WMO predicts first triple dip La Niña of the century

Geneva - It is likely the protracted La Niña event will last until at least the end of the year, becoming this century’s first triple-dip La Niña, spanning three consecutive southern hemisphere summers, according to the World Meteorological Organisation.

The WMO predicts La Niña to continue over the next six months, with a 70 percent chance in September-November but gradually decreasing to 55 percent in December-February 2022/2023.  It started in September 2020.

La Niña conditions in the tropical Pacific have strengthened as trade winds intensified during mid-July to mid-August 2022, affecting temperature and precipitation patterns and exacerbating drought and flooding in different parts of the world.

La Niña refers to the large scale cooling of the ocean surface temperatures in the central and eastern equatorial Pacific Ocean, coupled with changes in the tropical atmospheric circulation, namely winds, pressure and rainfall.

It usually has the opposite impacts on weather and climate as El Niño, which is the warm phase of the so-called El Niño Southern Oscillation.

However, all naturally occurring climate events now take place in the context of human-induced climate change, which is increasing global temperatures, exacerbating extreme weather and climate, and impacting seasonal rainfall and temperature patterns.

It is exceptional to have three consecutive years with a la Niña event. Its cooling influence is temporarily slowing the rise in global temperatures but it will not halt or reverse the long-term warming trend,” the WMO says.

The worsening drought in the Horn of Africa and southern South America bear the hallmarks of La Niña, as does the above average rainfall in south-east Asia and Australia and New Zealand.

The new La Niña Update unfortunately confirms regional climate projections that the devastating drought in the Horn of Africa will worsen and affect millions of people.

WMO will continue to provide tailored information to the humanitarian sector and to support sensitive sectors like agriculture, food security, health and disaster risk reduction.

It is also striving towards the goal that everyone should have access to early warning systems in the next five years to protect them against hazards related to our weather, climate and water.

Despite the stubborn La Niña in the equatorial central and eastern Pacific, widespread warmer than-average sea-surface temperatures elsewhere are predicted to dominate the forecast of air temperatures for September to November.