Probability of El Niño next winter increases to 78%

Probability of El Niño in a given three-month period (e.g. OND = October, November, December)

By on Thu, May 8, 2014

The National Weather Service has increased its estimate of the probability of an El Niño beginning in November from 66% to 78%.

There remains uncertainty as to exactly when El Niño will develop and an even greater uncertainty as to how strong it may become. This uncertainty is related to the inherently lower forecast skill of the models for forecasts made in the spring.

Many forecasters are expecting that if there is an El Niño that it could be unusually strong.

The structural similarity of SST [sea surface temperature] anomalies in the equatorial Pacific between 1997 and 2014–combined with numerical model projections for continued warming in the coming months–suggest that the it’s still rather likely that the Pacific is headed for a major El Niño event this year. By the end of May, we start to move past the Spring Predictability Barrier, so I expect that we’ll have a much better handle on where things are headed by early June.