Making Sense of El Niño and La Niña

weather pattern

Every few years, weather forecasters are abuzz with talk of El Niño and its effects. Many people see El Niño as a way to explain any peculiar or extreme weather conditions. Rain in December, snowfalls in the south—it’s all because of El Niño.

We know El Niño impacts the weather in strange ways. But what exactly is it?

Essentially, El Niño is a warming of the oceanic currents along the equatorial regions of the Pacific. On the flipside of this is La Niña, El Niño’s colder sister. Both are part of a climate cycle, with La Niña signaling the cooling of the air and ocean temperatures across the central Pacific.

During an El Niño year, you can expect warmer than average winters in the northern parts of the United States and wetter than average winters in the Southwest and Southeast. If it rebounds into a La Niña, the general weather patterns will cause warmer winter temperatures in the Southeast and colder than normal temperatures in the Northwest. Precipitation across the north is likely to increase during a La Niña cycle, but it decreases to below normal along the Southeast and Southwest. That’s a lot of generalizations to juggle, so let’s take a closer look at the current situation.

The 2016 forecast

So far, the 2015/2016 El Niño year has been one of the strongest on record, with ocean temperatures rising far above average. It has turned into what some have called a super El Niño, and it shows.

Over the holidays, people walked around New York City in T-shirts. Yet four weeks later, they were buried under record snowfall. In other parts of the country, unseasonably warm conditions sent tornados through Texas and Florida and major floods through Missouri. El Niño's effects are, in short, widespread and strange.

Because no two El Niño effects are alike, it's hard to say what will happen in the coming months. The upshot is that areas in the Southwest and California that have suffered droughts will see increased rainfall. After spring, the effects of El Niño will begin to taper.

“Just based on statistics, you might say there’s a 60 percent chance that this El Niño will revert to La Niña conditions by midyear 2016,” says Mike McPhaden, Ph.D., of the NOAA/Pacific Marine Environmental Laboratory.

What this will likely bring about is a cold, wet winter in the Northwest. As far as extreme weather goes, there will probably be an uptick in the frequency and intensity of hurricanes in the Atlantic and more tornadoes in the Midwest. 


The weather—and the damage it can cause—are unpredictable. One way to manage this risk is by having the right coverage for your car, home and business. An Erie Insurance agent in your community can tell you more about how to get the right coverage at the right price.

This year marks the return of both phenomena. Learn more about how El Niño affects weather patterns and what the lesser-known La Niña is all about. /blog/weather-forecasting-5 Erie Insurance