An above-average number of storms will emerge from the Atlantic this hurricane season, and the odds of the United States being hit by a major system are greater than predicted last year, Colorado State University researchers said.
Eighteen named storms will develop in 2013, the forecasters said in their initial seasonal outlook. Nine are expected to become hurricanes, four of them major systems of Category 3 or higher with winds of at least 111 miles per hour.
The Colorado State team estimated chances of a major hurricane strike on the country this year at 72 percent, compared with 42 percent last year. Sandy, which devastated parts of New York and New Jersey in October, had winds of a Category 1 level.
‘‘We think we will have a pretty active season here,’’ said William Gray, professor emeritus who pioneered long-range hurricane forecasting.
Atlantic hurricanes are watched closely because of their threat to major US population centers and to the Gulf of Mexico. The Gulf is home to 7 percent of US natural gas output, 23 percent of oil production, and 44 percent of refining capacity, according to the Energy Department.
Last year, the Colorado State forecasters predicted 10 named storms, about half of what developed. The 30-year average for the Atlantic storm period, which runs from June 1 through Nov. 30, is 12 systems, according to the National Hurricane Center in Miami.