Yucca Valley Flash Flood
August 9, 2005
Brief Summary: My initial target area was Twentynine Palms. My plan was to be there when the monster MCS roaring out of Vegas was to meet up with the moderate south flow coming up through the pass near Yucca Valley. As I had hoped would happen, a nice arc formed in the pass about 2:30 PM. I sat under the west flank of the arc just east of Johnson Valley on HWY 247 and watched as a thunderstorm / dust storm approached from the NE. My truck became stuck in sand as outflow from the MCS slammed into the convergence zone east of Johnson Valley. Huge storms fired along the convergence zone from desert slopes of the San Bernardino Mountians to just west-northwest of Yucca Valley with frequent cloud to ground lightning and very heavy rain. Good Samaritans stopped and were able to get me out of the sand before the storms hit. New outflow from the overhead storms pushed southeastward indirectly towards the MCS and incoming outflow from storms near Joshua Tree. I estimated the winds to be about 40 mph. I drove towards Yucca Valley where it looked as though two or three boundaries were to shortly intersect. Soon after, a very dark rain core develops under CB as I approach Yucca Valley. A few minutes later I am in torrential rains, and there are rivers literally popping up out of the middle of the desert and washing over the road. First I only encounter fast moving water... then small rocks... then boulders the size of basketballs! With each crossing, the water becomes deeper and faster. I begin to look for a safe place to pull off the road. The HWY then dropped into a steep canyon, and at that point, a small, but fast moving wall of water overtook my truck. Luckily, there was a road that went up a small hill to my immediate left. I bolted up the hill, and within minutes, the road became a roaring muddy river. Large boulders and trees began rolling down the road, and the roar of the water got louder with each passing wall of water. Two cars became trapped in the flash flood. Three road signs were washed away, as well as about a 75 ft stretch of pavement. The flash flood lasted less than an hour, with the first few initial walls of water flying down the canyon with quite impressive force... and subsequent waves of flood waters become shorter and less severe over time. There were at least two dozen waves that came down the highway... the tallest wave being around 4 ft, maybe 5 ft high and carrying boulders, trees, chunks of asphalt, and road signs. There were about a dozen other vehicles also stranded on the hill where I took refuge.
I first began to encounter flooding problems shortly after 4:15 PM north of Yucca Valley on HWY 247. The severe flash flooding that occurred along Old Woman Springs Rd (HWY 247) and Buena Suerte Rd began at 4:25 PM and ended at 5:15 PM. Everyone escaped without injury, however, one vehicle sustained major damage. A tree smashed the front bumper, boulders tore up the undercarraige pretty bad, and there was a ton of rocks, water, and debris in the engine.
These two pictures were taken 45 seconds apart. I snapped these shots immediately after I was forced to leave the highway in search of higher ground. Heavy rain quickly turned into torrential rain just before the onset of the Flash Flood. Notice how quickly the visibility dropped, and also notice how much more the road sign on the right is leaning. It was washed away moments after this picture was taken as a wall of water roared down canyon.
Highway 247 quickly became a river of muddy water.
Two vehicles are caught trying to drive through the river. The torrent stops the first car dead in its tracks.
Then it hits! This is what the initial wall of water looked like as it slammed into these two vehicles.
The car on the far side of the road managed to avoid the worst part of the inital wall of water, but still suffered a few hits by some rather large boulders.
Moments later, as the water level came down some, the car on the right tries to make a mad dash for it, but gets swept back about 30 ft by another wall of water.
This photo was taken about 15 minutes into the flash flood. The water level has gone down some but is still rushing by quite rapidly. There is one man still trapped in the vehicle.
San Bernardino County Fire showed up on scene at 4:47 PM. While flooding was still ongoing, the worst of it had passed.
The flooding was completely over by 5:15 PM. This shot is looking uphill through the canyon from where the flood initiated. Notice all the vehicles on the far right. This is the hill where many motorists (myself included) took refuge.
This is the view down canyon. Yucca Valley Police was on scene blocking traffic. It became apparent to all of us trapped up on the hill that the only way we were getting out of there is if we started moving boulders and clearing a path.
So that's what we did! After clearing a path that meandered around boulders too large to move, we all headed down the hill into Yucca Valley... where detour after detour greeted us. Apparently, we weren't the only road impacted by flash flooding that afternoon.
The following is a sequence of visible satellite images starting at early afternoon and ending after the flood. I plan to create an animated gif later, but for now, this will do.