Tuesday will be the first day since November where it feels humid outside. Dew point temperatures are expected to surge into the middle 50s...levels we really haven't seen in a while.
On top of that, an intensifying area of low pressure will move from the Plains into the Upper Midwest. This will cause thunderstorms to be a distinct possibility. Monday night into early Tuesday morning will bring us our first round of showers and thunderstorms. While no severe weather is anticipated with this, the same cannot be said for Tuesday afternoon.
A strong jet stream up within cloud level, coupled with dew points in the 50s, and an approaching cold front may work together to produce storms with damaging wind and hail. A more concentrated area of strong storms is expected east of the Quad Cities, including Indianapolis, Bloomington-Normal, and St. Louis.
We will turn much colder after the passage of the front. In fact, it may be cold enough for a few snow flurries or snow showers on Wednesday.