I know it's late but I'd get some really thick tubes put in my tires. You'll be going through puddles and picking up lots of nasty stuff on the road. You're a seasoned cyclist, so you know how wet weather + sharp stuff tends to adhere to tires.

Stay away from crowds. Some cyclists really don't know how to handle bikes in the wet & don't realize things like how their brakes don't work as efficiently. Stay off of the white stripe on the road because it gets very slick.

Remember how many times the weather forecast in Tucson is completely wrong. Right now it's supposed to be raining and it isn't.

Good luck! You're a smart and experienced cyclist & you'll be fine!