It wasn’t so much a surprise that there was thunder or that it was starting to shower again. It was that I was hearing thunder all around me — to the east toward Mt. Waterman and Twin Peaks, to the south toward Mt. Wilson and the San Gabriel Valley, and to the west toward Big Tujunga Canyon and the San Fernando Valley. This was clearly more than an isolated summer build-up. Pockets of showers, some light and some heavy, could be seen in the distance and I wondered just how wet I was going to get.
The answer was “pretty wet!” That was on a run in the San Gabriel Mountains on Saturday, and was the result of the first wave of moisture and instability associated with tropical system Dolores and a strong monsoonal flow from Baja. An even stronger surge of moisture followed Sunday afternoon with rain rates exceeding an inch an hour. From 5:15 p.m. to 5:25 p.m. a CBS Radio weather station on Mt. Wilson recorded a half-inch of rain in just 10 minutes!
Though the heavy rain created its own problems — including flash floods, debris flows and rock slides — the soaking rains helped quell the Pines Fire near Wrightwood and the North Fire near Cajon Pass. Over the three day period from Saturday to Monday the Big Pines Remote Automated Weather Station (RAWS), near the Pines Fire, recorded 3.12 inches of rain. Several stations in the San Gabriels recorded more than three inches of rain, including Clear Creek and Opids Camp.
Many locations set new records, not only for the date, but for any day in July. Downtown Los Angeles (USC) set rainfall records for the date on Saturday, Sunday and Monday. Downtown Los Angeles recorded 0.36 inch of rain Saturday. This is more rain than any day in any July since recordkeeping began in 1877. That one day of rainfall even broke the monthly record for July in Los Angeles! Prior to this event the wettest July on record was in 1886, when 0.24 inch was recorded.
Strengthening El Nino conditions and the active phase of the Madden-Julian Oscillation contributed to the development of Dolores in the Eastern Pacific, enhancing convection. Anomalously warm SSTs in the tropical and sub-tropical Eastern Pacific also played a role, helping to maintain the strength of Dolores and increasing the amount of water vapor entrained by the system.
This year’s El Nino is very different than last year’s on again, off again event. This year’s El Nino is already established, well-coupled with the atmosphere and growing in strength. It’s firing on all cylinders and at this point it appears the only question is, “How strong will it get?”
Following four rainfall years in which Downtown Los Angeles (USC) has cumulatively recorded less than half of normal rainfall and accrued a precipitation deficit of more than 30 inches, many of the valley oaks at Ahmanson Ranch (Upper Las Virgenes Open Space Preserve) are drought stressed.
The most obvious signs of drought stress in valley oaks and many other plants are a reduced number of leaves and reduced leaf size. In severely stressed valley oaks the foliage has the appearance of a tree that is recovering from a wildfire.
At Ahmanson the degree of stress varies widely from tree to tree. The “TV tree,” an aesthetically-shaped and often-photographed valley oak on the west side of Lasky Mesa appears to be showing a higher than average level of stress.
Valley oaks and live oaks cohabit the oak savannas at Ahmanson Ranch, but live oaks appear to be more drought tolerant. The lone Blue Oak at Ahmanson seems to be doing OK and has at least as much foliage as it did last year at the same time.
Even with a wind shell and multiple layers the gusts of wind were sharp-edged and penetrating. The weather was spectacular, but it was very windy and very cold.
My run on the PCT had started at Islip Saddle in the San Gabriel Mountains. At 8:00 am the temperature at 6593′ had been about 35 degrees. The north wind funneling through the saddle had roared through the pines, buffeting their stout limbs and telling me to put on every scrap of warm clothing I had in my pack.
The broad canyon of the South Fork seemed to act as a wind tunnel — drawing the wind from the high desert into and over the crest. Even with a gloved hand it took only a couple of minutes before my camera became too cold to hold.
I was on my way to Mt. Baden-Powell and nearly up to Mt. Hawkins. With every stride up the mountain the temperature had dropped. Father Frost had frozen the landscape and me along with it.
Had it really been just a week ago when I had broiled in 90+ degree temps on the south-facing sections of trail on the Leona Divide 50M course?
Well, maybe not Shangri-La, but a Lost World kind of morning on the Calabasas Peak fire road segment of the Secret Trail.
Calabasas Peak fire road traverses the rock formations on the left, descending to Stunt Road. At Stunt the route continues up the Stunt High Trail to the Backbone Trail. Here you can do an optional out and back to Saddle Peak, shrouded in clouds in this photo, or turn west on the Backbone Trail and continue mostly downhill to Piuma Road near Malibu Canyon Road. Malibu Canyon is in the distance on the right in the photo.
Although we are still experiencing a record-breaking drought, this rain season did provide a little short term relief to plants and wildlife. Compared to last year rainfall is up 27% at Los Angeles, 39% at Santa Barbara, 57% at LAX and 63% at Camarillo/Oxnard according to NWS data.
The increase in rainy season precipitation dramatically increased plant growth, the abundance of wildflowers, and temporarily increased the availability of key resources to wildlife.
Another thing it seems to have increased is the number of rattlesnakes. Over the past two years I have seen maybe two rattlesnakes total on my runs in the Santa Monica Mountains, San Gabriel Mountains, and in the Big Bear area and on San Gorgonio Mountain. In the Ahmanson Ranch – Cheeseboro area I’ve seen none.
With the increase in rainfall this season that has changed. The title photo was taken on the Leona Divide 50/50 course March 28. That day I encountered two rattlesnakes and talked to a runner that had seen three on the course the previous weekend. From March 26 to April 2 I encountered rattlesnakes on three out of four runs. Two of those were at Ahmanson and it seemed everyone I talked to on the trail was seeing rattlesnakes.
There has also been an increase in the number of encounters with non-venomous snakes as well. I’ve seen a number of gopher snakes and a California striped racer. Friends have mentioned seeing a ring-necked snake and California kingsnake.
Since the weather has cooled I haven’t encountered any rattlesnakes, but have seen their tracks. When I run, especially on single-track trails, my snake radar is on and I’m definitely on the lookout for the hard-to-see beasts.
Photography on the Run published its first image, Oat Mountain Snow, more than nine years ago. Following nearly a thousand posts and the publication of thousands of images, I have migrated the content from the DasBlog blog engine to WordPress. Some work remains to be done, but the blog is fully functional and all of the content is present and accounted for.
Most DasBlog-style links to the blog’s content should continue to work. Old permalinks and date and category views have been mapped to their WordPress equivalents.
The Feedburner feed is no longer supported. Please subscribe to the WordPress RSS feed or Atom feed instead.
At this time email subscriptions to the blog are not available.
If you receive an error or something doesn’t seem to be working properly, please let me know.
Following last year’s drought-induced hiatus goldfields are once again blooming in profusion on Lasky Mesa. The little yellow “belly flowers” tend to grow in low spots and along paths where rain water pools.
Race director Nancy Shura-Dervin picked a great year, and as it looks now, a great weekend for the inaugural running of the Ahmanson 12K Trails event.
The hills are lush and green; wildflowers are in bloom; valley oaks are sprouting fresh green leaves; and it’s looking like race day may be one of those “gotta run” kind of days.
According to today’s NWS forecast the area will see dry and warmer weather beginning Tuesday and continuing through race day. While there could be a remnant puddle here or there, four days will be plenty of time for the dirt roads to (mostly) dry out. The Cheeseboro RAWS automated weather station can be used to get an idea of the current weather in the vicinity of the race course.
Over the past 10 years I’ve logged approximately 6000 miles at Ahmanson Ranch (now Upper Las Virgenes Canyon Open Space Preserve) and the loop Nancy has selected for the course is a variation of a favorite.
Lasky Mesa has long been used to shoot movies, television, commercials, music videos, and even Internet games. Its wildland character and expansive views bely its urban location. For a few weeks one summer the Mission Impossible III bridge was a Lasky Mesa landmark. The aesthetically-shaped valley oak at the west end of Lasky Mesa is a favorite of production companies and I’ve spotted it in more than one commercial.
The Ahmanson 12K should be an outstanding event on an excellent course in conditions we haven’t seen at Ahmanson in several years.
Instability associated with an upper low resulted in some pop-up showers and thunderstorms today.
As I ran up the Chumash Trail on the east side of the Simi Valley I kept a close eye on a cell that developed near Ladyface in the Agoura Hills. That cell didn’t track as much to the east as I thought it might, but other cells were developing to the east and south of Rocky Peak and Santa Susana Pass area and at one point I heard the rumble of thunder.
As it worked out, I only had a few sprinkles on the run, but drove home in the rain!
The rising sun illuminates a translucent layer of cloud trapped by a shallow inversion in the San Fernando Valley. The mid-level clouds above are associated with a system that brought heavy rain to much of California, but would only produce showers in the Los Angeles area.