FWIW, yesterday afternoon the NWS predicted 0.5-1.0" of rain for the Des Moines/Ames area overnight Thurs/Fri morning and another 0.25-0.5" Friday night into Saturday morning. I don't know if that forecast has changed in the last 12 hours but as I type this, this morning's round of rain seems to be significantly less than predicted. Fingers crossed.
EDIT: 7:35 a.m. and I'm already retracting these comments. Watching this storm come in on the radar, I thought it would blow through quickly but it's really hung on, and the heaviest rain has been in the last 20 minutes. We're probably well over a half-inch by now. And Pollard already tweeted about parking adjustments in grass lots tomorrow...he didn't offer anything more specific than that.