Yep I am watching the weather like crazy. We also arrive on Saturday night and begin our trip on Sunday. We have a 6 week old, 1 year old and 2 two year olds so it is a bit of a concern for us. We won't cancel anything but we might have to try to push as much as possible into Sunday in case we have to spend some time in the hotel on Monday and Tuesday.
I have been so excited about this trip for so long and this rain is putting a crink in it. If it were just us adults I wouldn't be as worried.