Avalanche Forecast

Issued: Dec 22nd, 2022 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Persistent Slabs.

CB, Avalanche Canada

Glacier.

A warm, moist storm will start to build storm slabs on top of a weak cold surface.

Sluffing in steep terrain will be the main concern on Friday.

Summary

Confidence

Moderate

Avalanche Summary

Reports of settlements and whumphing continue to be reported in previously untracked terrain.

Isolated natural sluffs and small avalanches up to size 2 have been observed along the highway corridor in the past few days.

Snowpack Summary

An incoming storm will start covering a facetted surface and some wind slabs in exposed terrain in the alpine.

The Dec 16 interface is down ~10cm, it consists of surface hoar (up to 10mm at tree line and below) and a crust on solar aspects.

The Dec 5 and Nov 17 surface hoar layers are down ~40cm and ~70cm respectively and still producing easy to moderate snowpack tests in some locations.

Atypical early season hazards are present throughout the park. The snowpack is thin (~110cm at 2000m) and generally facetted.

Weather Summary

A MOIST PACIFIC FRONT IS APPROACHING!

Snow starts Friday as temperatures moderate, wind will be southerly, with moderate snowfall accumulations through the weekend.

Fri: Flurries, 9 cm, Alp High: -10*C, Ridge wind: S-15 km/h

Sat: Snow, 23 cm, Alp High: -5*C, Ridge wind: SW-35 km/h, Freezing level: 1100 m

Sun: Periods of snow, 18 cm, Alp High -2*C, Ridge wind: SW-20, gusting to 45 km/h, Fz lvl: 1600 m

Terrain and Travel Advice

Watch for fresh storm slabs building throughout the day.
Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
Minimize exposure during periods of heavy loading from new snow and wind.

Problems

Storm Slabs

Storm slabs will start to build on Friday. Watch for sluffing in steep terrain and denser snow forming a slab. This problem will become more hazardous through the weekend as storm snow accumulates and freezing levels rise.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The Nov 17 and Dec 5 surface hoar are down ~75cm and ~35cm respectively, and still producing whumphs and cracking. These layers are still reacting in the easy/moderate range in isolated snowpack tests.

Aspects: All aspects.

Elevations: Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 2.5

Valid until: Dec 23rd, 2022 4:00PM