Tuesday, January 24, 2012

Hint of Winter

It's been both a challenging and a welcome return to stormy winter weather over the past several days in Yosemite. Tioga, Glacier Point and Mariposa Grove Roads closed last week, we got rain and snow, and the waterfalls picked up in volume. It snowed a couple of inches in Yosemite Valley yesterday, then clearing sky and swirling clouds at sunset made magic.
Ranger Ryan Hiller was killed by a treefall during the rain and high winds over the weekend. Ryan spent much of last summer patrolling the busy Half Dome trail corridor and was planning to work at our ski area this winter. He was the 10th known person in park history to perish in this manner and his loss is deeply felt by all of us here.
On Sunday night a section of the north canyon wall above the Big Oak Flat Road came loose and wrecked part of that highway between the Merced River and the Foresta turn-off. The slide is below the 3 tunnels, includes a lot of smashed live oaks and some very big boulders. Moving the debris is one thing, but the roadbed itself has been broken through and pushed downhill. NPS has posted pictures on their Facebook site. I'd guess that this will take at least a few weeks to reopen. There is some Sherwin glacial till in that area but this slide looks like all talus and cliff material.
Badger Pass got about a foot of snow and groomers have been working on the slopes. Warm weather the rest of this week will not help retain this base, but -you hear it here first: all Badger Pass operations will open on Thursday.
UPDATE: The Big Oak Flat Road reopens Saturday 28 January! Amazing work by NPS Roads to make this repair. Caution: unpaved gravel surface in the slide area.

Friday, January 20, 2012

Finally wet

After being dry for nearly two months we have a series of storms coming through Yosemite. Light precipitation overnight left snow down below 7000' in places. More accumulation is expected over the next few days, perhaps as much as 2-3 feet at high elevations by Monday.
Tioga Road is closed. Glacier Point Road is closed. But the snow level is high enough that we don't have any chain restrictions in effect. Badger Pass, at 7200' has a ways to go before even cross-country skiing will be possible there.
The Merced River had gone down to 27 cfs at Pohono Bridge - a mere 20% of normal flow! The tiny bit of overnight rain is showing up in the river already with a slight rise. Last night was quite a bit warmer than usual due to the cloud cover that limited radiational cooling. Some of the many frozen waterfalls that have been so visible for the past few weeks are softening up in the warmth and rain.
While Tioga was open, park resources people made some sound recordings of the lake ice on Tenaya, Dog and Lower Cathedral Lakes. If you were up there, you know how eerie those creaking, groaning, pinging sounds were. I hope they'll have some of these unique recordings available online soon.
Meanwhile the dry landscape is soaking up liquid moisture and stacking up the solid form for later use...

Saturday, January 7, 2012

Wither Winter?

I saw a huge scorpion this morning. It was creeping slowly up into the southeastern sky just before dawn: Scorpio, a hint of distant summer. Vega was well up in the northeast- part of the Summer Triangle asterism. It's too close to solstice for these to really be harbingers, but (depending on your horizon; our irregular canyon walls can interfere with the trajectory of change) the sun is rising a bit earlier and setting later than it was a couple weeks ago. Mars and Saturn are also overhead before sunup; Jupiter and Venus after sunset.

The remarkable dry and mild season continues in Yosemite. January snow surveys show a fraction of normal snowpack (13% in the central Sierra) with some sample sites bone dry. Tioga Pass and Glacier Point Roads remain open. It is not true that our ski area is changing its name to "Badger Grass" (photo). While many have observed that this is the latest that Tioga Road has stayed open, others have wondered if instead it's actually the earliest (for next summer) that it's been open to vehicles...
The original road to Tioga Pass was built by hundreds of Chinese laborers. Some of the story of the contributions of non-Anglos to Yosemite is told in this new NPS video. I'm delighted with ranger Chan's research that brings to light more of the details of Yosemite's culturally diverse heritage (and future).
Western Bluebirds are seen at Crane Flat (99% snow-free at 6200'). Great horned owls are calling every night in El Portal, Foresta and the Valley. Chorus frogs are heard here and there, but only individually so far. The Merced River trickles at about 35% of normal flow.

Sunday, January 1, 2012

Sierra Sin Nevada

Yosemite does not notice as people replace old calendars with new ones today; there is no date on the park's schedule. It's only our transient culture that has the conceit that we've just entered something called 2012 this morning. Solstice, a week and a half ago, is a more significant transitional event for our mountains.
Our December was one of the driest on record. There are a few inches of snow in shady places, but Tioga Road and Glacier Point Road are both dry and open to vehicles. Being able to drive to Tuolumne Meadows and over Tioga Pass is most unusual for Christmas and New Year's.
Visitors have been very excited to ice skate on Tenaya (pictured), Tioga and Ellery Lakes, as well as those wilder lakes requiring a short hike. XC skiers are hiking in to stay at Ostrander Ski Hut but without skis. In Yosemite Valley, people are comfortable in shirt sleeves mid-day; it should be in the mid-50's this week.
The Merced River has continued to shrink in volume, during the time of year when it's typically rising. At Pohono Bridge the average for today is 102 cfs, but it's now flowing at 38 - the lowest its been since October of 2010. (1977 was drier; only 14 cfs trickled through on January 1.)
The Christmas Bird Count recorded a healthy 70 species, including both species of eagles and lots of other raptors. It's a good winter for varied thrushes here and our white-headed woodpecker sightings will again be at/near the most in the nation.