May 23, 2013

NOAA’s Climate Prediction Center announced today that a below-normal hurricane season is most likely for the Eastern Pacific this year. The outlook calls for a 55 percent probability of a below-normal season, a 35 percent probability of a near-normal season and a 10 percent probability of an above-normal season.

Seasonal hurricane forecasters are calling for a 70 percent chance of 11 to 16 named storms, which includes 5 to 8 hurricanes, of which 1 to 4 are expected to become major hurricanes (Category 3, 4 or 5 on the Saffir-Simpson Hurricane Wind Scale).

An average Eastern Pacific hurricane season produces 15 named storms, with eight becoming hurricanes and four becoming major hurricanes. The Eastern Pacific hurricane season runs from May 15 through Nov. 30, with peak activity from July through September. Tropical Storm Alvin, the season’s first named storm, developed on May 15.

The key climate factors behind this outlook are:

• A continuation of the climate pattern responsible for the ongoing era of low-activity for Eastern Pacific hurricanes that began in 1995;

• ENSO neutral (meaning  El Niño or La Niña is unlikely), but with near- or below-average sea surface temperatures in eastern equatorial Pacific Ocean.

“Although a below-normal season is most likely this year, we encourage everyone to get prepared for the start of the season and to check the forecast as storms develop,” said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center, part of the U.S. National Weather Service. “It only takes one storm making landfall in your area to make it a bad year for you, regardless of the overall activity predicted in the seasonal outlook. So residents, businesses, and government agencies of coastal and near-coastal regions should prepare for every hurricane season regardless of the seasonal outlook.”

The outlook is a general guide to the overall seasonal hurricane activity. It does not predict whether, where, or when any of these storms may hit land. Eastern Pacific tropical storms and hurricanes most often track westward over open waters, sometimes reaching Hawaii. However, some occasionally head toward the northeast and may bring rainfall to the arid southwestern United States during the summer or fall. Also, on average, two to three storms per season affect western Mexico or Central America.

NOAA’s hurricane outlook for the Central Pacific basin calls for a below-normal season while the Atlantic basin is expected to be above-normal.

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