Category Archives: weather

Blue Skies, Sunshine and Windstorm After Windstorm

blue sky, sunshine, high clouds and a trail on a hill

It looks like Downtown Los Angeles (USC) is going to end February — one of the wettest months of the rain year — with only a trace of rain. The current rain year total for Los Angeles is 4.39 inches, which is about 39% of the normal total for this date.

It’s been one of those years where missed rain opportunities have often turned into strong offshore wind events. This chart from MesoWest shows the wind speed and direction for the past 30 days for the Malibu Hills RAWS. Since mid February there has been five wind events with sustained wind speeds over 30 mph and gusts over 50 mph.

Current forecasts suggest Los Angeles will see at least some rain in March, with the first chance around midweek. We’ll see!

Related post: A Dry and Dusty Start to the Los Angeles Rain Year

Chasing a Sunrise, Taking a Moonshot, Los Padres Snow, and a Dark Line in the Sky

Colorful sunrise in the eastern Santa Monica Mountains

I was running up Calabasas Peak Mtwy fire road trying to get a better view of the eastern sky, but the view in that direction was blocked by a steep hillside. The road turned to the northeast up ahead, and I hoped the best moments of a rapidly-evolving sunrise would not be lost.

A couple of breathless minutes later, I rounded a corner and was rewarded with an unobstructed view of a vivid, pink-red-orange mackerel sky. Focusing on the ridgeline near Topanga tower, I shot several sets of bracketed photos.

Handheld snapshot of the Moon, using a Lumix ZS100
Handheld snapshot of the Moon. Click for larger image and more info.

Excited by the sunrise, I continued up the fire road, scanning my surroundings for another photo. My eye settled on the gibbous moon. High in the sky, it’s bright face was subdued by a thin veil of pinkish-gray cloud. I’d previously experimented with handheld shots of the Moon using my running camera — a Lumix ZS100. Zooming to an equivalent focal length of about 250mm, I held my breath, steadied the camera the best I could, and took a few shots. Here’s one of the images — cropped and sharpened — with enough detail to see craters, maria, and some other lunar features.

At the bottom of Topanga Lookout Ridge there were several bigberry manzanita bushes covered with flowers. A hummingbird was up before sunrise, buzzing about the blossoms, busily drinking the precious nectar. Although it had rained a couple days before, this rain year there had been little rainfall, and a corresponding scarcity of early season wildflowers.

As I climbed higher on the ridge, the mountains northwest of Los Angeles came into view, white with snow from the recent storm. The snow-covered peaks are south of Mt. Pinos and Frazier Mountain, in the area of San Raphael Peak, McDonald Peak, Sewart Mountain and Snowy Peak.

Contrail shadow near Los Angeles
Contrail shadow.

Like snow on a mountain, there is a purity in the form and appearance of clouds. When a long, dark streak appeared across a layer of high clouds, it was hard to miss. In this case, the dark line appears to be the shadow of a contrail of a jet flying above the clouds. At the time LAX was reporting scattered clouds at 19,000′ and 23,000′, with a broken layer of clouds at 28,000′. Given the height of the clouds and orientation of the contrail, it may have been from a flight from San Diego to San Francisco.

Topping out on the ridge, I smiled when I saw the masked couple dancing on the Lookout, and continued west toward Saddle Peak.

Some related photos: An Early Morning Dance at Topanga Lookout, Fallstreak Hole, Rainbow Colors in Cirrus Clouds Over Los Angeles

Musch Meadow Frost

Frost along the Backbone Trail at Musch Meadow

As I approached Musch Camp, a scrub jay flew from a trailside faucet and into a nearby eucalyptus. There had been a little rain the day before, but the birds at the closed camp were still thirsty. Less than a quarter-inch of rain had fallen, and nearby creeks were still dry.

Melting frost
Melting frost “steaming” at Musch Meadow

I was doing a run from the “Top of Reseda,” and on a warmer day would have topped off my water bottle at the camp. I stopped at the faucet and briefly turned on the spigot. Maybe that would make it easier for the jay.

Leaving the camp behind, I continued south on the Backbone Trail, across frost-covered Musch Meadow. Early morning sun had just reached the meadow, and water vapor from the melting frost steamed in the cold air.

In another mile I reached the Trippet Ranch trailhead, and then begin the six mile run back to the Valley. At several points on the run there had been wintry views of the local mountains. On the way back the best view of the snowy mountains was from the Hub, where Mt. Baldy could be seen gleaming white in the morning sun.

Some related posts: Garapito Trail Runs, Musch Trail Mule Deer, Musch Trail Morning

Moon and Sycamores, Malibu Creek State Park

Moon and Sycamores, Malibu Creek State Park

The photograph Moon and Sycamores was taken at dawn, near Malibu Canyon and Piuma Road, at the start of this morning’s Bulldog Loop trail run in Malibu Creek State Park.

A quarter-mile from the top of Bulldog Mtwy fire road in Malibu Creek State Park.
A quarter-mile from the top of the Bulldog climb.

According to the Tempe sensor on my pack, the temperature ranged from a chilly 32° F along Malibu Creek to around 65° F on the crest. It was a near perfect morning to be outdoors.

Here’s an interactive, 3D terrain view of my GPS track from a previous run of the Bulldog Loop from Malibu & Piuma.

Some related posts: Bulldog Loop Plus the Phantom Loop; Trees, Bees, and a Washed-Out Footbridge on the Bulldog Loop in Malibu Creek State Park; After the Woolsey Fire: Bulldog Loop

Winter Sky: Cirrocumulus Clouds

Cirrocumulus clouds from Upper Las Virgenes Canyon Open Space Preserve, also known as Ahmanson Ranch

Cirrocumulus clouds form at high altitude. They are primarily composed of ice crystals but also contain supercooled water droplets.

The photograph of cirrocumulus clouds was taken in Las Virgenes Canyon on a trail run from the Victory Trailhead of Upper Las Virgenes Canyon Open Space Preserve, also known as Ahmanson Ranch.

Some related posts: Pattern Change Ahead, Fallstreak Hole, Rainbow Colors in Cirrus Clouds Over Los Angeles

A Dry and Dusty Start to the Los Angeles Rain Year

dry and dusty Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch)

Except for a teaser storm system in early November that brought a smattering of rain to the metro area and some snow to the mountains, the Los Angeles rain year is off to a parched start.

As of December 1, Downtown Los Angeles (USC) has recorded only 0.11 inch of rain since July 1. Along with 1995, this is the 7th driest start to the rain year over the 144 years weather records have been kept in L.A.

Update December 29, 2020. In the first significant storm of the rain year, Downtown Los Angeles recorded 1.82 inch of rain, bringing the rainfall total up to 1.95 inches. The storm total was more than generally forecast, but L.A. is still about 2 inches below normal for the date. The rain does move 2020 out of contention for the driest first six months of the rain year.

Update December 20, 2020. The period July 1 – December 20, 2020 is the driest on record (for that date range) for Los Angeles. As of December 20, the rainfall total for Downtown Los Angeles (USC) remains at 0.11 inch.

While “past performance may not be indicative of future results,” I was curious to see if, historically, a dry start to the rain year has generally resulted in below average annual rainfall.

There have been 16 years in which Los Angeles precipitation was 0.25 inch or less for the period July 1 to December 1. Rain year precipitation (July 1 – June 30) for those years varied from a low of 4.79 inches in 2017, to a high of 23.43 inches in 1937. Overall, these years averaged 11.34 inches of rain annually, which is 3.66 inches below the current normal of 14.93 inches.

Whether or not annual rainfall this rain year is below normal we’ll have to see. An important consideration is that La Nina conditions are present in the equatorial Pacific. This doesn’t necessarily mean less rainfall in the Los Angeles area, but taking into account a number of factors, the Climate Prediction Center is projecting below average precipitation this Winter in Southern California.

The title photo of silhouetted mountain bikers is from this afternoon’s run at Upper Las Virgenes Canyon Open Space Preserve (Ahmanson Ranch). The image is an example of a “silhouette illusion.” Are the riders going toward or away from the camera?