In 1997, during the last very strong El Niño event, the late great comedian Chris Farley did a skit on Saturday Night Live. It was classic Chris Farley; he was dressed as a professional wrestler named El Niño.
As he called out to the other tropical cyclones, dark storm clouds appeared behind him with the sound of gale-force winds and a Weather Channel logo in the left-hand corner of the TV screen. Farley proclaims, “I am El Niño; all other tropical storms must bow before El Niño. ... If any of you hurricanes who are listening, step on up, because nobody can take El Niño. I challenge any of you ... tropical storms to a no-holds-barred cage match. Any time, any coast ... It’s time to pay the piper because El Niño is coming for you, and it isn’t going to be pretty.”
It’s one of my favorite skits on Saturday Night Live, and it’s difficult not to laugh out loud every time I see it.
But in this satire, Farley does make an important point. El Niño is not some gigantic vortex of gloom lurking somewhere in the equatorial Pacific. El Niño is an area of above-average sea surface temperatures in a central equatorial region of the Pacific Ocean called Niño 3.4. The fortunetelling temperature cycles in Niño 3.4 are categorized by the amount they deviate from the average.
So how do these above-normal seawater temperatures in an area so far away have such a profound effect upon California’s weather? The answer is in the winds, or should I say, the upper-level winds. These warmer waters in the eastern Pacific produce a greater amount of evaporation. As this water vapor ascends into the atmosphere, it often condenses into thunderstorms and releases tremendous amounts of latent heat, which further decreases the atmospheric pressure. This area of low pressure in turn changes the path of the southern branch of the polar jet stream, pulling it farther south.
The jet stream is typically a tubular ribbon of high-speed winds about 18,000 to 40,000 feet up, flowing in a wavelike pattern that circles the globe in an eastward direction. These upper-level winds steer midlatitude storms across the Pacific toward North America.
Since 2011, the jet stream has tracked mostly to the north of California and, combined with record-breaking high temperatures, produced one of the worst droughts in our state’s history. However, with this year’s El Niño event, the jet stream is expected to shift southward and bring storms to California.
So how do we know this may occur? The most recent ocean temperature readings from Niño 3.4 region indicate that this year’s event could be the strongest El Niño on record. If this year’s event is not the strongest, it will surely be among the top three El Niño events since 1950.
The previous three strongest El Niño episodes occurred in the 1972-73, 1982-83 and 1997-98 rain seasons. These generated huge amounts of precipitation later in the rain season for the Central Coast. The 1972-73 rain season (July 1, 1972, to June 30, 1973) totaled 38 inches of rain. The 1982-83 rain season totaled 47 inches, and the 1997-98 rain season hit 44 inches at the Diablo Canyon nuclear power plant’s rain gauge.
Historically, the seasonal precipitation averages about 23 inches. Needless to say, these events produced nearly twice the historical seasonal average.
The storm door didn’t entirely open until January or February during those El Niño episodes, and then San Luis Obispo and Santa Barbara counties saw as many as three or more cold fronts a week. The long-range numerical models and charts are still indicating that El Niño-driven storms will start this January.
In fact, January, February and March are predicted to produce well-above-normal rainfall for most of California. The wildcard in this prediction is climate change. Climatologists are not sure how this will affect this season’s anticipated rainfall. It should also be noted that even if we do receive record rain this season, it probably won’t end the drought. Water conservation and management will be critical in the years ahead.
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The last major El Niño storm season in 1997-98 created widespread flooding and caused power outages impacting more than a million PG&E customers. PG&E has been preparing for storms like those, while urging its customers to be ready for natural disasters. That includes having a family emergency plan and keeping emergency kits for your home, your office and your vehicle. PG&E offers emergency-preparation tips on its website at www.pge.com/en/safety/preparedness/index.page.
John Lindsey is PG&E’s Diablo Canyon marine meteorologist and a media relations representative. Email him at email@example.com or follow him on Twitter @PGE_John.