The Atlantic should produce a near-normal 12 storms during the hurricane season that officially began Wednesday, while the U.S. coastline has a below-average chance of being struck by a major system, according to Colorado State University’s forecast.

Of the 12 storms, five could become hurricanes and two could grow into major systems of Category 3 or stronger, said Phil Klotzbach, lead author of the closely watched seasonal outlook. The United States has a 50 percent chance of being struck by a major hurricane, just below the 20th century average of 52 percent.

“As is the case with all hurricane seasons, coastal residents are reminded that it only takes one hurricane making landfall to make it an active season for them,” Klotzbach said. “They should prepare the same for every season, regardless how much activity is predicted.”

In an average year, 12 systems of tropical storm strength or greater form from June 1 through Nov. 30. Already this year, Hurricane Alex formed in January and Tropical Storm Bonnie struck the coast of South Carolina last week.

Klotzbach said his prediction doesn’t include those two, so 2016 could end up with 14 in total. A weakening El Niño in the Pacific Ocean could make conditions in the Atlantic more conducive for tropical storms and hurricanes.

Atlantic hurricanes can exact a high toll in human life and damage and roil energy and agriculture markets.