MILWAUKEE - There has been a lot of talk lately about a so-called "Super El Niño." While there is no true scale for such a thing, there is growing evidence that a historically strong El Niño is developing and should peak by this fall.
In its latest update released Thursday, the National Oceanic and Atmospheric Administration said there is now a more than 80% chance that this El Niño will rank among the strongest ever on record. That is an increase from the 63% chance that was issued in its June outlook.
FREE DOWNLOAD: Get breaking news alerts in the FOX LOCAL Mobile app for iOS or Android
What is the El Niño-Southern Oscillation?
The backstory:
The El Niño-Southern Oscillation – or ENSO – is a naturally occurring climate pattern driven by changes in sea surface temperatures in the Pacific Ocean near Ecuador and Peru. These temperature changes influence atmospheric circulation around the globe, shifting the position of the jet stream, the fast-moving river of air that steers storms across North America and typically separates cold and warm air masses.
Think of it like dropping a pebble into a pond. A relatively small change in one part of the world creates ripple effects that eventually influence weather patterns thousands of miles away.
ENSO has three phases:
- El Niño: Warmer-than-average ocean water in the tropical Pacific
- La Niña: Cooler-than-average ocean water
- Neutral: Ocean temperatures remain near average
While these patterns can develop at any time of year, their influence is strongest during the winter months.
How El Niño affects Wisconsin
What we know:
During an El Niño winter, the polar jet stream typically shifts farther north. That tends to keep the coldest Arctic air locked in Canada instead of allowing it to plunge into the Upper Midwest and across Wisconsin.
For our area, that usually means:
- Milder-than-average winter temperatures
- Fewer prolonged Arctic outbreaks
- More winter precipitation falling as rain or sleet instead of snow
When it comes to precipitation, there is no consistent clear signal for above or below-average trends. Snowfall can and will still occur during El Niño winters, but warmer temperatures often reduce snow accumulation and increase the frequency of mixed precipitation events, especially across southern Wisconsin.
Wisconsin's biggest El Niño winters
Dig deeper:
Recent history offers some great examples of how powerful these climate patterns can become.
The winter of 2023-24 became Wisconsin's warmest winter on record, averaging 31.8 degrees, more than 12 degrees above normal. Northern Wisconsin also experienced a historic snow drought, with seasonal snowfall totals running 20 to 60 inches below average.
Another notable El Niño winter occurred during 1986-87, which remains Wisconsin's driest winter on record.
El Niño could impact your budget
Why you should care:
For those who aren't fans of snow and cold, an El Niño winter seems like a good thing. However, there is a hidden impact that might have you rethinking your position on the matter.
El Niño can have wide-ranging effects on Wisconsin's economy because warmer winters change consumer spending and reduce demand for winter-related industries. Ski hills, snowmobile trails, ice fishing guides and other winter recreation businesses often see far fewer visitors during mild, low-snow seasons. That means fewer dollars flowing into local businesses and reduced tourism from southern states looking for a Wisconsin winter retreat.
Agriculture can experience both benefits and challenges depending on spring moisture and growing conditions, which could help or hurt your grocery budget. At the same time, lower heating demand during warmer winters can reduce energy costs. El Niño creates both economic winners and losers across the state.
The bottom line
Big picture view:
ENSO is one of the world's most important climate patterns, and while it doesn't determine every storm or cold snap, it can significantly tilt the odds toward certain winter weather outcomes.
As we move closer to winter, keeping an eye on the developing ENSO phase provides another valuable clue about what Wisconsin may have in store.
The Source: Information in this story is from the FOX6 Weather Experts, Wisconsin State Climatology Office and NOAA