The La Nifia phenomenon has developed for the second consecutive year, with the weather pattern expected to intensify rainfall as well as droughts around the world.
The counterpart to the better known, opposing El Nifio phenomenon, La Nifia involves the large-scale cooling of the Pacific Ocean’s surface, which drives changes in wind and rainfall with consequences across the globe.
Both the World Meteorological Organization and Australia’s Bureau of Meteorology have in the past week confirmed the back-to-back years of La Nifia conditions, with scientific models indicating it will last into early 2022.
The 2021-2022 La Nifia would probably be “weak to moderate” and “slightly weaker” than the previous year, said the WMO. Yet it would still be likely to have a continuing effect on agriculture and water supply, as it would cause greater rain in some areas and less in others.
Typical effects of La Nifia have included unusually dry conditions in parts of the US and South America, as well as abnormal amounts of rain and more cyclones than normal in countries such as Australia, which has experienced the wettest November in 121 years of records for its most populated state.
“[La Nifia’s] impacts can really spread around the world because of the way global circulation works,” said Tim Stockdale, principal scientist at the European Centre for Medium-Range Weather Forecasts.