Officials from Parks Canada advised visitors to exercise caution and warned them to avoid the area if necessary.
Park officials stated that visitors should expect delays in traffic, debris on roads and possible closures of trails or parking areas while clean-up continues.
Due to trail damage, the popular Watchman Trail at the park's south entrance was closed. The status of other park services and amenities was also unclear.
The Monsoon season runs from mid-July through September. Flash floods can happen without warning. Park officials advised visitors to be prepared for all weather conditions.
Officials stated that flash floods can pose a real threat and could be life-threatening. Flash flood safety is based on three key steps: move to higher ground, avoid driving in water and keep informed. Don't drown if you see flooding in an area.
more than an inch of rain over the course of an hour Tuesday, officials said, with a search and rescue team called in to help close State Route 9, the roadway that passes through the main section of the park, and to respond to emergency calls.|Officials stated that the park received more rain than an inch in the space of one hour on Tuesday. A search and rescue team was called in to assist with closing State Route 9, which runs through the main portion of the park, as well as responding to emergency calls.}
In a tweet, the National Weather Service warned about flash flooding. "Remember that slot canyons and slick rocks areas, as well as normally dry washes, are the worst places to be during thunderstorms," it said.