La Nina outlook is easing says UN weather agency

Yahoo News 23 May 11;

GENEVA (AFP) – La Nina, the disruptive weather pattern behind floods and droughts, is easing and there are no signs suggesting a resurgence in the coming months, the UN weather agency said on Monday.

"The La Nina episode, which caused disastrously wet conditions in certain regions and drought in others, is coming to an end," the World Meterological Organization said in a statement.

The weather pattern, blamed for extremely heavy downpours in Australia, Southeast Asia and South America over late 2010 and early 2011, is unlikely to redevelop in the middle of the year, it added.

"Looking ahead beyond mid-year 2011, there are currently no clear indications for enhanced risk of El Nino or La Nina in the second half of the year," it said.

"Near-neutral conditions are currently considered the most likely scenario for the second half of 2011," it added.

La Nina is characterized by unusually cool ocean surface temperatures in the central and eastern tropical Pacific.

It leads to increased rainfall across the western equatorial Pacific, northern South America and southern Africa over December to February.

At the same time, drier than normal conditions are observed along coastal Ecuador, northwestern Peru and equatorial eastern Africa during the same period.

It also leads to sharply lower conditions throughout the world, including cooler than normal temperatures in Japan, southern Alaska and Brazil.

El Nino, meanwhile is the opposite condition of La Nina. It is characterised by unusually warm ocean temperatures in the central and eastern equatorial Pacific.