BROOKINGS – June in Brookings is usually the wettest month of the year, averaging about an inch of rainfall a week.
This year, conditions have been different. Instead of rain, the area has been experiencing drought conditions and above-average temperatures.
Laura Edwards, state climatologist working for South Dakota State University Extension, explains that the consistent high-pressure system this area is experiencing is the likely culprit for the rainfall shortage.
“This the time of the year where we really need it (rain) in the soil while the plants are small and the crops are small,” Edwards said. “Because then the soil can hold it for later in the summer when it does get warm again.”
“We are really losing our opportunity to get moisture here,” Edwards added.
Right now, Brookings is running at 50 to 80 percent of the average precipitation, which has caused drought conditions and low water levels in lakes and rivers. The Big Sioux River in particular is experiencing very low water levels for this time of year.
“Fall precipitation can play a role (in water levels), because we had a very dry fall and soils were very dry in the winter,” Edwards explained. “The snow melt goes in the soil and doesn’t run off into the river or lake because we had a very little amount of snow this winter. We also had a dry spring. Put all of it together and that makes for a dry Big Sioux.”
According to the High Plains Regional Climate Center, the month of June has seen an average high temperature of 89 degrees, much higher than the 30-year climate normal of 78 degrees for the month.
Edwards said the Brookings area is getting a break from the omnipresent heat of recent weeks, setting up for a cooler weather pattern for the last week and a half of the month. According to Edwards, this should cause temperatures to fall back to more seasonal or even cool temperatures.
This cooling pattern will likely mean that we will not see any June heat records for the area, despite the warm dry air.
The Climate Prediction Center (CPC) recently came out with its outlook for the next three months, however, predicting that the area is likely to see above average temperatures for the rest of the summer. The CPC is uncertain about what to expect on the moisture side for the next three months.
“That’s bad news, because our water demand is even higher for crops or vegetation,” Edwards said. “It takes even more water for the plants to overcome the heat.”
The month of June has also lacked humidity and severe weather – both cornerstones to South Dakota summers.
“We’ve had very little severe weather, and typically in the summer our moisture comes up from the Gulf of Mexico,” Edwards said. “That combination, along with jet streams, is often what brings our severe weather up here.”
Edwards explained that Brookings is not unique in this – the entire country has had a lack of severe weather.
“The way the atmosphere is behaving this year is just a little bit different,” Edwards said. “We are not getting that pull level jet, it’s like a low-level jet stream, and it’s not bringing up that humidity from the south that we usually get either.”
“This is really unusual.”
While Edwards is hesitant to attribute the unusual weather as a direct correlation to climate change, the patterns that she has seen have been consistent with a changing climate. The warming trend and drought are in line with a changing climate but is not entirely indicative.
“What we know about climate change and what we’ve observed and modeled for the future is really more extremes in general,” Edwards said.
For example, in 2019 the Brookings area and state of South Dakota had one of the wettest years on record. This year, we are experiencing very hot and dry conditions, some of the hottest and driest on record.
“That pattern (of extremes) is consistent with climate change,” Edwards said.
This means that the Brookings area is likely to see more extreme weather events in the future, whether that be in the winter, summer, spring or fall.
Further evidence of extreme weather events is the precipitation events the area has seen. Rain now falls in heavier, bigger amounts but happens much less often.
“More extreme rain events, but less of them,” Edwards said. “We now have fewer of the little (rain) events and more of the bigger, with short-term droughts in between.”
Edwards said that more precipitation will mean more humidity for the region, something there has not been a whole lot of in the summer weather so far.
“Climate change isn’t a steady line. You’ll have a lot of ups and downs,” Edwards explained. “An analogy I like is, if you’re walking your dog and you’re moving in this general direction but your dog is walking left and right in front of you – your still moving toward that general direction. The climate will have big ups and downs, but in general we are increasing.”
Contact Addison DeHaven at [email protected]