It was a little past 3:00 in the afternoon when I passed this straight-backed wooden chair along an Ahmanson Ranch trail. The Tempe thermometer clipped to my pack read over 100 degrees.
It gets REALLY hot at Ahmanson Ranch (Upper Las Virgenes Canyon Open Space Preserve). In the direct sun the temperature can be 10°F-15°F hotter than in the shade, and there is very little shade at Ahmanson. In-the-sun temperatures of 100°F or more are common in the Summer but can occur just about any time of the year.
There are two weather stations I use to get an idea of the weather conditions at Ahmanson Ranch — the Cheeseboro RAWS and Valley Circle Estates Weather Underground station. Weather station thermometers are usually shielded from the direct sun by a white, ventilated enclosure. The Cheeseboro RAWS includes a measurement of the “Fuel Temperature.” This is generally a better indication of the temperature experienced by a runner, hiker, or rider in the direct sun.
Update on July 29, 2023. Rounding the temperature to whole degrees, my West Hills weather station recorded a high of 100°F, or higher, for 15 consecutive days this July (7/13/23 to 7/27/23). The station is about three miles from the Victory Trailhead at Ahmanson Ranch.
Snow in the lee of the West Ridge of Mt. Baden-Powell.
You might not see it from the Los Angeles side of the mountains, but there is still some snow on the higher, north-facing slopes of the San Gabriel Mountains.
During and after storms, snow-laden southerly winds dump their load on the backside of the crest, creating deep drifts, cornices, and compacted slabs of snow. This snow is often the last to melt, not only because it doesn’t face the sun, but because there is more of it.
Mt. Burnham, Peak 9086, and Mt. Baden-Powell from near Throop Peak.
This morning, I was doing an out-and-back from the Windy Gap Trailhead in the Crystal Lake Recreation Area to Mt. Baden-Powell. The Windy Gap Trail climbs 1730′ in 2.6 miles, joining the PCT at Windy Gap. From there the trail follows the spine of the San Gabriels past Mt. Hawkins, Throop Peak, and Mt. Burnham to Mt. Baden-Powell.
I usually do this run from Islip Saddle, but with Angeles Crest Highway (Highway 2) closed between Red Box and Vincent Gap, the Islip Saddle trailhead isn’t accessible.
Snow at about 9100′ on the west side of Mt. Baden-Powell.
Whether you start at Crystal Lake or Islip Saddle, the length of the run is about the same — a bit over 16 miles. The main difference is that the Windy Gap Trailhead is about 800′ lower in elevation. On the plus side, the Windy Gap Trail is very scenic; on the minus side, it faces south and can bake in the midday sun.
On today’s run, I encountered the first snowbanks at an elevation of 8870′, near the Dawson Saddle Trail junction. Out of curiosity, I tried to follow the trail and soon realized that was a mistake. I was more or less forced to skirt the downhill side of a lengthy and deep drift — it being too steep and icy to cross directly.
Mt. Baldy from the summit of Mt. Baden-Powell. July 9, 2023.
For the remainder of the run, I switched to the early season tactic of staying on the crest when the trail deviated onto shaded, north-facing slopes. These areas might have significant snow on the trail. This only happens in a few places, such as when the PCT works around Mt. Burnham. There is a use trail that ascends the west ridge of Mt. Burnham, and then returns to the PCT.
The conditions today are reminiscent of those found here in early July 2005. July 3rd of that year there was still snow on the summit of Baden-Powell, and there was deeper snow in the areas where there was snow today. We had a lot of storms this rain season, but in Rain Year 2004-2005 Downtown Los Angeles (USC) recorded about 9 inches more rain than during the 2022-2023 rain year!
It had rained another inch overnight, and my shoes were soaked from the wet grass along the trail. Seeking some relief from the 20 mph northwest wind, I descended a single-track trail to an old paved road east of the ranch house on Lasky Mesa.
Motivated more by staying out of the wind than anything else, I did two sets of hill repeats on different sections of the road. Then, on tired legs, I jogged up to Lasky Mesa and was greeted by an Arctic blast. The temperature had dropped to the mid-40s, and the wind was blowing a steady 20 mph, gusting to around 30 mph. I didn’t need a wind chill chart to tell me the effective temperature was in the 30s.
I was so focused on dealing with the cold I wasn’t paying much attention to my surroundings. Deciding to do one more hill, I rounded a corner, and the brilliantly sunlit, snow-covered San Gabriel Mountains came into full view. It was just jaw-dropping!
April 26, 2023 Update. As it turns out, the shiny, new bridge on the Crags Road Trail that made it easy to cross Malibu Creek was not washed away! According to the Malibu Creek Docents, the bridge was designed to be portable, and was removed and stored before this Winter’s rain. It is expected to be reinstalled when the threat of flooding is over — which should be soon.
I was just a couple of miles into an extended version of the Bulldog Loop. The temperature was in the mid-30s, and once again, I was having to cross Malibu Creek on a makeshift bridge of wobbly limbs and debris.
Flood debris on the Crags Road Trail
The flood was the result of a series of three increasingly wet storms between December 30 and January 10. During that period, the Malibu Canyon RAWS recorded about 13 inches of rain. In the last storm of the series, 6 inches of rain was recorded in about 33 hours.
The flooding along the Crags Road Trail from the Forest Trail junction to the M*A*S*H site was similar to the February 2017 and December 2021 events. In the January 2023 event, more debris was deposited on the trail, and sections of the trail were obliterated. That stretch of trail is popular, and a new use trail is already taking shape.
Rainfall and runoff were even higher in Santa Barbara and Ventura Counties. The Rose Valley RAWS recorded over 22 inches of rain for the three storms. According to preliminary streamflow data, the Ventura River Near Ventura reached a new record stage height of 25.42 feet on January 9. The Sespe Creek Near Fillmore gage malfunctioned at the peak flow but reached at least 20.38 feet.
Several popular trails and fire roads in Topanga State Park have been damaged by the cumulative effects of Winter 2022-2023 rainstorms.
Since December 1, 2022, the Topanga Remote Automated Weather Station (RAWS) has recorded nearly 16 inches of rain. The most rainfall occurred January 9-10, when about 5.4 inches was measured.
On Sunday, January 15, I did an exploratory trail run from the Top of Reseda that took me through some popular areas of the Park. This included Fire Road #30, the Hub, Temescal Peak, Temescal Lookout, Temescal Ridge Fire Road, Eagle Springs Fire Road, Eagle Rock Fire Road, the Garapito Trail, and the Bent Arrow Trail.
There were numerous mudslides on the fire roads. The larger slides were on Fire Road #30 below the Hub and Temescal Ridge Fire Road between the Backbone Trail junction and Temescal Lookout. There was also significant roadbed and shoulder erosion in places. At the time, all were passable on foot.
The Garapito Trail was blocked in two places on the upper part of the trail. One problem was from a sluff of soil and brush sliding onto the trail. The other was from the collapse of a section of trail. There were additional sluffs, limbs, and washouts on the trail that were passable at the time.
Update February 5, 2023. The Bent Arrow Trail is closed. Fire Road #30, Eagle Springs Fire Road, and East Topanga Fire Road to Parker Mesa Overlook had all been cleared. The Musch Trail was eroded in spots but OK. Use of the Garapito Trail has moderated its condition. Some brush had been cleared and paths have evolved through the sections of collapsed trail. Extra care is required in some spots.
Other trails and fire roads in Topanga State Park likely had similar impacts. I would expect, like last year, sections of the Santa Ynez Trail lower in the canyon to be washed out.
La Ninas are fickle beasts, and particularly in a time of climate change, the existence of La Nina conditions in the equatorial Pacific is no guarantee of a dry rain season in Southern California.
According to preliminary rainfall data, from December 1, 2022, to January 16, 2023, Downtown Los Angeles (USC) recorded 11.01 inches of rain. This was 77% of the normal rainfall for an entire year.
This brings the Rain Year total precipitation for Los Angeles up to 13.38 inches — the sixth wettest for the date going back to 1877 — and 94% of the normal ANNUAL rainfall.
