Avalanche Forecast

A weak front should pass overnight Monday, followed by light showers tapering off Tuesday morning. Another frontal system is expected late Tuesday afternoon and night.  

New, shallow wind slab should be found mainly on lee north to east slopes near and especially above treeline. Generally avoid wind loaded slopes above treeline.  

Older storm slabs should have mostly settled and stabilized with some new storm slabs possible. Choose lower angled slopes if you find sensitive storm layers.  

Persistent weak layers have had a good test over the weekend from new loading. For slopes that have not released on these layers, the likelihood of triggering is slowly decreasing, but the consequences are increasing as the slab depth increases. Storm slabs that step down to persistent weak layer depths could become large enough to bury, injure or kill.

Wind slab should be found mainly on the lee northwest to east slopes near and especially above treeline. Generally avoid wind loaded slopes above treeline.  

There have been numerous reports of large tree bombs with the recent snowfall and fluctuating snow levels. Watch for the hazard above! 

Two fair weather periods earlier this month allowed surface hoar and near surface faceting to occur. These persistent weak layers were buried intact on Jan 3rd and 11th and have been reported as late as Monday the 18th from the Northeast WA Cascades in the Methow, the Icicle Creek drainage, the Blewett Pass area, the Nason Ridge area and Chiwaukum range east of Stevens Pass?. It's safe to say this layer is extensive throughout the east slopes.

On Monday the 18th, NWAC observer Tom Curtis found this layer buried from 30-35 cm and indicated propagation with PST and ECT tests. A 50 foot crack also released upon approach to a north facing starting zone near Diamond Head, also indicating this layer remains reactive. These weak layers are most likely to be found on non-solar (northerly) aspects and in the upper portion of the below treeline and the near-treeline elevation bands along the east slopes.

Jeff Ward found this layer on shaded slopes up to about 5000 feet Sunday in the Early Winters drainage. This layer was reactive and was remotely triggered by a solo traveler below treeline, prompting very cautious terrain selection of lower angled slopes.   

On Sunday, Scottish Lake High Camps reported a natural 12" slab release on a southerly aspect around 5000' and easily identified two buried surface hoar layers in N-NW snowpits at 5500 feet. 

On Saturday Mission Ridge pro-patrol found easy 6-8" ski cuts on lee aspects near and above treeline involving new storm snow.  It is thought that the buried surface hoar previously found in the Mission Ridge backcountry on northerly aspects was likely thoroughly tested earlier in the week and no longer a widespread issue in this specific area.  However, just east of Blewett Pass a surface hoar layer was identified 1/13 in snowpack tests via the NWAC observation page.

Last week, reports via the North Cascades Guides from Delancey Ridge Wednesday saw easily triggered wind slabs of about 20-25 cm on the north and south slopes at about 6000 feet which was releasing on a persistent layer crust sandwich buried on January 11th. Natural avalanches were also heard in the area.