El Niño and La Niña… we hear these two terms a lot when discussing weather but what do they really mean? We asked Washington State Climatologist and weather enthusiast Nick Bond. Keep reading for more El Niño/La Niña questions that didn’t make it into the video (but are just as interesting!).
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Q: Does El Niño or La Niña really affect our weather? It’s often stated they have big impacts, but it seems pretty unpredictable.
A: It’s not like every day in a La Niña winter is going to be cooler and every day in an El Niño winter is going to be warm; there’s still that variability in the weather day to day. Again, to use that casino analogy, it stacks the deck but it doesn’t dictate the deal of the cards. Mother Nature is dealing the cards, and she doesn’t always play fair.
Q: Why are the effects of El Niño and La Niña opposite in California versus Washington?
A: We tend to see opposite effects from El Niño and La Niña in the southern part of the Western U.S. versus the Pacific Northwest. In particular, El Niño/La Niña shifts storm tracks and so during El Niño, the storm track is more to the south and California tends to be wet and the Sierras tend to be snowy, and up here we tend to have quieter weather. Just the opposite happens during La Niña in which we get more storms coming out of the Gulf of Alaska and into the Pacific Northwest, giving us plenty of rain, often cooler temperatures, and much more often than not, greater snowpacks than usual at the end of winter.
Q: Are El Niño and La Niña events driven by the atmosphere or the ocean?
A: Both El Niño and La Niña are a coupled atmosphere/ocean phenomena in which the atmosphere creates, in the case of El Niño, warmer than normal conditions and in turn, those warmer than normal conditions produce wind patterns that reinforce it. In a similar way, the atmosphere and ocean work together for La Niña to both bring it into that cooler state and maintain that for months at a time.
Q: Why are they so important when thinking about weather?
A: El Niño and La Niña is so important because it’s one of the more, if not the most, predictable parts of the climate system that we can use to make seasonal weather predictions and so we can anticipate the El Niño and La Niña conditions up to six, sometimes even 12 months in advance. Because they tend to have systematic effects on weather in many parts of the globe, to better understand El Niño’s and La Niña’s impacts can do a lot towards better predicting the seasonal weather and being able to handle the variations that occur year to year.
