If you have last-minute Christmas gifts in transit, they may run into some delays after a sprawling winter storm battered much of the mainland United States.

Flurries of snow, dangerous winds and below-freezing temperatures have wreaked havoc on shipping giants FedEx and UPS, with both companies reporting "major service disruptions" at several key shipping hubs in the midwest.

FedEx reported "substantial disruptions" and its Indianapolis and Memphis hubs Thursday night, and said "potential delays" are possible for deliveries originally slated to arrive Friday and Saturday across much of the U.S.

You can track your shipments on fedex.com. Residential recipients can enroll in FedEx Delivery Manager to stay informed of their shipment’s progress.

UPS reported distruptions to its air and ground services, including vital hubs in Louisville, Ky., and Rockford, Ill.

It's not yet clear how long those disruptions will persist as a crippling cold front lingers into the weekend. The most up-to-date information on the status of UPS shipments is available by tracking a package on ups.com.

"We will work to ensure the safety of our employees while minimizing effects on service," UPS's website states. "Contingency plans are in place to help ensure that shipments arrive at their final destinations as quickly as conditions permit."