May 6 (Bloomberg) -- The Pacific Ocean warming phenomenon known as El Nino that helps retard development of Atlantic hurricanes will disappear by June, the U.S. Climate Prediction Center forecast said today.
One-third of weather models indicate a La Nina, or cooling, may develop in its place. “These forecasts, in addition to various oceanic and atmospheric indicators, indicate a growing possibility of La Nina developing during the second half of 2010,” the center said on its website.
El Nino is a warming that occurs every two to five years, on average, and lasts about 12 months. It is credited with making the 2009 Atlantic hurricane season the least active in 12 years, forecasters said. It also drove weather patterns worldwide contributing to record snows in Washington and Dallas, drought in Venezuela and flooding from rain in Peru.
The phenomenon enhances high level winds in the Atlantic, called shear, that tear hurricanes apart as they are forming or intensifying. The hurricane season begins June 1 and runs through Nov. 30.
Nine named storms formed in 2009, while the historical average is 11, according to the U.S. National Oceanic and Atmospheric Administration.
Active Season Forecast
The collapse of El Nino is another indication the Atlantic will have a more active hurricane season this year, said Jim Rouiller, senior energy meteorologist at commercial forecaster Planalytics Inc. in Berwyn, Pennsylvania.
“The environmental conditions are far more favorable for more sustained and more intense growth of hurricanes in the Atlantic this summer,” Rouiller said by telephone. “One of the things hurricanes hate is wind shear and when El Nino goes away, so does the wind shear.”
La Nina’s Effects on global weather are generally the opposite of El Nino’s, according to the National Oceanic and Atmospheric Administration. That means the U.S. winter season tends to be warmer and dryer in the South and cooler and wetter in the Pacific Northwest.
Much more hurricane damage is likely during a La Nina, according to an NOAA research paper. The last La Nina occurred from 2007 to 2008.
The 2008 Atlantic hurricane season was one of the most active years since 1944, NOAA reported. It produced 16 named storms, with winds of at least 39 mph (63 kph) and eight became hurricanes with winds of 74 mph or greater, including Gustav and Ike, which struck the U.S. Gulf Coast.
The Gulf of Mexico is home to about 27 percent of U.S. oil and 15 percent of U.S. natural gas production, according to the U.S. Department of Energy.
