Very rare "Lake Effect Storm" for late summer early fall. A result of this anomalously cool/cold weather spell
I posted yesterday about some of the crazy weather the Great lakes and Ohio/Valley have coming up this weekend, especially the wild up to 50 degree daily temperature swings we will be having through most of this week with lows progressing from the 30's to the 40's and 50's by mid week and highs in the 60"s to near 90 by midweek. You've heard of lake effect snow, how about lake effect storms in the late summer?
Here is a very rare example of such storms being caused by a combination of an east propagating very small shortwave low enhancing southerly flow and interacting with very cool land breezes over the still very warm waters of lake Michigan. The contrast of temperature over the lake, as in winter, is causing convection to form on the southern side of most of the lakes.
Think of a super sized version of early morning light fog or mist you may see over a pond or river. And sometimes you can see that light fog spinning in the am! That's what the Marine Warnings are for on the southern side of a few of the lakes as several water spouts have been sighted. Its the exact same thing only on a grand scale 
You rarely see convection this strong caused by the lakes in late summer, this is normally a very late fall, winter phenomena involving usually snow. While lake enhanced rain is not all that uncommon it is rarely isolated like this and even more rare causing convective cloud tops up to 30k feet. Very rare indeed!
Just a Saturday morning weather nerd alert lol 
Radar over Lake Michigan this morning with special marine warnings posted
Satellite view of some of the convection forming from the cold southerly breeze over the still warm lake waters of Michigan, Huron and Erie
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where it runs directly East to West. If the conditions are just right there in winter with a very cold north wind (and some other microclimate factors) when the river is still fairly warm and hasn't started to freeze over, the river is wide enough that areas just to south in IL can get a "river effect" snow sometimes up over a foot wile places beyond that short East West corridor of the river get zip! (I've actually driven over there to witness this lol). You can actually occasionally see a small snow band on radar in that area similar to what you would see in the massive lake effect snow bands that hit places like Buffalo NY. If your a weather nerd like me watch that area before the river starts to freeze in early winter. It's pretty wild to see an intense snow band all by it's lonesome with cold clear skies elsewhere.
There are many isolated instances in winter before lakes freeze where even moderate sized lakes (say 100 acres up) are known to cause microclimate lake effect snows of a few inches. While lake effect snows, isolated or not and enhanced rainfall closer to the lakes embedded in broader swaths of rainfall are expected, isolated strong summer convective bands like we saw this morning off of lake Michigan are pretty rare. There were also a few confirmed water spouts with that band over lake Michigan and some over both Huron and Erie this morning, which of course is a hazard to anyone in a boat or anyplace near the shore if the waterspout should move that way and become small tornadoes.
It's pretty amazing when we get these wide temperature variations between these bodies of water, both small and large, and the atmosphere. Obviously I'm a bit fascinated by these quirky weather setups. 