Issued: Mar 19th, 2023 4:00PM
The alpine rating is Wind Slabs and Loose Wet., the treeline rating is , and the below treeline rating is Known problems include
Buried surface hoar continues to be reactive, especially in wind loaded features.
Stick to conservative terrain free from overhead hazard, and watch for signs of instability increasing with daytime heating.
On Saturday, numerous loose wet to size 1.5 were observed in steep, rocky solar terrain. Several natural storm slab avalanches were observed up to size 2.5, likely triggered by the sun or cornice failure. A few skier triggered, size 1, avalanches were reported. These avalanches released on a weak layer of surface hoar underneath the storm snow.
Southwest winds have created reactive deposits of wind slab on north to east facing terrain features at ridge top. A melt freeze crust or moist snow exists on the surface at low elevations and on sun affected slopes.
A weak layer of surface hoar is found 20-50 cm down in sheltered terrain. On solar aspects, this layer appears as a melt-freeze crust. This layer continues to be reactive to skier traffic.
A second weak layer of surface hoar and/or faceted grains may be found about 60 cm deep, particularly on shaded aspects near treeline.
The remainder of the snowpack is consolidated and strong.
Mainly cloudy. Strong southeast winds at ridgetop. Treeline temperature 0°C. Freezing levels remain around 1400 m through the night.
Mainly sunny with cloudy periods. Moderate southeast winds at ridgetop. Treeline temperature +1°C. Freezing levels 1500 m.
Mix of sun and cloud. Moderate southeast winds at ridgetop. Treeline temperature +1°C. Freezing levels 1500 m.
Mainly clear. Moderate southwest winds at ridgetop. Treeline temperature -2°C. Freezing levels 1200 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be carefull around freshly wind loaded features.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Minimize exposure to sun-exposed slopes when the solar radiation is strong.
Storm snow has been redistributed by southwest winds into deeper deposits, primarily found on north and east facing terrain features.
A buried layer of surface hoar is increasing the reactivity and propagation of wind slabs. Avoid sheltered and shaded slopes where surface hoar is more likely to be found. On other aspects, this layer is present as a melt freeze crust which has also produced avalanche activity.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
With freezing levels remaining elevated overnight watch for an increase in avalanche hazard when the sun directly impacts slopes tomorow. Pinwheeling and recent avalanches are signs of a weakening upper snowpack.
Aspects: All aspects.
Elevations: All elevations.
Valid until: Mar 20th, 2023 4:00PM