Batten down the hatches! The El Niño is acomin! We are certainly hearing a lot about El Niño coming, hoping it will bring the wet year we so desperately need. But what exactly is an El Niño and will it really end our devastating drought?
El Niño is a climate cycle in the Pacific Ocean with a global impact on weather patterns. The cycle begins when warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America. Normally, this warm water pools near Indonesia and the Philippines. During an El Niño, the Pacific’s warmest surface waters sit offshore of northwestern South America.
Forecasters declare an official El Niño when they see both ocean temperatures and rainfall from storms veer to the east. Experts also look for prevailing trade winds to weaken and even reverse directions during the El Niño climate phenomenon.
El Niños occur every three to five years but may come as frequently as every two years or as rarely as every seven years. Each event usually lasts nine to 12 months. They often begin to form in spring, reach peak strength between December and January, and then decay by May of the following year.
El Niño was originally named El Niño de Navidad by Peruvian fishermen in 1600s. This name was used for the tendency of the phenomenon to arrive around Christmas. Climate records of El Niño go back millions of years, with evidence of the cycle found in ice cores, deep sea muds, coral, caves and tree rings.
The Good News
There is increasing evidence that we may well experience an El Niño year. The U.S. Climate Prediction Center, in its monthly long-term weather outlook, cited increased odds of greater-than-normal precipitation for nearly all of California this winter – including, crucially, the Sierra Nevada and most of Northern California, source of most of the state’s water supply. Snowmelt from the Sierra supplies the largest percentage of EBMUD water.
Increasing evidence for an El Niño year includes warmer ocean temperatures not only in the tropics but also in other parts of the Pacific. Unseasonably warm ocean temperatures have been measured along the coast. The higher ocean temperatures have the potential to increase the intensity of more frequent storms produced by El Niño.
Daniel Swain, a climate scientist at Stanford University, noted that the atmospheric ridge of high pressure off the coast, which he has dubbed the “Ridiculously Resilient Ridge,” is gone, thus removing a potential hurdle to wet weather. In previous years the ridge pushed storms north of California.
The Not So Good News
So there is general agreement by climate experts that we will experience El Niño conditions this winter. However, they also caution that even a few wet months won’t eliminate the water deficit created by the state’s four-year drought. More than twice the average rainfall would be needed to make up the shortfall, an amount that has not fallen in more than 150 years of recordkeeping. Even the state’s wettest years have seen just less than twice the average.
Additionally, El Niños tend to bring not only wetter weather but also warmer temperatures, meaning a quicker-melting Sierra snowpack isn’t expected to grow as much as it might otherwise.
The Bottom Line
Even if a robust El Niño year brings us substantial rainfall and snow melt it will not be enough to offset the water deficit created by our four-year drought. Additionally, California will continue to experience drought years in the future.
We’ve done very well in our conservation efforts. We’ve met EBMUD’s goal of cutting back 20 percent on our water use. It is imperative that we continue our efforts to conserve water and always try to think of new ways to conserve water.
We need to investigate ways to recycle the water we have such as the installation grey water systems and treatment of sanitary sewer water. So when the rains come and we wonder if they will ever stop, please don’t be tempted to take longer showers or let the water run when you brush your teeth.
CONSERVE. REUSE. RECYCLE.
This article first appeared in the Rossmoor News on November 4, 2015, by author Barbara Coenen.