The big weather stories are rain (or lack-thereof) and a warming trend starting this weekend. This evening brings a shot of moisture through KELOLAND. Later this afternoon, rains from Montana and Wyoming move eastwards into the Black Hills. With instability and lift from the Hills, some high-based storms could be severe. Some of these storms could be hailers and much of West River is under a "Slight Risk" for severe weather from the Storm Prediction Center. These storms look to form in a broken line but will then evolve into a cluster. That will most likely happen just west of the Missouri River.
All computer models have this system diving southeast but location is crucial during the morning hours. For that reason the rain chances in Aberdeen are less than Sioux Falls or Pierre. Most of the rains look to be gone into NW Iowa by midday so not too much of JazzFest should be impacted during the daytime. Another wave moves in tomorrow evening and the back edge could clip Sioux Falls but most of this looks to stay in Nebraska and NW Iowa.
We have another chance of rains Sunday, too, but for many there could be less moisture amounts. A dome of more heat arrives in the west by Sunday and will spread east for much of the workweek. Depending on how far south the pattern sets up, we could get a few isolated chances of rain but right now we've mainly kept it a dry forecast.