Warmer-than-average water temperatures are expected to help yield a few more Atlantic hurricanes than usual this year, forecasters said Thursday.

Forecasters predict an above-normal Atlantic hurricane season, with 13 to 20 named storms, seven to 11 hurricanes and three to six major hurricanes, the National Oceanic and Atmospheric Administration Climate Prediction Center said.

For the Atlantic Ocean, a normal season would produce 12 named storms, including six hurricanes and three major ones.

The Atlantic hurricane season runs from June 1 to November 30.

"This year, oceanic and atmospheric conditions in the Atlantic basin are expected to produce more and stronger hurricanes," said Gerry Bell, the center's lead seasonal hurricane forecaster. "These conditions include weaker wind shear, warmer Atlantic waters and conducive winds patterns coming from Africa."

A major hurricane, designated as Category 3 or greater, packs winds of well over 100 mph.

In addition, forecasters predicted a below-normal Eastern Pacific hurricane season, with 11 to 16 named storms, including five to eight hurricanes and one to four major hurricanes.

It is extremely rare for an Eastern Pacific hurricane to affect the U.S. mainland, though some do have an influence on Hawaii.

The Eastern Pacific hurricane season runs from May 15 through November 30.