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Sep

24

2015

Fact Checking El Niño

featureNINO

Remember the 1997-98 El Niño? Photographer Dave Cox does.

Mountain’s meteorologist breaks down the news from September 1-12.

Editor’s Note: Last week, we rolled out a story about this year’s El Niño (Run! It’s the Godzilla Niño!), relying on the expert feedback of Colorado meteorologist Nick Barlow. Here, and for the next few weeks, he weighs in on Niño-related rumors, predictions, and published stories.

Parched California Could Benefit by Forecast of Big El Niño, USA Today, September 11, 2015

Synopsis: A strong El Niño climate pattern could bring much-needed rain and snow to drought-stricken California, according to a new federal forecast out on September 10. The story also states that, “…strong El Niño events in the past have led to wetter-than-average conditions in the southern part of [California], but offered mixed results for California’s main water supply regions in the north…”

Barlow’s Take: There’s no guarantee of record snowfall with a big El Niño. The statistics just don’t back up a wetter-than-average winter for everyone. You could do hours of statistical analysis on El Niño Years vs. Snowfall, and still lack the ability to predict. But here are a couple of El Niño years I analyzed, just to prove a point.

Mammoth: Record snowfall (668 inches) was in 2011/12, a La Niña year [La Niña is characterized by cooling water in the Pacific Ocean, versus El Niño’s warming water]. In 2005/06, another big year, it was neutral (no Niña or Niño). The very strong El Niño years of 1982/83 and 1997/98 had 451 inches and 546 inches respectively.

Squaw Valley: They received record snowfall (near 700 inches) in 2010/11— a La Niña year. 1994/95 year was also big a big year, and it was a weak El Niño.

The main takeaway: Every El Niño is different. If we continue the drought in the Sierra this year, or if we have record snowfall—no one can say El Niño was the sole cause.

Record Southern California Rain Swamps Roads, Swells Rivers, the San Luis Obispo Tribune, September 9, 2015

Synopsis: A huge storm hit Southern California. Does it have anything to do with El Niño?

Barlow’s Take: Maybe this storm is El Niño, maybe not. We’ll have to look back on the season as a whole before we draw any conclusions. Even if the “Storm of the Century” hits, we can’t necessary blame El Niño. “Storms of the Century” hit every century, right?

Study Finds Snowpack in California’s Sierra Nevada to Be Lowest in 500 Years, The New York Times, September 14, 2015

Synopsis: Stanford University researchers used tree rings to study the historical context of drought; they report that when combined with previous studies, the tree rings help “provide strong evidence that global warming has substantially increased the probability of getting these extremely low snow conditions.”

Barlow’s Take: This is definitely an interesting article. The climate record requires a minimum of 30 years, so we should always be very skeptical about single seasons, or single storms. Essentially, climate is an average of extremes. It is a measure of trends. The article walks the line of confusing climate with weather, but doesn’t really do a bad job. The researchers’ findings are worth noting, certainly. It’s also worth noting that last year was the warmest globally on record. But it was just one year. Yet we’re seeing a trend in warming globally, which is why climate change is now accepted by scientists. Recent dry winters in the Sierra have our attention, but there’s not enough data to say why it is happening, or if it will continue. Sadly, it is often in retrospect—once we have an appreciable record of data to study—that we finally understand what was happening.

Snakes in Costa Rica Bite People More Often During El Niño Years, Gizmodo.com article from September 13, 2015

Synopsis: El Niño causes snakebites! A Costa Rican researcher studied snakebite records from 2005 to 2013, and found that more people reported snakebites during the hot and cold phases of the El Niño Southern Oscillation, compared with normal years.

Barlow’s Take:  Well, isn’t this interesting… But I’d suggest there isn’t sufficient evidence to support the claim. A study period of 2005 to 2013 is probably not long enough—though it’s entirely possible the snakes have a chip on their shoulder when the weather is warmer. If that is the case, then more people may get bitten. Whether or not it is actually true, I expect to see an increase in stories like these going forward. The planet is warming. It’s hard to imagine how powerful even a +1-degree Celsius global temperature increase is. It doesn’t seem like much, but Earth is a delicate system. Even minor perturbations can have exponential influences on the system’s balance. The oceans and the atmosphere are highly related. They are feedback mechanisms for one another, transporting heat and moisture and driving our weather. We (and the snakes) are simply witnesses to this unfolding drama.

See our original El Niño report, on where you should place your bets for snowfall this season.

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