Not much was normal about 2020, but coming off a historic weather year in 2019, weather came back to earth in South Dakota.
It was a calmer weather year, with fewer severe weather events, and precipitation fell off in a big way in the Mitchell area last year.
In Mitchell, 16.12 inches of precipitation fell in 2020, less than half of what it received in the historic and record-setting year of 2019 (36.47 inches).
In 2019, 11 out of the 12 months had at least 1 inch of precipitation (all but January), but in 2020, only four months in the middle of the year had at least 1 inch of precipitation (May, June, July and August).
“The big weather story for 2020 (for Mitchell) is the lack of precipitation, without question,” said Peter Rogers, a warning coordination meteorologist for the National Weather Service in Sioux Falls.
The number of days with at least one-hundredth of precipitation was 77, down by 40 days compared to 2019 and the lowest count in a year since 2012, when there were 70 days with precipitation.
Rogers said the dry year wasn’t that unprecedented but it stands out because of the contrast with 2019. 2020 was the driest year for Mitchell since 2011, when about 12 inches of rain fell. Coincidentally, that was a heavy flood year on the Missouri River, and in Mitchell, followed a 2010 with nearly 28 inches of precipitation, the second-most rainfall in the 2010s decade.
“Because of how wet it was in 2019, we had some residual moisture issues that affected planting in the spring (2020),” Rogers said. “But it’s really been mostly dry since then, and now going into this new year, we’re really going to be looking at how this all unfolds over the next few months and carries into the spring (2021).”
Of years with mostly complete data, 2020 was the 11th-driest year in Mitchell’s history. The driest year was 1925, with 11.55 inches of precipitation, followed by 2011 as the second-driest.
It was also a light year for severe weather. For the National Weather Service coverage area of southeastern South Dakota, southwestern Minnesota, northwestern Iowa and extreme northeastern Nebraska, just four tornado warnings were issued in 2020.
One severe weather event for the area came on June 9, with a severe storm coming up through Nebraska and northward through Wagner, Corsica and Mitchell, resulting in large hail, uprooted trees and property damage, with some areas recording 3 to 4 inches of rain over 48 hours.
For the winter season so far, Mitchell has received 14.7 inches of snowfall, about 9 inches behind the snowfall pace for early January from last season.
As the page turns to 2021, all 66 counties in South Dakota are dealing with abnormally dry or drought conditions, according to the U.S. Drought Monitor. Most of the southern half of the state is listed under “moderate drought” conditions, while the southeastern corner of the state has severe or extreme drought conditions centered around the driest conditions in Lincoln County.
Rogers said that it’s hard for drought values to move much during the winter, because of the status of the ground and snow.
“We will have to watch closely to see how much additional snowfall we get in the winter and how the spring unfolds," Rogers said. "We’re having a La Nina winter and climatically, there isn’t a good signal of wetter or drier conditions. It typically tends to be a little colder than normal and we’ve really had some pretty warm spells, including already for this time of January. We haven’t had a typical fall into the winter months, so we’ll be watching that."