Quick report
- Cracking
- widespread
Name of the game today was new snow and storm slab instability. Snowfall rates were increasing as the day went on and roughly 30cm of new snow had fallen with this current Atmospheric River. The old snow interface with saturated snow was also interesting though did take considerable force to fail, 21 hits in both CT and ECTs. Given this old snow had not yet refrozen and still had considerable liquid water present, this is the layer to watch as precipitation shifts to rain Sunday. Despite no ECT propagation, the poor structure alone (Fist hard old wet snow below 4 Finger new snow) is pause for concern. No crust was present at the top of this layer. Some cracking was observed within the new snow (top ~10-15cm), consistent with results from Compression and Extended Column Tests. Hand pits and test slopes were not overly reactive. No avalanche activity was observed, today's tour did not pass near any slopes >30°.
Weather
- Air Temp
- 24
- Cloud Cover
- obscured
- Wind Loading
- light
- Rain Elevation
- 1000
- Recent Snowfall
- 27
- Snow Avail For Transport
- moderate amounts
Snowfall rates increased as the day went on. Easterly winds also increased in strength throughout the afternoon with moderate wind transport evident in more exposed areas near ridgelines.
Snowpack
The snow that existed before the extraordinarily warm Atmospheric River event Mon-Wed has taken a beating and has still not refrozen entirely. Temperatures in this layer (15-40cm from the ground) were roughly -2C although I have concerns with the accuracy of my thermometer given the presence of liquid water with the rounded polycrystals. Interestingly, a refrozen rain crust existed 11-15cm from the ground with the snow below this layer mostly dry and well-bonded. ~27cm of new snow from today's activity was reactive although not cohesive enough to see propagation in Extended Column Tests. Failures in ECTs and Compression Tests were observed within the new snow, on the new/Thur. snow interface, and on the Thur. snow/wet snow interface without propagation.