A plastic poncho is better
Yes, an umbrella can passes the security check. Also recommend you to bring a raincoat too, because you can fold it into your backpack.
I agree. Plastic poncho is best. You can buy them cheap at most dollar stores. They are small and easy to carry just in case.
Definitely don't bring an umbrella. If it rains it will be very brief and you'll be dry soon after. The park has a lot of shaded areas also so, if you must; bring a poncho as others have said but an umbrella is more hassle than it's worth.
I believe so, but a raincoat or poncho is a good choice.
Thanks! Your answer is awaiting moderation.