The 2017 Atlantic hurricane season, which officially begins June 1, is likely to have above-normal activity, according to forecasters at the National Oceanic and Atmospheric Administration’s (NOAA) Climate Prediction Center.

NOAA forecasters said Thursday they expect 11-17 named storms to form in the Atlantic Basin this year, with five to nine of them becoming hurricanes, include two to four major hurricanes (Category 3 or higher).

Those numbers are higher than earlier predictions by two other prominent weather forecasters. In an extended range forecast released in April, scientists at Colorado State University (CSU) said they expected slightly below-average activity in the Atlantic Basin this year, with 11 named storms, of which four are expected to become hurricanes, including two major hurricanes. AccuWeather meteorologists have said they expect 10 named storms in the Atlantic this year, of which five could become hurricanes, including three major hurricanes.

There were 15 named storms, including seven hurricanes, four of them major hurricanes, in the Atlantic Basin in 2016. The median during 1981-2010 was 12 named storms, four of them hurricanes, including two major hurricanes.

The CSU forecast team based its outlook on the likelihood of a potential El Nino event limiting the tropical storm production in the Atlantic this year. NOAA forecasters believe El Nino will play a different role.

“The outlook reflects our expectation of a weak or nonexistent El Nino, near- or above-average sea-surface temperatures across the tropical Atlantic Ocean and Caribbean Sea, and average or weaker-than-average vertical wind shear in that same region,” said Gerry Bell, lead seasonal hurricane forecaster with the Climate Prediction Center.

NOAA’s tropical forecast numbers include Tropical Storm Arlene, a rare pre-season storm that formed in April over the eastern Atlantic.

Despite the even more unusual formation of a hurricanein January 2016, the Atlantic Basin last year produced relatively few storms that had significant impact on U.S. oil and natural gas interests.

In early September, Hurricane Hermine made landfall as a Category 1 hurricane near St. Marks, FL, and forced nearly 20% of Gulf of Mexico (GOM) oil production and nearly 11% of GOM natural gas production to be temporarily shut in. A month later, Hurricane Matthew slammed into Florida’s east coast, knocking out electricity to hundreds of thousands, resulting in a 0.5 Bcf/d drop in natural gas demand in the state.

A combination of fewer tropical storms and a lessening reliance on GOM oil and natural gas production (thanks to the growth in production from inland shale plays) has kept hurricane-related damage to the nation’s energy infrastructure and markets to a minimum in recent years.