Did an enjoyable run at Sage Ranch today that started and ended in showers, but also included a few moments of subdued sun.

The shrub with the yellow-orange leaves is rain soaked poison oak. As I took the photo, a California towhee landed in its limbs, probably a little concerned about the unexpected house guest. From a towhee point of view, a thick chaparral shrub is a homey place with all of the creature comforts.

In chaparral areas towhees are common, and I frequently see them on my runs. Over years of running I've learned some of their habits.

Many times when I encounter a towhee on the trail, it will flutter and scurry along the ground just ahead of me, and then dart into a bush. Although not as dramatic as the broken wing act of a killdeer, this "catch me if you can" behavior is probably intended to draw a potential predator away from the bird's nesting and living area.

Very different animals will often cooperate to benefit each other. In the case of a towhee, one of its best buds is apparently the cottontail rabbit. On occasion I will see the bird and rabbit foraging together on a trail. When trying to keep a wary eye out for potential predators, four eyes are much better than two.

Where there is one towhee, there will often be another nearby -- presumably its mate. At Sage Ranch, I've repeatedly encountered a pair of towhees near a particular shrub over a period of several years.

Clouds swirled around me as I worked up the steep trail toward an overlook near Rocky Peak. I stopped and listened to the patter of the rain against the rocks, its intensity rising and falling with the gusts of wind.

The wind-driven rain trickled down my face, tasting cool and clean. It didn't matter that my running clothes were soaked and that with each gust I could feel a chill. It was raining!

In the same manner that a color will sometimes appear especially pure and vibrant, there was an unusual liveliness to this rain.

Who would think a western Pacific typhoon could so directly affect California's weather? But that's what is happening. The moisture from typhoon Melor, which was over Japan just a few days ago, was captured by an extending and strengthening jet stream. This has resulted in an atmospheric river of moisture, stretching across the Pacific and into California.

This morning, Intellicast composite radar shows Northern and Central California already being hammered by the system. Southern California has seen a few showers, and several stations have already recorded significant rainfall. As of 9:00 a.m. the CNRFC Precipitation Map shows isolated 24 hr. rainfall amounts in the foothills and mountains of Santa Barbara, Ventura, and Los Angeles County ranging from about 0.16 inch at Sandberg to 0.61 inch at West Big Pine.

The last day there was measurable rainfall at Downtown Los Angeles (USC) was on June 5, 2009, when 0.13 inch was recorded. Computer weather models forecast the best dynamics and highest rainfall totals will be in the northern two-thirds of the state, but in recent days have been trending wetter in the Los Angeles area, particularly in the mountains.

With so much moisture in the atmosphere, it takes very little lift to produce rain. Onshore winds, full of moisture, are lifted by foothills and mountains across the flow, and the result is rain -- sometimes lots of it. In this case it appears the south to west facing mountains and foothills of Santa Barbara, Ventura and Los Angeles counties may record much higher rainfall totals than the lowland areas.

In a decade characterized by unusual El Ninos, the ongoing El Niño of 2009-2010 is another strange one. El Niño signals continue mixed. The Aug-Sep Multivariate ENSO Index (MEI), decreased from 0.978 to 0.754, however other El Niño signals appear to be rebounding. In the last two weeks low level equatorial westerly anomalies have increased significantly. The reduction in the strength of the trade winds, and a downwelling Kelvin wave resulting from a very strong westerly wind burst already appear to be increasing upper ocean heat content in the central equatorial Pacific. The 30 day moving Southern Oscillation Index (SOI) has been dropping, and should return to negative territory in a day or so.

Recurring equatorial westerly wind bursts and enhanced west-central Pacific convection has been slowly migrating eastward. The most recent round of enhanced convection was centered at about 160E. This is consistent with a developing El Niño, and may have contributed to the creation of the atmospheric river now affecting California, by helping to extend the Pacific jet stream following an East Asian mountain torque event.

However, total and relative AAM remain negative, and are lower than is generally the case during a developing El Niño. Of the weak to moderate El Ninos that have occurred Since 1959, only the 1977-78 and 1994-95 El Niños have had negative average July-September relative AAM values comparable to the current El Niño. Since 1959, only 4 of 15 El Niños have had negative average relative AAM values during the Southern California rain season of November to March. (Revised 12/14/09)

Moderate El Niños come in many flavors and have varying impacts. Under the guise of such El Niños Los Angeles experienced its second wettest water year on record in 2004-2005, when 37.25 inches of rain was recorded; then in 2006-2007 had its driest water year on record, when only 3.21" was recorded. What flavor will the 2009-2010 El Niño be?

The photo of the tree and clouds is from yesterday's run at Ahmanson Ranch.

Related post: How Does the El Nino of 2009-10 Compare to Other Warm ENSO Episodes Since 1950?

The windward side of this foxtail pine snag has been blasted by the icy winds of a multitude of Winter storms. The wind has sculpted the mineral-like wood, exposing and accentuating its inner layers.

The photo is from last Saturday's Cottonwood Pass - New Army Pass trail run. Nearly all of this route is above 10,000 ft. and 12 miles of it are above 11,000 ft. This relatively dry, high altitude habitat is home to the southern foxtail pine (Pinus balfouriana subsp. austrina).

One of the less common Sierra conifers, the tree is a long-lived species that is closely related to the bristlecone pine. The FEIS database references a southern foxtail pine 3400 years old, and the Gymnosperm Database a specimen with a crossdated age of 2110 years.

Because the tree grows so slowly, the wood is dense, and dead trees are slow to decay. In the vicinity of Cirque Peak, and a few other areas, dead foxtail pines and remnants are found above the current tree line. By crossdating tree ring sequences, a study published in 1997 found that over the past 3500 years the tree line in this part of the Sierra has generally been higher than it is now.

The study deduced that one period of reduced tree abundance and lowered tree line elevation was associated with warmer temperatures, and at least two severe multi-decade droughts. In contrast, the most recent decline has occurred during a cold, wet period that started about 450 BP.

It is remarkable that some of the dead foxtail pines studied here were alive during the Bronze Age, 4000 years BP.

Or should that be ramping UP for Mt. Disappointment? Anyway, started tapering for the Mt. Disappointment run next Saturday. Did the 13 mile Cheeseboro Canyon keyhole loop from the Victory Trailhead of Ahmanson Ranch yesterday, and then stretched the legs at Sage Ranch today. Both mornings were cool, with low clouds and fog -- very pleasant!

Here's hoping for "not too hot" weather for the race. At the moment, the GFS and ECMWF weather models show a weak upper level trough moving through California in the Friday-Saturday timeframe. Such a scenario should increase the chances of "seasonable" temps for the race -- which would still be quite warm, but maybe not crazy hot.

Update Friday Morning 8/07/09. Broad upper level trough over California this morning is keeping things cool. Yesterday the high recorded at Mt. Wilson was 70, and the low overnight was 48! Southern part of the trough is forecast to hang back over Southern California through Saturday, which could result in temps a little BELOW normal for the Mt. Disappointment race. We'll see!

Related post: Mt. Disappointment 50K 2008 Notes

Poison Oak Along the Blue Canyon Trail.

Since nearly all my weekday runs are in the afternoon, on Summer weekends I usually like to escape the heat and do a run in the mountains -- the higher, the better. But today even the mountains were going to be hot. Hot enough that the National Weather Service had issued an Excessive Heat Warning for a combination of heat and humidity that would "create a dangerous situation in which heat illnesses are likely."

It would be cooler at the higher elevations of the Sierra, but there was good chance of thunderstorms developing along the crest of the Sierra, as well as most of the higher mountains of Southern California. Considering the options, I finally decided to do an early morning run in Pt. Mugu State Park. If I was going to run in the heat, it might as well be a scenic run close to home. Maybe the weather in the mountains would be better next weekend.

Last year on this date, Southern California was in the middle of a heatwave. On June 20, 2008, Los Angeles Pierce College in Woodland Hills reached a record-setting high of 111°F, and on June 21 the temp reached 108°F!

Not so this June! So far this month, Downtown Los Angeles has not had a day when the average temperature was above normal. And it's not only the low elevation stations that have been cool. Several times this month the overnight low at the Big Pines RAWS, near Wrightwood in the San Gabriel Mountains, has dropped into the thirties, and daytime temps have averaged more than 10 degrees below normal.

This translates to great running weather in Southern California, and near perfect weather for trail running in the San Gabriel Mountains. Today, did the Three Points - Buckhorn loop, along with a short detour up to the summit of Waterman Mountain. The route worked out to about 23 miles with a reality-checked elevation gain/loss of about 3800'. Here's a Google Earth browser view of a GPS trace of the run.

The title photo is of Dave Burke, cruising down a nice section of the PCT between Cloudburst Summit and Cooper Canyon.

Related post: Three Points Loop Plus Mt. Waterman

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.

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 Google Earth 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.

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

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.)

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 Google Earth 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!

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

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!