Avalanche Forecast

Another potential major wet loose avalanche cycle is likely during frontal passage and heavy rain or snow at warmer temperatures Saturday afternoon and night. Cornice failures are also likely during that period.

But rain or snow showers decrease rapidly on Sunday morning at slightly cooler temperatures. Significant new snow is not expected or should be very limited. A decreasing avalanche danger is expected on Sunday.

The main concern will be lingering wet loose snow avalanches. This is most likely on steep slopes that do not release on Saturday night. Watch for further pinwheeling of surface snow and wet snow still deeper than a few inches which often precede this type of avalanche. Loose wet avalanches may still entrain deeper wet snow and be large and destructive.

New small shallow of wind slab might be possible above treeline. The lack of new snow should limit this new concern. Watch for signs of firmer wind transported snow.

Small shallow new areas of storm slab might be also be possible above treeline. But again the lack of new snow and the cooling trend should greatly limit this concern.

Past

A two week storm cycle ended about 25 February that produced about 9 feet of generally wet heavy snowfall at Hurricane and avalanche cycles across the region.

Warm and mainly dry weather at the end of February led to wet snow avalanches and melt/freeze crusts throughout the region. 

The current storm cycle began last weekend with initially cool temperatures and poor bonds to the end of February crust in many areas. This storm cycle is turning out to be almost as wet as the last one! Water equivalents and snowfall for the current storm cycle will be about 5 inches but only about 2 feet of snowfall at Hurricane ending Sunday morning. This cycle has been producing many avalanches all week in the Cascades including reports from Holden Village, Stevens Pass, Tumwater Canyon, Alpental and Snoqualmie with pass closures at times last week.

Recent

A short break in the current storm cycle was seen on Friday causing some further consolidation and temporary stabilizing.

NWAC observers Tyler and Katie Reid on Friday reported wet and saturated upper snow pack layers with no positive snow pit test results but with numerous wet loose avalanches to size 2. Warming effects had penetrated quite deeply into upper snowpack layers.

Here is a video from Tyler and Katy at Hurricane on Friday.

A refreeze of wet snow surface on Friday night should have brought some temporary relative stability on Saturday morning.

The mid and base pack around Hurricane Ridge should still consist of stable crusts and melt form layers from periods of warm weather earlier this winter. Also in the below tree-line zone on solar aspects rain and mild temperatures may keep the shallow snowpack wet and unconsolidated.