NOAA Forecasts Historic El Niño Will Drive Warmer, Wetter Winter

National weather agencies predict a winter defined by extreme conditions as a powerful El Niño event takes hold. The National Oceanic and Atmospheric Administration forecasts warmer-than-average temperatures across much of the continental United States. This warmth will accompany above-average precipitation in several key regions. The agency describes the current atmospheric shift as a strong, if not historic, El Niño going into the season.

Ken Graham, director of the National Weather Service, stated that these seasonal predictions provide a critical roadmap for cities. Local governments use this data to allocate resources and prepare for potential impacts. Graham noted that earlier and better decisions save lives. The forecasts allow officials to assess risks and mitigate damage before storms arrive.

The physical mechanism driving these changes begins in the tropical Pacific Ocean. A vast area of water in the eastern Pacific has warmed near the equator. This release of heat into the atmosphere shifts global weather patterns. Josh Willis, a climate scientist at NASA’s Jet Propulsion Laboratory, compares the event to the monster Godzilla. Willis explains that the pattern breathes fire on Indonesia and Southeast Asia, causing severe drought and wildfires. Its tail kicks up hurricanes and storms on the North American Pacific coast.

The West Coast is already feeling the effects of this shift. A Kelvin wave raised sea levels in early October, increasing the risk of coastal flooding. This wave contributed to the extensive flooding associated with Tropical Storm Rachel. Another wave is currently moving between Los Angeles and San Francisco. More waves are expected through the fall and early winter. Dillon Amaya, an assistant professor of atmospheric sciences at North Carolina State University, explained that these waves do not cause flooding alone. Instead, they load the dice, increasing the likelihood of flood events.

The Southwest experienced its share of extreme weather in late October. Severe flooding in the Four Corners region forced rooftop rescues and evacuations. Daniel Swain, a climate scientist with the University of California Agriculture and Natural Resources, attributed the severe thunderstorms to large amounts of moisture in the atmosphere. This moisture came from record-warm waters off the West Coast. Swain cautioned that these wet conditions do not end the ongoing water crisis in the Colorado River basin. Lake Powell and Lake Mead remain at record low levels.

Forecasters expect the South to have the best chance of above-average precipitation this winter. Northern Texas may see snow in areas that rarely experience it. Florida is bracing for heavy rain in regions that do not normally see such downpours. This follows an unusually quiet Atlantic hurricane season that produced only one named hurricane, Isaias. The state’s tornado risk remains higher during El Niño years. In 1998, Central Florida experienced a deadly tornado outbreak that killed 42 people during a similar climate event.

The Midwest faces a different set of challenges. The Upper Midwest is expected to have a smaller snowpack than normal due to warmer temperatures. Michigan, Ohio, and Indiana tend to be drier during El Niño winters. Iowa tends to be wetter, according to the U.S. Geological Survey. Jon Gottschalck, a branch chief for NOAA, said drought situations are expected to persist across the Midwest. There is growing concern that the current drought will worsen rather than improve during the winter months.