Cooling trend, snow and cloud in the forecast.Monday's freezing levels are uncertain and there is still a potential for the heat of the afternoon to increase the hazard below tree line.
Wind slabs formed last week are very stiff with stubborn sensitivity to trigger.Watch for drum like sounds in shallow areas, where wind slabs may be sitting over a shallow layer of facets.
Persistent slabs sit over different weak layers depending on elevation & aspect. Above 1950m a buried facet layer down 20-40cm is the primary concern. Below 1950m, a faceting crust down 40-70 is presenting a more stubborn version of a similar problem
Likelihood of triggering wet loose avalanches is decreasing with cooling temperatures and increasing cloud cover. There is still enough energy in the upper snowpack for the problem to persist into the heat of the day on Monday.
Monday:Cloudy with sunny periods and isolated flurries.
Precipitation: Trace.
Alpine temperature: High -3 °C.
Ridge wind west: 10-25 km/h.
Freezing level: 1700 metres.
Tuesday:A mix of sun and cloud with isolated flurries.
Precipitation: Trace.
Alpine temperature: Low -11 °C, High -7 °C.
Ridge wind northwest: 10-30 km/h.
Freezing level at valley bottom.
Weak temperature crust on all aspects up to 1900m with a sun crust on solar aspects extending into alpine. Upper snowpack has settled but expect reactivity to increase during peak warming of the day. Exposed alpine stripped to rock at ridge top & open features. Dec Facets down 20-70cm. Basal faceting & depth hoar widespread throughout area.
1 large natural cornice triggered slab observed on the Icefields road patrol on Sunday.No other avalanche activity observed on the Icefields Parkway or Maligne Lake Road Feb 11-12.
