Ongoing wind slab formation is expected on Sunday in exposed terrain at higher elevations due to periods of moderate northerly wind. Use extra caution around cornices and steep south-facing slopes during the heat of the afternoon.
Wind slab formation is expected to be ongoing on Sunday as we continue to expect moderate winds from the north. Dry snow was reported above 1500 m so wind transport should be expected above that elevation in wind-exposed terrain.
Cornices were reported to have grown large during the recent storm. They could still pose a threat from above or below, and are expected to become weak when the sun is at its strongest.
With each subsequent day of melt-freeze conditions, loose wet avalanches will become less likely. However, extra caution is still recommended on steep sun-exposed slopes during the heat of the afternoon. Where the crust is breaking down or non-existent, loose wet avalanches will be more likely.
A ridge of high pressure brings one more day of dry and sunny conditions for Sunday before conditions change on Monday.
Saturday Night: Clear, moderate N wind, freezing levels around 2000 m with an inversion.
Sunday: Mainly sunny, moderate to strong N wind, freezing levels reaching as high as 2500 m with an inversion.
Monday: Mainly cloudy with sunny breaks, strong NW wind, freezing levels 1500-1800 m.
Monday night and Tuesday: Periods of light snowfall, moderate to strong NW wind, freezing levels around 1000 m.
No new avalanches have been reported since Wednesday. A natural avalanche cycle had occurred during the storm at the beginning of last week.
A melt-freeze crust is now expected to be capping the snowpack on all aspects to at least 1500 m and on sun-exposed slopes into the alpine. On north aspects at higher elevations, the snow surface may still be dry and crust-free. In exposed terrain at higher elevations, the recent storm snow may be wind-affected and ongoing wind transport is expected due to moderate northerly winds over the weekend.
A melt-freeze crust from mid-February can be found approximately 80 cm beneath the surface with some spotty surface hoar crystals above. Recent snowpack testing suggests the crust is bonding well to the surrounding snow in some areas. However, this MIN post from Thursday shows a weak bond to the crust in the Mt. Washington area. With several subsequent days of melt-freeze, the bond is assumed to have improved since this observation but it is worth investigating further before committing to avalanche terrain. A strong, well-settled middle and lower snowpack exist below the crust.
