UPDATE: The threat for severe thunderstorms is over for the evening. The Severe Thunderstorm Watch has expired for the Stateline, as thunderstorms have moved into the Chicago metro. There were a few storms that dropped small hail, including one severe t-storm that tracked from Marengo to McHenry. The rest of the activity this evening produced brief, heavy rain and plenty of lightning.
Now that the storms have passed, the weather will cool off dramatically behind them. A strong cold front that produced the storms will drop temperatures down into the 50's tonight, then leave use in the 60's at the warmest this week. More rain is possible during the middle of this week, with amounts up to 1" between Wednesday and Thursday. Check out www.wrex.com/weather for updates throughout the week on the rainy weather ahead.
Severe thunderstorms may brew up throughout the afternoon and evening, as the weather cools off in a big way between today and tomorrow. The National Weather Service has issued a SEVERE THUNDERSTORM WATCH until 10 pm, for all counties in the Stateline, including most of southern Wisconsin as well. Pay close attention to the weather, and have a way to get warnings if they are issued.
The primary threat this evening is very large hail. Make sure to take cover immediately if you hear thunder, and try to park your vehicle under shelter, preferably in a garage or parking structure to protect it from hail. The risk for damaging wind gusts and tornadoes is low, but can't be ruled out in any stronger storm this evening.
Storms are already brewing in the Stateline, as a Severe Thunderstorm Warning was issued for Boone County for a short period while a system worked through the area.
The storms should be moving past the Rockford area by 7 pm this evening. The storms will also be moving fairly fast, so the severe threat will be quick-hitting but over just as fast. Again, keep one eye on the sky this evening, as the storms may not give you a ton of time to reach a safe place inside.
Once the storms and the cold front driving them in pass by, temperatures will be dropping dramatically. Conditions will drop from the 80's today to the 60's by tomorrow.
Stay with the 13 Weather Authority on-air and online at www.wrex.com/weather for updates throughout the evening.