We had a couple isolated thunderstorms form near the Nebraska border early this morning and move to the NE before dying out as they approached Sioux Falls and I-29. There was a report of egg size hail near Springfield, but nickel to quarter size around Dimock and Emery. Leftover clouds from those thunderstorms moved away to the east, leaving mostly sunny skies across KELOLAND. A Heat Advisory is in effect for most of central and eastern KELOLAND. It is hot and humid, with temperatures in the upper 80s to 90s and muggy dew points in the 70s making it feel like a hundred degrees or worse.
Tonight we will be mostly clear and warm and humid, with overnight lows in the upper 60s to low 70s. But thunderstorms are likely in the NE quarter of South Dakota, and they will likely be severe. The severe weather risk has been raised, with the far NE tip of South Dakota now in a moderate (2nd highest) level of threat. The main concern is damaging wind, but there could also be hail and even a few tornadoes. Also, there could be some heavy rain in NE South Dakota. You might want to have your weather radio on during the overnight hours in NE South Dakota.
Behind that front, Saturday will be partly cloudy, and it will again be hot and humid. Temperatures should be in the upper 80s to mid 90s. There could be some more thunderstorms east of I-29, which is rated a slight risk of severe weather. The expected combination of heat and humidity has resulted in an Excessive Heat Watch in parts of eastern KELOLAND, which means it will be dangerously muggy outdoors. Eventually winds will switch to the north, which will diminish those conditions Saturday night.
Sunday will be partly to mostly sunny and cooler, with a northwest breeze pushing humidity away and dropping daytime highs near-normal, in the low to mid 80s across KELOLAND. Winds will be stronger in western and central South Dakota and from a northerly direction.
Thunderstorms chances will increase Monday and Tuesday of next week, and there may be some more significant rainfall in southern KELOLAND – including SW South Dakota, which is experiencing drought conditions. Temperatures will remain more comfortable, in the low to mid 80s. We’ll continue with low-end thunderstorm chances as warm air streams back into KELOLAND for the second half of next week.
The end of next week and the weekend (July 25-26) looks hot, probably excessively hot. We expect temperatures to be well into the 90s across KELOLAND starting as early as Thursday, but especially Friday through Sunday. Right now it appears temperatures will cool back to normal after that, with 80s for the last week of July.