La Niña Is Back After About A Decade: WMO

• 03 Nov 2020

• According to the World Meteorological Organization (WMO), La Niña is back in the central and eastern equatorial Pacific Ocean, after nearly a decade’s absence.
• It has the opposite impacts on weather and climate as El Niño, which is the warm phase of the El Niño Southern Oscillation (ENSO).
• The cooling of these large ocean areas have a significant effect on the circulation of the atmosphere that’s flowing over them. And the changes in the atmosphere in turn affect precipitation patterns around the world.
• In India, La Niña means the country will receive more rainfall than normal, leading to floods.

WMO Predictions on its Effects

• This is expected to result in sea surface temperatures between two and three degrees Celsius cooler than average.
• The Horn of Africa will see below average rainfall, as will Central Asia.
• Above-average rainfall for Southeast Asia, some Pacific Islands and the northern region of South America.
• East Africa is forecast to see drier than usual conditions, which together with the existing impacts of the desert locust invasion, may add to regional food insecurity.
• There is a 90 per cent chance of tropical Pacific sea surface temperatures remaining at La Niña levels for the remainder of the year, and a 55 per cent chance that this will continue through March next year.

No Respite from Heat

• Although La Niña typically has a cooling effect on global temperatures, there’s little chance that 2020 will buck the trend of increasingly warm years. That’s because of all the heat trapped in our atmosphere by greenhouse gases.