This is the final daily avalanche bulletin for the season. We will update if there are significant changes. Contact the Visitor Safety staff at Rogers Pass for help with safe trip planning in the spring and summer seasons.
Weather Forecast
Check out the following websites to help forecast the mountain weather:https://www.snow-forecast.com/ https://spotwx.com/ (drop a spot on the map to find weather models)
Snowpack Summary
Melt/freeze crusts exist on all but high North slopes. Deep persistent layers are becoming reactive as the snowpack warms up. See the weather station link below to see if there is an overnight freeze. Stations like Fidelity will indicate precipitation and temperatures, while Round Hill and Macdonald West Shoulder are good for wind loading patterns.
Avalanche Summary
Very large and impressive avalanches were triggered by avalanche control yesterday, including size 4's off of Avalanche Crest. Several naturals to size 3.5 occurred from all aspects. Wide, deep crown lines indicated that deep persistent layers are still reactive and that the snowpack is capable of producing very large and destructive avalanches.
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.
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.
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.