Many residents were awakened by the sound of thundery rain, while travelers needed rafts to get around in parts of the Midwest Tuesday night into Wednesday morning.
Torrential rainfall resulted in widespread flooding problems in parts of eastern Iowa, southern Wisconsin, central and northern Illinois, northern Indiana and southern Michigan.
Streets turned into rivers, while water flooded neighborhoods as rain overtook storm drains and sent streams on the rise.
Tuesday evening started off like a typical June evening with spotty strong thunderstorms. However, the storms continued to grow in size, creating a large swath of torrential rain.
Flooding impacted large cities, suburbs, small towns and rural areas alike from Chicago to Madison, Wis., Independence, Iowa, and Michigan City, Ind.
Up to 3 feet of water swamped vehicles in Madison early Wednesday morning. A mudslide also occurred just south of the city. High winds also hit the Madison area, just prior to the deluge with gusts of 59 mph at Truax Airport and 66 mph near East Towne Mall.
Independence, Iowa, was hit by over 6 inches of rain early Wednesday morning. Flooding conditions were sited as being unprecedented and historic over much of Buchanan County, Iowa, according to a storm report filed by the Quad Cities, Iowa, National Weather Service office just past 5:09 a.m. CDT, Wednesday.
In Iowa, the Wapsipinicon River is forecast by National Weather Service hydrologists to reach record high levels between 23 and 25 feet Wednesday at Independence.
According to Tai Burkhart, spokesperson for Buchanan County Emergency Management, "Sandbagging operations are in effect as we prepare for flooding higher than in May 1999."
On May 5, 1999, water levels reached a record 22.35 feet. At the expected water level later Wednesday, a significant part of town would be flooded.
Record or near-record flooding is projected downstream along much of the Wapsipinicon River into the end of the week.
The risk of flooding downpours and damaging thunderstorm winds will continue over much of the same areas Wednesday.
The worst of the rain will settle slowly eastward over the Ohio Valley states Thursday.
The pattern causing the drenching rain will be squeezed to the Appalachians and Atlantic Seaboard late this week into next week, where it may stall and have similar consequences as tropical moisture feeds in.