El Niño – it sounds like a big, bad and scary weather phenomenon, but it’s not. While it may enhance problematic weather in some parts of the country, it also provides beneficial effects to others.
El Niño and La Niña, both of which fall under the umbrella of something called El Niño Southern Oscillation (ENSO), have to do with sea surface temperatures in the eastern equatorial Pacific Ocean. El Niño is the above average phase of ENSO, while La Niña is the below average phase of ENSO.
Regional impacts from El Niño are most noticeable in the wintertime, though some weather events during the spring, summer and fall can be attributed to what’s going on in the Pacific Ocean.
In recent weeks, parts of Oklahoma and Texas received historic amounts of rain. Oklahoma City, Oklahoma set the wettest May on record, with 19.48 inches falling. Dallas-Fort Worth,
Texas also experienced the wettest May on record, with 16.96 inches.
Those are examples of disruptive weather enhanced by El Niño, as intense flooding turned deadly and destructive. But El Niño may help southwest portions of the United States.
California and Nevada have been in a drought for years, now the Drought Center classifies it as an exceptional drought. During an El Niño winter, rainfall has historically been well above average on the Pacific coast, particularly in California.
New England can see an above average amount of precipitation during an El Niño winter.
That begs the question, does it mean more snow? Looking at the average snowfall seen during El Niño years, the simple answer appears to be yes.
But according to longtime meteorologist Fred Gadomski, there is little value in analyzing all
El Nino years lumped together, when it comes to the above average snowfall result. “Through the magic of what we call arithmetic, it ends up above. But I think’s it’s a tenuous, tenuous relationship that we’re dealing with here, this El Niño business.”
Gadomski has worked in the Department of Meteorology at The Pennsylvania State University since the early 1980s. Before that, he worked in New England and even rode out the Blizzard of 1978 in Bedford, MA.
“I think we’ve come to understand El Niño is a big thing when it comes to global weather patterns, but it’s not the only thing. Therefore, knowing about El Niño is not going to give us the answer to weather, particularly in places that are a long distance away from where El Niño does its business, which is in the equatorial eastern and central Pacific Ocean,” says Gadomski.
“Generally speaking, there is not a strong correlation between snow in the northeast and the presence of an El Niño.” Gadomski says. According to him, a juiced-up southern jet stream is an important factor to get big snows in the northeast, but beyond that, “it’s a crapshoot on storm tracks and things like that, so this is where the statistics of this just, I think, fall apart.”
One or two big storms can define a season, especially in places like New York, Boston or Hartford where blockbuster snow isn’t typical. That means El Niño winters with little snow get dwarfed by the blockbuster El Niño snowfall seasons, and the averaged snowfall signal is muddled or perhaps even misleading. The strength and trend of an El Niño can also have big implications.
And what if El Niño goes away? Government forecasters don’t think it will. The start of the current El Nino can be traced back to early last fall, and is projected by weather models to either sustain its current weak to moderate ranking or even strengthen into a strong El Nino for the duration of 2015.