- A strong El Niño is still favored in late fall and into winter.
- The El Niño phenomenon is likely to continue through the spring.
- El Niño could affect weather conditions this winter, but it is only one factor.
Strong El Niño conditions are still favored this winter, which could impact the weather conditions we see in the coming months, according to a just-released monthly update from the National Oceanic and Atmospheric Administration (NOAA).
Here are the key takeaways from the October update:
1. Forecasters from NOAA's Climate Prediction Center still favor a strong El Niño event late this fall and into winter, or a 75-85% chance for November-January. This means that seasonal average sea surface temperatures in a given region of the tropical Pacific will be at or above a threshold of 1.5°C (2.7°F) warmer than average.
2. NOAA says there is an 80% chance that El Niño will continue through the spring (March-May).
3. There is a 3 in 10 chance that this event will warm further and become historically strong, or a so-called super El Niño, meaning sea surface temperatures will be more than 2 degrees Celsius (3.6 degrees Fahrenheit) warmer than average. threshold. There have been three super El Niño winters since 1950 in 2015–16, 1997–98 and 1982–83.
Here's what El Niño is and why it's important: El Niño is a periodic warming of a band of water extending along the equator in the Pacific Ocean, as shown in the general area shown in the map below. El Niño occurs approximately every two to seven years.
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 threshold for the current event was first reached in June.
El Niño can affect weather patterns thousands of miles away in the United States and around the world. Since most El Niños peak in late fall or winter, they can have their strongest impact in the colder months of the year.
Sea surface temperatures compared to average in the tropical Pacific.
Here's how El Niño typically affects winter weather in the United States: In general, classic strong El Niño winters tend to be wetter than average across much of the southern United States, from parts of California to the Carolinas, partly due to the path of the stronger southern jet stream.
In much of the northern United States, stronger El Niños tend to produce warmer winters.
We've found that some cities in the Southwest, Southern Plains, and Mid-Atlantic experience their snowiest winters during El Niño.
(More: What could El Niño mean for snow this winter?)
Typical impacts during El Niño from December through February in North America.
(NOAA)
However, El Niño is not the only driver that can affect winter weather: First, not all El Niños are exactly the same. Even a stronger El Niño does not necessarily guarantee strong effects on the weather pattern as shown in the map above.
Just as the price of gasoline does not control the entire economy, the El Niño phenomenon is not the only factor that affects winter weather.
Two wild cards that meteorologists are watching that could overcome the influence of El Niño for part of the winter are the polar vortex and the Greenland Blocking. But it is difficult to predict months in advance what, if any, impact these factors might have in the winter.
Our official winter forecast will be released on Weather.com on Saturday, so check back this weekend to find out what to expect.
Chris Dolce He has been a senior meteorologist at Weather.com for over 10 years after starting his career with The Weather Channel in the early 2000s.
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.
