I wouldn't do it. There is supposed to be significant street flooding and with that comes stuff in the road that you can't see, which could cause an accident. Of course, I may be more cautious than you, but you're a regular rider, even if you haven't been training for the century. It probably is going to be OK Sunday afternoon. Monday and Tuesday look nice, too.
I did a century with no training, just lots of riding, lots of hills and nothing over 60 miles. Sure, it was flat, but there were horrible headwinds, torrential rain and thunder. I imagine that storm was a little like what tomorrow's weather is going to be.
Be safe!