This hurricane season is expected to be one of the most active since 2012, when Superstorm Sandy caused massive flooding and damage in the Northeast, the federal government said Thursday.

The National Oceanic and Atmospheric Administration said it is raising the number of severe hurricanes expected this season, which runs from June 1-Nov. 30, from its May forecast. Mid-August to mid-September is the most active hurricane period for the East Coast and Caribbean.

"We've raised the numbers because some conditions now in place are indicative of a more active hurricane season, such as El Nino ending, weaker vertical wind shear and weaker trade winds over the central tropical Atlantic, and a stronger west African monsoon," said Gerry Bell, the agency's lead seasonal hurricane forecaster at the Climate Prediction Center.

"However, less conducive ocean temperature patterns in both the Atlantic and eastern subtropical North Pacific, combined with stronger wind shear and sinking motion in the atmosphere over the Caribbean Sea, are expected to prevent the season from becoming extremely active."

At the same time, the agency is lowering the chances of this year becoming "a below-normal season" to only 15 percent, with a 50 percent chance of it being an above-normal season and a 35 percent chance it will be a "near-normal" season. Nevertheless, the agency said it is "expected to be the most active since 2012," when Sandy pummeled the East Coast.

Federal forecasters are predicting a 70 percent chance that 12-17 storms become named, which means they have reached significant force and could evolve into a hurricane. Nearly half of those, about five-eight, are expected to become full-fledged hurricanes. And two-four of those became "major hurricanes."

The agency initially predicted one-four becoming major hurricanes this season. The seasonal averages are 12 named storms, six hurricanes and three major hurricanes, according to NOAA.

A major hurricane hasn't hit the U.S. in 11 years. Sandy wasn't actually a hurricane when it hit the East Coast, as it had turned into a post-tropical cyclone.