWeather shows expected weather impacts across the country as nearly 80 million Americans will travel for the holidays, AAA reported. AccuWeather predicts that “significant travel disruptions are expected for tens of millions” of travelers.

The busiest travel days are expected to be Tuesday and Wednesday, but for people traveling shorter distances, saving the trip until Thanksgiving morning could mean a fair amount of travel disruption.

Showers and thunderstorms are expected to hit much of the country Thursday, from Louisiana northeast to Pennsylvania, which could delay travelers, according to a map from AccuWeather. Further north, several inches of snow could cause disruptions in the Midwest and into the Northeast.

Although bad weather can occur after the busiest travel days, AccuWeather senior meteorologist Tom Kines said Newsweek that winter weather could still impact those who leave their trip until the last minute, or who have less than a few hours to drive to their destination.

National Weather Service (NWS) offices in affected regions are already issuing warnings about the possibility of severe weather.

“A mix of rain and snow will move through the region Wednesday through Wednesday night. While most will see little to no snow accumulation, there is potential for a narrow band of snow somewhere north of I-70 to bring at least an inch of snow. (30-40 percent chance),” the NWS office in Lincoln, Illinois, said in a dangerous weather forecast. “If this happens, there could be minor travel impacts.”

Even if people reach their destinations safely on Turkey Day, a “significant” lake-effect snow event could disrupt travel in the Northeast as people return home on Friday or over the weekend.

“The potential exists for a significant extended snow event with lake effects. There is significant uncertainty regarding exact band placement and amounts, but multiple periods of heavy snow are possible,” NWS Buffalo warned during a winter storm watch. “Travel may be very difficult to impossible with very poor visibility and deep snow on the roads. Some major roadways may be temporarily closed. The hazardous conditions could impact the post-Thanksgiving travel season.”

Meanwhile, the latest atmospheric river to dump a deluge on California earlier this week will have left the region, leaving travelers in the West free to travel home without weather disruptions.