Retailers, take note. Traffic at the nation's major retail container ports is expected to surge to new highs this summer, setting a record in July before immediately breaking that record in August. And that's two months before the normal peak shipping season begins.

According to the monthly Port Tracker report released by the National Retail Federation (NRF) and Global Insight, July's volume will reach 1.54 million TEUs (twenty-foot equivalent units), which would surpass last October's high of 1.51 million. The forecast calls for August's volume to reach 1.57 million TEUs.

Global Insight economist Paul Bingham says he hasn't seen any indications of trouble yet. "The docks, rails, and trucks are keeping up," he reports, "So as long as we don't see any new weather disruptions, shippers can expect acceptable system performance for the next six months."

Just the same, retailers will want to remain vigilant, says Erik Autor, the NRF's vice president and international trade counsel. "The ports are going to be busier than ever this summer," he says. "It's crucial that retailers keep a close eye on these numbers to ensure that the goods end up on store shelves when … they're needed."