The Memorial weekend for most was a bit of a washout. Unfortunately the forecast didn't play out as originally thought. But it didn't just rain, we had a deluge. I was caught out in it at one point and I think the raindrops were as big as my head. Well, maybe that's a bit of an exaggeration.
So the airmass was super moist and we were in a situation where thunderstorms just kept developing and moving over the same areas over and over. There were numerous reports of flash flooding. Roads were closed and people were having a hard time getting home. People were getting turned around and didn't have any other way to go. I hear there were lots of people just congregating at gas stations and such. What a mess.
As much trouble as that kind of situation may have caused some folks, closing those roads were absolutely the right thing to do. Flash flooding is the #1 weather killer and most deaths occur when people drive their cars into areas where water covers the roadway. It's very difficult to gauge how deep that water is, and it's even worse at night. Plus it doesn't take a whole lot of rushing water to wash your car right off the road, generally only about 2 feet.
I saw one report out of Piasa, IL (Macoupin Co) where the roads were flooded with water up to 5 feet deep!
Here is a look at just some of the impressive rain totals I was able to find from Sunday's rain. These numbers are for the 24 hour period that ended at 7am Monday.
4.53" Jerseyville, IL
4.14" O'Fallon, MO
3.64" St. Louis
3.30" Red Bud, IL
3.24" St. Peters