Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Feb 12th, 2019–Feb 13th, 2019

Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.

Regions

.

Give the snowpack time to adjust to the new snow. Use extra caution around slopes steeper than 35 degrees. The most dangerous avalanche conditions exist near above treeline where the wind drifts new snow and where older stiff slabs are buried on south and west aspects.

Discussion

Snow and Avalanche Discussion

The Mt. Baker area received over two feet of new snow (1.20in SWE) in the past two days, the majority of which fell overnight on Monday. The storm brought a slight warming trend and was accompanied by little wind. The new snow is very light, cold, and cohesionless in most areas. Natural and triggered loose dry avalanches were reported Tuesday in steep terrain near and above treeline. Natural slab avalanches were reported Tuesday as well - up to 12in thick and 50ft wide failing within new snow. Snowfall should taper off overnight, light to moderate winds will continue to blow from the southwest, and skies may clear by the afternoon on Wednesday.

Avoid southeast through southwest slopes where you find stiff slabs below the snow surface. The new snow has hidden older slabs, formed on February 9th, by north and east wind. This wind event created unusual wind loading patterns. On southeast through southwest aspects near and above treeline, these stiff slabs sit on a layer of weak sugary facets with an underlying crust. This was the snowpack structure at the site of a remotely triggered avalanche on Sunday:

This large, remotely triggered wind slab avalanche occurred near Ptarmigan Ridge in the Mt Baker backcountry. The avalanche was approximately 2 feet deep and failed on a layer of sugary facets. Unusual avalanches like this should cause us to take notice. Avalanche details: SW aspect, 5200 ft. 45-degree slope. Lee Lazarra Photo

Snowpack Discussion

New Regional Synopsis Coming Soon

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.