Pacific El Nino equals Atlantic hurricane calm: experts

October 18, 2009 by Juan Castro Olivera

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People are seen silhouetted against the Atlantic Ocean, in Florida. The Pacific's El Nino ocean-warming phenomenon has resulted in an especially calm Atlantic hurricane season -- a welcome respite for Caribbean and southeastern US residents still smarting from a 2008 pounding.

The Pacific's El Nino ocean-warming phenomenon has resulted in an especially calm Atlantic hurricane season -- a welcome respite for Caribbean and southeastern US residents still smarting from a 2008 pounding.

There have only been two hurricanes in the 2009 Atlantic season, which runs from June 1 to late November 30, but normally peaks in September and October.

Hurricane Bill reached powerful Category Four intensity on the five-point Saffir-Simpson scale in mid-August. It bypassed most of the Caribbean and the US east coast, making landfall in southeastern Canada and causing modest damage.

Hurricane Fred formed in the Atlantic in early September, but petered out over the ocean before making landfall.

"We were expecting very little activity this season," said Lixion Avila, a weather expert at the Miami-based National Hurricane Center.

"This happens when the El Nino phenomenon is present in the Pacific, the water warms up there, and that leads to hurricanes forming there and not in the Atlantic."

Every three to six years, water currents shift along the equator in the Pacific and the ocean warms a few degrees, a phenomenon dubbed El Nino -- Spanish for "the boy," a reference to Christ the infant because the warming is usually noticed around Christmas.

The El Nino effect was powerfully demonstrated on Saturday after warm waters prompted Hurricane Rick to roar to top Category Five status as it barreled up Mexico's Pacific coast.

This hurricane season "could end with no impact against the US nor the Caribbean," noted William Gray, a hurricane expert at Colorado State University who has been forecasting hurricanes for 25 years.

El Nino conditions in the Pacific "result in a higher vertical wind shear over the Atlantic region, which is considered to be unfavorable to hurricane formation and intensification," said Shuyi Chen, a meteorology and oceanography professor at the University of Miami.

Less Atlantic hurricanes however do not necessarily mean weaker hurricanes that stay in the ocean, Chen warned.

"In 1992, we had a strong El Nino condition," said Chen. "Although there were less hurricanes overall, Andrew was a Cat-5 major hurricane that made landfall in Florida and near New Orleans," she said.

Hurricane Andrew, which ripped across southern Florida in 1992 before slamming into Louisiana, was blamed for 65 deaths and caused more than 30 billion dollars in damage, including massive wreckage to Homestead Air Force Base.

The US National Oceanic and Atmospheric Administration (NOAA) forecast in May said there could be between four and seven hurricanes, and between nine and 14 tropical storms in the 2009 season.

There have been eight tropical storms and two hurricanes so far.

The calm weather is a godsend for Cuba and Haiti, two countries that suffered mightily from the effects of the 2008 storms.

Three hurricanes and a tropical storm tore through Cuba last year, killing people, flooding buildings and destroying crops.

Two hurricanes and two tropical storms struck Haiti, already the poorest country in the Americas. Landslides and flooding killed some 1,000 Haitians, and widespread flooding caused millions of dollars in damage.

In the United States last year, Tropical Storm Fay ravaged Florida, while hurricanes Gustav and Ike slammed the coasts of Louisiana and Texas, killing 60 people and causing some 20 billion dollars in damage.

(c) 2009 AFP