"NRF's annual forecast says retailers should see solid growth during the holiday season this year and these cargo numbers back it up," said Jonathan Gold, NRF vice president for supply chain and customs policy. "Increased imports show that retailers have gauged the market and expect increased sales."

U.S. ports followed by Global Port Tracker handled 1.42 million twenty-foot equivalent units in August, the latest month for which after-the-fact numbers are available. That was up 6.7 percent from July and 3.3 percent from August 2011. One TEU is one 20-foot cargo container or its equivalent.

September was estimated at 1.49 million TEUs, up 8 percent from last year, and October is forecast at 1.45 million TEUs, up 9.9 percent. August, September and October are the three busiest months of the year as retailers bring merchandise into the country for the holiday season, and volume for the three months combined is up 7 percent. While cargo volume doesn't correlate directly with sales, NRF forecast last week that holiday sales will increase 4.1 percent to $586bn this year.

With most holiday merchandise already at least in distribution centers by the end of October, monthly cargo volume will drop off for the remainder of the year but will remain above 2011 levels. November is forecast at 1.32 million TEUs, up 2.4 percent from last year, and December is forecast at 1.28 million TEUs, up 4.6 percent. After the holidays, January 2013 is forecast to stay at 1.28 million TEUs, down one-half of 1 percent from January 2012, and February is forecast at 1.19 million TEUs, up 9 percent from a year earlier.

The first half of 2012 totaled 7.7 million TEUs, up 2.9 percent from the same period last year. For the full year, 2012 is expected to total 16 million TEUs, up 4.1 percent from 2011.

Hackett Associates founder Ben Hackett noted that some retailers brought cargo into the country early because of the threat of a strike when the labor contract covering East Coast and Gulf Coast longshoremen was set to expire September 30. The strike was averted when labor and management agreed to continue talks through December 31.

"Inventories are up, which could be due to lack of demand but it could also be due to pre-stocking in anticipation of the dock strike that didn't come," Hackett said. "Either way, it is within a narrow range of movement and it does not suggest that we are sliding into another recession."

Source: National Retail Federation