A weather-roiling La Nina appears to have emerged across the equatorial Pacific, setting the stage for worsening droughts in California and South America, frigid winters in parts of the U.S. and Japan and greater risks for the world’s already strained energy and food supplies.
The phenomenon—which begins when the atmosphere reacts to a cooler patch of water over the Pacific Ocean—will likely last through at least February, the U.S. Climate Prediction Center said Thursday. There is a 57% chance it be a moderate event, like the one that started last year, the center said. While scientists may need months to confirm whether La Nina has definitely returned, all the signs are indicating it’s here.
“Everything you want to see in having a La Nina we are seeing,” Michelle L’Heureux, a forecaster at the center, said in an interview. “We are pretty confident La Nina is here.”
Signs have been emerging for months that the pattern was likely forming, marking the world’s second La Nina in a row. La Nina—like its counterpart, El Nino—usually peaks in the Northern Hemisphere’s winter, but its effects can trigger widespread consequences across the globe. Its onset this season could have a powerful impact on agriculture markets relying on South American crops, which could face dryer conditions, as well as palm oil across Indonesia, where there may be increased flooding. Cold and storms tend to favor the U.S.’s Pacific Northwest and northern Plains when La Nina emerges, squeezing regional energy markets.