Weather for this weekend is looking to be ~OK~ at this point. Temperature is looking good to be near 70 degrees on Saturday and about 65 on Sunday. They are calling for some rain but I wouldn't bet on that quite yet this far out.
Oh, and for the timing thing, no GPS will be needed for this weekend's event since it will be timed. If you want to make a random run at it some other time, you need to have the GPS data uploaded to a PC.