Morning storms in the northern half of South Dakota have been the dividing line between cooler air to the north and another very warm day in the south. Severe storms are already starting to pile up over the Black Hills.
It could be another long night for folks in the Black Hills and south-central South Dakota. There is a lot of energy and instability, in many places much more than last night. We should begin to see more storms blooming in the late afternoon heat within the next two hours. They’ll likely try to form over the north-central and southwestern areas. There is an elevated severe risk area that includes most of West River tonight. We could easily see a Severe Thunderstorm Watch issued. We’re also concerned about the chance of very heavy rains, due to slower storm motion and lots of moisture. Storms will be the big weather story in the short term but changes are arriving tomorrow.
A stout late-summer cold front is already starting to move into South Dakota. That will make most areas cooler, with Sioux Falls being a big exception. Compressional warming out ahead of that will keep Sioux Falls warmer than today, as we close in on the 90s! Storms are possible during the morning across much of the area. These will be leftovers from the overnight storms. Another round of storms is likely behind the front late tomorrow near Sioux Falls and the southeast. These look to continue into early Tuesday. After that, skies clear and we have a GREAT string of days lined up during midweek.