Avalanche Forecast
Jan 22nd, 2019–Jan 23rd, 2019
Alpine
3:
Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3:
Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2:
Moderate
The avalanche danger rating below treeline will be moderate
Alpine
3:
Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2:
Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
2:
Moderate
The avalanche danger rating below treeline will be moderate
Regions: Cascades - West.
The Bottom Line: New and thick storm slabs should form overnight and into the morning as a moisture-laden winter storm impacts the West - Central region. You will be most likely to trigger avalanches in locations above the overnight rain/snow line where more than 8 inches of snow accumulated, or the wind drifted the snow to greater depths. You can avoid triggering an avalanche by staying away from open slopes greater than 35 degrees.
Snow and Avalanche Discussion
A winter storm is impacting the West-North area Tuesday night into Wednesday morning. We don’t know whether the impressive forecasted ~1.5†of overnight snow water equivalent will materialize. We expect avalanche danger to peak overnight during the heaviest precipitation and warmest temperatures which are expected to occur Tuesday night. Avalanche danger should then slowly decrease throughout the day as precipitation ends and temperatures cool. However, avalanche danger may increase locally during periods of heavier snowfall under an anticipated convergence zone which may develop near or north of Stevens Pass.
Two small skier triggered avalanches were reported to the north of this zone in the Mt Baker backcountry Tuesday. These small slides highlight the presence of a firm crust below the recent snow. Avalanches Wednesday could slide on this old crust allowing them to run farther and faster.
Avalanche Problems
Loose Wet
This warm system will bring rain up into the near treeline band. The Loose Wet avalanche concern will peak overnight or early in the day as rain and warmer temperatures continue to add liquid to the snowpack. These can ruin your day particularly if they push you into a trap or obstacle or over a cliff. Cooling temperatures should limit this problem to below treeline during the daytime hours.
Aspects: All aspects.
Elevations: Below Treeline.
Likelihood: Possible
Expected Size: 1 - 1
Storm Slabs
We expect new snow to fall with warming temperatures and moderate winds. This should create upside-down storm snow. If this occurs, you will be to trigger avalanches on open slopes greater than 35 degrees. Avalanches will grow larger and be easier to trigger as you go up in elevation, or venture into areas where the wind drifted the new snow. You can use small slopes to test the storm snow. Has the area received more than 8 inches of new snow? Do you see cracking? Can you feel stronger snow over weaker snow? Do you see signs of wind drifted snow? When you answer yes, storm slabs are nearby.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 2 - 2