We were there last weekend in the monsoon. Here are a couple vids of upper rattlerock in the rain. We crawled lower but upper was pretty much a throttlefest to the exit. You guys have fun!
http://www.youtube.com/watch?v=TBbDCA1Rqpo
http://www.youtube.com/watch?v=x2KeWlzj0Qg
http://www.youtube.com/watch?v=Vhyd2wu7smY