Winter Sky: Cirrocumulus Clouds

Cirrocumulus clouds from Upper Las Virgenes Canyon Open Space Preserve, also known as Ahmanson Ranch

Cirrocumulus clouds form at high altitude. They are primarily composed of ice crystals but also contain supercooled water droplets.

The photograph of cirrocumulus clouds was taken in Las Virgenes Canyon on a trail run from the Victory Trailhead of Upper Las Virgenes Canyon Open Space Preserve, also known as Ahmanson Ranch.

Some related posts: Pattern Change Ahead, Fallstreak Hole, Rainbow Colors in Cirrus Clouds Over Los Angeles

A Dry and Dusty Start to the Los Angeles Rain Year

dry and dusty Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch)

Except for a teaser storm system in early November that brought a smattering of rain to the metro area and some snow to the mountains, the Los Angeles rain year is off to a parched start.

As of December 1, Downtown Los Angeles (USC) has recorded only 0.11 inch of rain since July 1. Along with 1995, this is the 7th driest start to the rain year over the 144 years weather records have been kept in L.A.

Update December 29, 2020. In the first significant storm of the rain year, Downtown Los Angeles recorded 1.82 inch of rain, bringing the rainfall total up to 1.95 inches. The storm total was more than generally forecast, but L.A. is still about 2 inches below normal for the date. The rain does move 2020 out of contention for the driest first six months of the rain year.

Update December 20, 2020. The period July 1 – December 20, 2020 is the driest on record (for that date range) for Los Angeles. As of December 20, the rainfall total for Downtown Los Angeles (USC) remains at 0.11 inch.

While “past performance may not be indicative of future results,” I was curious to see if, historically, a dry start to the rain year has generally resulted in below average annual rainfall.

There have been 16 years in which Los Angeles precipitation was 0.25 inch or less for the period July 1 to December 1. Rain year precipitation (July 1 – June 30) for those years varied from a low of 4.79 inches in 2017, to a high of 23.43 inches in 1937. Overall, these years averaged 11.34 inches of rain annually, which is 3.66 inches below the current normal of 14.93 inches.

Whether or not annual rainfall this rain year is below normal we’ll have to see. An important consideration is that La Nina conditions are present in the equatorial Pacific. This doesn’t necessarily mean less rainfall in the Los Angeles area, but taking into account a number of factors, the Climate Prediction Center is projecting below average precipitation this Winter in Southern California.

The title photo of silhouetted mountain bikers is from this afternoon’s run at Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch). The image is an example of a “silhouette illusion.” Are the riders going toward or away from the camera?

Looking for Boney Bluff

Boney Bluff from the Backbone Trail

Every time I’ve run the Chamberlain segment of the Backbone Trail, I’ve looked at the intriguing rock formation near the top of the trail and wanted to climb it. Looking a bit like an aircraft carrier that’s run aground on a mountain ridge, it’s one of the most prominent peaks along Boney Mountain’s western escarpment. Named “Boney Bluff” by rock climbers, several sport climbing routes were established on the southeast side of the peak in the early 2000s.

Located just northwest of the junction of the West Tri Peaks Trail and the Backbone Trail, the peak is visible from many points in Pt. Mugu State Park. According to lidar-based 1-meter resolution 3DEP data, its elevation is 2985′, which is slightly higher than the 3DEP elevation of nearby Exchange Peak.

Boney Mountain plateau.
Boney Mountain plateau. Click for larger image.

Boney Bluff is one of many small peaks and rock formations that are found across the Boney Mountain plateau. Comprised of a fused mishmash of volcanic breccia, the rock quality of these formations ranges from very good to quite bad. Seemingly solid handholds or footholds can break, and because of the way the rock erodes, low-angle sections are often littered with granular rocks that can be very slippery.

Boney Bluff from the east.
Boney Bluff from the east.

Having climbed the Western Ridge on Boney Mountain, I approached Boney Bluff from the north, via the Tri Peaks Trail. My route climbed a slope to the east side of the peak, then traversed right to the base of a jumbled face with several oddly eroded ledges. A short, steep crack and grassy ramp provided access to the ledges above. NOTE: There may be a better way to climb the peak. I was trying to do a relatively direct route and avoid bushwhacking. The route is somewhat manky, but worked for me.

Summit block of Boney Bluff
Summit block of Boney Bluff.

The high point of the peak is on top of a summit block that caps the “island of the carrier.” Many of the formations on Boney Mountain have summit blocks, and these are often the most difficult part of the climb. Rule #1 involving summit blocks: Don’t climb up anything you can’t 100% for sure climb down! This one looked like it might be tricky, but with careful route-finding was pretty straightforward.

Because Boney Bluff is perched on the edge of the Boney Mountain plateau, on a clear day there are outstanding panoramic views of Pt. Mugu State Park and the Boney Mountain area from its summit. Today, the visibility was excellent and Mt. Baldy was visible, 75 miles to the east.

Lidar-based 3DEP Elevation Estimates of Some Boney Mountain Peaks
Lida-based 3DEP elevation contours of Boney Bluff. Click for a larger image.

The resolution of the 3DEP Elevation Data is very impressive. While checking the elevation of Boney Bluff, I also noted the 3DEP elevation of several other peaks in the Boney Mountain area. For more info about 3DEP see this U.S.G.S. website.

  • Sandstone Peak 3116′
  • Tri Peaks 3039′
  • Boney Bluff 2985′
  • Boney Crest 2974′ (Accessed via Western Ridge or Cabin Trail)
  • Exchange Peak 2969′
  • Big Dome 2934′
  • Boney Peak 2849′ (Both summits)
  • Inspiration Point 2811′

Some related posts: Looking for Boney Mountain, Looking for Boney Peak

Photography and inspiration from running and other adventures in the Open Space and Wilderness areas of California, and beyond. No ads. All content, including photography, is Copyright © 2006-2024 Gary Valle. All Rights Reserved.