Category Archives: nature|weather

La Nina Fades as SoCal Rain Season Nears End

Sun-parched mustard leaf at Ahmanson Ranch.

It’s been late February since Southern California has had a good soaking rain. As of May 1, the water year rainfall total for Downtown Los Angeles (USC) stands at 13.42 inches. This is 90% of the 1921-2006 average of 14.87 inches. According to the NWS 1921-2006 dataset, the average amount of precipitation in May and June is 0.3 inch and 0.1 inch, respectively. We’ll see if we get that much this year!

La Niña appears to be winding down.  In it’s April 30 ENSO Wrap-Up, the Australian Bureau of Meteorology characterizes Pacific climate patterns as being generally neutral, “with the majority of indicators returning to near-normal levels.” The April 28 ENSO Update from the CPC suggests that La Niña will continue through May-July 2008, but many of the factors discussed indicate general weakening of La Niña. Based on the ONI and MEI, La Nina conditions have existed since about August of 2007.

The photograph of the sun-parched mustard leaf is from a run at Ahmanson Ranch on April 29, 2008.

Google search: $g(la nina), $g(Los Angeles weather)

A Long Run Kind of Day

Saddle Peak from the Backbone Trail, in the Santa Monica Mountains, near Los Angeles. Mt. Baldy can be seen in the distance.

The beauty and intensity of the day was infectious. Hours before a cold low pressure trough digging down from the Pacific Northwest had carried showers, thunder, hail, and chilly temps into Southern California. Its rainfall had refreshed the greens of the hills, and accentuated the yellows, purples and reds of the wildflowers along the trail. Its blustery winds had cleansed the sky.

A few minutes before I had completed one run, and now was starting another. I wasn’t certain how much farther I would run — I just knew I had to run.

The day had begun with friends on the Secret Trail in Calabasas. We had run up and over the shoulder of Calabasas Peak, and then ascended Saddle Peak via the Stunt High Trail and Backbone Trail. The view from the summit of Saddle Peak had extended beyond Santa Monica Bay and Palos Verdes Peninsula to the South Bay and Saddleback Mountain. New snow glistened on Mt. Baldy, and to the west the rocky summits on Boney Mountain stood in bold relief.

That 14.5 mile run had ended at Tapia Park. Now I was on the Tapia Spur Trail on the first climb of the Bulldog Loop. On the wind sheltered slope the bright yellow blossoms of tree poppy had begun to unfurl, absorbing the warmth of the midday sun. Distant peaks loomed to within an arm’s reach, and my legs seemed to draw energy directly from the trail. It was a long run kind of day.

Notes: The title photograph is of Saddle Peak from the Backbone Trail, in the Santa Monica Mountains, near Los Angeles. Mt. Baldy can be seen in the distance. The combined length of the runs was about 29 miles with an elevation gain of about 5000 ft.

Some related posts: Tapia Bound, Bulldog Loop and the Corral Fire, Fog Along Malibu Creek

Los Angeles Basin Fog

An offshore wind scours out low-lying fog trapped in the Los Angeles basin by a low altitude temperature inversion.

This photograph of downtown Los Angeles and Century City was taken Sunday morning from the Backbone Trail in Topanga State Park while doing the Will Rogers – Temescal Loop from the “end of Reseda” in the San Fernando Valley.

At the time an offshore wind was scouring out low-lying fog trapped in the Los Angeles basin by a low altitude temperature inversion.

Related posts: California State Park Closures, Will Rogers – Temescal Loop

Vernal Pool at China Flat

Vernal pool near the sheep corral at China Flat in the Simi Hills.

In normal to wet rain seasons vernal pools can be found throughout the Simi Hills. The pool pictured above is near the sheep corral at China Flat, and another small pond was found nearby, along Albertson Motorway fire road. I’ve also found vernal pools in the Rocky Peak area and near Sage Ranch.

Geologically, the Simi Hills are characterized by the sandstone rocks of the Chatsworth formation. These inclined layers are of varying hardness, and erode at different rates. It’s my guess that water collects in sandy soils between, or at the base of, the more resistant layers.

The photographs of the ponds at China Flat are from Sunday’s Scenic Route to Simi Peak run.

Return to Hidden Pond

A trail runner on the Hidden Pond Trail in Pt. Mugu State Park.

Southern California can have inclement Winter weather. This January downtown Los Angeles experienced a streak with 8 days of measurable rain, and last year temperatures in the suburbs plunged to a frigid 20°F. Maybe this doesn’t compare to Seattle’s 2005-2006 rain streak of 27 days, or International Falls’ recent record low of 40° below zero, but it qualifies as rainy and cold none the less.

Today it was not rainy and cold. It was just about as pleasant as a day could be. Skies were blue, winds were light, and the temperature was in the mid-seventies. Starting at the Wendy Dr. trailhead on Potrero Rd., we enjoyed the perfect weather by doing a 14.5 mile variant of the Boney Mountain Half Marathon Course.

The photograph above is of the Hidden Pond Trail near Hidden Pond — recently restored by Winter rains.

Related posts: Boney Mountain Half Marathon, Big Sycamore Canyon Circuit, Boney Mountain – Big Sycamore Canyon Circuit