Avalanche Forecast
Regions: Cascades - South East.
The avalanche danger is expected to be low Wednesday east of the crest. Watch for non-avalanche terrain hazards due to the thin snowpack. Be prepared to self-arrest if traversing steep and icy slopes.
Detailed Forecast
Sunny mild weather should be seen at higher elevations through Wednesday. Low clouds or fog will probably persist at lower elevations east of the crest. This should not significantly change the snowpack or overall low avalanche danger east of the crest. Previous loose wet avalanches, previous consolidation and low solar input should make more loose wet avalanches very unlikely. Loose wet avalanches will not be indicated as an avalanche problem but watch for soft wet snow on steep solar slopes or initial natural releases that would indicate conditions are be different than expected.
The only highlighted avalanche problem east of the crest will be in the Central Zone where the likelihood of triggering a persistent slab is considered very low.
On backcountry travel safety note, watch for terrain hazards (exposed rocks, trees, streams, etc.) at lower elevations and on wind scoured aspects. On non-solar aspects with a slick and supportable crust, take extra caution when traversing steep slopes and be prepared to self-arrest if necessary.
Note that an increasing avalanche danger should begin Thursday afternoon mainly in the Olympics and north Cascades.
Snowpack Discussion
East of the crest about 6-12 inches of snowfall on 4 January was followed by about 1-3 inches of rain on 5 January with a warming trend. This led to a natural avalanche cycle east of the crest. In the northeast Cascades at higher elevations more of the precipitation fell as snow before precipitation ended than elsewhere.
Dry and unseasonably warm weather followed last week. This drained, further consolidated and generally reset the upper or entire snowpack. There were also some loose wet avalanches east of the crest. Melt-freeze crusts of varying thicknesses formed over stabilized snow. Some windward or southerly aspects probably have little snow cover.
Backcountry skier/pro patroller Dan Veenhuizen was on Mt Cashmere last Tuesday and noted debris from large avalanches from 4 and 5 January. At 6900 ft he found what should be the December facet layer at about 90 cm below the surface but it was not reactive in an ECT. Also from this cycle, the North Cascade Mountain Guides reported widespread large avalanches up to size D3 in the Washington Pass area, including reaching Highway 20 but not crossing the closed road.
Facet layer in a pit on Mt Cashmere on Tuesday by Dan Veenhuizen.
The Mission Ridge pro-patrol on Friday reported that the wet and warm weather had stabilized the upper snowpack and formed a supportable crust in most areas. Depth hoar involved in large skier triggered avalanches in this area around the New Year remained intact but unreactive to explosives on previously uncontrolled slopes. While it is highly unlikely for a human to trigger a persistent slab down to this layer we will continue to call this avalanche problem out in the central east zone.
Minor weather systems were seen over the weekend. Sunny weather with mild temperatures at higher elevations has returned this week which has not significantly changed the overall stable snow pack. No avalanches have been reported for several or more days east of the crest.