South Rockies

Cooling is on the way but likely not in time to reduce the hazard on Saturday. Human triggering of deep persistent slab avalanches remains possible.

Moderate - Track of incoming weather systems is uncertain

FRIDAY NIGHT: Clear skies / Light, westerly winds / Alpine low 0 C / Freezing level dropping to 2500 m.SATURDAY: Increasing cloudiness in afternoon / Light, easterly winds / Alpine high 1 C / Freezing level dropping to 2000 m.SUNDAY: Cloudy with flurries; 3-5 mm. / Light, easterly winds / Alpine high -3 C / Freezing level 1700 m.MONDAY: Sunny / Light, westerly winds / Alpine high 0 C / Freezing level 2000 m.

On Thursday, there were numerous reports of skiers triggering what started as small loose wet avalanches and then gathered mass and entrained the entire snowpack to the ground running much further than expected, up to size 2. Check out this video from our South Rockies Field Team HERE.On Wednesday, an explosive control mission produced an avalanche with every shot placed (nearly 20 in total). They were loose wet avalanches on sun-exposed slopes and dry, slab avalanches on northerly aspects, up to size 2.5. Additionally, large (size 2-2.5) loose wet natural avalanches continue to occur on solar aspects.A report from our South Rockies Field Team on Tuesday in the Elk Valley described numerous natural persistent slab releases reaching size 2 (large) on southeast aspects at around 2200 m. Further to this activity, any sun-exposed snow became isothermal (slushy and cohesionless), and large whumpfs that collapsed the basal snowpack were triggered during ski touring. Check out their video HERE.

Upper snowpack: Getting warm and moist during the day, likely forming weak crusts overnight that deteriorate during the day. On sunny aspects the upper snowpack has become increasingly isothermal (slushy and cohesionless) with successive days of warming. Mid pack: The mid-snowpack consists of weak facets (sugary snow) and layers of harder wind effected snow. Recent loose wet avalanches have been entraining additional mass by gouging into this faceted snow. These facets have also acted as a failure plane in recent slab releases.Lower pack: The strength of the lower snowpack is increasingly in question in shallower areas where the February cold was able to weaken basal (bottom of the snowpack) layers and warm temperatures are increasing the strain on these weaknesses each day. Many of the recent slab avalanches failed on these facets sitting just above the ground.