Just a brief rain shower over the desert floor can create a wall of water only a few inches deep to race down the dry stream beds at higher speeds than a person can stand up in. It would be like trying to stand up while someone is blasting your ankles with a fire hose connected to a hydrant on full blast.
You lose your footing, and it's curtains for you. You just get carried a few hundred yards along with the water banging your skull on exposed rocks while nature tries to drown you at the same time. Even if you survive it initially, you're likely to be gravely injured out in the middle of the desert in need of emergency medical care that you just won't get.
Until I saw my first flash flood, I had a hard time understanding these warning about how so little water in an arid desert can accumulate fast enough to cause a flash flood. It sure as hell can, and it's frightening to witness. People have died in just a few inches of fast moving water that's had time to build up speed.
I’ve hiked in the Mojave and have seen (and been in) those washes though they were bone dry at the time. It was clear they had seen significant water flow in the most recent wet season, and I’d not like to be caught in one.
Sent you an FR message. Forgot about this one from just the other day:
Oregon rangers rescue man from fall at Crater Lake http://www.freerepublic.com/focus/news/2747492/posts
Once again someone going beyond the barrier and he could have ended up dead just like the guys from Yosemite.