Category Archives: weather|southern california

A La Nina During an El Nino?

Grass along the margins of the main drag in Upper Las Virgenes Canyon Open Space Preserve,formerly Ahmanson Ranch.

Sporadic rain in the Los Angeles area has finally produced a little green in local open space areas. Here, along the margins of the “main drag” in Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch).

As of today, (preliminary) NWS climate data indicates Downtown Los Angeles (USC) has recorded 1.92 inches of rain since July 1. This is 7.31 inches below normal. Leafing back through weather service data prior to July 1, this is the total rainfall recorded since May 22, 2006 – a period of nearly nine months.

What happened to our El Nino rains? According to NWS scientist Ed Berry, “the global circulation has been generally La-Nina like since about late November.” This is despite an El Nino event that peaked in November or December, and persisted at moderate strength into January. See his blog Atmospheric Insights for the technical details.

A period of unsettled – possibly showery – weather is forecast for the Los Angeles area beginning Sunday evening and continuing pretty much through the week. At the moment* the best chance for measurable rain appears to be on Monday and Thursday. We’ll see!

*Updated Saturday, February 17, at about 11:00 a.m.

Related posts: The Color of Rain, El Nino Drought, Sunset Snow Shower, Rainy Morning on Rocky Peak Road.

Rainy Morning on Rocky Peak Road

Steam rises from Rocky Peak Road near Fossil Point.

It was nice to start a run in the rain and see a few mud puddles along the way! Southern California has had so little rain the last several months that any rain is something to celebrate. Since the start of the water year on July 1, the official weather station for Los Angeles at USC has recorded only 1.48 inches of rain. This is more than 5 inches below normal for the date, and depending on the rain received the next three days, the July 1 to January 31 rainfall total could be the 5th driest since recordkeeping began in 1877. (Downtown Los Angeles recorded only 0.02 inch over the three days, and according to a NWS statement issued February 1, July 1 to January 31 was the 5th driest on record.)

Unless you are particularly fond of mud, Rocky Peak Road is usually a good choice for a run if it’s raining, or has rained recently. Perched on a ridge on the border between Los Angeles and Ventura counties in Rocky Peak Park, its sandy soils are generally well drained. Except for a few short sections of road, mud isn’t too much of an issue unless you run beyond “fossil point,” the high point of the road at about mile 4.8. Here there is an outcrop of fossil scallop shells.

Related posts: San Fernando Valley from Rocky Peak, Chumash-Las Llajas LoopSunset Snow Shower

Sunset Snow Shower

Low angle rays of the setting sun highlight a snow shower over the Rocky Peak

When I heard the news reports of snow in the Santa Monica Mountains along Kanan-Dume road near Malibu, I hoped to find a little snow or hail up at Sage Ranch Park on my afternoon run.

The isolated snow showers, hail and sleet were produced by convective cells that developed as a result of instability associated with a passing upper level low. Some of these cells also generated some lightning and thunder.

There was no snow on the ground at Sage Ranch, but the low angle rays of the setting sun did highlight a snow shower over the Rocky Peak Park area. In March of last year there was snow at Sage Ranch and Rocky Peak.

Related posts: Chumash Trail Snow, Oat Mountain Snow, San Fernando Valley from Rocky Peak.

El Nino Drought

Grasslands west of Rocketdyne in the Simi Hills.

The open space areas in which I run would normally be lush and green by this time of year, particularly when there is an El Niño. But in the past 231 days (including today) the official weather station for Los Angeles has recorded only 1.31 inches of rain, and the hills remain a dank sun bleached gray-brown.

As mentioned in my post The Color of Rain, usually when there’s an El Niño, wet Winter weather can be expected to occur in Southern California. This year’s El Nino was late to develop, became stronger than expected, and may have already peaked.

Warm water in the tropical western Pacific contributes to the development of an El Niño, and studies show this pool of warm water has been increasing in temperature, perhaps increasing the strength and frequency of El Nino’s. The quirkiness of this year’s El Niño may be related to these changes.

Is any relief to our drought in sight? Not in the short term. A system forecast to affect the Los Angeles area Thursday and Friday will likely result in cooler temperatures and more wind, but little – if any – rain*.

In his blog Atmospheric Insights, NWS scientist Ed Berry discusses the possibility of a high impact precipitation event developing in California later this January*. A flow pattern with a strong lower latitude jet stream is typically associated with El Niño induced precipitation events in California.

California weather this rain season will be closely monitored by scientists participating in NOAA’s Hydrometeorological Testbed (HMT) Program. This program is “aimed at accelerating the infusion of new technologies, models, and scientific results from the research community into daily forecasting operations of the National Weather Service (NWS) and its River Forecast Centers (RFCs).”

The photograph of the dry grasslands in the Simi Hills west of Rocketdyne was taken on a run to the northern boundary of the Upper Las Virgenes Open Space Preserve on December 24, 2006. The photograph of the green hills in the Ahmanson Ranch area of the Upper Las Virgenes Open Space Preserve is from a run on January 18, 2005.

*Updated 01/10/07. Today’s runs of the computer weather models are projecting from about 0.1 inch to 0.25 inch of rain from this system at Los Angeles. Also, see the January 10 update to Ed Berry’s Atmospheric Insights blog. Consolidation of the Pacific jet now appears unlikely, so we may not see typical El Nino impacts developing in California this month. There may be rain, but perhaps not as a result of a classic El Nino pattern. We’ll see!

The Color of Rain

Glistening in the morning sun, the wet trunk of a manzanita glows in iridescent shades of orange and red, pink and purple.

Glistening in the morning sun, the wet trunk of a manzanita glows in iridescent shades of orange and red, pink and purple. Decorated with raindrops, the chaparral, and all within, breathe a deep sigh of relief. It has rained!

Prior to Saturday night’s storm Los Angeles had recorded only 0.5 inch of rain in the last six months. Even by Southern California’s arid standards, this is a meager amount.

Usually when there’s an El Niño, wet Winter weather can be expected to develop in Southern California. But this year’s El Niño has been a little quirky, developing later than usual, and becoming stronger than expected. So far this Autumn, the weather here has been somewhat quirky as well, with record setting high temperatures and below average rainfall. An El Niño, even a strong one, does not guarantee wet weather in our area. Whether or not the usual El Niño impacts eventually develop, we’ll just have to see.

Another system is expected to produce some rain in Southern California this weekend, but in the last couple of days the computer weather models have been backing off the rainfall amounts. This morning’s computer-based precipitation forecasts are nearly dry. Given the difficulty the models have had with this system, and the long fetch of moisture over the Pacific, maybe the forecast will change. For additional info about the El Niño and Southern California weather, check out my Southern California Weathernotes web site.

The manzanita photograph is from the Reseda to Trippet Ranch run described in my previous post, Musch Trail Mule Deer.

Thunderstorm

Developing cumulonimbus near Mt. Abel

Developing Cumulonimbus Near Mt. Abel

Saturday, Pierce College in Woodland Hills set an all-time record high temperature of 119°F. Following a preliminary review, a NWS forecaster said this was probably the highest temperature ever recorded at an official weather station in Los Angeles County.

To escape this oppressive heat, and avoid the scorching temperatures of last week’s long run, my intent was to get to the highest elevation possible, as early as possible, and stay as cool as possible. At an elevation of about 8400′, the Mt. Pinos Chula Vista trailhead is nearly 2000′ higher than Islip Saddle in the San Gabriel Mountains, and is usually a good choice for a run on a warm day.


San Gabriel beardtongue (Penstemon labrosus) near Sheep Camp.
A little after 7:30 a.m., under nearly cloudless skies, I jogged out of the Mt. Pinos parking lot reveling in the cool mountain air. I didn’t have a specific route in mind, but thought I would probably do a longer variation of the Mt. Pinos to Mt. Abel run described in my Vincent Tumamait Trail post. Energized by the cool temperature, it didn’t take long to work up and over the summits of Mt. Pinos (8831′) and Sawmill Mountain (8816′), and then down the North Fork Trail to the spring at Sheep Camp (8200′).

Surrounded by the greens of the spring, and the yellows and reds of wildflowers, I gulped cold water, and thought about where to run. A sign at the “T” with the Tumamait Trail listed the distance to “Lily Meadows Camp” as 3 miles. I hadn’t been on that section of North Fork trail since preparing to run the Inca Trail in 2003.

Deciding to continue down to Lily Meadows Camp, I crossed over the spring and followed the little used, pine needle covered trail southeast along the hillside. The trail dropped steeply along a rounded ridge, where mountain quail fretted among the manzanita and fallen trees, and the minty fragrance of Pennyroyal drifted up from the margins of the trail. Quicly losing elevation, I reminded myself that whatever I ran down, I would have to go back up.

After about a mile and a half, the path switchbacked down to the North Fork of Lockwood Creek. Here, the grade lessened and long stretches of nearly perfect trail running led to Lily Meadows Camp (6250′). Old growth Jeffry pines towered above the camp, and a Monarch butterfly flittered about on a current of air. The pleasant, Sierra-like environment was a welcome change from the 100 degree heat of the previous week!


The first cloud!
An 1800′ climb and an hour later, I’m back at Sheep Camp, refilling my Camelbak®. Suddenly a shadow sweeps over the forest, and a small cloud – the first cloud – looms overhead. It’s just after 11:00 a.m., and the heat of the day has triggered some cloud development. After taking a few photos and eating a Clif® Bar, I decide I better get going, and jog up to the junction with the Tumamait Trail.

Reaching the trail junction at about 11:30 a.m., what had been a single tattered cloud in the sky is now several, and my “inner voice” of experience says, “Turn right, you can be back to the car in under an hour!” But it has been such an enjoyable day, and there aren’t that many clouds… I turn left towards Mt. Abel.

At first, shadow and sun play tag among the trees and I join in, chasing the clouds down the twisting and turning trail. The partly cloudy skies are postcard perfect, and I wonder if my concerns are ill-founded. But as the superb downhill segment transitions to up, a gray gloom invades the forest. At Mt. Abel Road, it’s noon. Rationalizing that the extra minutes required to scramble up to Mt. Abel’s summit won’t hurt, I cross the road and head up the steep slope.


The sun breaks through the darkening sky, illuminating the face of Grouse Mountain.
Seven minutes later, I’m back at Mt. Abel road. For a brief moment, a narrow shaft of sun breaks through the darkening sky, illuminating the face of Grouse Mountain. It washes across the slopes of the mountain, and then suddenly all is in shadow. At that instant, I know I’m in a race that I cannot win.

A quarter mile down the trail, the first cold drops of rain dampen my bare legs, and in another quarter mile, there is a rumble of thunder to the north, and then another rumble behind me. Part way up Grouse Mountain, there is a flash, and then directly above me an immediate ear-splitting, crackling clap of thunder. From the first few clouds to the first lightning has taken little more than an hour!

In an astonishingly short period of time, the rain, lightning and thunder grow in magnitude. Flash – boom! Flash – boom! The storm engulfs me as it grows in intensity. In the expanded microseconds that follow each lightning flash, I  breathe a sigh of relief that I’m not struck, and then bodily recoil from the immediate and overwhelming power of the crashing thunder.

Cresting the shoulder of Grouse Mountain, I think back to a storm in the San Gabriels, where instead of striking an obvious ridge, a bolt of lightning struck a nondescript tree on the slopes below. There is no place to hide from this monster. I adopt a tactic of almost sprinting through open areas, past tall trees, and when the electric motor smell of ozone fills the air. In areas that seem a little safer, I slow my pace.

At the top of another long climb, near the North Fork trail junction, I’m surprised to see a group of 8 or 9 hikers huddled under a pine tree. They are probably surprised to see someone running along the hilltops. From the first rumble of thunder, I’ve been considering whether hunkering down in the forest off the ridge might be a better strategy. If I had my shell pants, or my runner’s emergency bivi sack (a plastic trash bag), it might be. But wearing just my rain shell, a short-sleeve synthetic top and running shorts, I’m under-dressed for this get together.

Off to the east, in the direction of Mt. Pinos, the sky seems lighter. Maybe the wind is shifting the cells to the west and north. I have no idea how long this thing is going to last, and the pounding rain and gusty winds are sleety cold. I don’t want to stop. Not at all sure it is the better choice, I wish the hikers the best, and continue up the trail toward Sawmill Mountain.

The storm, and my emotions, wax and wane in a recognizable, but hard to define pattern. Periods of awe, elation and fear cycle with the storm. It has only been 30 minutes since the rain and thunder began, but in my distorted world, it might have been 30 hours. The steady rain has flooded the trail, and I feel like I am crossing a never ending creek.


Hurried photo near the top of Sawmill Mountain, when the storm was nearing peak intensity.
As I near the summit plateau of Sawmill Mountain, erratic gusts of wind tear at the trees. Then suddenly, as if a dam has broken, a deluge of lightning, thunder, rain and hail spills from the sky. It is the most intense rain I have ever experienced. A pounding rain, thick with hail, driven by a downburst of wind and gravity. Torrents of water cascade down the trail. It is ferocious.

Running through the maelstrom across the plateau, ahead I can see the point where the trail drops off the summit, and descends to a saddle. I just have to get there. Lightning flashes, and thunder booms behind me. My feet are numbed and cold, and I wonder how water on the trail can be calf deep.  Reaching the shoulder of the mountain, I start to descend. From time to time I get a glimpse of Mt. Pinos, and I can see a little smudge of blue under the dark clouds over the summit. As I descend toward the saddle, the intensity of the storm seems to be diminishing. There is still lightning, thunder and rain, but for a moment the focus of the storm seems to be shifting elsewhere. I take a deep breath, and debate what I’m going to do about getting over the exposed summit of Mt. Pinos.


Looking back at ridge on Sawmill Mountain from shoulder of Mt. Pinos.
There are still two groups of active cells. The main thunderstorm complex seems to be behind me, toward Mt. Abel; but there is also an active group of cells just north of Mt. Pinos. While I’ve seen no lightning strike the summit of Mt. Pinos, it is almost a certainty. I decide to work up the switchbacks toward the summit, continuing my tactic of minimizing my time in areas that are exposed. The rain has nearly stopped, and I haven’t smelled ozone since on Sawmill Mountain, but some sections of the trail are frighteningly exposed. Working up to the highest point that appears to offer some protection, I pause and listen. The timing may be right. The thunderstorm activity seems to be in a down cycle.

I leave my alcove. In seconds I’ve rounded a rocky rib of the peak, and am suddenly the tallest and most linear object on its bare shoulder. Thunder rumbles off to the north, a reminder I don’t need. Heart pounding, I’ve already pushed the pace as much as the grade, elevation, and my body will allow, and now there is nothing for me to do but run.

It is not a relief to reach the summit. I see a bolt of lightning strike to the northeast, near a radio tower less than a quarter mile away. Partially hidden from view, I can’t tell if the lightning struck the tower, or a ridge beyond. It doesn’t matter. I have to get off the summit.


Mariposa lily (Calochortus invenustus) west of Mt. Pinos.
Running along the road from the observation point, I’m nervous about going in the direction of the relay tower, and the last lightning strike. I know the road will soon turn downhill, but as hard as I am running, I don’t seem to be getting anywhere. Finally, I see, and then round the turn. Another 50 yards, and for the moment I’m safe. A dash across one meadow, and then another, and the main danger is past.

To the east, I see more blue sky, and broken clouds. Continuing to descend, I hear a group of Chickadees chattering in a nearby tree. They sound happy. So am I.

Here’s a Google Earth image and Google Earth KMZ file of a GPS trace of my route.

Epilogue: According to the American Meteorological Society, lightning kills more people per year on average than hurricanes and tornadoes combined. For more information regarding lightning safety, please see the National Weather Service Lightning Safety page. Here’s what the thunderstorm looked like on radar.

(The title photograph is of a developing cumulonimbus near Mt. Abel. It was taken on a run at Sage Ranch on July, 19, 2006.)