It was a cool start to the day!
Now cumulus towers are going up, especially in eastern Illinois with shortwave. This shortwave is dropping to the southeast.
A few isolated showers/t'showers are beginning to pop with the shortwave. A few more will develop & these will all track southeastward.
So, a quick shower/t'shower is possible here & there late this afternoon-this evening before any dissipate, followed by a clearing sky with some patches of fog overnight (with 50s).
Cumulus with sun tomorrow will give way to mostly sunny & much hotter weather late week through the weekend.
Humidity should remain relatively low & comfortable until late Saturday. Then, dew points should reach 65-70.
They should run 67-71 Sunday & Monday before reaching 73-76 Monday night.
Heat indices should peak in the Saturday-Monday period at 99-104.
A round of showers/storms are possible Monday night & again Tuesday. Tuesday looks quite cloudy with second round occurring midday to afternoon, so it should hold the temperature down into the 79-84 range (though it looks muggy).
After partly cloudy skies Wednesday, some scattered showers & storms are possible late in the day & into the evening as a cold upper trough swings through, which will bubble the cumulus clouds up.
Highs should run 79-85 after 60s Tuesday night-Wednesday morning.
Cooler, wetter pattern (overall) should follow through early August.
Another heat wave is possible with highs 92-97 in late August with largely dry weather.
Cooler, wetter pattern should arrive by Labor Day & continue afterward.