Category Archives: weather

A Second Spring at Ahmanson Ranch

Lupine at Ahmanson Ranch blooming in October as a result of the rainfall from T.S. Hilary
Lupine blooming in October!

It’s been about a month and a half since Tropical Storm Hilary soaked Southern California with record-setting rainfall.

The unusual amount of Summer rain has resulted in a second Spring at Ahmanson Ranch, with some plants behaving as if it were March or April.

Not only are plants growing as if it were Spring, some are flowering. The lupine pictured above usually blooms at Ahmanson Ranch in March, April, and May. Now, as a result of T.S. Hilary’s rain, it’s flowering in October!

Those plants that usually flower in the Fall, such as telegraph weed, vinegar weed, and common sunflower, are much more widespread than usual.

Here are a few photos of the unusual conditions at Ahmanson Ranch (Upper Las Virgenes Canyon Open Space Preserve).

Spring-like conditions are present in many areas of Southern California. On Sunday, I ran the Phantom Trail in Malibu Creek State Park. Some sections were so overgrown that it was challenging just to navigate the trail, much less run it. Ticks were also a problem.

Some related posts:
Lake Vista Ridge, the Forest Trail, and September Wildflowers
Looking For Local Impacts of Tropical Storm Hilary

Looking For Local Impacts of Tropical Storm Hilary

New grass in Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch), 10 days after the passage of Tropical Storm Hilary
Rare Summer grass at Ahmanson Ranch as a result of Hilary’s rain.

Update September 14, 2023. Mustard is sprouting along Ahmanson’s fire roads, and more surprising — a few mushrooms.

Update September 8, 2023. The new grass from T.S. Hilary’s rain is coming in nicely at Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch).

Tropical storms are a different kind of weather beast than usually seen in Southern California. The warmer air associated with such storms can carry much more water and produce unusually high amounts of precipitation.

The first hints of Hilary approaching Los Angeles
The first hints of Hilary approaching Los Angeles.

The rain resulting from Tropical Storm Hilary shattered many daily and monthly records. Over decades of record keeping, most stations in the greater Los Angeles area had previously measured only a trace of rain on August 20 or 21, or at best, a few hundredths of an inch. Some stations had never recorded any rain on these days.

This Google Earth image with precipitation data from the California-Nevada River Forecast Center (CNRFC) shows the remarkable rainfall totals across Southern California for the 24-hour period ending at 5:00 a.m. on Monday, August 21, 2023.

A little mud in Las Virgenes Canyon after Tropical Storm Hilary. August 22, 2023.
A little mud in Las Virgenes Canyon.

The highest rainfall amounts occurred where the precipitation was enhanced by mountainous terrain. The northeast-facing slopes of the eastern San Gabriel Mountains, near Wrightwood, were ideally positioned in Hilary’s circulation to enhance rainfall. The Big Pine RAWS recorded over 6 inches of rain for the storm, Lewis Ranch slightly over 7 inches, and Lytle Creek nearly 10 inches.

Detailed observation and impact reports for Hilary are available from NWS Los Angeles/Oxnard, NWS San Diego and the Center for Western Weather and Water Extremes.

Crossing of Las Virgenes Creek, south of the pipeline station, on August 22, 2023, following Tropical Storm Hilary.
This crossing of Las Virgenes Creek was about the same as before Hilary.

Curious to see some of the local impacts of the storm, I ran at Ahmanson Ranch on August 22 and then a few days later at Malibu Creek State Park.

My West Hills weather station, about three miles from Ahmanson Ranch’s Victory Trailhead, recorded 3.86 inches of rain for the storm. After an initial technical hiccup, the Cheeseboro RAWS, overlooking Las Virgenes Canyon, recorded 3.52 inches of rain. This and other data suggest rainfall amounts in the Ahmanson area of at least 3.5 – 4.5 inches.

My Ahmanson run started at the Victory trailhead, went out East Las Virgenes Canyon, through part of Las Virgenes Canyon, and then up to Lasky Mesa. With that much rain, I was sure I would be wallowing in the mud and wading the creek crossings. But my shoes didn’t even get muddy!

Dry streambed of Las Virgenes Creek, north of the Las Virgenes Trailhead, on August 22, 2023, after Tropical Storm Hilary
Dry streambed of Las Virgenes Creek, north of the Las Virgenes Trailhead

There was certainly some mud, puddles, and a little erosion, but the impact of Hilary on Ahmanson was surprisingly minor. The ground must have been desiccated because Las Virgenes Creek had almost no increase in flow. The creek crossings near the pipeline station and south of the station were essentially the same as before Hilary. Even more surprising, there was no water at the crossing a little north of the Las Virgenes Trailhead.

As Hilary moved northward in California, the counterclockwise circulation of the storm increased the rainfall in the Santa Monica Mountains. Automated RAWS stations in Topanga, the Malibu Hills, and in Malibu Canyon recorded 4.0 to 4.5 inches of rain during the storm. CNRFC gridded precipitation data indicated higher amounts in some parts of the range.

Las Virgenes Creek, about 5 miles downstream of Ahmanson Ranch, in Malibu Creek State Park, a few days after the passage of Tropical Storm Hilary.
Las Virgenes Creek in Malibu Creek State Park, about 5 miles downstream of Ahmanson Ranch.

On August 27, I ran the Bulldog Loop in Malibu Creek State Park. The run started at a small parking area at the junction of Malibu Canyon & Piuma Roads. As I was running up the Tapia Spur Trail, I wondered if State Parks had — as a precaution — removed the seasonal bridge across Malibu Creek on the Crags Road Trail. On August 19, the day before Hilary drenched the area, the bridge had been in place for the Bulldog Ultra. If it wasn’t removed, did Malibu Creek get high enough to damage it?

Once again, I need not have worried. The bridge was just fine, and the reeds in the water near the bridge suggested only a modest increase in streamflow.

Slopes along Bulldog fire road following Tropical Storm Hilary.
It’s unusual for the slopes along Bulldog fire road to be this green in Summer!

It looked like Malibu Creek State Park received more rain than Ahmanson Ranch. There was slightly more erosion on the dirt roads and some small sluffs/slides, including one tree that slid onto Mesa Peak Mtwy fire road. A tree had also fallen near the beginning of the Forest Trail.

Back at Ahmanson on August 31, things were drying out, but it was beginning to look like Spring. Grass was sprouting all over Ahmanson Ranch. It will be interesting to see if the grass survives the inevitable heat and grows enough to turn the hills green. The little bit of rain and cooler weather over Labor Day weekend will help. Some out-of-season wildflowers could also result from a false Spring.

Yesterday, I did a run in Topanga State Park, and the story was much the same. There was some minor erosion on the fire roads, but none of the larger sluffs and slides seen during the rainy season. There was no new damage to the Musch or Garapito Trails. It did look like the flow had increased on Garapito Creek with Hilary’s rain, and there was a still little water in the mainstem of the creek.

Dealing with the Heat on Strawberry Peak and San Gabriel Peak

Early morning view of Strawberry Peak from the Strawberry Trail, near Lawlor Saddle.
Strawberry Peak from the Strawberry Trail, near Lawlor Saddle.

Last weekend I’d considered doing a run from Red Box, but finally decided to go to higher elevation and do a combination run and climb.

Blazing star near the bottom of the Bill Riley/Mt. Disappointment Trail
Blazing star.

The puzzle to solve this weekend was to find a run that was closer to home, higher than the Santa Monica Mountains, and had a “decent amount” of elevation gain. The solution put me right back at Red Box, doing two of the most popular peaks in the Front Range — Strawberry Peak (6164′) and San Gabriel Peak (6161′).

I’d done these peaks as a duo several years ago. The basic details remain the same and are described in this post.

The main difference is that the 2018 run/hike was on a cool day in March, rather than a hot day in August. In 2018, I did San Gabriel Peak first, then Strawberry. The order didn’t matter. The temperature on both peaks that day was mostly in the 40s.

Mt. Disappointment (left) and Strawberry Peak from the San Gabriel Peak Trail.
Mt. Disappointment (left) and Strawberry Peak from the San Gabriel Peak Trail.

Today, it was essential to do Strawberry first, and get started early. The use trail between Lawlor Saddle and Strawberry’s summit faces south and east, and has very little shade. It’s steep and strenuous an no fun at all in the hot sun.

I left the Red Box parking lot at about 6:00 a.m. On the way up, the temperature ranged from the mid-50s to the mid-70s. On the way down, in some places it was already in the 90s. While it was hot in the sun on the upper part of the mountain on the descent, the traverse around Mt. Lawlor on the Strawberry Trail was still mostly in the shade and a relatively cool 75 to 80 degrees.

San Gabriel Peak isn’t the solar oven that Strawberry is. Much of the Bill Riley/Mt. Disappointment Trail faces north and a scrub oak forest provides some shade. Continuing up San Gabriel Peak after doing Strawberry, the temps were generally in the low to mid-80s.

Some related posts: Front Range Duo: San Gabriel Peak and Strawberry Peak, Blazing Star

A Warm Day on Blue Ridge and the North Backbone Trail

Clouds, pines, and Pine Mountain from Blue Ridge in the San Gabriel Mountains

Angeles Crest Highway was still closed between Red Box and Vincent Gap, and the heatwave continued. I was trying to decide where to run.

I briefly considered the Circuit Around Strawberry Peak, but yesterday at 10:00 a.m., the “in-the-shade” temperature at Clear Creek was already 92°F, and the “in-the-sun” fuel temperature 109°F. By 1:00 p.m., the fuel temp reached a scorching 122°F!

Although trailheads such as Three Points and Islip Saddle couldn’t be accessed using Angeles Crest Highway, the highway was open from Wrightwood to Inspiration Point and Vincent Gap. After seeing the temps at Clear Creek, it took about two seconds to make the decision to head to the San Gabriels’ high country.

 sulfur flower-lined section of the PCT east of Inspiration Point
sulfur flower-lined section of the PCT east of Inspiration Point

From Inspiration Point (7,365′), I ran east on the PCT about 7 miles to the North Backbone Trailhead on Mt. Baldy. Over most of that stretch, the temperature was a blissful 60-something degrees. Other times, I’ve driven to this trailhead — which requires a high-clearance vehicle — or run to the trailhead from Wrightwood. But the run along Blue Ridge is a favorite. It is especially scenic, with fantastic views of Mt. Baden-Powell, Iron Mountain, Pine Mountain, and Mt. Baldy.

About a quarter-mile east of the top of the Acorn Trail, the PCT passes within a few feet of one of the Wright Mountain landslides. The canyon-size landslide is prehistoric, but smaller landslides and mudflows occur periodically within the primary scar. The debris cone of a dramatic 1941 mudflow is an unmistakable feature on satellite photos.

Peak 8555 and Pine Mountain from the PCT.
Peak 8555 and Pine Mountain from the PCT.

Less than a mile beyond the overlook of the landslide, I left the PCT and jogged down to the North Backbone Trailhead. After a short descent, I started up the steep use trail toward Peak 8555. On the way up, San Gorgonio Mountain and San Jacinto Peak were visible in the haze to the east.

Peak 8555 is the first high point on Baldy’s North Backbone. It is an idyllic spot with a great view of Mt. Baden-Powell and the surrounding terrain. But you might not want to linger here in a thunderstorm — spiral scars on the trunks of trees suggest the point is repeatedly struck by lightning.

Crossing the top of a chute on Mt. Baldy's North Backbone.
Crossing the top of a chute on Mt. Baldy’s North Backbone.

Following a short descent, I resumed climbing the steep, somewhat loose ridge. After about ten minutes, I scrambled onto the crest of the ridge and crossed the top of a prominent, rocky chute. More than a thousand feet below, avalanche-hardened snow gleamed white in the sun at the base of the chute.

Another 10 minutes of climbing and I reached the Pine Mountain Juniper. Straddling the rocky crest at an elevation of about 9000′, this stalwart tree is estimated to be 800 – 1000 years old. It is a remarkable tree in a remarkable location. Except for one short, steep, eroded section, the remainder of the trail to the top of Pine Mountain (9648′) was relatively straightforward.

Dawson Peak and Mt. Baldy from Pine Mountain's south summit.
Dawson Peak and Mt. Baldy from Pine Mountain’s south summit.

Pine is the second-highest peak in the San Gabriels and has excellent views of the surrounding terrain. It is higher than Mt. Baden-Powell (9399′) and Dawson Peak (9575′) but a few hundred feet lower than Mt. Baldy (10,064′).

From Pine Mountain, the North Backbone trail continues over Dawson Peak another 2.5 miles to Mt. Baldy. There was still a long ribbon of snow along the east side of the upper North Backbone, but it looked like the trail might avoid it. I would have liked to confirm that, but today the top of Pine was my planned turnaround point. As it was, with the warm weather, I thought I might run short on water on the return to Inspiration Point.

Leaving Pine behind, I started back down — jogging when it made sense — but trying not to do anything stoopid. On the way down, I kept reaching behind me and squeezing the bladder in my hydration pack. I guess I was hoping that it would magically be more full than the last time I checked. It never was.

San Gabriel beardtongue along the PCT on Blue Ridge.
San Gabriel beardtongue along the PCT on Blue Ridge.

Back at the North Backbone Trailhead, and definitely low on water, I decided it was a good time to run the dirt road back to the top of the Acorn Trail and see how much shorter it was than the PCT. The answer was not much — only about a tenth of a mile.

I’d been willing to push the water envelope because it had been a heavy snow year. I expected the spring near Guffy Camp would probably be running. I’d passed the side trail to the spring a bunch of times but never ventured down the steep slope. My impression was that the spring was often low or nearly dry. This time when I reached the side trail, I headed down.

Pumphouse at Guffy Spring, surrounded by giant larkspur.
Pumphouse at Guffy Spring, surrounded by giant larkspur.

And down and down… It sure seemed like a long way to the spring, but when I checked the track, it was less than a quarter-mile with an elevation loss of about 200′.

As I walked up to the spring, a flurry of birds scattered in every direction. Eight-foot-tall larkspurs surrounded the spring, and an old pump house was adjacent to it. While not exactly gushing, the flow from the spring was more than adequate and refreshingly cold. I drank several cups of water and added some to my hydration pack.

Clouds over Mt. Baden-Powell from the PCT east of Inspiration Point
Clouds over Mt. Baden-Powell

Back on the PCT, the temperature was generally in the mid-eighties but was warmer on south-facing slopes. At about 1:00 p.m., the in-the-sun fuel temperature at the Big Pines RAWS was 109°F. I was very happy to have the extra water.

Here are a few photos from the out and back trail run to Pine Mountain from Inspiration Point.

Explore the scenery and terrain of this out-and-back trail run and hike from Inspiration Point to Pine Mountain using our high resolution,  interactive, 3D viewer. The imagery is so detailed, it’s almost like being there! To change the view, use the control on the upper right side of the screen, the CTRL key and your mouse, or touch gestures. Track and placename locations are approximate and subject to errors. Snow, ice, poor weather, and other conditions may make this route unsuitable for this activity.

Some related posts: Inspiration Point to the Pine Mountain Juniper and Pine Mountain, Mt. Baldy from Wrightwood Via the Acorn and North Backbone Trails, North Backbone Trail Revisited

Ahmanson Ranch Hot Seat

Ahmanson Ranch Hot Seat. Photography by Gary Valle'.

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.

Some related posts: Some Summers Are Hotter than Others, Run to the Cheeseboro Remote Automated Weather Station

It’s Mid-July And There Is Still Snow in Los Angeles County!

Snow in the lee of the West Ridge of Mt. Baden-Powell.
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.
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 on the west ridge of Mt. Baden-Powell. July 9, 2023.
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.
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!

Here is a short slideshow of some photos taken on the run. I’ve also included a few photos from the run to Baden-Powell in 2005 for comparison.