While the best riding conditions may be found on north facing, alpine slopes - persistent weak layers may still be reactive here.
Watch for changing surface conditions on sunny slopes.
Concern remains for human-triggering a persistent weak layer on sheltered north aspects above 2000 m. If triggered, avalanches will be large and destructive. Avoid shallow snowpack areas where triggering is more likely.
Potential for wet avalanche activity (slab and loose) increases as temperatures rise, but concern is greatest on steep, sun affected slopes. Avalanches may initiate easily on the smooth crust below.
On Thursday, a size 1 rider triggered slab was reported. While the slab was only 10 cm deep, this shows the potential of small avalanches in steep or unsupported terrain features.
We are still awaiting observations but expect a loose wet avalanche cycle to have occurred during the rapid warm up on Sunday, and to continue on Monday. There is also potential for the persistent slab problem to reactivate in the warm temperatures.
Around 5 cm of moist or wet surface snow sits over a widespread crust. On steep south facing slopes the crust below may also break down in the warm temperatures.
The facet/crust layer that produced large avalanches during early March is buried 80-150 cm deep. While no recent avalanche activity has been observed on this layer, it continues to produce concerning snowpack test results. It has become a low-probability, high-consequence problem on north-facing slopes above 2000 m. It is uncertain how this layer will react to rising temperatures.
Sunday night
Partly cloudy. 10 to 20 km/h southwest ridgetop wind. Freezing level 2500 m. Treeline temperature 0 °C.
Monday
A mix of sun and cloud. 10 to 20 km/h suthwest ridgetop wind. Freezing level 2500 m. Treeline temperatures near +2 °C.
Tuesday
Freezing levels remain above 2000 m overnight and throughout Tuesday. A mix of sun and cloud with flurries starting in the afternoon, around 5 cm. 40 to 50 km/h southwest ridgetop wind. Treeline temperature +2 °C.
Wednesday
Overnight freezing level drops below 1000 m. 5-15 cm of new snow overnight then clearing to a mix of sun and cloud. 20 to 30 km/h southwest ridgetop wind. Freezing level 1300 m. Treeline temperature -2 °C.
More details can be found in the Mountain Weather Forecast.
