It has been another warm and humid day in eastern KELOLAND, with cooler and drier air behind a front that is splitting KELOLAND in half. We’ve been in the 80s to low 90s in eastern KELOLAND, with cumulus clouds forming in the humid air. Rapid City and the west has been 10-20 degrees cooler, with a brisk NW breeze.
Tonight we expect thunderstorms to erupt in central South Dakota during the late afternoon and early evening hours, and then slowly march to the east. Much of eastern KELOLAND is rated a slight risk for severe weather, mostly in the form of large hail and damaging winds, though a tornado is not impossible. There is also a Flash Flood Watch posted in parts of eastern South Dakota overnight due to the potential for flash flooding. Temperatures will fall into the 60s overnight, and the 50s in western South Dakota where skies will be mostly clear.
Thunderstorms will continue early tomorrow morning along and east of the James River. A few may linger into the afternoon hours, mainly east of I-29. Two day rainfall totals are likely to give eastern KELOLAND a general swath of ½” to 1” of rainfall, though the makeup of the atmosphere and an abundance of moist air mean there will probably be some locally heavier amounts. Behind the rainfall, skies should clear with afternoon highs in the mid to upper 80s.
Thursday will be mostly sunny and hot as humidity quickly returns. Thursday’s highs will be in the low 90s. Winds should be light in Eastern KELOLAND, but a brisk south breeze West River. There are some hints that a few showers may develop around Rapid City and the Black Hills.
Friday will also be mostly sunny and hot (and humid East River). Highs will be in the upper 80s to low 90s East River, with some mid 90s in the central and west.
Saturday, the 4th of July, will be mostly sunny with continued heat and humidity East River. Highs will be in the low to mid 90s across KELOLAND. There is a slight chance of thunderstorms in western and northern South Dakota. Sunday we’ll have slight rainfall chances of showers or thundershowers, but it will still be hot with highs in the low to mid 90s.
Thunderstorms chances will increase a bit on Monday as a cool front drops down from the north. But temperatures won’t be affected too much. In fact, looking at the longer range forecast models, Sioux Falls and SE KELOLAND are likely to be warmer than normal every day for the first two weeks of July. Get ready for a prolonged spell of heat and humidity.