NOAA 2005-061
Contact: Carmeyia Gillis
NOAA News Releases 2005
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Below Normal Seasonal Activity Expected in 2005

NOAA, the National Oceanic and Atmospheric Administration, today released its 2005 East Pacific Hurricane Season Outlook. The outlook calls for a high likelihood of below normal activity. NOAA scientists are expecting 11-15 tropical storms. Six to eight of these are expected to become hurricanes, including two to four major hurricanes.

“There tends to be a seesaw affect between the East Pacific and North Atlantic hurricane seasons,” said Jim Laver, director, NOAA’s Climate Prediction Center in Camp Springs, Md. “When there is above normal seasonal activity in the Atlantic there tends to be below normal seasonal activity in the Pacific. This has been especially true since 1995. Six of the last ten East Pacific hurricane seasons have been below normal, and NOAA scientists are expecting lower levels of activity again this season.”

The seesaw effect between the East Pacific and North Atlantic hurricane seasons occurs because the two dominant climate factors that control much of the activity in both regions often act to suppress activity in one region while enhancing it in the other.

Like the Atlantic hurricane season, the El Niño/La Niña cycle is a dominant climate factor influencing the East Pacific hurricane season. “However, this hurricane season we are most likely to be in a neutral pattern in regards to El Niño/La Niña,” said Vernon Kousky, NOAA’s El Niño/La Niña expert.

While the thought of a hurricane is a sobering image to many people, there are some positive aspects in regards to the East Pacific hurricane season. In contrast to its sibling - the North Atlantic hurricane season, which can cause deadly storms in the southern and eastern United States - “the East Pacific hurricane season can bring much needed precipitation to the usually dry southwestern United States during the summer months,” said Muthuvel Chelliah, NOAA’s Climate Prediction Center’s lead coordinator for the East and Central Pacific Hurricane Season Outlooks.

“Most East Pacific tropical storms trek westward over open waters, sometimes reaching Hawaii and beyond. Yet, during any given season, one or two tropical storms can either head northward or re-curve toward western Mexico,” said Chelliah.

After two years of successful experimental outlooks issued by NOAA in 2003 and 2004, the East Pacific Hurricane Season Outlook becomes an operational product this year. Unlike the North Atlantic, the East Pacific Hurricane Season Outlook does not have a scheduled mid-season update at this time.

The East Pacific hurricane season runs from May 15 through November 30, with peak activity occurring during July through September. In a normal season, the East Pacific would expect 15 or 16 tropical storms. Nine of these would become hurricanes, of which four or five would be major hurricanes.

The East Pacific Hurricane Season Outlook is a product of NOAA’s Climate Prediction Center, Hurricane Research Division and National Hurricane Center. The National Hurricane Center has forecasting responsibilities for the East Pacific region.

NOAA, an agency of the U.S. Commerce Department, is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of the nation’s coastal and marine resources.

On the Web:


Background on the Eastern Pacific Hurricane Season:

NOAA’s Climate Prediction Center: