El Niño has arrived.
The Climate Prediction Center announced Thursday that El Niño conditions were present and expected to grow stronger in the coming months. Forecasters give it a 56% chance of developing into a strong El Niño, and an 84% chance of topping “moderate” strength.
This year’s El Niño has shown up ahead of the typical schedule. In the past decade, El Niños have started in late summer or early fall. Its early appearance “gives it room to grow,” Climate Prediction Center meteorologist Michelle L’Heureux, told the Associated Press.
This year’s El Niño is expected to keep building and remain strong through the 2023-2024 winter.
This year is predicted to be the inverse of what we’ve seen the last three years, in which we have had back-to-back La Niña seasons.
El Niño typically brings cold, wet winters to the Southern U.S. A strong El Niño, in particular, is associated with lots of rain for the Southwest and California — though California already saw a cold, wet winter this year, even without El Niño in control.
On the other hand, El Niño usually means a warm, dry winter for the Pacific Northwest, Ohio Valley, northern Rockies, and parts of the Midwest. Hawaii also often sees below-average rain during an El Niño fall, winter, and spring season.
While El Niño can strengthen hurricane season in the central and eastern Pacific, it tends to contribute to weaker hurricanes forming in the Atlantic basin.
Even a strong El Niño isn’t a guarantee those exact scenarios will play out, NOAA warns.
“‘Associated with’ doesn’t mean that all of these impacts happen during every El Niño episode. However, they happen more often during El Niño than you’d expect by chance, and many of them have occurred during many El Niño events,” the agency writes.
Whether we’re in a La Niña year, El Niño year, or neither is determined by sea surface temperatures near the equator over the Pacific Ocean. The temperature of the water and air above it can shift the position of the jet stream, which impacts the types of weather observed on land.