A patch of clouds leftover from some early day showers is passing through SE KELOLAND. A few of these contain some lightning, so we’ll have at least a chance of spotty showers and thundershowers in Sioux Falls and SE KELOLAND into the early evening. The rest of the area has clear skies. Today’s temperatures are a little warmer than yesterday, with the exception of areas underneath that patch of clouds.
Tonight we’ll have mostly clear skies. But a south wind will develop, pumping moisture into the region. The chances for thunderstorms are low – but not zero – as the warm air pushes in. Overnight lows will be quite warm, in the upper 60s to the mid 70s. South winds will be strongest west of the James River.
Tomorrow will be mostly sunny and breezy across the area, as we warm back to the upper 90s, with Aberdeen and Pierre and central South Dakota surging above 100. That is during the day, because a cold front will drop down on the area late in the day. There could be some thunderstorms, mainly in northern and western South Dakota. If any of them turn strong, the most likely hazard will be damaging winds.
There is a marginal risk of severe weather, which is fairly low on the 1 to 5 scale from the Storm Prediction Center. The most likely time for thunderstorms to develop is during the evening and overnight time period, well after peak heating has occurred.
Scattered to widespread thunderstorms will be possible on Saturday, our best chance for meaningful rainfall anytime soon. In fact, rainfall will be widespread but potentially excessive, with amounts over two inches possible in some locations. Make sure your sump pump is working.
The risk of flash flooding rainfall exists on Saturday. It’s listed as the second level on a scale of one to four as issued by the Weather Prediction Center. That means flash flooding is possible, even in areas that have been suffering from drought, because it could be too much rain too fast.
Those thunderstorms could produce lingering rainfall into Sunday morning. Sunday afternoon should have clearing skies, with highs that are actually below-normal for the first weekend of August, in the upper 70s to low 80s.
There could be a few showers around on Monday, but maybe not worth mentioning, as temperatures will be pleasantly in the upper 70s to mid 80s, which is close to where they should be this time of year.
After that, another heat ridge looks to build back in, with little in the way of rainfall chances. We’ll climb through the mid to upper 80s Tuesday and Wednesday, and keep above-normal temperatures for the second half of next week through the following weekend (August 13-14).