Indications are that this winter’s weather will fall into an El Nino pattern in the Upper Midwest, meaning the region could see above average precipitation and warmer temperatures, according to historic data presented last week by the National Oceanic and Atmospheric Administration (NOAA).

“El Nino is really setting in and giving us a wintertime pattern,” said Brian Fuchs of the National Drought Mitigation Center at the University of Nebraska-Lincoln, Sept. 21. But, he cautioned, “outlooks are tendencies, not truths.”

El Nino conditions, which are a warming of surface water temperatures in the Pacific Ocean along the equator, tend to impact the weather in North and South America. For the past three years, the Pacific Ocean has experienced La Nina conditions, meaning a cooling of water temperatures. It is believed this pattern is partially to blame for the extended drought in the Midwest and Plains states.

Modeling by NOAA indicates Iowa has an equal chance of above or below normal temperatures and precipitation for October through December. 

“We really do not see any strong signals either way,” Fuchs said. 

Iowa still dry

While the future outlook remains murky, the current state of conditions in the Midwest is all too clear. Right now, much of Iowa is at least 3 inches behind normal precipitation since Jan. 1. And the hardest hit portions of the state are between 12 to 15 inches behind. 

This deficit led last week to portions of eastern Iowa moving into D4, or exceptional drought, the highest or most severe drought designation. Prior to rains moving across the state Sept. 19 and 20, 5% of the state was in the D4 category, the highest reading since the scale’s introduction in 2000.

The next drought monitor will be published Sept. 28 and will show how much impact recent rains have had on the hardest hit areas.

Mississippi concerns

Fuchs said Mississippi River levels will continue to decline this fall without significant precipitation increases. 

“The river levels are already below 10 feet in some areas and could go as low as 5 feet,” he said, noting this will inevitably lead to disruptions in river traffic.

An estimate of the 28-day average stream flow in Iowa showed effectively all Mississippi River tributaries in the state were low. 

This was also true for most of Minnesota, where the Mississippi River originates.

Meanwhile, the Missouri River water levels remain seasonally normal, thanks to more rain in western Nebraska, the Dakotas and the mountain states. Stream flows through Missouri were also listed as normal in the last month.

Gulf coast question

Fuchs said one area of concern is the extreme drought along the Gulf of Mexico, including eastern Texas, Louisiana, Mississippi and Alabama.

“This may indicate more drought for us going forward,” he said, since the Midwest sources a lot of moisture from the Gulf.

As of last week, Fuchs estimated about 81.5 million people in the U.S. were living in areas considered in drought.