The National Oceanic and Atmospheric Administration (NOAA) has announced the end of the La Niña weather pattern after three years. As forecast models begin to predict a strong El Nino later this year, or possibly even a ‘Super El Nino,” local communities begin to prepare for any inevitable weather incidents.
El Niño, along with its counterpart La Niña, are climatic phenomena capable of influencing temperature and precipitation patterns across the globe. During El Niño, warmer-than-average sea surface temperatures prevail in the Pacific Ocean. La Niña occurs when sea temperatures are cooler than usual in the central and eastern tropical Pacific Ocean. But their effects on weather are far from straightforward.
El Niños have shown both insignificant and profound impacts on rainfall patterns. Sometimes it has minimal effects, while other times its influence is substantial. Typically, Southern California witnesses increased rainfall during El Niño, whereas Northern California, Oregon, and Washington tend to experience drier conditions. During La Niña, atmospheric rivers are less pronounced on the West Coast, leading to drier conditions in the southern U.S. and wetter conditions in the north.
This year’s El Niño development is unusual due to its alignment with a global temperature surge, raising the specter of intensified heatwaves and deadly floods, with both extremes experienced recently in Northern California in both 1997-98 and 2015-16.
El Niño’s influence on Northern California’s rainfall is not absolute. It can either bring increased rain or have a relatively minor impact. This is attributed to the phenomenon’s ability to shift storm tracks, often directing rainfall further south. The Farmers’ Almanac forecasts “wintry temps” for California and predicts a “snowy and wet winter” for the Pacific Northwest, which might extend to California.
To understand what a ‘strong El Nino’ could bring this year, we can look at the 8 we’ve seen over the past 70 years to see what it could potentially mean for California (the darker the green colors, the wetter the year was):
Much has been made about the possible impact of El Nino in Northern California. Will we see another wet winter? Only time will tell.