It is not going to be a total loss at the parks, but you may need to duck and cover around lunch. Showers and storms will move in from the northwest late Saturday morning and into early Saturday afternoon.
Ahead of the rain it will be very warm and windy. Highs will be around 80 degrees.
Most if not all of the rain will be out of here by dinner and especially for fireworks. You may need the light jacket by them as temperatures dip behind a cold front.