'Super El Niño' Odds Now A Coin Flip, NOAA Says | Weather.com (2024)

El Niño is now flirting with "super" status, and while that will influence weather in the United States and around the world, it may behave differently this winter than past strong El Niños.

Here are the main takeaways:

1. In the latest monthly update from NOAA's Climate Prediction Center, above-average sea surface temperatures (SST) across the equatorial Pacific Ocean were indicative of a strong El Niño, with anomalies that "abated in early December" after increasing in November.

That means the three-month average of sea-surface temperatures in a certain region of the equatorial Pacific Ocean have been above the threshold of 2.7 degrees Fahrenheit warmer than average. The latest three-month average from September through November was just above that at 3.64 degrees Fahrenheit above average.

2. NOAA says El Niño conditions will continue through winter.

3. NOAA also said there is a 54% chance that El Niño could strengthen even further and become historically strong, or a so-called super El Niño, during the November through January period. That means sea-surface temperatures would cross the 3.6-degrees-warmer-than-average threshold over a three-month period. It has already topped that threshold for the latest one-month period in November. There have been three super El Niño winters since 1950 in 2015-16, 1997-98 and 1982-83.

4​. As often happens, El Niño is expected to disappear, with conditions expected to become "neutral" (neither El Niño nor La Niña) by late spring or summer, according to the latest model forecasts.

Here's why this matters: A​n El Niño is a periodic warming of a strip of water straddling the equator in the Pacific Ocean.

NOAA declares that an El Niño has developed when sea-surface temperatures in a certain region of the equatorial Pacific Ocean have reached at least 0.9 degrees above average for at least a month and are accompanied by changes in the atmosphere. That threshold for the current event was first reached in June.

El Niño can affect weather patterns thousands of miles away in the U.S. and around the world. Since most El Niños peak in late fall or winter, they can have their strongest influence in the colder months of the year. El Niño events occur about every two to seven years.

Here's how El Niño typically affects winter weather in the U.S.: In general, t​he classic strong El Niño winter tends to be wetter than average through much of the southern U.S., from parts of California to the Carolinas, due in part to a stronger, more southern jet stream track.

A​cross much of the northern U.S., a stronger El Niño tends to produce a warmer winter.

We found that some cities in the Southwest, Southern Plains and mid-Atlantic have their snowiest winters during El Niño.

(​MORE: What El Niño Could Mean For Snow This Winter)

But this El Niño may be different: Not all El Niños are exactly the same. Even a stronger El Niño doesn't necessarily guarantee strong impacts on the weather pattern like shown in the map above.

T​he last two strong El Niños proved this by having extremely different outcomes. Winter 2009-10, for example, was much colder than expected in the U.S. during a strong El Niño winter.

A​nd there are indications this strong El Niño may be behaving like 2009-10, at least initially.

S​cientists use a variable called the multivariate ENSO index, or MEI, to not only capture water temperatures, but also how the atmosphere responds to the ocean water.

A​nd when you plot that index, as done in the graph below, this strong El Niño's response in the atmosphere is closer to 2009-10 than to the previous super El Niños such as 2015-16, 1997-98 or 1982-83. That was also noted in the large-scale pattern of rising and sinking air in the atmosphere differing this El Niño compared to others, by New Zealand-based meteorologist Ben Noll.

El Niño isn't the be-all and end-all: T​wo of the wild cards meteorologists watch for that can override El Niño's influence for a part of winter are the polar vortex and Greenland blocking.

While it's difficult to forecast months ahead of time what, if any, influence those factors could have, there are hints of a polar vortex weakening or stretching that could lead to increased Greenland blocking and a colder pattern in the U.S. in January or February.

E​l Niño's fade: As we alluded to earlier, the latest model forecasts suggest El Niño may disappear by late spring or summer. That's typical even for stronger El Niños. According to NOAA, the average El Niño lasts nine to 12 months.

T​hat disappearance could have at least one significant impact in 2024.

Despite 20 storms and an average number of hurricanes, El Niño didn't appear to have its typical suppressing influence on the 2023 Atlantic hurricane season.

N​ow, imagine taking whatever suppressing influence of El Niño away, but still having abundant, possibly record-warm ocean water in the Atlantic Basin next hurricane season. Those two factors alone argue for far-above-average Atlantic Basin activity in 2024, unfortunately.

M​ORE EL NIÑO COVERAGE ON WEATHER.COM:

6 Changes El Niño Might Bring Compared To Last Winter

E​l Niño Is Good News For Southern Drought

W​hat El Niño Could Mean For California

H​ow El Niño Got Its Name

Jonathan Erdman is a senior meteorologist at weather.com and has been covering national and international weather since 1996. His lifelong love of meteorology began with a close encounter with a tornado as a child in Wisconsin. He studied physics at the University of Wisconsin-Madison, then completed his Master's degree working with dual-polarization radar and lightning data at Colorado State University. Extreme and bizarre weather are his favorite topics. Reach out to him on X (formerly Twitter), Threads, Facebook and Bluesky.

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