La Niña (La Nina, "little girl" in Spanish) is characterized by an abnormal decrease in the sea surface temperature in the central and eastern tropical Pacific Ocean. This process is the reverse of the El Nino (El Nino, "the boy"), which is associated, however, with the warming in the same area. These states follow each other at regular intervals for a year.
After a period of neutral cycle of El Niño — La Niña, observed in mid-2011, the tropical Pacific region in August began to cool, and from October until now observed phenomenon La Nina weak and moderate strength. By early April, the La Niña has completely disappeared.
According to the WMO, neutral state, set in the equatorial Pacific from mid-spring, there is there now and is likely to continue at least until July.
"After July likelihood of El Niño is slightly higher. Return of La Niña is considered extremely unlikely," — said the organization.
Experts point out that it is difficult to estimate the strength and scale of the possible phenomenon, although most climate models that predict his return to the Pacific Ocean, while predicting a relatively weak El Niño conditions, which will continue until the end of 2012. More accurate assessment of the situation, scientists hope to get to August.
And El Niño and La Niña affect circuit circulation of ocean and atmospheric currents, which in turn affects the weather and climate around the globe, causing drought in some regions, storms and heavy rains — in others.