Category Archives: weather

PCT from Inspiration Point to Islip Saddle

View from near the summit of Mt. Baden-Powell.

Overnight the lows on the high peaks had dipped into the 30’s, and today the high temps would be 15-20 degrees below normal. If I could have ordered the perfect mix of temperature, clouds and sun for running in the Angeles high country, it would be difficult to top the weather this weekend and last.


Clouds and pines along south ridge of Mt. Baden-Powell in the San Gabriel Mountains.
Now that Hwy 2 was open between Islip Saddle and Vincent Gap, and we could do a car shuttle, Miklos, Krisztina and I had decided to run from Inspiration Point to Islip Saddle on the PCT. Starting at Inspiration Point instead of Vincent Gap adds about 4.5 miles to the run, but the miles are relatively easy, and the stretch is a good warmup for the 2800 ft. climb up Mt. Baden-Powell.

Here’s a Cesium browser View of a GPS trace of our approximately 18 mile route. We wandered down the south ridge of Mt. Baden-Powell, so this is a little longer than the usual route. The elevation gain was about 3300 ft., with an elevation loss of about 4000 ft. Continuing over Mt. Williamson to Eagle’s Roost would add about 4 miles and 1400 ft. of elevation gain.

Note: The speck in the summit photo is one of several violet-green swallows working lift and zooming along the top of southeast face.

Southern California Thunderstorms an El Nino Calling Card?

Valley oak on Lasky Mesa, with a line of thunderstorms in the distance.

Off to the south, I heard the distant rumble of thunder. The developing line of thunderstorms had swept through the West Valley about an hour before I began my run at Ahmanson Ranch.

Unusual weather for June. Not so much that there were thunderstorms, but that the thunderstorms were in part the result of an unseasonably strong jet embedded in the base of an upper level low.

It’s a bit of a stretch, but an argument could be made that these storms were a calling card of an increasingly energetic atmosphere, and a developing El Niño.

Several factors point to an increased probability of El Niño conditions developing over the next few months. Among them, Equatorial Pacific SSTs have increased, and the subsurface heat content is the highest it’s been since the El Niño of 2006-07.

But as the short-lived 2006-07 El Niño event demonstrates, an El Niño is more than just warm Pacific equatorial SSTs. Through complex forcing and feedback mechanisms, the atmosphere and oceans have to cooperate on a global scale. Generally speaking the atmosphere speeds up when there is an El Niño, and slows down during a La Nina.

And it looks like the atmosphere may be speeding up. Orbits of the Global Wind Oscillation, a measure of atmospheric momentum, have been shifting upward, in the direction of more energetic values usually associated with an El Niño.

But an El Niño is not a done deal. The climate system is just leaning in that direction. As climate scientist Klaus Wolter has pointed out, in a similar situation in 1973-1975, the climate fell back into a La Niña for another year. At this point it appears we may be diverging from that analog case. We’ll see!

Update June 6, 2009. The April-May Multivariate ENSO Index (MEI) value, released today, has increased by 0.54 to +0.34. As discussed by MEI originator, Klaus Wolter, the 3-month rise of the MEI since January-February is the 4th highest on record for this time of year, exceeded only by the strong Niño of 1997. According to Dr. Wolter, if next month’s MEI rank is at least the same as this month (37th), “it would be unprecedented for it to drop below that high-neutral ENSO-phase range by the end of 2009, virtually excluding a return to La Niña, based on the MEI record since 1950.”

Related links: ENSO Diagnostic Discussion, ENSO Wrap-Up

Presidio: Inspiration Point – Golden Gate Bridge Loop

So far, Brett’s intro to Bay Area trail running had taken me to the Marin Headlands and Pt. Reyes National Seashore — outstanding areas in which to run and hike, with great scenery, terrain and courses. An area that might be overlooked by a visiting trail runner is the Presidio. That’s where we were running this morning.

Warm weather had chased the fog away. Saturday, the high temp at SFO was 89 degrees, and today the high was forecast to be in the 90s. So it wasn’t a big surprise that at 7:30, the temp was already near 70 when we descended the stairs at Inspiration Point. (SFO would set a record high of 93 later in the day.)


Brett at the start of the East Battery Trail on our Presidio loop trail run.
Our loop started on the Ecology Trail and then worked down through the Main Post, under the 101, across Crissy Marsh, and onto the Golden Gate Promenade (Bay Trail). From the Promenade there were iconic views of San Francisco Bay, Alcatraz, Marin, and the Golden Gate Bridge. Just past the Warming Hut we turned up the East Battery Trail stairs, and then continued west, under the southern abutments of the bridge.

Here we followed the Coastal Trail past several 100+ year old defense batteries, to another nice overlook of the Golden Gate. After clambering up on one of the battlements, we headed east to Fort Scott and picked up the Bay Area Ridge Trail. This segment took us through the Presidio’s trademark pine, cypress and eucalyptus forest to the high point of the course near Rob Hill Campground, then along the Presidio Golf Course, and finally down past Andy Goldsworthy’s cypress spire to the car. From the point of view of this out-of-towner, the course was spectacular, and it’s hard to imagine an urban run with more variety!

Our particular loop worked out to about 5.5 miles, with an elevation gain/loss of about 450 ft. Here’s a Presidio Trust map of Presidio Trails and Overlooks (PDF), a NPS Presidio Map, and a Cesium browser View of a GPS trace of our loop.

I had a great time in San Francisco, and can’t wait to get back and see more… Thanks Brett & Amanda!

Rocky Peak Running Weather

View northwest from Rocky Peak

Brrr… I picked up the pace — even with long sleeves it was COLD on Rocky Peak Road. Another in a series of blustery April systems was stirring up the weather in Southern California. Thickening clouds spritzed rain, and a belligerent wind told me in laughing gusts that I could not run fast enough to stay warm.

Occasionally a patch of sun would find its way through the clouds, briefly warm and encouraging. I needed only  to think of the 100 degree days ahead to appreciate the chilly temps.

Another cool system is forecast to move through Southern California on Friday, bringing with it a chance of rain — and more great running weather. Easter weekend should be spectacular!

Some related posts: Simi Valley from Rocky Peak, San Fernando Valley from Rocky Peak

Southern California Warming Up and Drying Out?

Trail leading to Lasky Mesa at Ahmanson Ranch.

There are still a few rogue mud puddles out at Ahmanson ranch, but the Goldfields are blooming, the meadowlarks singing, and it feels like Spring!

Last week it looked like our rain season might not be over. Now I’m beginning to wonder. This week the GFS and ECMWF forecasts have been much drier in Southern California, with most of the activity focused on the Pacific Northwest. No significant rain is forecast here over the next week, and both the 6-10 and 8-14 day forecasts project below average precipitation in Southern California.

If these medium range forecasts are on the mark, March rainfall for Downtown Los Angeles (USC) will fall well below the 3.14 inch norm. Normal April rainfall is 0.83 inches, and May only 0.31 inches. Beyond March it becomes increasingly unlikely that a big rain event will significantly boost our rainfall total.

Since November 1, Downtown Los Angeles has recorded 8.80 inches of precipitation. This is about what would be expected during a La Nina, and within the range indicated in the composite precipitation map included in the post Southern California 2008-2009 Winter Precipitation Outlook, back in October.

In his March 6 post, Ed Berry suggested the possibility of “more energetic progressive troughs” in the western U.S in the week 2-3 timeframe. That wouldn’t necessarily result in rain in Southern California, but might improve our chances. Numerical weather model performance generally suffers during seasonal transitions, so maybe there are still some surprises lurking in the Pacific. We’ll see!

Malibu Creek State Park Shadow & Sun

Malibu Creek State Park

My trail running shoes had not been wet or muddy since sometime in December. During the entire month of January, Downtown Los Angeles (USC) recorded about one-third of an inch of rain. Not only had it been dry, it had been warm. On a dozen of those January days, the high temperature topped eighty degrees, setting a new record!

But Winter had returned. The past three days, Los Angeles had received about 1.5 inches of rain, valley and foothill locations 2-4 inches, and some mountain stations as much as 5-7 inches. And more Winter weather was on the way. Excited about the change in the weather, today’s run was one with good muck and mire potential — the Bulldog Loop in Malibu Creek State Park.

We were not disappointed. Near Century Lake, mud the consistency of peanut butter pulled at our shoes and slowed the climb up Crags Rd, Further west, near the M*A*S*H site, calf-deep water on the trail washed the gunk off.


Pt. Dume from the Mesa Peak ridgeline.
The trail conditions on the remainder of the loop were more straightforward. From time to time, shafts of sun would pierce the clouds, resulting in a patchwork of shadow and sun that emphasized the rugged terrain. Along the crest, the ocean views were superb! Before descending to Tapia Park we ran out to Mesa Peak, and then followed the ridgeline to an overlook of the coast. (Marked peak 1800 on the topo.)

Including the side trip to the overlook, this variation of the Bulldog loop worked out to an exhilarating 16.5 miles, with an elevation gain/loss of about 2700 ft.

If current forecasts and outlooks for this month hold true, this won’t be our last wet and muddy trail run this February. In a couple of weeks, Los Angeles rainfall totals may climb above normal for the first time this rain season. We’ll see!

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