The photo above is from an afternoon run at Sage Ranch Park on August 31, 2017, during our recent heat wave. The thunderstorm in the distance is over Santa Clarita.
Around the time the photo was taken the temperature at the Cheeseboro RAWS was 110 °F, with an “in the sun” fuel temperature of 119 °F. The temperature at Ahmanson Ranch, where I often run on weekdays, was probably higher. I was running at Sage Ranch to try and take the edge off the heat — even if the reduction in temperature was only a few degrees.
During the heat wave the high temperature at Pierce College in Woodland Hills in the West San Fernando Valley exceeded 100 °F on nine consecutive days (August 24 to September 3) and exceeded 110 °F on five consecutive days (August 28 to September 1). Numerous temperature records were broken in Southern California and across the state. On September 1, Downtown San Francisco set a new all-time record high temperature of 106 °F.
At my West Hills weather station the high temperature for the month of June was 109 °F; for July 111 °F; for August 112 °F; and so far this September the high has been 113 °F. If I’m not heat-acclimated by now, I never will be.by
Developing thunderstorm over the Acton area, north of Los Angeles, from Ahmanson Ranch near the Los Angeles County – Ventura County border. The photo was taken about 4:10 p.m. PDT today, during another hot and humid Ahmanson run.
Cloud tops were reported to be over 50,000 feet. The distance from Ahmanson Ranch (now Upper Las Virgenes Canyon Open Space Preserve) to Acton is about 35 miles.by
I rounded the corner, driving from deep shade into the golden glare of the rising sun. There was almost no traffic on Angeles Crest Highway. Up ahead, in the shade of some trees, there was something in the road. Was it a rock or a pine cone? Driving into the sun it was hard to tell. At this time of the morning — before the CalTrans truck has swept the road — one small rock can ruin your whole day. Getting to the trailhead unscathed is always the first challenge of the day.
Today, Craig and I were planning to do a point to point run from Inspiration Point to Islip Saddle — one of the best stretches of trail in the San Gabriel Mountains.
PCTA volunteer Ray Drasher often takes care of clearing the trees from this section of the Pacific Crest Trail. It’s quite an undertaking to get the required stock and equipment to the trailhead and then cut trees spread over several miles of trail. Because of conflicting reports, Ray wasn’t sure whether there were trees still on the trail or not. We’d let him know after the run.
On the drive up you could see it was going to be a spectacular day in the Angeles high country. A low pressure trough moving through central California had pulled in the marine layer and a tumultuous ocean of cloud reached from the south-facing canyons far out over the Pacific.
I drove through the double tunnels at Mt. Williamson and then around a left-hand curve. Up ahead I could see the northwest ridge of Mt. Islip dropping down to Islip Saddle. What the heck? Orange cones? The gate is closed? The HIGHWAY is closed? That didn’t make sense; the Winter closure had ended weeks before.
After parking, I talked to a hiker who said it was closed for “road work.” I assumed there must have been a rock slide in one of the problematic areas between Islip Saddle and Vincent Gap. Later I learned the problem was a “sink hole” west of the Grassy Hollow Visitor Center.
After Craig arrived we discussed route options to Mt. Baden-Powell. Either we did the South Fork loop, which I’d done a couple weeks before, or we did an out and back on the PCT. We opted for the out and back.
The run was as spectacular as expected. The visibility above the deck of stratus was at least 100 miles. San Bernardino Peak, San Gorgonio Mountain and San Jacinto were easy marks to the east and Owens Peak and the Southern Sierra could be seen to the north. Before it was immersed in a tide of cloud, the summit of Santiago Peak (Saddleback) had been visible to the south. High clouds and a gusty westerly wind kept the temperatures moderate. Only one very small patch of snow remained on the trail.
I’d hoped to be able to tell Ray the trees had been cleared from the trail, but no — they were still there. He said the next time I ran there, they would be gone. Thanks Ray!by
This is a view of East Las Virgenes Canyon from the power line service road that connects the Las Virgenes Canyon Trailhead to Cheeseboro Ridge. East Las Virgenes Canyon is part of the Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch).
From this afternoon’s keyhole loop run from the Victory Trailhead to Cheeseboro Ridge.by
View of upper Santa Ynez Canyon and the Eagle Rock area of Topanga State Park from East Topanga Fire Road. From today’s run from the Top of Reseda to the Los Liones Trailhead and back.by
At the start of my run from the Top of Reseda (Marvin Braude Mulholland Gateway Park) the visibility above the fog-filled San Fernando Valley was at least a hazy 25 miles.
Ahead of another rainstorm, offshore pressure gradients had weakened and the onshore flow was rapidly increasing, pushing marine layer clouds into the coastal canyons of the Santa Monica Mountains and spilling over the low points of the crest.
My first stop was going to be Temescal Peak. This little peak is about 3.5 miles from the trailhead, near the junction of Temescal Ridge fire road and the Backbone Trail. It’s a nice way to start a run, and on a clear day it can have surprisingly extensive views.
Fog flowed over Fire Road #30 between Rustic Canyon and Garapito Canyon, but once through this ethereal river, it was clear all the way up to the Hub. I wondered if I was going to be able to see Mt. San Jacinto from the top of Temescal.
The answer to that question turned out to be no. In fact I could barely see my nose from Temescal Peak. In the 12 minutes it had taken me to get to the peak from the Hub the entire area, including the summit of Temescal Peak (about 2100′), had become enveloped in fog.by
From yesterday’s run on the Cheeseboro Ridge Trail. The old mustard stalks are probably from Spring 2012, when there was prolific growth of mustard in Upper Las Virgenes Canyon Open Space Preserve.by
The oval disturbance in the layer of altocumulus clouds in this photograph is a relatively rare phenomenon called a fallstreak hole or hole punch cloud.
These altocumulus clouds are formed from super-cooled water droplets many times smaller than a raindrop. The droplets are in a liquid state even though the temperature is well below freezing. When disturbed by an aircraft passing through the layer the droplets freeze and precipitate out of the cloud as virga. This and other processes create the hole.
The photo was taken on Saturday, January 21, 2017 at 2:23 p.m. near the Las Virgenes trailhead of Upper Las Virgenes Canyon Open Space Preserve. The hole was well south of the area.by