Thunderstorm chances return early Tuesday, last day of heat and humidity

 For the seventh time this month the high temperature reached 90 degrees, or above, with Monday's high reaching 93. Combine that with dew points that were in the 70s all afternoon and it felt more like temperatures were close to 100 degrees.

The rain and thunderstorms from the morning were quick to move out leaving skies mostly sunny for most of the afternoon. A few thunderstorms developed well east of the Stateline, closer to the suburbs and Chicago, along a lake breeze and numerous outflow boundaries. A couple of those boundaries did stretch as far west as Winnebago County, but our skies remained dry.

Temperatures won't fall much through the night as we maintain a very warm and humid air mass. Overnight lows will only dip into the low 70s. A Severe Thunderstorm Watch has been issued just to our west until 4am Tuesday for an ongoing thunderstorm complex producing very strong winds over northwest Iowa. Another storm complex is currently moving east of Minneapolis into Wisconsin. Both storm complexes are moving to the southeast and will likely impact at least a portion of the viewing area early Tuesday morning.

The storms should slowly weaken through the night but there will likely be just enough instability to maintain at least the threat for some strong, gusty winds in southwest Wisconsin and northwest Illinois during the pre-dawn hours Tuesday. We remain under a marginal risk for isolated severe weather, primarily for strong winds, through Tuesday morning.

Depending on how long the storms stick around will have an impact on how hot temperatures get during the afternoon. Right now, it looks like we should clear quick enough to allow highs to warm back into the upper 80s, close to 90 degrees, with the heat index back into the mid-90s. Thunderstorms will be possible once again Tuesday night and Wednesday ahead of a cold front that'll clear the region Wednesday evening. Once it does, a much more comfortable air mass will be in place through the end of the week. The only thing we may need to watch out for would be the smoke and haze from the wildfires in Canada. We may end up with a few hazy days following the cold front.