Clearing clouds, northwest of Los Angeles, following the passage of an upper low storm system that resulted in widespread rainfall in Southern California. Several rainfall records for November 26 were broken in Los Angeles County.

Update 12/5/08 P.M. High amplitude flow continues to wreak havoc with forecasts. Our on-again, off-again chance of a shower this weekend might be on again. Original cut-off upper low center is still well offshore, but another low center has developed on the downstream side of high amplitude ridge, and this one is much closer to the Southern California coast. The low appears to be entraining some moisture, and could produce some showers, particularly as the low moves onshore and is absorbed in the main flow. We'll see!

Update 12/5/08 A.M. No rain is expected in SoCal this weekend... The cut-off upper low set up much further west than suggested by models Tuesday and now is spinning out in the eastern Pacific, nearly halfway to Hawaii. At the moment, it looks like it could be mid-month before our next chance for significant rain.

Update 12/2/08. Computer models have been having a tough time with both the short and medium term forecasts for Southern California. Recent runs have been hinting at the possibility of some rain Saturday or Sunday. This would depend on the strength, position and behavior of an upper low that is forecast to form off the Southern California coast Thursday.

From a run at Sage Ranch Park, near Simi Valley, California.

We stopped for a few moments at the river crossing, where water stood in pools waiting for Winter rain. Instead, cold air flowed down its course, cool and refreshing. From this point there would be little shade. Rarely cold, the climb out from the West Fork San Gabriel River to Shortcut Saddle is often warm, and sometimes debilitating.

From a run at Ahmanson Ranch, now Upper Las Virgenes Canyon Open Space Preserve, Wednesday evening.

The Fossil Trail is a steep, approximately mile-long trail in Pt. Mugu State Park that connects the Upper Sycamore Trail, near its junction with Sycamore Canyon Road, to the Old Boney Trail. The most obvious fossils are shell impressions and remnants found in an exposed layer of sandstone about a tenth of a mile below the Old Boney Trail junction. Some of the shell impressions are palm-sized and larger.

The shells appear to be a type of cockle (Anadara devincta) that is an indicator of Miocene-age formations. (See the Oregon Sea Grant publication "Fossils You Can Find on Oregon Beaches.")  In this case, the fossil exposure appears to be in the Lower Topanga Formation, which is believed to have been formed in the middle to early Miocene, about 20 million years ago.

The shape, thickness and ribbing of this type of shell increases its strength and resistance to crushing -- improving the shell's chances of remaining intact when buried in sediment, and during subsequent geologic processes. This may be one of the reasons it is a prevalent indicator fossil.

The photograph is from Sunday's run from Wendy Drive to Serrano Valley.

Scruffy clouds clung to the mountain ridges and summits, confirmation that a weak cold front was moving through the area, cooling temperatures and stirring up the wind. The forecast for the Santa Monica Mountains National Recreation Area had mentioned 25 to 35 mph winds with gusts to 60 mph. So far the weather in Pt. Mugu State Park had been nearly perfect -- breezy and little chilly, but without the impenetrable winds that can take all the joy out of running.

Only three weeks after the area was burned in the 2008 Sesnon Fire, this yerba santa shrub on the Chumash Trail has started the process of foliage replacement. In many areas along the trail, grasses and other annuals (many invasive) were consumed, but adjacent chaparral shrubs were only scorched. Many of these shrubs look like they will be able to recover through budding of existing stems, rather than crown-sprouting.

Some related posts: Chumash Trail - Sesnon & Simi Fires, Rocky Peak After the Sesnon Fire

A view of the eastern Simi Valley and Simi Hills from Rocky Peak.

From a run in Rocky Peak Park today.

When I woke to the rumble of thunder, rain pounding the roof, and wind roaring in the trees, I wondered if a planned run of the Boney Mountain Half Marathon course with John Dale was going to turn into an epic. Radar and satellite imagery showed subtropical moisture streaming in from the southwest, producing bands of showers and thunderstorms. Things don't always look as bad at the trailhead as they do on weather radar, so I grabbed my gear and headed for Wendy Drive.