Rising freezing levels and the strong March sun can pack a punch and quickly destabilize the snowpack. Natural and human-triggered avalanches are likely.
Large looming cornices exist along ridgelines. Cornices become weak with daytime warming and sun exposure. Give cornices a wide berth while traveling ridgelines and avoid slopes below them.
Storm slabs may continue to be reactive to human triggering, especially where they sit above a hard crust. Strong southwest wind may build pockets of wind slab on lee slopes at upper elevations.
Strong solar radiation and rising freezing levels may weaken the surface snow creating wet loose avalanches on all aspects below 1300 m and steep solar slopes above.
On Tuesday, natural and skier-triggered dry loose avalanches up to size 1 were reported from the North Shore mountains.
On Monday, natural dry loose avalanches were reported from steep terrain features and explosive control initiated several storm slabs up to size 1. The storm slabs were 5 to 20 cm thick with very limited propagation and entrainment.
On Sunday, a skier-triggered size 2 wind slab was reported as a MIN (check it out here) the skier was knocked off their feet but able to ski out with no injuries. A natural size one wind slab avalanche was reported in the Sky Pilot. This was in the alpine on an east aspect.
Natural and human-triggered avalanche activity will likely occur throughout the week with rising freezing levels and solar radiation.
Surface snow will likely become moist during the day with warming and solar radiation. The recent 40 cm of storm snow is generally settling but may not have a good bond to the underlying sun crust on solar aspects and melt-freeze crust at lower elevations. Southerly winds have also created wind slabs in exposed terrain at higher elevations.
In general, the mid and lower snowpack is well-settled and bonded.
Wednesday Night
Clear with some cloudy periods. Treeline temperatures near -1. Wind light 15 km/hr and freezing level valley bottom. 3-5 cm of new snow.
Thursday
A mix of sun. Treeline temperatures near +3. Winds southeast 10-20 km/hr. Freezing level 1400 m. l
Friday
A mix of sun and cloud. Treeline temperatures near +3. Wind southeast 10-20 km/hr. Freezing level 1500 m.
Saturday
A mix of sun and cloud. Winds 10-20 km/hr from the southeast. Treeline temperatures near +4 with freezing levels 1700 m.
More details can be found in the Mountain Weather Forecast.
