Forecasters predict the 2014 Atlantic hurricane season will be "near or below average," thanks to an expected El Nino phenomenon, the National Oceanic and Atmospheric Administration said Thursday.

But the US agency said residents in hurricane-prone areas should still be on their guard during the season, which stretches from June 1 to November 30.

This year, the region could see between eight and 13 tropical storms originating in the Atlantic Ocean, of which three to six could rise to hurricane strength.

And only one or two of the hurricanes will likely reach category-three wind speeds, NOAA chief Kathryn Sullivan said at a press conference.

She said several factors contributed to the relatively moderate forecast, including the expected arrival in late summer of El Nino, when a huge mass of warm water builds in the western Pacific and eventually shifts to the eastern side of the ocean.

Sullivan said "near average" water surface temperatures in the Atlantic -- in contrast to recent years with warmer than usual temperatures -- would also contribute to the quiet season.

The last time El Nino made an appearance was in 2009-2010.

Nevertheless, Sullivan urged Americans to stay vigilant.

"We are starting hurricane season, any section of our coast line can be hit by a tropical storm," she said. "It takes only one land-falling storm to cause a disaster."

And NOAA predictions aren't set in stone.

Last year, NOAA forecast a more active than usual hurricane season, with up to 30 tropical storms and three to six hurricanes.

But in the end, the Atlantic storm season was the calmest on record since 1982, with just 13 storms, only two of which rose to become category one hurricanes.

NOAA chief forecaster Gerry Bell also emphasized that in the Atlantic -- where 12 of the past 20 seasons have exceeded averages -- a climatic cycle set off in 1995 has been marked by stronger and more numerous storms.

The average for the Atlantic season is 12 storms, including six moderate hurricanes (categories one and two) and three major hurricanes (categories three or higher).

Storms ranked category three or higher on the Saffir-Simpson scale are characterized by winds at least 111 miles (179 kilometers) per hour.

At category five, the highest level on the five-point scale, winds exceed 155 miles per hour.