Climate update: Wetter forecast likely for South Dakota

BROOKINGS — As La Nina conditions are likely to affect Americans into the fall and winter, wetter conditions could come to South Dakota, said Laura Edwards, SDSU Extension Climate Field Specialist.

Edwards based her comments on the latest National Oceanic Atmospheric Administration (NOAA) Climate Prediction Center outlook for August and the season ahead, released July 21, 2016.

“The outlook shows increased probability of wetter than average climate for South Dakota,” she said. “In August, a large region of the northern Great Plains is now projected to receive more rainfall than normal. Several long-term climate computer models have been consistent in forecasting these wetter conditions for the weeks and months ahead.”

The outlook for potentially wetter conditions could be good news for South Dakota farmers and ranchers. “Moisture at this time of the growing season can help with grain fill in corn and reduce stress during pollination season for soybeans,” Edwards said. “Although, there may be some increased concerns with late season diseases and weeds, should rainfall come to the crop growing regions.”

As far as temperatures go, Edwards said the outlook is less clear.

“In August, the climate update now indicates equal chances of warmer, cooler or near average temperature for South Dakota. Previously, our region had been favored to be warmer than average.”

She added that this could come as good news to row crop producers. “We are in the midst of the strongest heat wave of the season. Temperatures are soaring to 100 Fahrenheit or higher across much of the state. A respite from the heat would be a welcome change as we move into August.”

Drought conditions continue in western South Dakota

The July 21 U.S. Drought Monitor also shows increasing area and severity in drought along the western side of the state. “Some rainfall would be greatly beneficial in improving water supply and quality across the region, albeit too late for many of the forages and crops,” Edwards said.

La Nina now has a 55 to 60 percent probability of affecting our climate in North America in the fall and winter season. “The longer term climate outlook reflects a typical La Nina pattern, with an area favored to be wetter over Dakotas in the August through October period. Nationwide, temperatures are still leaning to be warmer than average in the fall season,” she said.

During La Nina years, August and October tend to be wetter, on average, especially in eastern South Dakota. Generally speaking, there isn’t much of a La Nina signal in fall season temperatures, but there are long-term trends and other indicators that are showing warmer conditions for the season ahead in many of the climate computer models.