Settled Snow Depth: 40 inches
High temperature: 40°F (February 9)
Low temperature: -13°F (February 9)
Ski Conditions and Weather
Tuolumne Meadows had its most wintry weather of the season this week. It started with thirteen inches of high-density new snow and ended with frigid temperatures. The average low temperature over the past five days was -11°F. This combination of dense snow followed by cold temperatures, has produced a supportable snow surface that has become softer as the cold clear nights sublimate some of the moisture from the upper snowpack. The rain crust that we discussed in our last post is now buried 65 centimeters (cm) deep beneath the new snow. Powder can be found between 9,000 to 11,000 feet on all aspects but south. Higher up in the alpine zone, the snow surface is a patchwork of wind hardened snow, and shiny wind scoured ice.
Prior to these subzero temperatures, even the north-facing creeks had open water running in them. This is not often the case in February and therefore provides a unique opportunity for both wildlife and backcountry travelers to find a drink in an otherwise snow-covered landscape (although many openings are surrounded by steep vertical walls of snow!). In the alpine zone, water has percolated among the steep rocks, making for a surprise icy turn in addition to the exposed areas of rain crust.
Avalanche and Snowpack Conditions
Please refer to the Eastern Sierra Avalanche Center (ESAC) and the Bridgeport Avalanche Center for the avalanche advisories for this part of the Sierra Nevada.
The snowpack became more complex as a result of the aforementioned weather this week. There are now two rain crusts buried in the snowpack with faceted snow metamorphosing adjacent to them.
Early in the week with the initial snow loading, we observed collapsing and propagation cracks near tree line. The weight of this new snow plus a skier caused failure in the old, faceted snow (which was a result from the dry January). As the week progressed, and the snowpack became deeper, this failure become more stubborn, and we have not observed snowpack instability for a few days now. Don’t be fooled by these apparent signs of snowpack stability. Persistent slab problems now exist in our snowpack, and these can be the most troublesome to navigate and unpredictable to trigger.
Wildlife
This week despite the cold temperatures, golden-crowned kinglets were active among the conifers along the Elizabeth Lake trail. We don't hear or see these little guys every season, but yesterday we even caught glimpses of their crowns. "How these tiny birds, which are not known to roost in holes or go into torpor, survive subfreezing temperatures is still a mystery [although according to Heinrich 2003 this species of birds has been seen] ‘tightly huddled together, headfirst into a fluffed-up ball of feathers.’" (Beedy)
How adorable! During breaks in the storm, go out with a loved one for Valentine's Day and try to discover what these and other birds do to stay warm. Celebrate our feathered friends during the Great Backyard Bird Count this weekend.
Questions
The Tuolumne Meadows Ski Hut is open. This primitive cabin is the campground reservation office in the summer and is located along the Tioga Road at the entrance to the campground. It is marked with a sign. There is firewood and 8 bunks that are available on a first-come, first-served basis. For those visiting the Tuolumne Meadows Ski Hut from the east (only) permits are self-issued at the Ski Hut. For those entering from other areas, please see Yosemite’s website: https://www.nps.gov/yose/planyourvisit/wildfaq.htm#winter or you may contact the wilderness office at 209/372-0740. Do not rely on electricity or phone service at the ski hut.
Come prepared, and please make good decisions while traveling in the wilderness!
Read through the following three pages before embarking on any day or overnight snow travel within this park:
You may contact us with any additional winter Tuolumne Meadows related questions but response times may vary if we are away on patrol.
References
Beedy and Pandolfino. Birds of the Sierra Nevada, their natural history, status and distribution. The Regents of the University of California, 2013.
We love winter!
Laura and Rob Pilewski - Tuolumne Meadows winter rangers