Start and finish you day early as warm sunny weather could cause large avalanches on sun-exposed slopes.
Summary
Confidence
Moderate - Uncertainty is due to rapidly fluctuating freezing levels. Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.
Weather Forecast
TUESDAY NIGHT: Clear skies, light northwest wind, freezing level drops to 1500 m with treeline temperatures dropping to -2 C.
WEDNESDAY: Sunny with some clouds in the afternoon, light northwest wind with some moderate gusts in the afternoon, freezing level climbs to 2400 m with treeline temperatures reaching +3 C.
THURSDAY: Scattered flurries bring 5-10 cm of snow above 1800 m and light rain in the valleys, light northwest wind, freezing level around 1800 m with treeline temperatures around -2 C.
FRIDAY: Mix of sun and cloud with some isolated flurries, light wind, freezing level climbs to 2000 m with treeline temperatures reaching -1 C.
Avalanche Summary
Avalanche activity has quieted down since temperatures cooled on Sunday. On Saturday there were widespread wet loose and wet slab avalanches on sun-exposed slopes. The wet loose avalanches were mostly size 1-2, but some of the wet slab avalanches were quite large and destructive (size 2.5-3.5). The large wet slabs were mostly on south and west facing slopes.
On Wednesday there is an increased potential for another cycle of large wet avalanches with temperatures staying mild overnight and then freezing levels spiking to 2400 m in the afternoon.
Snowpack Summary
A surface crust will form overnight and then gradually break down with daytime warming. Dry snow may still be found in high north-facing terrain (above roughly 2300 m). There are no layers of concern in the snowpack, which has been melting and settling over the past week. Large cornices loom along many ridgelines.
Terrain and Travel
- Avalanche hazard is expected to to increase througout the day, think carefully about your egress.
- Avoid exposure to steep sun exposed slopes.
- Avoid lingering or regrouping in runout zones.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
Problems
Loose Wet
Expect wet loose avalanches to run naturally when steep slopes are exposed to the sun. Activity will start on east-facing slopes in the morning, south-facing slopes throughout the day, and continue on west-facing slopes into the evening.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Wet Slabs
Warming could trigger very large wet slab avalanches on sun-exposed slopes. Be careful below avalanche paths as wet slabs can run surprisingly long distances.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices are large and fragile when exposed to the sun. Cornice falls are dangerous on their own and can possibly trigger avalanches on slopes below.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 21st, 2021 4:00PM
