Issued: Nov 26th, 2022 4:00PM
The alpine rating is Storm Slabs., the treeline rating is , and the below treeline rating is Known problems include
Cautiously assess conditions as you travel - the fresh snow will hide reactive slabs or, more likely, early-season hazards.
Last week through Friday, dize 1-2 wind and storm slabs were reactive in wind-loaded and ridge features at upper treeline and above with the past storms. A few loose-wet and snowballing were reported below 2000 m into the BTL.
Looking forward, we expect new storm slabs to become increasingly reactive as snowfall accumulates overnight, first in wind-loaded areas and then becoming widespread Sunday morning.
Overnight snowfall covered wind-affected snow and crust at upper elevations and moist snow and dirt at treeline and below.
Where the snowpack is growing, a weak drought layer is down 20-50 cm. This layer consists of hard, wind-affected snow in the alpine, surface hoar or facetted snow in sheltered areas, and a crust on solar aspects and on all aspects below 2200 m. Below this layer, several other facet-crust interfaces exist in the snowpack.
Terrain features poke through a building snowpack that ranges from 80-150 cm in the alpine and 50-70 cm at treeline. Below treeline is below the threshold for avalanches.
Heavy precipitation and extreme southwest wind will peak around midnight, then temperatures cool and winds decrease. 15-30 mm precipitation overnight, alpine high -1 C, snow/rain line peaking around 1000 m.
Up to 30 cm new snow by morning, and convective flurries possible throughout the day. West wind decreasing to moderate, treeline temperatures dropping to -10 C, and freezing level dropping to valley bottom.Monday
Cold and sunny, with patchy clouds. Moderate northeast wind, treeline temperatures around -12 C, and freezing level falling to valley bottom.Tuesday
Cold with a mix of sun and cloud. Light to moderate southerly wind, treeline lows down to -16 C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Investigate the bond of the recent snow before committing to your line.
- Dial back your terrain choices if you are seeing more than 25cm of new snow.
- Be especially cautious as you transition into wind affected terrain.
Strong winds impacting overnight snow likely formed reactive slabs, the deepest and most reactive deposits will be in open and wind-loaded areas. Be mindful that you may find reactive slabs lower on the slope than usual as a result of the strong winds.
Valid until: Nov 27th, 2022 4:00PM