El Niño returns with more intensity. This winter will be the first in five years with an El Niño trend, following years of La Niña.
The last El Niño occurred in winter 2018-2019, but it was much smaller than the current one.
El Niño winters provide wetter weather to the southern portion of the US, including California. Where that dividing line occurs fluctuates year. The Pacific Northwest and Ohio Valley are dry and warm. El Niño years often result in below-average rainfall in Hawaii.
La Niña causes an opposite effect: less precipitation in the south and colder, wetter conditions in the Pacific Northwest.
El Niño impacts a new long-term winter forecast provided by the Climate Prediction Center on Thursday. The maps below indicate half the country, from California to the Upper Plains, Midwest, and Northeast, expecting above-average December-February temperatures.
Rainfall is projected to be most prevalent in southern states during El Niño years. Wet winters are 60% to 70% likely in the Gulf states.
The likelihood of a “strong” El Niño this year is over 55%, according to national analysts. It could be one of the strongest ever, like 2015-2016 or 1997-1998, with a 35% possibility.
“El Niño may increase the likelihood of certain climate outcomes, but it does not guarantee them,” according to meteorologist Michelle L'Heureux of the Climate Prediction Center.
Sea surface temperatures near the equator of the Pacific Ocean determine whether we are in a La Niña or El Niño year. The jet stream's position is affected by water and air temperature, which affects land weather.