BROOKINGS, S.D. - The northern Great Plains had cooler summers the past few years, but the shift from El Nino to La Nina weather means a more normal or hotter-than-normal August and September are expected.
That’s the message from Eric Snodgrass, director of undergraduate studies in atmospheric sciences at University of Illinois and co-founder of Agrible, Inc., which performs predictive analytics for farming. Snodgrass was one of a panel of climate experts speaking at the South Dakota Governor’s Ag Summit in Brookings.
El Nino is the warming and La Nina is the cooling in the Pacific Ocean, and both have effects on North American weather.
Snodgrass said scientists are advancing the ability to predict weather stresses to correlate the predicted weather on crop yields, customized to every county in the country that grows row crops. This year, the key factors are precipitation and extreme heat in July.
“This year there certainly is the potential for above-average temperatures through July, August and September time frames,” Snodgrass said. The Dakotas will likely see the warmest temperatures in August and September.
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Experts aren’t expecting the banner production year realized in 2015 in the region, but they are still predicting average or above-average crop yields. The same conditions will cause more stress in the eastern Corn Belt states, but there is nothing that indicates drought effects like 2012 when corn spiked to more than $7 per bushel.
Frost-free Huron Snodgrass used Huron, S.D., as an example to illustrate a trend in the number of frost-free days. Minimum temperatures at night are increasing, even as daily maximum temperatures are not.
“Back to the 1970s, pretty often you’d have frost-free seasons of 120 days or less,” Snodgrass said. “Since 1974, we haven’t had a frost-free season of less than that. Since the mid-2000s, you haven’t had a frost-free season in Huron of less than 130 days.”
Combining that with increasing seed technology for drought resistance, and increased seed population has increased corn production from the state. A bad year now “would have been a fantastic year 15 years ago,” he said.
Dennis Todey, state climatologist and associate professor at South Dakota State University, said it’s been relatively wet this spring, which has been relatively good for most parts of the state. “We have some issues in the southeast part of the state where it looks excessively wet,” he said. “We’ve seen 6 or 7 inches of rainfall in May - over 20 inches of precipitation,” this year.
Southeast South Dakota “We have some fields that have been planted when perhaps they shouldn’t have been, and we have some fields that are likely to go unplanted because they’re going to be too wet,” Todey said. “We know we’ve had some people shift from corn to soybeans because they’re hoping things will dry out so they can get some soybeans in.”
In the middle and east-central part of the state conditions are relatively good, he said. The northeast part of the state has some dry areas.
The U.S. Drought Monitor has identified some northeast areas as “D0,” meaning it is abnormally dry, which indicates slowed planting, or growth of crops and pastures. Other dry areas include the Black Hills, where rangeland has taken a hit from May dryness and a mid-May freeze.
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Darren Clabo, a fire meteorologist at the South Dakota School of Mines and Technology in Rapid City, S.D., said more precipitation in one year can grow more fuel for fire seasons in subsequent drought years. The Black Hills National Forest has been dry for 30 days.
“If we don’t see precipitation in June, I’m going to have a lot of concern for fire season come July and August,” he said, although central and eastern South Dakota aren’t of much concern.
