First time I saw this with my own eyes, I knew it would be something I would always keep in mind when I'm out in the desert. We were hiking and it started to drizzle, and we got just a few minutes of cloudburst over our head. The people I was with said "Let's get up on high ground right now, and hurry.". Couple minutes later, someone pointed it out saying "There it is" and we saw a wall of milkshake-thick foaming mud come straight down the gully we just crossed.
Later, the guide said "See these rocks up here on this hill and how jagged and sharp they are? Now look at these stream bed rocks and how they're like rounded potatoes. How do you think that happens?"
I asked "How often do flash floods occur out here?" and he said "Every single blessed time it rains for more than a minute."
That video you posted was great. All greenhorn desert hikers out there damn well better believe.
We aren’t really super outdoorsy people as in doing anything extreme, but we like to do road trips and see the National Parks etc. I’ve been to Utah a few times. We’ve never seen a flash flood, but we’ve been there after they’ve had rainfall and seen the evidence. Mother Nature can mess you up in a hurry. I try to be careful at the National, state parks, etc. with the kids and myself, but sometimes things happen even if you are being careful and learning from other people’s missteps. I always stress with the kids, epsecially with heights or water, this is not the place to be acting like a nut. We have not been to Yosemite. It looks super-beautiful, but every year I year about something happening there or some other National Park. It would have been better for the last two to have just let the other one go down, but they weren’t thinking at that moment and obviously not minutes before about the extreme danger they were in. Unfortunately, no do-overs in life. I always pray to goodness that my kids will be safe. I don’t know how parents keep on living after those kind of tragedies.