(Bloomberg) -- The weather-roiling La Niña that forecasters have been predicting for months will likely arrive late and in a weakened form, limiting its impact and allowing other climate patterns to hold more sway.
There is an 83% chance La Niña, a cyclical cooling of the Pacific, will take shape in November, December and January, up from 74% a month ago, the US Climate Prediction Center said in its latest outlook Thursday. This comes after months of predictions that the phenomenon — which can lead to drought in California, Brazil and Argentina and rain in Indonesia and Australia — was about to get started.
“Clearly the forecast models were a little too bullish on this event,” said Michelle L’Heureux, a forecaster with the Climate Prediction Center. “They were predicting onset in the summer and that didn’t happen.” The world is currently in a neutral phase after El Niño, a warming of the Pacific, ended earlier this year.
A later start to La Niña means its influence on the atmosphere is weaker and it won’t last as long, L’Heureux said. That will likely lead to other, smaller patterns having more clout. For instance, while La Niña brings cooler temperatures across the northern US and often leads to storms riding up the East Coast, the Northeast could see greater impacts from a phenomenon known as the North Atlantic Oscillation, which can play a role in whether the region has a mild or chilly winter.
L’Heureux said after months of waiting, there’s greater confidence La Niña will arrive because forecast models in the Northern Hemisphere’s fall tend to be more accurate.
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