Wet and cool pattern fades into summer season

SDSU Extension
Farm Forum

BROOKINGS —According to April 19, 2018 National Oceanic Atmospheric Administration (NOAA) Climate Prediction Center outlooks, the relentless cool and wet climate pattern throughout South Dakota is likely to fade away as summer approaches.

“The outlooks show a transition away from cool and wet in the month ahead,” said Laura Edwards, SDSU Extension state climatologist.

Based on the models, Edwards said South Dakota is less likely to have cooler than average conditions in May, with the exception of the northwest.

Record breaking spring

Reflecting on the cooler than average start to the month, Edwards said that some South Dakota locations, like Sioux Falls, broke monthly snowfall records.

“The growing season is off to a slow start with cold air and soil temperatures, and not just wet, but snowy conditions. The first half of April has been the coldest start on record across the region,” she said.

Already this winter and spring, there have been record or near-record snowfall in central and eastern Montana as well. Moving into May, the outlooks show Montana and a portion of northwest South Dakota are likely to continue to be wetter than average.

“Gradually, the drought is easing in the Northern Plains region,” Edwards said. “Even with cold temperatures, stock ponds are refilling and soil moisture is being slowly replenished.”

She referenced the U.S. Drought Monitor’s maps over recent weeks which shows improvements across the region. The worst drought areas from 2017 are now in D0, Abnormally Dry, or D1, Moderate Drought, severity levels in South Dakota.

“This is a two-class improvement from mid-winter,” Edwards said.

The U.S. Army Corps of Engineers have been keeping a close watch on snowpack in Montana as it has melted. They are prepared for the remaining snowmelt runoff and any spring rainfall to be captured in the reservoir system.

“The Corps is expecting higher runoff than usual this season. However, reservoir levels are low enough to accommodate the snowmelt runoff and rainfall from the prairies and mountains,” Edwards said.

Summer 2018: What can we expect?

Looking ahead to the early summer season, Edwards said it is predicted that the wet soils will prevent air temperatures from getting very warm in the region.

“For the months of May through July, South Dakota has equal chances of warmer, cooler or near average temperatures overall,” she said.

Precipitation is often a challenge for long-term climate forecasts in the summer season in the Northern Plains. Currently, according to NOAA, our region has equal chances of wetter, drier or near average rainfall.

“The forecast for the next one to two weeks gives some optimism that spring-like temperatures will finally arrive, as warmer air gradually comes in from the west,” Edwards said.

She added that drier weather is expected overall, which will help to melt snow and dry the soils.

“This spring has been one of the most difficult for calving and lambing in recent years, with a continued pattern of cold, wet mud and snow. Perhaps at last we can plant spring wheat, and get ready for corn and soybean planting in the coming weeks,” Edwards said.

May 2018 Temperature outlook for the United States. Cooler than average temperatures are favored over Montana, North Dakota and northwest South Dakota. Courtesy of NOAA Climate Prediction Center