What Do You Need to Know About El Niño? These 10 Things.

AP_97120502441.jpg

1. Why is this El Niño so special?

This year's El Niño is so strong that some are calling it a "super" El Niño. In fact, the National Oceanic and Atmospheric Association (NOAA) predicts that there is now over a 90 percent chance that this will be one of the strongest El Niños on record. Since 1950, there have been only two other El Niño winters of this magnitude, one in 1982-1983 and another in 1997-1998. According to CNN, the 1982-1983 El Niño caused more than $8 billion in damage worldwide. The 1997-1998 event caused flooding in the southeast, a severe ice storm in the northeast, $550 million in rain and flood damages in California, and tornadoes in Florida. Overall, the last strong El Niño resulted in $35 billion in damage and 23,000 deaths worldwide. While no two El Niño events are the same, we can compare past events to try to predict what will happen this year.

2. What exactly is El Niño?

El Niño occurs when ocean water temperatures in the central Pacific Ocean become warmer than normal. While this may not sound like a big deal, it can have profound impacts on weather patterns around the world and it can create very severe weather in the United States. Some El Niños are strong and some are mild, but all El Niños influence global weather patterns. El Niños occur every 3-5 years but can happen as often as every two years or as rarely as every seven years. Each event usually lasts 9-12 months and peaks in January or February.

3. Is El Niño the same thing as La Niña?

Nope. La Niña refers to times when waters in the tropical Pacific are colderthan normal. Typically, El Niños occur more frequently than La Niñas.

4. What causes El Niño?

No one really knows what triggers an El Niño cycle, but the change in weather pattern is caused by trade winds in eastern Asia. These trade winds weaken and cause warm water to pile up and migrate towards South America. Head over here for a primer on what the equatorial Pacific Ocean looks like under neutral, El Niño, or La Niña conditions.

5. What does El Niño mean for temperatures this winter? 

According to NOAA, this year's El Niño will likely bring warmer temperatures to the northern half of North America and colder temperatures to the southern half. That means that it's unlikely that Boston will see a repeat of last year's never ending winter.

6. What does El Niño mean for precipitation this winter?

The northern half of North America will see less precipitation this winter, especially Idaho, Montana, and the midwest. The southern half of the United States should see more precipitation. Historically, El Niño winters have meant less snow in the Northeast.

7. Can El Niño pull California out of the drought? 

No, but it can help. Because California has been in the midst of an epic four-year drought, everyone wants to know if El Niño is the solution. And while a wetter-than-normal winter would certainly help California's water supply, the state's drought problem can't be solved in just one winter. It will take multiple years of above average or average precipitation to make a dent. It also matters where El Niño's biggest storms hit. The backbone of California's water supply, delivery system, and reservoir capacity is in Northern California. If El Niño storms deliver more water to Southern California, it won't be as helpful to the drought. But if heavy rain falls north of Sacramento, where some of the state's largest reservoirs are located, the El Niño precipitation would be much more helpful. Best case scenario? The entire state sees substantial rainfall and enough snowfall to replenish both California's reservoirs and its high-altitude snow fields.

It's also important to note that El Niño is not the only factor that influences global weather patterns. Last year there was a weak El Niño in place for much of the winter but warm water in the northeast Pacific Ocean (also known as the Blob), had a much stronger influence on snowfall amounts. While last year's high pressure ridge seems to have broken down, we won't really see the strongest effects of El Niño in California until December or January.

8. Does El Niño only matter to California?

No. The El Niño weather pattern influences the entire country, just in different ways. While people in Los Angeles and San Francisco could see record rainfall and flooding, people in Chicago and Detroit can expect a milder winter. Likewise, New York City could see a major El Niño ice storm, while Miami might face severe thunderstorms and high winds. With an El Niño this strong, extreme weather is highly likely.

9. Will this El Niño cause weather-related damage? 

Yes, it's possible. Because El Niño often brings severe weather — flooding, ice storms, blizzards, and even tornadoes — there's a good chance that this year's strong El Niño will cause damage. In anticipation of severe storms, the Federal Emergency Management Agency (FEMA) has established an El Niño-specific website. The good news is that you can make some preparations in advance. In Los Angeles, homeowners are rushing to fix their roofs before the El Niño rains, overwhelming the roofing industry. The Los Angeles Times even has a list of 28 things to do to prepare for El Niño.

10. Is there anything good about El Niño?

Despite the risk of floods and severe weather overall, El Niño isn't all bad. During strong El Niño years, hurricanes in the Atlantic are often suppressed and warmer temperatures in Northeastern North America can help ensure that cities like New York or Chicago aren't buried under record-breaking amounts of snow. El Niño can also be a boon to ski areas (depending on where they are).

Overall: Whether you're in Brooklyn or San Diego, El Niño matters. Here at Curbed, we're on the El Niño-beat, ready to bring you coverage on everything from what's flooding to which ski areas will be hit with the best El Niño snow. We'll also tackle helpful stories like how to sell your house in an El Niño year and bring you top-notch photos of the most extreme weather. Have a tip or an El Niño story idea? Send them our way. Stay safe out there; winter is coming.

Learn more at ski.curbed.com

Chris Alexakiswater