Import volumes at the nation's major container ports in November is projected to rise 5.9 percent over the same period a year ago despite the supply chain disruptions caused by mega-storm Sandy, according to a monthly report published today by the National Retail Federation (NRF) and consultancy Hackett Associates.

The U.S. ports followed by the study, known as "Global Port Tracker," handled 1.42 million twenty-foot equivalent units (TEUs) in September, the latest month for which actual numbers are available. That number was the same as August but up 3.3 percent from September 2011 figures. One TEU is one 20-foot cargo container or its equivalent.

Volumes in October are estimated at 1.46 million TEU, up 10.7 percent from last year. November volumes are projected at 1.37 million TEU, up 5.9 percent, and December is forecast at 1.34 million TEU, up 9.4 percent, according to the report.

Looking to 2013, January is forecast at 1.39 million TEU, up 8.2 percent from January 2012; February at 1.22 million TEU, up 12 percent; and March at 1.26 million TEU, up 1.6 percent, according to Port Tracker estimates.

For the year, volumes at the ports are expected to rise 4.5 percent year-over-year to 16.1 million TEU, the report projected.

"Sandy certainly caused major problems that are still being cleaned up, but retailers managed to get their cargo into the country and will have plenty of merchandise on store shelves for the holidays," said Jonathan Gold, NRF's vice president for supply chain and customs policy, in a statement. "While there was clearly a regional impact, at this point the storm is not expected to have a major effect on holiday sales numbers."

"The full extent of the impact from the mayhem and destruction of Hurricane Sandy is still being assessed, but it should hopefully not have too much of a detrimental effect on trade," added Ben Hackett, founder of Hackett Associates, in the same statement. "The New York/New Jersey terminals were impacted for a short period, but cargo destined for there was handled elsewhere until service returned. Rebuilding of infrastructure and homes should cause an uptick for imports of construction materials."

The powerful storm closed the Port of New York and New Jersey's marine terminals for about a week.

Volumes for August through October were up 5.8 percent from the same period a year ago, NRF said. August, September, and October are the three busiest months of the year as retailers bring merchandise into the country for the holiday season.

The year-over-year increase in volumes may also have been influenced by importers adding inventory to ensure they would have enough stock in hand in the event of a threatened Sept. 30 strike at East and Gulf Coast ports by the International Longshoreman's Association (ILA). The ILA and ship management have agreed to continue working under the existing contract (which was set to expire Sept. 30) until the end of December while negotiations continue under the supervision of a federal mediator.

Based in part on its cargo projections, NRF forecasts 2012 U.S. holiday sales will increase 4.1 percent year-over-year to $586.1 billion. The retailer trade group said, however, that shipping volumes don't always correlate with holiday buying activity.

Global Port Tracker covers the Ports of Long Angeles/Long Beach, Oakland, Seattle, and Tacoma on the West Coast; New York/New Jersey, Hampton Roads, Charleston, Savannah, Port Everglades, and Miami on the East Coast; and Houston on the Gulf Coast.