Severe thunderstorms are rapidly firing up across the Upper Midwest this afternoon, with tornado watches in effect from central Missouri through the western shores of Lake Michigan. The largest cities under the risk for tornadoes this afternoon are Chicago and Milwaukee. Some of the tornadoes could be strong in the most well-organized supercells.

The first day of a two-part severe thunderstorm event is unfolding across the middle of the country, with an enhanced risk for severe weather—three on a scale from zero to five—possible in Oklahoma, Arkansas, and Missouri. Storms could produce very large hail, damaging winds, and a few tornadoes.

A resident of St. Louis took an awesome time lapse of a strong thunderstorm rolling across his neighborhood yesterday. The storm bubbled up on the horizon before racing towards the camera, developing an awesome shelf cloud along the way.

In addition to the excessive heat brought into Ferguson by the authorities, Mother Nature is bringing some of her own. A dangerous combination of heat and humidity prompted forecasters to issue an Excessive Heat Warning until Sunday for the St. Louis area, including Ferguson.