Numerous small loose wet avalanches were reported off steep rocky solar exposed cliff faces at all elevations over the past three days, as one would expect as warm spring temps are now reaching up higher into the mountains.
Past Weather
Clear, sunny skies and positive temps Tuesday warmed the upper snow pack then cooled at night creating a crust. 10 to 20 cm of new moist snow fell early Wednesday morning fallowed by a few flurries Thursday.
Weather Forecast
Mild Friday with a moderate storm event forecast for Saturday into Sunday.Friday - 0 to a trace of new precip, winds light SW, temps 0 to 2, freezing level 1500 to 1700 mSaturday - 7 to 15 cm of new snow, strong S winds easing to moderate SW, temps 0 to -4, freezing level 1000 to 1400 mSunday - 2-4 cm of new snow, light SW winds, temps a cool -2 to -4, freezing level 850 to 1100 m
Terrain Advice
Avoid exposure to all large steep slopes in the treeline and below, during daytime warming (no solar faces when the suns out or temps rise above freezing) or when/if rain saturates the upper snow pack on big terrain. Stay way from and give terrain traps a wide berth during warm and or rainy times (cornices, gullies, cliffs, depressions, creeks, bands of trees...). Keep off wind loaded N to NE avalanche terrain in the alpine and treeline elevation bands during and after the storm (Saturday into Sunday). Give the winds slabs, that will form, a bit of time to bond and settle to the old snow and crust that they will form on.
Snowpack Summary
10 to 20 cm of new moist snow fell above 1000 m over the past three days on top of a crust that formed prior.
Snowpack Details
- Surface: moist new snow
- Upper: a breakable crust over well settled moist warm storm snow from last weekends blizzard
- Mid: well settled
- Lower: well settled
Confidence
High - Weather models in agreement, good field data but the type of precip you get will depend on what elevation you are at (rain/mixed/snow)
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.