Current jet stream forecasts show the river of air at the top of the atmosphere to be moving fast right overhead. This will allow several fronts to enter the area and move along under the jet. This is a classic set-up for flash flooding (and perhaps severe weather).
First, thunderstorms are exiting this evening. Our next bout of wet weather will come late Tuesday night with a round of potentially damaging thunderstorms. These storms will race across Iowa during the late-afternoon and evening hours of Tuesday. I expect them to cross the Mississippi between 10pm and midnight and affect Northern Illinois during the wee hours of Wednesday. The main threat with this batch will be very heavy rainfall amounts and damaging wind.
Additional thunderstorms are likely Thursday and then again Saturday into Sunday.
This post was written by Eric Sorensen on May 31, 2010