The rapidly increasing number of Super El Niños will have a major impact on winter weather in the United States.
Winter is not only the time when El Niño events reach their peak strength, but also when their impact on global weather is most pronounced.
Ask a Scientist: What is Super El Niño?
🌊 The full “Ask a Scientist About El Niño” interview is available only on the CNN Weather app. 👨🏻🔬
El Niño is a natural climate cycle characterized by warmer than average water temperatures along the equator of the Pacific Ocean. Rising ocean temperatures trigger corresponding changes in the atmosphere that have a domino effect on weather patterns around the world, usually in a predictable way far in advance.
The stronger El Niño is, the more likely these expected weather patterns will develop. And this one might strike gold.
It is rapidly gaining strength and is predicted to become a Super El Niño by October at the latest, and there is a nearly 70% chance that it will become the strongest El Niño on record by the end of the year.
Nat Johnson, a meteorologist at the National Oceanic and Atmospheric Administration’s Geophysical Fluid Dynamics Laboratory, said this potentially record-breaking El Niño is a “very rare, if not once-in-a-lifetime event.”
It is important to note that a historically strong El Niño does not mean that historically severe weather or climate impacts will develop. It just increases the likelihood that certain weather patterns will develop, NOAA said.
Here’s what the U.S. could experience this winter thanks to El Niño.
Although no two El Niño winters are the same, most winters share temperature and precipitation trends. That’s because El Niño events typically send the jet stream (a transcontinental river of air into which storms flow) south of its normal location and into the southern tier of the United States.
As a result, the southern part of the country tends to have more storms, be wetter and colder, while the northern part tends to be drier and warmer, NOAA said. (Yes, snow-loving Northeasterners. That means there’s less snow on average in strong El Niño winters.)
The opposite is true in the Southeast and parts of the southern Plains, where El Niño’s cooling trends and increased precipitation make snow, sleet, and freezing rain more likely. How difficult it will be to overwinter in these areas depends on how cold it gets.
Additionally, there is an impact on severe thunderstorms. Thunderstorms typically peak in the spring and then pick up again near and along the Gulf Coast in late fall and early winter.
El Niño makes Florida especially at risk during the winter months. Michael Tippett, a climate scientist at Columbia University, said this scenario is reversed because other parts of the Gulf Coast are experiencing less activity than usual.
Winter is still months away, but NOAA’s Climate Prediction Center is always looking ahead. Their temperature and precipitation forecasts for December through February show characteristics of El Niño.
The highest potential for above-average temperatures will be spread throughout the northern tier. This includes regions from the Pacific Northwest to the Midwest, which experience warmer than normal winters during El Niño.
In particular, temperatures are likely to be higher than normal in more than half of the areas above 48 degrees. El Nino isn’t the cause of everything. Global warming due to fossil fuel pollution is a constant influence. Winter is the warmest season in most parts of the United States, according to an analysis by the nonprofit research group Climate Central.
The El Niño phenomenon is also seen in this winter’s precipitation trends. Much of the U.S., including Southern California, all of the Southern Tier states, and even the East Coast, could experience wetter-than-normal rainfall. The highest confidence regarding these conditions so far is concentrated in the Southeast.
Areas that are expected to be drier than usual are limited to the northern tier, which is expected to be hotter, although not fully consistent with El Niño conditions. And the combination of heat and dryness does not produce snow.
Similar to winter temperatures, research shows that climate warming has been impacting snowfall for decades. Since 1970, annual snowfall has decreased in nearly two-thirds of the United States, according to Climate Central.
Only time will tell how cold this winter will be, but there is little doubt that El Niño will play a leading role alongside the warming climate.
