Heat remains the major piece of your forecast, with some staring down near record temperatures tomorrow.
We have two main systems we're watching. At ground-level, there is a low in Montana that will drift into North Dakota. That brings isolated thunderstorm chances this evening and tomorrow for far western South Dakota. Any storms are likely to be higher-based. The raindrops will have to travel farther to the ground and a lot of it will evaporate. What that brings is the potential for dry lightning, which could spark forest fires. Tomorrow there is a Red Flag Warning for the west, which means conditions are favorable for wildfires to spread (once formed). The winds will pick up across the map tomorrow with humidity spreading eastwards. We will all heat up tomorrow, too.
The other system we're watching is the main culprit for the hot streak. The upper-level high also pushes most rain chances well north into southern Canada. Until this breaks down in a major way or has something else to push it east, we are largely dry. There are still slim chances of showers in a few locations, but there isn't much in the way of organized rains.
Most will have a quiet forecast, even as a cold front moves into KELOLAND late tomorrow into Wednesday. While it should knock down the strongest heat, by the time it arrives east of the James River, most of its cooling power looks tapped. Rapid City again has very isolated shower chances Thursday.