ARCHIVED Avalanche Advisory

Snoqualmie Pass
Issued: 6:18 PM PST Monday, April 10, 2017
by Garth Ferber

The Bottom Line: Watch for recent and new wind slabs on lee slopes in steep terrain mainly above 
treeline. Sun breaks can quickly create loose wet avalanche conditions on steep solar slopes. 
Give cornices a wide safety margin.

All Elevations, Tuesday - Moderate - Heightened avalanche conditions on specific terrain features. 
Evaluate snow and terrain carefully; identify problem features.

Avalanche Problems for Tuesday

Wind Slab

Wind slabs can take up to a week to stabilize. They are confined to lee and cross-loaded terrain 
features and can be avoided by sticking to sheltered or wind scoured areas.
    Likelihood - Possible
    Size - Small to Large

Loose Wet

Loose wet avalanches occur where water is running through the snowpack, and release at or below 
the trigger point. Avoid terrain traps such as cliffs, gullies, or tree wells. Exit avalanche 
terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.
    Likelihood - Possible
    Size - Small to Large

Cornicesi

Cornices are easy to identify and are confined to lee and cross-loaded ridges, sub-ridges, and 
sharp convexities. They are easiest to trigger during periods of rapid growth (new snow and wind), 
rapid warming, and during rain-on-snow events. Cornices often catch people by surprise when they 
break farther back onto flatter areas than expected.
    Likelihood - Unlikely
    Size - Large to Very Large