A very rainy and thunderous morning in eastern KELOLAND today, with over 500 lightning strikes in just 20 minutes around Sioux Falls in the 7:00 AM hour this morning. Rainfall in the Sioux Falls area caused flash flooding, as rain fell at a rate of 2 inches every 30 minutes. Highest rainfall totals were in and south east of Sioux Falls at two and a half inches. Lyon County, Iowa continued to get thunderstorms through midday, with a flash flood warning and rainfall total over 3 inches. After the storms passed, however, we were left with warm and humid conditions, rebounding into the 90s in south central South Dakota.
Clear and calm tonight as most precipitation will be to our east. Some models put precipitation in Iowa just grazing the Sioux Falls area, but chances are low for any rainfall. Humid conditions continue with low temperatures just under 70.
Warmer conditions tomorrow, with a spike of heat in the west. Most of eastern KELOLAND will be in the upper 80s under partly cloudy skies, while the west will be in the mid to high 90s. An easterly breeze will reinforce humid air, so it is likely to be muggy.
Cloud cover continues to diminish Saturday, so with mostly sunny skies all of KELOLAND should reach the 90s, with areas near Pierre possibly reaching 100. Rainfall redevelops Sunday afternoon in western South Dakota and moves East River during the evening. With all the heat providing energy, some of these storms could be strong.
There will be at least a chance of showers and thunderstorms next week, as temperatures cool slightly. Severe weather potential could also decrease as the week progresses. Daytime highs get back down into the 80s with persistent humidity. We’ve included a chance of rainfall on the 4th of July, but the confidence in that forecast is limited with differing model solutions.