One of the most exciting and dangerous events in the desert is the onset of heavy rain. Where I live in the north east corner of the Mojave Desert, in Southern Utah, we tend to have several months of eternally blue skies from late spring to early summer. But then in July we have what some people refer to as “monsoons”. They aren’t monsoons but they are a period with high chances of violent thunderstorms. This July has had a larger than usual number of flood producing storms but it’s not just Southern Utah. Flash floods have been occurring all over the world this summer. Ten teenagers died on a suspect hike in Israel. Athens has burned and now is flooding. Colorado and the East Coast have also been flooding this July.
In July we can get around 1/2 an inch of rain on average but if a powerful storm develops the area beneath can receive 4 inches of rain in 1 hour. That can cause a flood anywhere but when it happens over a burn scar or sparsely vegetated soils baked in the sun, or especially the wide expanses of barren rock we call slickrock, then the water will run off very quickly into drainages and slot canyons.
One of the weird things about flood producing storms where I live is that they often don’t reach their full power until after sunset. As a result, many of the floods occur in darkness, making them all the more dangerous. Only dawn reveals what damage they may have done.
Wildlife becomes restless before the onset of a major storm.
During or after a major downpour, what are normally bone dry stream beds can start to flow like a river.
Within minutes the water can rise into a rapid torrent. I’ve seen floods where the even after the front end of the flood passed, I could see the water continue to rise with my naked eyes.
The lip of a falls.
I had to wait two years before I ever saw this waterfall flow. The falls only lasted at this rate for about 15 minutes and then quickly diminished.
In Hellhole Canyon a big rain can produce a nearly 1,000 foot waterfall. Hellhole Falls must be one of the highest waterfalls in America during the few times that it flows.
The clouds still hang over the mountain the morning after a night of heavy rain in Ivins.
A splash of rainbow as a sunset storm passes over St. George.