As a cool front moves into the moist and unstable air mass that has been in place all week, scattered thunderstorms are possible this evening Some could have gusty winds, and it's possible a couple may reach severe limits. Keep an eye on the following information, especially if planning on being outdoors:
Thursday afternoon saw scattered thunderstorms develop which produced gusty winds, and were likely a sign of what is possible later this afternoon given a similar very moist and unstable air mass. One of the storms produced a 69 mph gust at Aurora Airport in Sugar Grove, IL at 3:37 pm. Here is a 3D radar reflectivity loop of that storm. The red colors basically indicate 50 dBZ of higher power being reflected back to the radar, which is heavy rain, even some hail aloft. Notice how that core of the storm descended rapidly north of Yorkville which is where the airport is located. This process is what we call precipitation loading given the very moist atmosphere (more droplets for evaporational cooling), and with the instability present for strong downdrafts this was likely responsible for the quick descent and the high wind gusts.