Avalanche Forecast
Issued: Nov 27th, 2022 4:00PM
The alpine rating is Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeBecause of the thin, soft, early season snowpack the best riding will also be where avalanches are most likely. Avoid overhead hazards, keep slope angles moderate, and stick to places sheltered from the wind.
Summary
Confidence
High
Avalanche Summary
New on Sunday: Explosives released several size 2 storm slabs and one size 3 that propagated across the entire feature and ran far (typical length of a size 3 is 1000 m). Whumphs were reported from the Flathead.
Previously Reported: one size 2 natural from the Lizard Range during Friday's storm was up to 40 cm deep, 150m wide and ran 300m.
Something to Ponder: by Sunday night the snowpack may have received 60mm of water equivalency in the last two storms. Adding 50% or more load to a young, thin snowpack is significant. I'm thinking it's possible something might scrub down into the lower snowpack or even to ground.
Snowpack Summary
Upper snowpack: consists of the 45 to 60 cm of snow over the past week. At the bottom of this recent snow is a layer of surface hoar. Take a look under the hood from Harvey Pass. ESPeters10 - thanks for sharing.
Lower Snowpack: sugary faceted snow and with a rain crust just above the ground.
Snowpack depths at treeline are 45 to 75 cm, and in the alpine 65 to 125 cm.
Weather Summary
Sunday NightIt's going to be a clear and cold night. No new snow, light west wind, and touching -20 C.
MondayDry, mix of sun or cloud, depending where you are, light wind veering to the north or east, and temperatures around -15 to -20 C.
TuesdayVery similar to Monday. Maybe a touch colder, maybe a bit more sun, maybe the wind will back to the SW late in the day.
WednesdayA weak system arriving from the coast. Currently it looks like a dusting to 10 cm of snow but it should warm up dramatically with the southwest wind.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Be especially cautious as you transition into wind affected terrain.
Problems
Storm Slabs
It's possible avalanches can scrub down into the faceted lower snowpack. This suggests the possibility of wider and larger events than normally expected.
Thin early season snow depths mean you'll be searching for deeper areas to ride; that'll take you to where avalanches are most likely. Selecting moderate (less steep) slopes will help manage both early season hazards (like knee and A-arm wrecking rocks) and avalanche hazards. Less windy areas will be the sweet spot for both best riding quality and avoiding avalanche issues.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 28th, 2022 4:00PM