Storm Chaser Patrick Sullivan

08/16/2025

Time lapse of the shelf cloud moving overhead

08/16/2025

Huge shelf cloud off the incoming storm near Lily Lake, IL.

08/16/2025

[2:09 PM CDT Sat Aug 16]

A severe thunderstorm watch has been issued until 7 PM for the following areas. We're still expecting scattered thunderstorms later this afternoon into perhaps into early this evening. We're not confident in how widespread thunderstorms will be this afternoon, some areas may well get missed by storms, but conditions are favorable for thunderstorms to be capable of torrential rainfall and locally damaging downburst winds where storms do develop/occur.

08/16/2025

⚠️ A Severe Thunderstorm Watch is in effect for parts of southern Wisconsin, northeastern Illinois (including Chicago), and far northwest Indiana until 7 PM. Damaging winds and large hail are possible this afternoon. Stay weather aware.

08/12/2025

[Tuesday August 12 12:24 PM CDT]
Scattered to numerous thunderstorms are expected to develop this afternoon and persist through the evening mainly south of a Mendota to Waukegan line. Strongest storms this afternoon will be capable of damaging winds to 60 mph and torrential rainfall which could result in localized flooding. Keep an eye on the sky this afternoon!

07/28/2025

Dangerous heat and humidity expected today through Tuesday with heat indices around 105°F. Thunderstorms will also be possible again Tuesday morning especially across far northern IL. A cold front will bring cooler conditions to close out the week along with dangerous swimming conditions at the beaches.

07/28/2025

07/24/2025

Hot and humid weather continues today, with heat indices once again topping 100 degrees in much of northeastern IL and northwestern IN. Strong heavy rain producing storms will develop over northern IL with a cold front this afternoon. Additional waves of heavy rain producing showers and thunderstorms are expected at times through Saturday.

07/24/2025

Thunderstorms will develop across northern IL with a cold front this afternoon. The strongest storms will be capable of producing damaging wind gusts to 60 mph and torrential rainfall, which could result in localized flash flooding. The graphic displays the favored timing for thunderstorms this afternoon and evening.

07/23/2025

Here is an updated timeline for the upcoming heatwave. The worst conditions will be today and Thursday, including the overnight period. Chances for storms will increase Thursday afternoon into Friday, quelling the heat.

07/23/2025

Hot and humid weather is expected this afternoon through Thursday. There is a chance for isolated thunderstorms today. However, several waves of heavy rain producing thunderstorms are expected late Thursday into Saturday. Localized flash flooding will be possible in areas that see repeated thunderstorms.

07/21/2025

Dangerous heat index values of 105 to 115 degrees are expected Wednesday and Thursday. This stretch of heat will also include very warm conditions Wednesday night and possibly Thursday night. Stay up to date on the latest forecast.