The Chicago area may be in for a particularly interesting winter as the possibility of a "super El Niño" looms on the horizon. This phenomenon, while not a technical term, refers to a very strong El Niño event, characterized by sea surface temperatures (SST) far above average. The last strong El Niño, in 2015-2016, brought about 16 inches of snow and temperatures 4.2 degrees above average to the Chicago area, and scientists predict that this year's potential "super El Niño" could have similar, if not more extreme, impacts.
El Niño and La Niña are phases of the El Niño Southern Oscillation (ENSO) that occur in the Pacific Ocean near the equator. ENSO is a natural climate pattern that involves shifts in wind patterns and sea surface temperatures. El Niño is defined as a period when the mean SST is 0.5 degrees Celsius above the climate average over a three-month period, while La Niña is when it's 0.5 degrees below. These phases significantly influence global weather patterns.
During El Niño, Chicago typically experiences warmer and drier winters. However, the stronger the ENSO event, the more extreme the weather impacts can be. This could lead to drought conditions in the Midwest and Pacific Northwest, while heavy rain and flooding are more likely in other regions, such as southern California and the Gulf Coast. The potential "super El Niño" this year could exacerbate these effects, making it crucial for residents and authorities to prepare.
Climate change is expected to play a significant role in the increasing strength of El Niño events. The ocean is absorbing and storing about 90% of the excess heat from global warming, leading to stronger ENSO events. As the world continues to warm, the likelihood of "super El Niño" events increases, further highlighting the need for adaptation and mitigation strategies.
The ENSO forecast predicts a 62% chance of El Niño emerging by the June-July-August period, with a high likelihood of it strengthening by winter. This aligns with the predictions of moderate to strong El Niño events, as indicated by forecast models. The potential impacts on Chicago and the broader region are significant, and residents should stay informed and prepared for whatever weather conditions may arise.
