Category Archives: weather

Cool Running in the Simi Hills

Cool running at Ahmanson Ranch in the Simi Hills.

For the last couple of days of January, all of February, and the first third of March, the temperature at Downtown Los Angeles (USC) and many other Los Angeles area locations did not reach 70 °F!

Will have to think of days like today when it’s 100 degrees and I’m picking foxtails out of my socks and shoes!

After the Woolsey Fire and a Lot of Rain: Upper Las Virgenes Creek

Upper Las Virgenes Creek on March 7, 2019, following the Woolsey Fire and frequent Winter rain.

It’s not often we get to hear the burble and gurgle of Las Virgenes Creek in Upper Las Virgenes Canyon Open Space Preserve. Last Winter it didn’t run at all.

There were two crossings of the creek on my run today. My shoes were already wet from running on wet trails, so I didn’t worry about keeping my shoes dry.

Here’s a video snapshot of the creek on Vimeo. It’s carrying a bit more sediment than normal, as a result of the Woolsey Fire.

Rainbow Along the Garapito Trail

Rainbow Along the Garapito Trail

There sure have been a lot of raindrops and rainbows lately. It seems like every run I do my shoes get muddy — and there are even creeks to cross!

Last year on this date, Downtown Los Angeles (USC) had recorded only 2.55 inches of rain since July 1. This year we’ve received 16.69 inches, and as I’m sure you’ve heard, there’s more on the way.

It may seem like a long time since Los Angeles has been this wet, but actually it’s only been a couple of years. Year before last we’d received 18.5 inches of rain by this date. We need about 1.81 inches of rain from this week’s system to catch up.

Recognize this section of the Garapito Trail? See the large embankment along the right side of the trail? In 2005, during the second wettest Rain Year in LA on record, the hillside slumped around 12′. The trail is on top of the section that dropped.

During the 2004-2005 Rain Year Downtown Los Angeles recorded 37.25 inches of rain!

Warrior’s Plume Along the Cheeseboro Canyon Trail

Warrior's plume (Pedicularis densiflora) along the Cheeseboro Canyon Trail, one of the areas burned in the November 2018 Woolsey Fire.

Warrior’s plume (Pedicularis densiflora) along the Cheeseboro Canyon Trail, one of the areas burned in the November 2018 Woolsey Fire.

With this rain season’s abundant rainfall, displays of wildflowers will be more extensive than usual and of greater variety — both inside and outside the Woolsey Fire burn area.

Simi Valley Snow Shower

Simi Valley Snow Shower

There were many reports of snow, sleet, hail, and graupel around the area yesterday.

It was definitely cold! The afternoon temperature at 1700′ at the Cheeseboro RAWS was around 42°F. And the temperature was probably cooler in the vicinity of convective showers, such as the one above.

The photograph is from Sage Ranch, at an elevation of about 2000′. I was hoping to see some snow on the ground — but no cloud buildups cooperated.

Related post: Snow on Oat Mountain (December 2008)

Run to the Cheeseboro Remote Automated Weather Station

Cheeseboro Remote Automated Weather Station (RAWS)

This afternoon’s run was to the Cheeseboro Remote Automated Weather Station (RAWS). The station is perched on the ridge between Las Virgenes Canyon and Cheeseboro Canyon, along the Cheeseboro Ridge power line service road.

It is about 5 miles from the Victory Trailhead of Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch) and one of many good runs from that trailhead into the Cheeseboro – Palo Comado Canyon area.

California poppies in Las Virgenes Canyon
California poppies in Las Virgenes Canyon

Runs in the Ahmanson Ranch area are especially scenic at the moment. Above average rainfall has produced lush green growth in the oak grasslands following the Woolsey Fire. Many of the oaks are beginning to sprout new leaves and poppies and other wildflowers are beginning to bloom. Today there was a nice show of poppies in Las Virgenes Canyon at the connector leading to Cheeseboro Ridge and Cheeseboro Canyon.

Operated by the BLM and NPS the Cheeseboro RAWS (CEEC1) has been in service since September 1995. The station was in the area burned by the 2005 Topanga and 2018 Woolsey Fires and was active throughout each event.

Following are some of the extremes recorded by the station:

• Highest hourly temperature was 115 °F on July 7, 2018.
• Lowest hourly temperature was 32 °F on December 12, 1998.
• Maximum hourly wind speed was 37 mph on October 22, 2007.
• Maximum wind gust was 92 mph on January 6, 2003.
• Maximum daily precipitation was 5.01 inches on February 12, 2003.

So far this rain year (July 1 to June 30), 15.67 inches of rain has been recorded by the station.

Related post: Southern California Trail Running Temps