For the 19th time this year, Chicago has registered a high of 90 degrees or better. Humidity levels, while noticeable, should not lead to any heat advisories this afternoon. Of more concern is the potential for thunderstorms, especially late this afternoon and overnight. A couple of areas of low pressure lurk to our west. One will pass to our north, the other just to our south by tomorrow afternoon. These disturbances are already triggering thunderstorms, some of which have crossed the Mississippi River into western Illinois as of 1:30 this afternoon. A few of those storms could reach Chicagoland before nightfall. A Severe Thunderstorm watch has been hoisted for us until 8pm. While I have been more concerned with the heavy-rain potential here, strong winds may accompany some of the storms. It looks like the risk of storms will linger until around midday tomorrow, with the passage of a cold front ending those chances from northwest to southeast during the day. Temperatures behind this front will only be a few degrees cooler than today,a lthough areas close to the lake may benefit both tomorrow and Sunday. A stronger push of cooler air will arrive Wednesday, but even then, it only looks like a return to "normal" temperatures, with highs in the upper 70s to near 80.
Mike
