The La Nina climate pattern that egged on a record 2020 Atlantic hurricane season and left the western U.S. parched will likely fade in the next few months, but there’s a chance it could return later in the year. The odds are 66% that the equatorial Pacific Ocean will be in its neutral state in May, June and July, with water temperatures close to normal, the U.S. Climate Prediction Center said. But by October, the chances rise to 51% that the Pacific’s surface will cool, forming La Nina and creating conditions that can disrupt weather the world over.
While it’s not clear whether La Nina will make a comeback later this year, “it is something to keep an eye on, especially for planning purposes,” said Michelle L’Heureux, a forecaster for the U.S. Climate Prediction Center.
La Nina can lead to dry conditions across the southern U.S. and parts of Argentina, pushing those regions toward drought and setting the stage for potential wildfires in the U.S. West. It can also limit storm-ripping wind shear in the Atlantic, creating the potential for more hurricanes there.
In 2020, when the Pacific shifted to La Nina in September after being in a neutral state for much of the year, the Atlantic produced a record 30 named storms by the time its six-month storm season ended in November.
If the Pacific transitioned to its warmer phase, called El Nino, weather patterns could ease drought across the U.S. and South America, while decreasing the chances for Atlantic hurricanes. But the odds of that happening are 10% or less through September, October and November, the Climate Prediction Center said.