HAIL YES!...
After an absolutely beautiful afternoon and highs in the upper 70s to near 80, conditions became conducive for severe hail along a southward advancing cold front Tuesday evening. Storms rapidly developed and it just so happens that I was in the right place for some of the bigger stones. Here in Marion, Iowa and parts of NE Cedar Rapids, golf ball sized hail (with some stones as big as tennis balls) broke some car windows and damaged the body of many others. In my neighborhood there was all kinds of excitement following the show as kids shrieked with amazement as they ran through yards collecting the biggest chunks of ice which they loaded into buckets.
This is my dog Nimbus curiously inspecting a golf ball sized hailstone.

Here's an image taken by the Iowa Storm Chasing Network of tennis ball sized hail near Cedar Rapids.

This shot was sent to me by meteorologist Nick Stewart of stones that damaged numerous cars at KGAN TV, my old station.

East central Iowa and northern Illinois were at the epicenter of the hail storms. Just before 9:30 Tuesday evening SPC indicated 187 hail reports with 19 of large hail (2" diameter or greater).

Below you can see the 2.5" diameter reports around my place in Marion. It was sweet to watch.

A much stronger cold front will arrives Wednesday afternoon and once again mild air will be in place at the surface. By afternoon, temperatures in the lower to mid 70s will combine with the front and dew points in the upper 40s to mid 50s. This combination will provided high clouds bases for any storms but like Tuesday, deep layer shear and steep mid level lapse rates will bring a threat for organized cells. With a stronger cold front Wednesday, a more widespread coverage is likely in the afternoon and early evening hours, especially over the southeast half of my area. With high clouds bases, any tornado threat is low, but a deeply mixed inverted-V should support momentum transfer into the downdrafts and this could support a wind threat. Any storms are likely to organize an outflow boundary and quickly form into a line, exiting the area early Wednesday evening.
Then the winds increase and the temperatures decrease as the Midwest enters into one of the coldest final 3 weeks of April in the past 2-3 decades. Just one look at the projected 500mb pattern on the EURO April 14th tells you all you need to know. A big west coast ridge and a central U.S. trough mean well below normal temperatures.