Lots of recent new snow and rain with many reports of touchy avalanche conditions. Pay close attention to any solar radiation we may receive later today as it will likely induce natural avalanche activity.
Weather Forecast
Unsettled weather for the next few days. Mostly cloudy this morning with light flurries/rain with possible clearing later today. Freezing levels are expected to rise to 1550m. Similar weather for tomorrow but with slightly cooler temperatures. Alpine winds are forecast to stay light for today and tomorrow.
Snowpack Summary
40-45cm of recent storm snow above 1800m, much of that fell as rain below that elevation. The upper snowpack is a complex mix of crusts, facetted snow and surface hoar which have been reactive to skier triggering as slab and loose avalanches. Below 1900m the top 40cm of the snowpack is moist.
Avalanche Summary
Yesterday there was a small natural avalanche cycle, numerous avalanches to size 3 in the highway corridor east of the Rogers Pass summit. Backcountry user reported very touchy conditions just west of the Park below 2000m releasing avalanches 30-60cm deep. 2 days ago, a field team ski cut moist avalanches to size 2 running far on Grizzly Shoulder.
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.
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.