Approaching the top of Marmot

Clearing skies last night brought cooler temps and fueled vitamin D deficient skiers into the backcountry today.

Since 11/3 new snow totals at Independence Mine Wx Station indicate around 17in/43cm. This was verified today. With wind deposition some slopes saw an added 50-60cm, bringing their total HS to 95 cm.

Winds over the week have been relatively calm by instrumentation, however, in reality the snow was highly affected which indicates stronger winds. Many slopes from SW to NE are wind scalloped, slabbed and pressed. Still, there is relatively undisturbed snow offering good riding conditions.

Snow depths (HS) range from 20-95cm. Most ridges are still much thinner than their bowls and starting zones. This means you are generally skinning or booting up thin snowpacks that are not representative of the slopes you will likely ride down. A note from observations in the field: Often one will see riders climbing up under large planar slopes or starting zones. An alternative is to approach the mountain from the relative safety of a ridge feature and descend the starting zones in the downhill mode. It is much easier to attempt an escape from an avalanche if you are pointed downhill instead of uphill. That being said it is easy to avoid avalanches if you do not enter their lair.

BOTTOM LINE:

Natural avalanches unlikely, human triggered possible. Small avalanches in isolated areas or larger avalanches in specific areas.

Wind loaded areas are mostly in the SW-NE aspects at 2500 to 4000 feet.

Recent storm activity has overloaded the snowpack. The surface instability (mentioned in the last bulletin) avalanched easily during the storm with the added load. Most of the avalanches littering the landscape at Hatcher are of this variety; thin small slabs. However, the added load tipped the balance point enough to allow humans to trigger the basal layer. This means that much thicker avalanches were and still could be triggered by humans. Fortunately, these deeper slabs, have also been relatively small. Given the variability in the snowpack, consistent with stability tests, and the fact the natural and human triggered avalanches were relatively small, the chances for wide propagation and large avalanches is reduced. This is the upside. The downside is that it is still possible to trigger small avalanches that could bury, injure and/or kill you. In addition there are some thick hard slabs out there that may have a more uniform structure prone to a larger size avalanche. While they will be more stubborn to trigger, they also pose a greater threat. These are easy to identify because most are wind scalloped. The surface patterns and shapes are easily seen. Avoiding these will help you avoid high consequence avalanches and your quality of riding will be better too.

–Jed Workman

If you have been out and about in the mountains and would like to share your observations, please send them along to: jedworkman@hatcherpassavalanchecenter.org