Dec 11, 2023 - Snowpack Update Evening Ridge, WH20 Backcountry

• Date: Dec 11, 2023

• Submission: Michael Wigley, CAA 1/CSGA 1

• Location: Evening Ridge, Whitewater Ski Resort Backcountry

• Aspect: E

• Elevation: 2050m 

• HS: 115 cm

Observations: 

👉 The sun was radiant during the day warming the top 5cm on solar aspects (SE-SW). Which formed a sun crust by later afternoon. 

👉 On the surface of polar aspects (E-NW) overnight growth of Surface Hoar (3mm) was found.

👉 The height of snow was 85cm at 1700m and up to 120cm at 2100m. 

Snow Profile Obs:

I dug a snow profile on an East aspect at 2050m, -2C, at around noon with a snowpack of 115cm. 

👉  Found the Dec 6 rain crust down 45cm and was 5cm thick 

👉  Dec1 surface hoar down 60cm. The surface hoar was still well preserved with an average size of 15mm and getting up to 20mm. 

👉 I had no results on an extended column test. 

👉 With a compression test I had a moderate broken result down 35cm with a change in snow density. Also, I had a hard sudden collapse result down 90cm on rounding facets (1-2mm) above the freezing rain crust we had around Nov12. 

Summary: 

I feel the snowpack is bonding well and the Dec 06 rain crust is bridging the upper snowpack and not seeing results on the Dec 01 surface hoar. 

I will still caution and monitor the Dec 01 surface hoar, it’s still well preserved in the snowpack and large in size. The sudden collapse on the rounded facets is also on the back of my mind. The snowpack has strength but it’s still shallow, finding a weak point on an open slope may produce a significant avalanche. Monitor the Dec 06 rain crust, look for the Dec 01 surface hoar, and keep those weak facet layers near the base of the snowpack in the back of your mind. Early season risks are still out there! Watch for terrain traps, open creeks, and partially buried rocks/stumps. 

Always check Avalanche Canada before heading out into the backcountry!