Colorado State University meteorologists Philip Klotzbach and William Gray

Seven of the 14 storms expected next year will become hurricanes, above the 50-year average of six that typically form in the June-November season, scientists Philip Klotzbach and William Gray said in their annual outlook. Three of next year's storms are forecast to become major hurricanes, defined as having winds of at least 111 miles per hour.

Gray and Klotzbach said there was a 64 percent chance that a major storm would strike the US, compared with the 50-year average of 52 percent. The Eastern Seaboard has a 40 percent chance of being hit, while the Gulf of Mexico has a 40 percent chance, they said.

Nine weather systems this year reached tropical-storm force with winds of more than 39 mph, the threshold at which they are given names. Of those, five became hurricanes, with two strengthening to major status.