- El Niño has now developed.
- This is the first time these conditions have been applied in nearly four years.
- These warm waters near the equator in the Pacific Ocean can affect weather patterns thousands of miles away.
- This could affect the summer, hurricane season, and next winter.
El Niño conditions have developed, and that could impact the hurricane season and next winter, according to just-released forecasts.
NOAA's Climate Prediction Center (CPC) issued an El Niño warning in its regularly scheduled monthly update issued Thursday.
This means that El Niño conditions have been observed and are expected to continue. This warning is somewhat similar to any other warning or alert, but for a much longer period of time.
What is the El Niño phenomenon? El Niño is a periodic warming of a strip of water along the equator in the Pacific Ocean. The National Oceanic and Atmospheric Administration (NOAA) declares that an El Niño has developed when sea surface temperatures in a particular region of the tropical Pacific Ocean reach at least 0.5 °C (0.9 °F) above average for at least a month and are accompanied by By changes in the atmosphere. This warming occurs at the surface and a few hundred meters below the surface, supporting the developing El Niño phenomenon.
Sea surface temperature anomalies in the monitored region due to El Niño on June 8, 2023.
When was the last El Niño event? This is the first El Niño phenomenon in four years. This band of water has been cooler than average for most of the past three years and is known as a La Niña phenomenon. But that ended by March, and water temperatures in this region have now risen to levels above El Niño standards.
Sea surface temperature anomalies in the region we monitor for El Niño and La Niña from 1982 to May 2023. Positive anomalies are shown in red, while negative anomalies are shown in blue. Thresholds of +/- 0.5°C for El Niño and La Niña are shown by the red and blue horizontal lines, respectively.
(NOAA/CPC)
How long will it last? It is expected to continue through the winter. The Chinese Communist Party expects El Niño to persist not only through the peak of hurricane season but also through at least the first three months of 2024. This is typical of both El Niño and La Niñas. It usually peaks in late fall or winter before diminishing the following spring.
El Niño can be strong. Weekly sea surface temperature anomalies at the end of May were approximately equal to those prevailing at the end of May before the strong El Niños of 1997 and 1982.
A number of computer models continued to predict either a moderate (at least 1°C) or strong (at least 1.5°C) temperature anomaly.
These are model predictions of sea surface temperature anomalies (°C) in the region we monitor for El Niño until early 2024. A departure of at least 1°C is considered a moderate El Niño. A temperature of at least 1.5 degrees Celsius is considered a strong El Niño phenomenon.
(Noah/Eri)
Potential effects
Atmospheric circulation is affected when this band of ocean water is either continuously cooler or warmer over several months.
This was the final criterion needed to declare El Niño conditions.
In an El Niño event, the typical trade winds near the equator weaken, resulting in less rainfall near Indonesia and increased rainfall over the central or eastern tropical Pacific.
Although El Niño is not the only influence, it can ultimately drive weather patterns in parts of the world, including the tropics and the United States. The stronger it is, the greater its impact. Here are some possible effects.
summer
Both El Niño and La Niña typically have the greatest impact on winter weather when they have been in place for several months. But if El Niño intensifies quickly enough, it could at least slightly affect temperatures and precipitation in the United States this summer.
According to forecasts from The Weather Company, IBM Business, and Atmopheric G2, this summer could be less hot in parts of the East and wetter in the Southeast due to the development of El Niño. However, most northern states could be headed for higher temperatures due in part to El Niño.
Hurricane season
El Niño can also be one of the strongest influences on hurricane season.
In El Niño hurricane seasons, stronger wind shear often occurs over at least the Caribbean Sea and some adjacent parts of the Atlantic Basin.
This tends to reduce the number and intensity of storms and hurricanes, especially if El Niño is stronger, as we examined in an article published in March.
However, separate forecasts from Colorado State University, the National Oceanic and Atmospheric Administration (NOAA) and The Weather Company indicated that a warming Atlantic Ocean may work against the influence of El Niño in 2023.
Storms could be crushed this season in the southern Gulf of Mexico and Caribbean Sea due to El Niño-enhanced wind shear and sinking air, while The most typical activity is cruising the rest of the Atlantic From West Africa to the Bermuda Triangle.
Winter 2023-24
Most El Niños peak in late fall or winter and therefore have their strongest effect on weather patterns in the colder months.
Classic El Niño winters are fairly warm from Alaska to western and central Canada and then into the northern tier of states from the Pacific Northwest to the western Great Lakes.
The weather tends to be cooler and wetter than average across much of the southern United States, especially from Texas to the Carolinas. We've found that some cities in the Southwest, Southern Plains, and Mid-Atlantic experience their snowiest winters during El Niño.
Other factors can affect winter weather patterns, including the polar vortex. But if El Niño becomes strong, this may be the general picture expected next winter.
Typical impacts during El Niño from December through February in North America.
(NOAA)
Global temperatures
NOAA's ENSO blog noted that the warmest year of any decade tends to occur during an El Niño event.
But the planet's warming now means that even recent La Niña years are warmer than El Niño years of decades past, as the chart below shows.
Monthly global temperature anomalies (°C) from 1980 through March 2023 in El Niño months (red), neutral months (gray), and La Niña months (blue), compared to the 20th century average (1901-2000). Every month since 1979 has been at least somewhat warmer than the 20th century average.
(NOAA)
In fact, May 2023 it was The second warmest May on the planetAccording to an analysis by the European Center for Medium-Range Weather Forecasts.
So it's certainly possible that 2023 could end up surpassing the warmest year of 2016. NOAA's calculations as of its April report give it about a 25 percent chance of doing so.
More on Weather.COM:
Summer 2023 forecast
2023 Hurricane season forecast
How can El Niño affect hurricane season?
How could El Niño affect next winter in California?
When was the last “quiet” hurricane season?
Jonathan Erdmann is a senior meteorologist at Weather.com, and has been an incurable weather geek ever since a tornado missed his childhood home in Wisconsin when he was seven years old. Twitter And Facebook.
The Weather Company's primary journalistic mission is to report on breaking weather news, the environment, and the importance of science in our lives. This story does not necessarily represent the position of our parent company, IBM.
