National Weather Service United States Department of Commerce

Significant heat and humidity will briefly build into the area early this week. Temperatures peak on Tuesday with highs in the 90s to near 100, easing a bit on Wednesday before a more pronounced cooldown later this week. Parts of the area will be in a Major Heat Risk Tuesday, which means heat-related illness is possible for those without effective cooling or hydration. If you will be working or enjoying the outdoors Monday through Wednesday, please be sure to drink plenty of water, and take periodic breaks in the shade or air conditioning!
Late this afternoon and evening, there is a marginal risk (level 1 of 5) of severe thunderstorms for Nebraska and eastern South Dakota, into far western Minnesota. If storms are able to develop, conditions will support isolated wind gusts to 60 mph and hail up to 1.5 inch in diameter.
Tuesday will see a Level 2 of 5 (Slight) risk of severe storms across most of southeast South Dakota, northern Nebraska and western Minnesota, mainly impacting these areas between 7 PM Tuesday and 1 AM Wednesday. Large hail of 2 inches or larger will be the primary threat with initial storms in the early evening, with the threat transitioning to damaging wind gusts as storms move northeast later evening into the overnight hours. Isolated tornadoes are also possible. Have multiple ways to receive warnings, especially at night.
Here's a closer look at the potential hazards with storms Tuesday evening. Large hail is the primary threat with initial development in the early evening, especially in the hatched area west of De Smet to Mitchell where hail could exceed 2 inches in diameter. As the storms move east and northeast during the evening, the primary threat will transition to damaging winds up to 70 mph. A few tornadoes are also possible.
Locations east of I-29 could see isolated to scattered severe storms Wednesday afternoon. However, the timing and location of storm development will depend on how quickly the cold front moves east. The primary threats will be large hail and damaging winds.