We are expecting significant snow and wind by tomorrow afternoon. Watch for rapid hazard changes if the amount of snow/timing varies from the forecast.
Confidence
- Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Flurries will change to real snow by late afternoon tomorrow. Amounts vary, but we're hoping for 20-30 by saturday morning. True to form, the winds will accompany the incoming snow. Winds of about 40km (treeline) from the SW are the expected numbers. The temps will remain average (around-8), but fall off the chart by Sunday. Lows are expected to be around -30 by sunday night.
Avalanche Summary
Nothing new.
Snowpack Summary
Wide spread wind effect in the alpine. Treeline is mostly broken down, facetted surface slabs with facets/depth hoar below. There are pockets of harder and likely reactive windslabs kicking around the more exposed areas, but for the most part the snowpack is improving from a hazard perspective despite getting weaker overall... a little counter intuitive. Valley bottoms are still on the skimpy side for coverage, but the upside is the lack of any avalanche problem.
Problems
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.