A major storm that will plow into the eastern half of the United States late this week could throw a wrench into plans for early holiday travelers as well as holiday shipping.  AccuWeather Chief Broadcast Meteorologist Bernie Rayno said major travel delays are likely as the storm shifts from the Southeast to the Northeast.

“This late-week storm is gonna impact a large chunk of the eastern half of the United States with rain and wind,” Rayno said. “Travelers via airways or roadways can expect delays. Also, holiday shipping is gonna be impacted as well.”

“It always pays to order online early because it’s possible that shipments can be delayed by a couple of days by storms so it’s always advisable not to order something on the 23rd if you want something by the 24th,” said AccuWeather President and Founder Dr. Joel N. Myers.

While several deadlines for major courier services have already come and gone, there is still time this week to ship items in time for Christmas.

The United States Postal Service lists a variety of deadlines for different types of mail service, including international or military mail, in order for items to reach their destination before Christmas. The deadline for sending anything using First-Class or Priority Mail Service in the contiguous U.S. is Dec. 20, while the deadline for Priority Mail Express Service is Dec. 22.

The USPS said the week of Dec. 17-23 is the busiest week of the holiday season, with nearly 3 million pieces of mail, which includes packages, processed and delivered.

For those planning to use UPS, for packages to arrive by Monday, Dec. 24, the deadline for UPS 2nd Day Air delivery is Thursday, Dec. 20, while UPS Next Day Air is Friday, Dec. 21.

This Thursday and Friday are the cutoff days for select overnight and two-day delivery options for FedEx services within the U.S. However, FedEx does offer “SameDay” delivery services in select metro markets on Christmas Day.

In an interview with AccuWeather earlier this month, UPS Public Relations manager Jim Mayer urged customers to “ship now, don’t wait” to avoid the risk of any possible delays.