As September draws to a close temperatures will continue to range well above the normal highs, currently in the upper 60s. In the wake of a cold front, Sunday’s highs will tumble more than 10 degrees from Saturday’s summery mid 80s to the low 70s, but readings will quickly rebound to the mid 80s by Tuesday, signaling another week dominated by late-season warmth.
A jet stream, positioned well north of Chicago will ensure that the summer-like warmth holds through much of the upcoming week. The warm weather will be accompanied by an increase in humidity setting the stage for some much-needed showers that could arrive by late Wednesday.
A buckle in the jet stream is forecast to develop late in the week setting the stage for a reversal of fortunes, as sharply cooler air arrives by Saturday, when high temperatures will struggle to reach the lower 60s.