AccuWeather Meteorologist Explains El Niño Forecast

This year’s El Niño cycle — dubbed a “super El Niño” by some — will reach a climax this fall and winter. The Climate Prediction Center of the National Oceanic and Atmospheric Administration (NOAA) and international forecasters confirm that El Niño is firmly established and actively strengthening in the central and eastern equatorial Pacific Ocean.

What does that mean for river levels during this year’s harvest season? Paul Pastelok, senior meteorologist for AccuWeather, spoke with The Waterways Journal about where the El Niño cycle could go.

Pastelok has been with AccuWeather, a highly respected private weather forecasting company, for more than 30 years. The company that would become AccuWeather was founded in 1962 by Joel Myers in State College, Penn., with a local gas company as his first client. It adopted the name AccuWeather in 1971 and expanded into radio and TV, introducing the first seven-day local TV weather forecast in 1975. It launched its website in 1996.

Pastelok cautioned that his team has not yet completed its winter forecast. He said about 85 percent of the outlook is “all El Niño,” but that other local factors making up 15 percent can complicate forecasts.

He compared the behavior of this year’s El Niño’s “super-cycle” with those of past years in the 1970s, 1980s, 1990s and early teens. However, he said, the comparisons can’t be exact because the overall climate changed over those decades. Highs are becoming higher and lows lower; he noted that sometimes the storm tracks can shift farther north, similar to the 2015-16 season.

In the short term, Pastelok sees a dryer, hotter period extending into the first or second week of September, which will affect early harvest season river levels. That could be succeeded by a wetter period, he said. Much of that rainfall will go to the Tennessee River Valley and Lower Mississippi River basin for a wetter than usual late fall and winter.

“By October, we should be seeing more moisture coming up out of the Gulf and Southeast, converging in the Lower Mississippi River basin,” he said.

What about winter snowpack? There, Pastelok is less encouraging. In an El Niño cycle, “There’s typically not much high snowfall in the upper Midwest and Upper Misssissippi River basin,” he said. “The central and southern parts of the basin should do fine” with regard to rainfall. “It could be tough in the north.” However, Midwestern states like Nebraska and Kansas could do better with some rain and snow due to storms rolling in from the Rockies.

Mid-Southern states like Kentucky and Tennessee would see higher than usual snowfall, combined with higher than usual rainfall. “A lot of that snowfall in that area melts quickly and is washed downstream,” he said, but with frequent rainfall events, can likely pose a flood risk.