Weak La Niña most likely scenario for remainder of 2011, says WMO

The World Meteorological Organization (WMO) has published its latest update on the El Niño & La Niña weather phenomena in the Pacific ocean which have wide ranging effects on the global climate and weather patterns. The most likely scenarios are for the continuation of near neutral conditions or the formation of a weak La Niña over the remainder of 2011.

A weak La Niña would be characterised by cooler than normal central and eastern tropical Pacific ocean surface temperatures. The last La Niña experienced was linked to was linked to flooding in parts of Australia, Indonesia, Southeast Asia, and portions of northern South America (e.g. Colombia), and drought in parts of the Horn of Africa, central southwest Asia, southeastern South America and the southern United States of America.

La Niña is also typically linked to flooding in Asia-Pacific regions, drought in Africa and a more intense hurricane season in the Atlantic. The last La Niña event was a moderate to strong occurrence between September 2010 and May 2011 and has been blamed for much of the flooding that was seen in Asia and Australia.

Current conditions in the Pacific look like a La Niña event could be forming but the WMO say that it is too early to tell and conditions could return to normal. They do say that it is very unlikely that an El Niño event will be seen this year.

Re/insurers will be hoping that a La Niña does not form before the end of the Atlantic hurricane season as it could stimulate storm intensification.