La Niña latest

La Niña conditions, which started in the third quarter of 2007, continue across the central and eastern equatorial Pacific. Basin-wide features are now typical of the mature stage of a La Niña event, including in the western equatorial Pacific. The La Niña event is expected to continue at least through the first quarter of 2008. Many La Niña events in the historical record are found to decay rapidly during the March-May period. By the middle of the year, La Niña and, what are referred to as “neutral conditions”, are considered to be equally likely, with El Niño continuing to have a low likelihood of occurrence at this stage. Long-term statistics indicate neutral conditions should currently be considered a more likely outcome for the latter part of 2008.

The magnitude of the event continues to be in the middle range of those observed in the historical record.

	La Niña refers to the extensive cooling of the central and eastern Pacific. La Niña is preceded by the build-up of cooler-than-normal subsurface water in the tropical Pacific. Wave action and easterly winds pull this colder water to the surface off the coast of Peru and Ecuador and, as the easterly trade winds strengthen, the effect becomes stronger. La Niña can last for up to 12 months.
Comparison of water conditions for an El Niño event and a La Niña event

International Research Centre on “El Niño”

El Niño/La Niña update

Press Release No. 810