El Niño: what it is and what to expect. Comic by Laila Milevski, reporting by Cody Boteler
In early June, National Oceanic and Atmospheric Administration scientists confirmed El Niño emerged in the Pacific Ocean, conditions that will continue this winter and into the new year. NOAA scientist says: we’ve monitored sea surface temperatures for months. The averages have been warm for long enough to be El Niño. El Niño is part of a regular climate cycle in the Pacific Ocean that affects weather across the globe. Its counterpart, La Niña, ended earlier this year.
What is El Niño? When El Niño develops in the spring or summer, east-to-west winds above the Pacific weaken, and unusually warm surface water temperatures gather in the ocean off the coast of South America. Those shifting winds change the weather around the globe during the fall and winter — such as making wildfires more likely in Australia or increasing rainfall in Argentina.
How does El Niño influence U.S. weather? During the winter months, El Niño makes wetter and cooler conditions more likely in the southern states, and drier and hotter conditions more likely in the northern states. It affects hurricanes as well: El Niño can weaken or suppress Atlantic hurricanes, while increasing the number of storms in the eastern Pacific.
What does this mean for Maryland? It might not mean much, at least not right away. Michael Allen, assistant professor of climatology at Towson University says: Baltimore is in a transition zone. Sometimes we fall into Northern characteristics, sometimes into Southern. But in the winter, we could see effects on the weather. Professor Allen says: During recent El Niño events, we had some significant snowfall in the Baltimore metro area, like Snowmageddon 2010.
Why does it keep happening? El Niño and La Niña aren’t unusual. They’re expected climatological events in a cycle that could last from three to seven years before conditions return to “normal.” How does global warming affect El Niño? As global temperatures continue to rise, a lot of the energy caught in the atmosphere sinks into the ocean, creating higher temperatures, Allen said.
While Allen didn’t say that El Niño and La Niña are increasing in frequency, global climate changes make the effects of these cycles “potentially more significant.” Professor Allen says: It’s like adding an ace to a deck of cards. You’re increasing the probability of drawing a Hurricane Katrina.