Storm Slabs
- Alpine
- Treeline
- Below treeline
- Likelihood
- Very Likely
- Size
- 1–2
A switch to snowfall at high elevations will result in a new storm slab problem to manage Thursday. Expect this problem to increase in seriousness as you gain elevation.
The hits keep coming. A mix of heavy snow and rain will maintain dangerous avalanche conditions on Thursday. Hunting for dry snow in the alpine will put you closest to harm's way.
A switch to snowfall at high elevations will result in a new storm slab problem to manage Thursday. Expect this problem to increase in seriousness as you gain elevation.
Continuing rainfall should maintain weak upper snowpack conditions at lower elevations, meaning wet avalanches will remain possible in steep terrain below treeline.
A widespread avalanche cycle took place in the region over the weekend and through Monday, with numerous wet slab and wet loose avalanches to size 4 (very large) seen in a wide range of terrain. One report from Tuesday featured a size 4 with a crown fracture over 3 km long!
Looking forward, a switch to snowfall will reinvigorate surface instabilities Thursday. This and the sheer scale of recent natural activity should suggest a very cautious approach to terrain selection.
30-40 cm of new snow may accumulate in the alpine by end of day Thursday, with amounts tapering at lower elevations. The new snow accumulates on a thin existing cover of new snow over newly formed crust above about 2000 m and on rain soaked snow below this elevation.
Below any new crust at treeline, and especially below treeline, the snowpack is largely isothermal.
The mid and lower snowpack consists of various old crusts and is generally well-settled and well-bonded.
Wednesday night
Cloudy with wet flurries and a possible 10-20 cm of new snow accumulating in the alpine, rain below 1700 m. Southeast alpine winds 30 to 50 km/h.
Thursday
Cloudy with easing flurries bringing 10-20 cm of new snow above 1500 m. Southeast alpine winds 30 to 40 km/h. Treeline temperature around 0°C with freezing level around 1600 m.
Friday
Mostly cloudy with flurries continuing from overnight bringing 10-20 total cm of new snow. South alpine winds 10 to 30 km/h. Treeline temperature -1°C with freezing level around 1400 m.
Saturday
A mix of sin and cloud. Alpine winds shifting northerly, 5-10 km/h. Treeline temperature -1°C with freezing level around 1400 m.
More details can be found in the Mountain Weather Forecast.