Remember the halcyon days of 2016, when we were bidding adieu to El Niño and recovering from the death of Harambe? Well, the beloved gorilla may have departed this world for good, but El Niño will return. It always does.
Typical weather impacts of El Nino during December through February. Image: National Weather Service
Perhaps even as soon as this spring.
On Thursday, the US National Weather Service’s Climate Prediction Center (CPC) released its monthly El Niño forecast bulletin, pegging the chances of the Pacific climate pattern developing in the spring of 2017 at 45 per cent. El Niño, for the uninitiated, starts when abnormally warm surface water builds up across a vast stretch of the equatorial Pacific, disrupting circulation in the ocean and the atmosphere and leading to predictable patterns of drought and heavy rainfall worldwide.
On average, El Niño recurs every three to seven years, according to the Scripps Institute for Oceanography.
But… it’s only been a year.
The monster El Niño of 2015/2016 was declared dead on 23 May 2016, followed just a few months later by a rather lacklustre La Niña. Is it just our rotten luck that the El Niño beast is rumbling in its sleep again so soon? Or are such climatological encores to be expected when we’ve just lived through one of the most powerful El Niño on record?
“It’s hard to say — because we’ve really only had three strong El Niño events with good observations,” Phil Klotzbach, a tropical storm expert at Colorado State University, told Gizmodo. “None of the other ones went back to El Niño again so quickly,” he noted, referring to the El Niño events of 1982 and 1997.
Still, it’s hard to decipher a pattern with only three data points. Klotzbach noted that there have been instances in which we’ve dipped into weak El Niño conditions again and again over a period of several years. “That’s not unusual,” he said.
Then again, as NOAA points out over at its excellent ENSO Blog, we’ve only seen a sequence of El Niño, La Niña and El Niño again in three consecutive years once since 1950.
The latest CPC forecast estimates a close to 50 per cent chance of El Niño developing in spring, which still leaves a lot of room for things to go the other way. To declare a bonafide El Niño event, temperatures across the central and eastern equatorial Pacific not only have to be elevated at least 0.5C above average, we have to be pretty sure they will remain elevated for several straight months. Right now, average model forecasts suggest surface ocean temperatures in that El Niño sweet spot will hover right around +0.5C mark for the winter — but the models could be wrong. Things could wind up being hotter, or cooler.
El Niño could be your introverted friend who bails on the party at the last minute, or it could be the dude who arrives liquored up and ready to rage.
“I think if we make it to El Niño [conditions], we’re just going to make it,” Klotzbach said. Which is to say, we’re probably not in for a repeat of last year’s Godzilla El Nino, which, along with that little thing called climate change, pushed 2016 to become the hottest year on record. “Maybe I’m wrong — but if the model consensus is right, it will be right on the money.”