Avalanche Forecast
Issued: Mar 8th, 2019 4:23PM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate -
Weather Forecast
FRIDAY NIGHT - Mainly cloudy with clear periods / northwest winds, 10 km/h / alpine low temperature near -12SATURDAY - A mix of sun and cloud / northwest winds 10 km/h / alpine high temperature near -11SUNDAY - Mainly sunny / northwest winds 10-15 km/h / alpine high temperature near -9MONDAY - Flurries, 5-10 cm / south winds 20-40 km/h / alpine high temperature near -6
Avalanche Summary
On Friday, there were preliminary reports of a natural wind slab avalanche cycle to size 2.5 in the neighboring Glacier National Park region.On Thursday, there were several reports of human triggered wind slab, storm slab and loose snow avalanches, size 1-1.5, and natural loose and storm slab avalanches up to size 2.5.On Wednesday, a size 2 persistent slab avalanche was triggered by a cornice failure on a southeast aspect in the alpine. This avalanche reportedly failed on the late-January persistent weak layer.Persistent slab avalanche activity on the buried surface hoar layers (described in more detail in the Snowpack Summary) has tapered significantly. This has evolved into a low likelihood avalanche/high consequence avalanche problem at treeline and below.
Snowpack Summary
15-35 cm of recent storm snow is sitting mainly on wind slabs and facets (sugary snow), as well as surface hoar (feathery crystals) in sheltered areas and a crust on sun exposed slopes. There are two weak layers of surface hoar in the upper snowpack that were buried in late January and early February. They can be found between 40-90 cm below the surface. These layers consist primarily of surface hoar, though they may be associated with crusts on steeper, south facing slopes. These weak layers are most prominent at lower elevations, especially below treeline. The lower snowpack is generally considered to be strong, except for shallow, rocky areas where the cold temperatures continue to facet (weaken) the snowpack.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Mar 9th, 2019 2:00PM