El Niño was once viewed as the potential savior from California’s historic drought. Now that it has finally arrived — a year later and much weaker than hoped for — the global climate pattern is unlikely to have any impact on California’s weather.
Scientists with the National Oceanic and Atmospheric Administration (NOAA) announced on Thursday morning that the conditions needed to declare an El Niño have developed.
“After a year of watching this El Niño, it’s finally arrived. It’s not particularly impressive in terms of strength, but it has met our minimum threshold for a warm enough ocean and some type of atmospheric response that we typically associate with El Niño, at least in the tropics,” said Mike Halpert, deputy director of NOAA’s Climate Prediction Center.
Historically, strong El Niños, or so-called ENSO events, have correlated with a higher than average number of wetter winters in California. Forecasters with NOAA declared an El Niño watch on March 6, 2014. Early on, it was believed that if an ENSO event developed, it would be a strong one.
That expectation was repeatedly downgraded over the course of a year, as the necessary conditions failed to emerge. Halpert said that ocean temperatures met the warmth threshold last fall, but the correlating atmospheric response did not occur until last month.
Halpert said that with so little of the rainy season remaining, El Niño will likely have little impact on precipitation in California.
“It’s kind of so weak and so late that it’s probably not going to do anything for you this year,” he said.
Now, he said, scientists will look into how long the event is likely to persist. One of the longest ENSO events on record lasted for 18 months from 1986–1988.
Halpert said, however, that the current ENSO event seems more similar to one that occurred in 2004-2005.
“That one didn’t last all that much longer once we got into the spring, so we’ll have to see whether this plays out like that one did,” he said.