Persistent Slabs
- Hochgebirge
- Waldgrenze
- Unterhalb der Waldgrenze
- Wahrscheinlichkeit
- Possible
- Größe
- 2–3
A combination of buried surface hoar, facets, and old crust may become reactive with the addition of new snow.
Heavy precipitation and warming temperatures are expected to result in dangerous avalanche conditions on Friday. Travel in avalanche terrain is not recommended.
A combination of buried surface hoar, facets, and old crust may become reactive with the addition of new snow.
New snow and strong winds are expected to form widespread storm slabs on Friday.
Wet loose avalanches are expected on steep slopes at lower elevations where rain is soaking the upper snowpack.
On Thursday, the field team observed small wind slab avalanches. On Wednesday, a skier triggered a small wind slab on a north aspect.
Widespread natural avalanche activity should be expected heading into the weekend as the series of storms brings periods of heavy snowfall and rain.
At higher elevations, new storm snow falls on old wind-affected snow, facets, surface hoar, and/or a melt-freeze crust. The bond of the new snow to the underlying layers is unknown. In exposed terrain, the wind has redistributed the storm snow into fresh wind slabs in leeward terrain.
A widespread crust, sometimes accompanied by a thin layer of weak facets, was buried 30-70 cm beneath predominantly low-density snow before the storm.
The mid and lower snowpack contains no other layers of concern.
Thursday Night
Cloudy with 10 to 30 mm of mixed precipitation. 50 to 70 km/h southwest ridgetop wind. Freezing level 1400 m.
Friday
Cloudy with 20 to 40 mm of mixed precipitation. 70 to 90 km/h southwest ridgetop wind. Freezing level 1200-1700 m.
Saturday
Cloudy with 20 to 60 mm of mixed precipitation. 70 to 100 km/h southwest ridgetop wind. Freezing level 1400-2000 m.
Sunday
Cloudy with 20 to 40 mm of mixed precipitation. 50 to 80 km/h southwest ridgetop wind. Freezing level 1300-1800 m.
More details can be found in the Mountain Weather Forecast.