Thanks to a reader for the link.
Video taken by a local resident and Bad Astronomy blogger familiar with the area. Remember, floods kill more people than any other natural disaster. The energy the water carries is deceptively powerful. Safe places can become very unsafe, very quickly. Once you’re swept away, that’s usually the end of you.
This is probably a 50 or 100 year flood, with some areas in the foothills receiving as much as 8 inches of rain in a few hours. The area’s also had fires recently, causing less soil absorption so all that water flows down and picks up an especially nasty mix at the front end. Thoughts and prayers to the families of those lost and/or missing.
National Weather Service statement here.
In the mountains, it doesn’t always have to rain where you are for flash flooding to occur. Avoid low places and arroyos. Know your terrain and stay aware of the weather. Fascinating video of rainwater and debris flow making its way into washes in southern Utah. Don’t try this at home:
If you’re into this stuff, check out The Landslide Blog. Great and current videos from around the world of erosion, earth movement, flash flooding, debris flows in different materials, geology, etc. You can get sucked in and carried away (ha-ha)
Here’s a video from JPL discussing features on Mars that indicate drainage, liquid flow and similar features here on Earth. Evidence of an ancient liquid past and a current dry environment is one mystery the Curiosity Rover is trying to solve by going to Mt. Sharp. Go Rover!
Red Cross information here.