DR. ELWYNN TAYLOR, Iowa State University’s climatologist, offers visitors at the World Pork Expo on June 8 an outlook for the weather during the remainder of the growing season.

DES MOINES – As the third strongest El Nino weather pattern on record breaks up, a shift to a La Nina pattern or neutral between the two extremes is not expected to significantly affect corn yields this year.

That short-term weather assessment was offered June 8 by Dr. Elwynn Taylor, Iowa State University’s climatologist, during a presentation at the World Pork Expo in Des Moines.

Taylor’s long-term assessment is a different matter.

Short term

Speaking to a lunch crown in the Pork Checkoff tent, Taylor told his audience that if weather shifts suddenly to a La Nina pattern, the weather effects will not arrive in Iowa for another 90 days, which will be too late to adversely affect yields.

“So most likely the U.S. corn yield will be 173 bushels per acre,” Taylor said. “Trendline is 168 bpa. So if 173 happens, expect December corn futures to be at $3.50 per bushel.”

Long term

“The same weather that cut yields in half in 1936 and in the 1980s is the same weather that will cut yields in half in the next decade or so,” Taylor told the audience.

Historically, La Nina weather dominated from 1979 to 2006. In the eight years since, El Nino dominated with several record-yield seasons.

But he thinks the weather in the next decade will be primarily dominated by La Nina’s hotter, drier conditions. The jet stream will have more volatile wave action with stronger winds to blow more insects into the state from the south.

“We have just come back into a variable weather pattern like the 1980s,” Taylor said. “And the worst weather of the century is likely to happen on either side of the 2025, similar to the 1936 Dust Bowl.”

This prediction comes after studying historical weather patterns, he said. Dust Bowl weather patterns were recorded in 1847, and again in 1936.

“It happens about every 90 years,” Taylor said, so should be again during the 2020s.

Drought now?

In the meantime, he said La Nina could still turn 2016 into a drought year.

“But if La Nina is not in place by July,” he said, “don’t worry about it.”

At least for 2016; but 2017 should give cause for concern.

“Gear up for high-risk, below-trend yield and high feed prices” in 2017, Taylor said.