AIR cargo customers are experiencing shipping delays in parts of North America because of winter storms and Delta's regional jet crash in Toronto, reports New York's FreightWaves.

Toronto airport has closed two runways, one of which is the busiest runway in Canada, resulting in reduced flight capacity as it recovers from the Delta crash and three major snowstorms recently. Two other runways are open to traffic, according to airport duty manager Jake Keating.

The airport is limiting the number of departures it will allow throughout the day to ensure operations aren't overwhelmed and aircraft aren't stuck on the airfield waiting for gates.

Investigators say the Delta CRJ-900 jet that flipped over will remain on the runway for 48 hours while they continue to gather information about the cause of the accident.

After the aircraft is removed from the runway, the airport will still need to conduct inspections to make sure the runway and equipment are not damaged before it can be opened to commercial traffic, Mr Keating said.

Adverse weather conditions disrupted FedEx flights at its hub in Memphis, and customers suffered delays, the company said.

Several inches of snow and sleet fell across the mid-South, including Memphis.

FedEx notified customers early last week of possible delays related to the heavy flooding in Kentucky.

The snowstorm also reached Louisville, Kentucky, home to UPS' main air hub. The express delivery and logistics giant said scheduled delivery times for a limited number of air and international packages may be affected by operational disruptions at the Worldport facility.