Where Is El Niño? And Why Do We Care?


From Climate Central (Andrea Thompson):

the reason we still care so much about it, following all of its tiny fluctuations toward becoming a full-blown El Niño, is that it can have important effects on the world’s weather, including in the U.S. It can even boost global temperatures, helping set the planet on the course to be the warmest year on record.

In their monthly update, scientists at the National Oceanic and Atmospheric Administration’s Climate Prediction Center and the International Research Institute for Climate and Society at Columbia University said there is still a two-thirds chance that a weak El Niño event emerges and that it will likely do so in the October-to-December timeframe, lasting until spring 2015.

“I think it’s pretty safe to say that we’re essentially taking one step forward, that is one month forward since last month,” CPC forecaster Michelle L’Heureux told Climate Central.

While the conditions that mark an El Niño — such as warmer-than-average sea surface temperatures in the tropical Pacific and a reversal of prevailing winds in the region — haven’t fully gotten in synch, they still can, and in some cases are, impacting the global climate and weather.

There’s a robust connection between El Niños and quiet Atlantic hurricane seasons, which the 2014 season has turned out to be, and hurricane experts have said that the burgeoning El Niño is part of the reason.

Even though waters in the eastern and central parts of the tropical Pacific haven’t consistently been warm enough to herald an El Niño, they are still affecting the atmosphere in a way that creates more stable, subsiding air over the Atlantic and more wind shear. Both of those factors tamp down on hurricane formation and development.

“This is fairly typical in fall” when the system is leaning toward El Niño conditions, L’Heureux said.

Those warmer waters, particularly ones in the central tropical Pacific, also helped bump this past summer into the books as the warmest summer on record. That heat has put 2014 on the path to possibly becoming the warmest year on record. If the El Niño continues to develop and forms before the end of the year, it will help nudge the planet toward that record.

The story isn’t quite the same for other El Niño impacts, namely the connection to a wet winter in Southern California. Only strong El Niños are associated with above-average winter precipitation there, something the region desperately needs in the midst of a three-year drought that is one of the most intense in the state’s history. But with this El Niño expected to be a weak one, the picture for California’s winter is unclear right now.

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