Though the most recent encounter with El Niño last summer has barely faded from memory, the chance of the weather pattern striking in the coming months is on the rise. As Gary Robbins reports for the San Diego Union-Tribune, forecasters think the phenomenon could be taking shape.
In a recent assessment, weather experts from the Climate Prediction Center, the National Weather Service and other groups said that the likelihood of an El Niño developing by late summer or fall is now 50 percent. That’s a ten percent rise from their prediction earlier this year—and if the weather pattern does hit, it could spell wetter, warmer weather for much of the United States.
Currently, forecasters have not activated a watch or advisory for an El Niño. But as sea surface temperatures rise in the Northern Hemisphere during the summer months, that could change. The weather phenomenon is driven by particularly warm ocean temperatures along the central and eastern tropical Pacific Ocean. Those warm waters whip up changes in the ocean currents and winds, causing heat to redistribute throughout the atmosphere.
On land, El Niño’s impacts vary depending on location. In the United States, the odds of wetter weather over the southeast and southwest are common, and hurricanes in the Atlantic can drop off. Mild, warmer winters and fewer tornados usually accompany an El Niño, too. But the weather pattern can have extreme side effects, like droughts, floods and starvation for sea animals due to a dropoff in phytoplankton production.
El Niño is one half of a naturally occurring, ongoing phenomenon called the El Niño Southern Oscillation that happens as water moves throughout the Pacific. Its sister, La Niña, means a cooler year worldwide. Right now, forecaster note, we’re somewhere between Niño and Niña, and should be through June. But by late summer and fall, another El Niño could be in store—unusually close to the last such event in 2015.
A word of warning before you break out the raincoat: It’s still much too early to declare with certainty that a warm, rainy winter is on the way. “The climate signals we get don’t necessarily guarantee things one way or another,” an NWS forecaster tells Robbins.
Even if El Niño comes, regional variability means it’s unclear how it will impact a certain region’s weather. When it comes to the temperamental weather event, it’s never clear what might happen—or if it will happen at all.