Avalanche Forecast
Issued: Dec 27th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
CG,
Avalanche Canada
Underneath the new storm snow lurks a weak, sugary snowpack...and that sugar ain't sweet, if you know what I mean!
There may be some significant settlement of the snowpack in the coming days, with whumpfing and shooting cracks alerting you to dangerous conditions.
Summary
Confidence
Moderate
Avalanche Summary
Natural avalanche activity has reduced with the decreased snowfall/winds.
Artillery control on Xmas and Boxing Day had good results, with many avalanches observed in the sz 2.5-3.5 range. There was evidence of step-down avalanches on the persistent weak layers.
Be suspicious of slopes that do not appear to have avalanched in the last few days.
Snowpack Summary
The Xmas storm came in windy and warm, and now this dense, heavy storm slab is squishing down a below-average depth, weak, faceted snowpack.
The storm slab interface (down 55-65cm) was reactive in snowpack tests, while the persistent weak layers (PWLs) were stubborn in tests today at Fidelity.
The reaction of the PWLs to the overlying burden is the thing to watch the next few days. Dig down and test them.
Weather Summary
A gradual cooling and clearing trend sets up for Rogers Pass for the rest of the week.
Tonight: flurries, 5cm, Alp low -6*C, light SW winds, 1200m FZL
Wed: scattered flurries, trace snow, Alp high -6*C, moderate W winds, 1200m FZL
Thurs: sunny periods, trace snow, Alp high -9*C, light SW winds, 700m FZL
Terrain and Travel Advice
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Problems
Storm Slabs
Heavy, warm storm slabs sit atop a weak, faceted early-winter snowpack. Steeper slopes (50*+) have likely shed this slab, but the most "fun" inclines (30-45*) may have held back from avalanching. Stick to supported, lower angle slopes with limited overhead hazard.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Persistent weak layers permeate the upper and mid-snowpack. Step-down crown-lines from the last few days of avalanche activity confirm their sensitivity to additional loading.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 28th, 2022 4:00PM
