Factbox: More active Atlantic hurricane season seen for 2016

(Reuters) - With the start of the 2016 hurricane season less than a week away and a possible storm already brewing off the U.S. East Coast, most meteorologists agree that this year will be more active than last year, in part because of the expected end of the El Niño weather phenomenon and the coming of La Niña. El Niño is a warming of the water in the central Pacific Ocean and has been linked to weak hurricane seasons such as the one in 2015. La Niña, a cooling of those same waters, has been linked to more active hurricane seasons. The U.S. National Oceanic and Atmospheric Administration (NOAA) on Friday predicted a 70 percent likelihood of 10 to 16 named storms with winds of 39 miles per hour (63 km per hour) or stronger, of which four to eight could become hurricanes with winds of 74 mph or stronger, including one to four major hurricanes with winds of 111 mph or more. The current El Niño, which started early in 2015, was the strongest since 1997. It is expected to end in the late spring or early summer, according to the U.S. Climate Prediction Center. The 2015 hurricane season was mostly quiet, due in part to the strong El Niño. There were 11 named storms, including four hurricanes, of which two were major, according to federal data. The system brewing north of the Bahamas has a 90 percent chance of developing into a tropical storm over the next day or two as it moves toward South Carolina, according to the U.S. National Hurricane Center. Hurricanes do not pack the same punch for the U.S. natural gas market as a decade ago because the bulk of the nation's production has moved from the storm-prone Gulf of Mexico to shale fields located far from the coast, such as the Marcellus formation in Pennsylvania and West Virginia. U.S. gas futures hit record highs of around $15 per million British thermal units in 2005 in the months after hurricanes Katrina and Rita slammed into the Gulf Coast. At that time, more than 20 percent of U.S. dry gas output came from the federal waters in the Gulf of Mexico. Spurred in part by those high prices, producers figured out how to free gas trapped in shale rocks economically, with technologies such as horizontal drilling and hydraulic fracturing sparking the so-called shale revolution. Today, the seven biggest U.S. shale fields provide more than 60 percent of the nation's dry gas production, while federal waters in the Gulf of Mexico account for a mere 4 percent. Below are meteorologists' forecasts for named tropical storms and hurricanes in the North Atlantic, Caribbean and Gulf of Mexico for the June 1-Nov. 30 season. Forecaster Named Hurricanes Major Date Storms Hurricanes U.S. NOAA 10-16 4-8 1-4 27-May Tropical Storm Risk (TSR) 17 9 4 27-May IBM's The Weather Co 14 8 3 27-Apr North Carolina State University 15-18 8-11 3-5 15-Apr Colorado State University 12 5 2 14-Apr Global Weather Oscillations 17 9 4 13-Apr MDA - EarthSat 14 7 3 7-Apr AccuWeather 14 8 4 7-Apr NOAA Normal (1981-2010) 12 7 3 The Weather Co Normal (1950-2015) 12 7 3 The Weather Co Normal (1995-2015) 15 8 3 TSR Normal (1950-2015) 11 6 3 TSR Normal (2006-2015) 14 6 3 * The named tropical storms may or may not include Alex, which formed in January 2016. (Reporting by Scott DiSavino in New York; Editing by Matthew Lewis)