In the wake of the cool and showery conditions on Sunday, there will be a late season surge of mid-summer heat and humidity Tuesday through Thursday. As a warm front lifts north late tonight into Monday morning, widely scattered showers and a few thunderstorms are possible across portions of northern and central Illinois. The afternoon hours should be primarily dry. Another round of isolated to widely scattered showers and thunderstorms is possible after midnight Monday night along and north of I-80. While a few showers or storms can’t be ruled out Tuesday daytime through Thursday afternoon, more widespread coverage of showers and at least scattered storms are probable Thursday night with a cold front passage.