Highway 9 through Zion, aka the Zion-Mount Carmel Highway, is completely closed - including the tunnel, due to a rockslide that has caused major damage to the foundation of the road. This means there is virtually NO access to the National Park from the east, and people heading to/from Bryce Canyon or the North Rim of the Grand Canyon are looking at significant detours.
Here is the official announcement from the National Park Service.
Here are the detour options, and how much additional time they will require.