A government weather forecaster said on Thursday, Dec. 10, that there is a 65 percent chance that El Niño will hit the northern hemisphere this spring.
Meteorologists Anticipate El Niño Event
The prediction comes after months of warming in the tropical Pacific as sea surface temperature continue to rise above normal. However, do not expect extreme conditions similar to the last El Niño that took place from 2016-2016 — the strongest on record. While the water is warming, circulation patterns in the atmosphere have not shifted.
The El Niño weather will still happen this year but, because it got a late start, its effects are likely to be weaker.
"However, given the timing and that a weak event is favored, significant global impacts are not anticipated during the remainder of winter, even if conditions were to form," explained the National Weather Service's Climate Prediction Center.
An El Niño event happens when the surface waters in the central and eastern Pacific Oceans becomes warmer than normal. The atmosphere changes, too; the easterly trade winds that blow from the Americas toward Asia slows down or, sometimes, reverse and become westerlies.
This causes the warmer water in the Pacific to migrate eastward to the Americas.
However, part of the reason why the atmosphere has not shifted yet to form an El Niño is that the Madden-Julian Oscillation (MJO) — a weather event characterized by enhanced and suppressed tropical rainfall over the Indian Ocean and the Pacific Ocean.
As soon as the MJO moves eastward, experts expect the El Niño formation to begin.
El Niño In The US
While the majority of the action happens in the Pacific, an El Niño event affects the weather around the world. In the United States, it can increase the likelihood of rain in the southern half of California and across the U.S. Southwest — a welcome impact especially to the Four Corners region that is currently suffering from persistent drought.
An El Niño has not formed yet, but the Climate Prediction Center expects above-average rainfall in the southern deserts of California in the next three months.