IF 10 inches of Rain hits desert Areas of Southern California you can basically expect almost anything to happen next week

This is because there is absolutely nothing to hold back the rain like enough trees and shrubs in Desert areas. 

The following is a real experience of mine when only around 1 inch of rain fell in the mountains near Yucca Valley. I was out near Old Woman Springs Road near the dirt road that connected the desert to Big Bear Back then. I recently in a 4 wheel drive tried to drive this route to the desert from Big Bear and someone has built a fence (not sure it's legal to do this) on the road so you couldn't even get to the desert fully and I had to go back up an almost impassable 4 wheel drive road up to Big Bear.

Anyway, where this road used to meet the desert I was on a paved road in my Brand new 1968 Camaro when I suddenly noticed a wall of water enough to lift me and my car and kill me pushing the car and me across the desert likely sideways. I burned rubber trying to change direction 180 degrees suddenly so I could outrun the water before it destroyed me and my car. 

Obviously I succeeded and didn't die that day when I was 20 or 21 years of age. But, the point is if 10 inches of rain hits the deserts and what happened to me was only 1 inch of rain coming out of the mountains near Big Bear, you can imagine just how bad this could be if 10 inches of rain hits the desert from Hurricane Hillary which is a really huge storm reminding me more of Hurricane Katrina or other large Hurricane!

So, what I saw was a wall of water taller then my car coming at me washing through Joshua trees and cholla Cactus bushes and the like so debris was including in this wall of water of everything that floats as well. This is the kind of thing you can expect in desert areas too down dry washes wherever this storm hits if it hits the desert like on the last map I posted.