Extremely Active 2013 Hurricane Season Expected

May 23 -- A year after Superstorm Sandy, residents along the Atlantic and Gulf coasts should prepare for "an extremely active" 2013 hurricane season, U.S. forecasters say.

There is a "70 percent likelihood" that will be three to six major hurricanes this year with winds above 111 mph, according to the 2013 hurricane outlook unveiled by the National Oceanic and Atmospheric Administration's Climate Prediction Center on Thursday.

During the six-month hurricane season, which begins June 1, forecasters anticipate 13 to 20 named storms (winds of 39 mph or higher). Of those, seven to 11 could become hurricanes (winds of 74 mph or higher).

Those ranges are above normal. According to the National Hurricane Center, the seasonal average is 12 named storms, six hurricanes and three major hurricanes. Hurricane season ends Nov. 30.

The dire forecast comes as many shoreline residents—particularly in New York and New Jersey—are still recovering from Sandy, which killed 147 people and caused more than $75 billion in damage in October 2012. It was the second-costliest hurricane in U.S. history.

The 2012 hurricane season produced 19 named storms, including 10 hurricanes and two major hurricanes—Sandy and Michael, a Category 3 storm that stayed over the open Atlantic. The number of named storms and hurricanes were above average, but the two major hurricanes was below the average of three.

Climate factors—including warmer-than-average water temperatures in the Atlantic Ocean—contributed to 2013's active forecast, the NOAA said.

And homeowners should begin their storm preparations now.

"Take time to refresh your hurricane preparedness plan," Kathryn Sullivan, NOAA acting administrator, said during a news conference in College Park, Md., on Thursday. "Bottom line is become weather-ready now—that means starting today."

NOAA also unveiled plans for a new "supercomputer" that will run an "upgraded Hurricane Weather Research and Forecasting models." That, combined with new Doppler technology from NOAA's"hurricane hunter" aircraft, is expected to improve forecast accuracy "by 10 to 15 percent," the NOAA said.

The seasonal hurricane outlook does not predict how many storms will hit land or where a storm will strike. For people living on the shorelines, Sullivan said, "this is your warning."