Avalanche hazard will likely increase throughout the day, be sure your plans allow for a safe retreat from the mountains.
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Synopsis: The front breaks down Wednesday night opening the door to zonal flow. A series of weak disturbances should deliver daily precipitation through the weekend.Thursday: Freezing Level: 1000m - 1700m; Precipitation: 1:6mm - 1:10cm; Wind: Treeline: Light, S | Ridgetop: Strong, SWThursday Night: Precipitation: 1:8mm - 1:15cmFriday: Freezing Level: 1100m - 1700m; Precipitation: 1:5mm - 1:10cm; Wind: Treeline: Moderate, SW | Ridgetop: Strong, SWFriday Night: Precipitation: 1:5mm - 1:10cmSaturday: Freezing Level: 1300m - 1900m; Precipitation: 1:6mm - 1:10cm; Wind: Treeline: Light, SW | Ridgetop: Strong, SW
Avalanche Summary
Warming temps induced cornice fall Tuesday. A notable event occurred on a NE facing slope at 2100m when a falling chunk of cornice triggered a small slab immediately below the ridge. The avalanche in motion stepped down to what was likely the late March crust resulting in a size 2.5 avalanche. Another large natural avalanche was reported from a W/SW facing feature at 2300m. This one failed on the same interface, likely initiated by Tuesday's intense solar.
Snowpack Summary
The snow surface is a mix of surface hoar and melt freeze crusts.Recent warm temperatures have helped to settle and strengthen the upper snowpack. Down 15 - 70 cm below the surface, snowpack tests are still producing results on the late March crust.The mid March surface hoar/ crust interface now down 80 - 110cm seams to be decreasing in it's sensitivity to triggering.The early-March crust/facet layer is down about 100-150 cm and the early February layer is now down close to 200 cm. These layers are largely dormant at this time.The lower snowpack is strong and well settled.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.