By Jon Erdman and Chris Dolce, weather.com
El Niño is forecast to weaken through the spring with conditions in the equatorial Pacific Ocean potentially transitioning to La Niña next fall, according to the latest monthly outlook issued Thursday by NOAA.
Sea-surface water temperatures (SST) in the equatorial east and central Pacific Ocean were still well above average during January, indicating strong El Niño conditions remained in place. Water temperatures appeared to reach their peak in mid-November, but have been cooling slowly the last couple of months, according to fine-resolution weekly SST data from NOAA’s Climate Prediction Center.
Citing the latest model guidance, NOAA/CPC said Thursday El Niño, as it typically does, will continue to weaken through the spring, eventually disappearing by late spring or early summer. This means sea-surface water temperatures in the equatorial central and eastern Pacific Ocean will return to near-average levels (neutral conditions) from their current above-average state.
Though El Niño is forecast to weaken, NOAA said that we will continue to see temperature and precipitation impacts through late winter and into spring in the United States and elsewhere. You can find more information on those impacts at the bottom of this article.
La Niña Conditions Arriving in the Fall?
After transitioning to neutral conditions, it’s possible that sea-surface water temperatures in the equatorial east and central Pacific Ocean could continue to cool to the point that La Niña may emerge in the fall, NOAA said. However, they cautioned that much uncertainty remains, though there is computer model and physical evidence that La Niña conditions could develop.
La Niña is the opposite of El Niño, namely, a cooling of the equatorial east-central Pacific Ocean.
Of course, if La Niña does develop, the strength of it (weak, moderate or strong) will determine what impacts it may have on the weather in North America and elsewhere next winter (2016-2017). The downward trend in the graph lines from left to right below illustrates the computer model forecast for cooling SSTs through spring, summer and into next fall.
Image credits: (top right) Forecasts from seven climate models for the 3-month-mean average sea surface temperature anomalies in the Niño3.4 region (Oceanic Niño Index). The first 3-month-mean period shown is March—May 2016, “MAM”; the last is December 2016—February 2017. Model data from the North American Multi-Model Ensemble (NMME). Climate.gov figure.