El Nino could develop within weeks: U.S. forecaster

Reuters 5 Jun 09;

SINGAPORE (Reuters) - The El Nino weather pattern, which can bring global weather chaos such as droughts and floods, could develop within weeks, the Climate Prediction Center in the United States said.

El Nino is driven by an abnormal warming of the eastern Pacific and the forecaster said conditions were favorable for a switch to El Nino conditions during June to August 2009.

The forecast is the latest warning of the increased chances of El Nino developing after months of rising ocean temperatures in the tropical Pacific.

Australia's Bureau of Meteorology said on Wednesday that if recent trends in Pacific climate patterns held up, there was an above-50 percent chance an El Nino event would be established by July.

El Nino occurs when the eastern Pacific Ocean heats up, with warmer, moist air moving east, leaving drier weather in the western Pacific and Australia and putting crops at risk of failure.

The most devastating El Nino was in 1997/98, when it caused drought in Australia and Indonesia and floods in Peru and Ecuador. El Nino can also bring wetter weather to parts of the United States and can affect the monsoon in India.

The prediction center, part of the National Oceanic and Atmospheric Administration, said sea surface temperatures had risen for the fifth consecutive month in the equatorial Pacific.

Sub-surface temperatures also continued to rise.

"These surface and subsurface oceanic anomalies typically precede the development of El Nino," the center said in a statement.

"Current observations, recent trends, and the dynamical model forecasts indicate that conditions are favorable for a transition ... to El Nino conditions during June-August 2009."

(Reporting by David Fogarty; Editing by Alex Richardson)

Forecasters say El Nino may be developing
Yahoo News 8 Jun 09;

WASHINGTON – A new El Nino could be approaching.

Sea-surface temperatures have been warming in the tropical Pacific Ocean, suggesting the potential for the development of the El Nino climate phenomenon this summer, according to the National Oceanic and Atmospheric Administration.

El Nino conditions are associated with increased rainfall across the east-central and eastern Pacific and with drier than normal conditions over northern Australia, Indonesia and the Philippines. A summer El Nino can lead to wetter than normal conditions in the intermountain regions of the United States and over central Chile. In an El Nino year there tend to be more Eastern Pacific hurricanes and fewer Atlantic hurricanes.

In recent months conditions have been neutral — between the warmer than normal El Nino and the cooler La Nina conditions.

Water below the sea surface has been warmer than normal, NOAA said, and warm conditions both on the surface and below normally precede the development of an El Nino, changing wind patterns and potentially affecting climate worldwide.

Computer models that forecast climate differ, the agency noted, with some predicting arrival of El Nino while others expect continued neutral conditions.