Strong solar radiation may increase the likelihood of triggering lingering winds slabs on lee features below alpine ridgetops. Any appearance of the strong April sun can initiate a loose wet avalanche cycle.
WEDNESDAY NIGHT: Clear / Light, northwesterly winds / Alpine low -6 C / Freezing level 1000 m.
THURSDAY: Sunny / Light, southwesterly winds / Alpine high 0 C / Freezing level 2000 m.
FRIDAY: Mix of sun and cloud / Light, northwesterly winds / Alpine high 0 C / Freezing level 2000 m.
SATURDAY: Cloudy with isolated alpine flurries; 3-5 cm. / Moderate, southwesterly winds / Alpine high -4 C / Freezing level 1500 m.
On Tuesday, several natural loose wet avalanches to size 1.5 were reported on northerly aspects below 2000 m. There are currently very few professional observers submitting daily observations. Please submit your observations to the MIN. Photos of avalanches or current conditions are particularly useful.
On Saturday, numerous natural loose wet avalanches up to size 1.5 were reported on all aspects/elevations.
Last Friday, Numerous loose wet and slab avalanches to size 2.5 on all aspects in the alpine were reported. Although not in this region, check out these two MINs from Saturday in Glacier National Park HERE. and HERE
5-15 cm. of new snow sits on a crust everywhere except high north facing terrain. Wind slabs created by last weeks storm may still linger in lee terrain below ridgetops. A layer of surface hoar (weak, feathery crystals) in the upper snowpack could still be reactive to human triggers in isolated locations such as high elevation, north facing terrain.
Below treeline, snow is disappearing rapidly.
Strong solar radiation may increase the likelihood of triggering lingering winds slabs on lee features below alpine ridgetops.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- Pay attention to changing conditions with elevation/aspect.
- Use small slopes without consequence to test the bond of the recent snow.
Aspects: North, North East, East, South East, North West.
LikelihoodLikely - Possible
Expected Size1 - 2
Strong solar radiation may trigger loose wet avalanches on steep terrain; especially at upper elevations where there is new snow.
- Avoid terrain traps such as cliffs and gullies that increase the consequence of small avalanches.
- A moist/wet snow surface, pinwheeling and natural avalanches all indicate a weakening snowpack.
- Cornices become weak with daytime heating, travel early on exposed slopes.
Aspects: All aspects.
Elevations: Alpine, Treeline.