'Cooler than average' temperatures expected this winter
MITCHELL — South Dakota, brace for an extra-cold winter.
The inevitable South Dakota winter is nearing, and while residents are used to this sort of weather, the state's climatologist says this year's winter might be colder than usual.
Laura Edwards, South Dakota's climatologist, said the United States is preparing for a La Nina climate cycle — the chillier rival of the El Nino.
"That typically means for us in the Dakotas a cooler than average winter," Edwards said. "That's like the December, January and February time frame. So something to maybe look forward to. Last year we had an up-and-down winter. It was cold, then warm, cold, then warm."
The La Nina climate pattern refers to the cooling of the central Pacific Ocean, while an El Nino is the natural warming of oceanic temperature. These climate cycles drive the weather patterns in the U.S. and around the world, specifically in the late fall, winter and early spring according to the National Weather Service (NWS).
For Mitchell, a good example of the "up and down winter" mentioned by Edwards occurred in February. Mid-February saw temperatures reaching near 70 degrees, but by the following week several inches of snow dropped on the area.
But shifty weather wasn't the only notable difference this past winter. Edwards said the 2016-17 winter season also saw large periods of ice and few snowstorms.
"We always see snowstorms, but I remember a lot of ice last year," she said. "So hopefully we can avoid that this winter. Crossing our fingers on that."
The NWS said La Nina occurs every three to five years, but occasionally can occur over successive years. The NWS Climate Prediction Center estimates La Nina conditions are favored at about 55 to 65 percent during the 2017-18 fall and winter.
Drought no longer a concern
What once devastated South Dakota's agriculture economy is no more.
Edwards said drought is no longer a concern, especially in Davison and Sanborn counties, where it is now considered "drought-free."
But as fall 2017 continues, there will be a lot of "variability" in the climate, she said, adding that the end of October may warm a bit before dropping in temperature in mid November.
Instead, Edwards is worried about next spring for parts of southeastern South Dakota. South of Mitchell, she said, nearing Yankton and Vermillion, saw "unusually wet" conditions.
"When you get a wet fall, that increases the potential for flooding in the spring," Edwards said. "On the flip side, it can be good news because you have soil moisture and the crops can get a decent start. It's a fine line."