Forecasters look to possibility of El Niño’s return later this year
Beginning in 2015, a powerful El Niño system unleashed torrents of rain on Texas, causing flooding in some areas of the Brazos River basin and filling up reservoirs that had remained low through years of drought conditions. What followed was a weak La Niña, the opposite of El Niño conditions, normally bringing dryer conditions. But this La Niña quickly fizzled out.
“Well, that was quick!” said Emily Becker, who writes a blog for the Climate Prediction Center. “This La Niña wasn’t exactly one for the record books.” By late January or early February, La Niña was history and the return to neutral conditions put “an end to the not-so-great La Niña of 2016-17.”
With an absence of both the El Niño and La Niña weather phenomena, Texas is enjoying neutral or average weather conditions. According to the National Weather Service’s Climate Prediction Center, an average spring and early summer will prevail this year. Neutral conditions are likely to remain in place at least until July. During neutral conditions “ocean temperatures, tropical rainfall patterns, and atmospheric winds” remain near average.
What’s in store for later in 2017? Some forecasters are predicting the return of El Niño.
Models currently suggest we'll be in the neutral category through the spring and into the summer months (June-July-August), but after that, sea temperatures could be warm enough for El Niño conditions to take over, said Jonathan Belles with The Weather Channel. The likelihood of El Niño’s return during the heart of hurricane season (June - November) generally would mean a less active than usual hurricane season, Belles said.
Texas Climatologist John Nielsen-Gammon agreed with that assessment. He also said that although El Niño brought heavy rains in 2015-2016, that may not be the case for this summer. However, wetter weather would be more likely later in the year.
“An El Niño would tend to reduce hurricane activity in the Atlantic,” he said. “There’s not much known effect on summertime rainfall in Texas, but by October or so, the odds of above-normal rainfall increase with an El Niño.”
While it’s too soon to know if an incoming El Niño would pack the same kind of powerful punch as the last one, this El Niño would be arriving sooner than usual based on weather patterns of the past.
Nielsen-Gammon said the most recent version of La Niña was never considered a strong weather pattern, but it would be rare for another El Niño to develop so soon.
“It was always a marginal La Niña, but it is a bit unusual to have an El Niño so quickly on the heels of the previous El Niño in 2015-2016,” he said. “It’s not certain that one will develop, but it seems likely. Meanwhile, as a general rule, ENSO (El Niño –Southern Oscillation)-neutral conditions mean no major tweaks to the seasonal weather outlook beyond what the long-term trends would predict.”
“There are increasing odds for El Niño toward the second half of 2017 (50-55 percent chance from approximately July-December),” according to a Climate Prediction Center report.
The only way to know for sure what the rest of 2017 holds is to wait until a clearer pattern develops, and that likely won’t manifest itself until this summer or fall, forecasters say.
Regardless of what weather pattern (La Niña, El Niño or neutral) hovers over Texas, one thing the state is likely to see is warmer than usual temperatures, Nielsen-Gammon said.
He pointed to the seven months of consecutive above-normal temperatures (from September through March). “Beyond that, no guarantees, but the long-term warming trend combined with warm Gulf of Mexico temperatures will continue to favor above-normal temperatures,” Nielsen-Gammon said.