Avalanche Forecast

Colder air trapped along the east slopes and easterly flow near the Cascade crest should translate to a slow warming trend on Tuesday despite mostly sunny skies near and above treeline.  

E-SE winds should be light, except moderate near the Cascade crest for the central and southeast Cascades. This will locally help redistribute recent snowfall to non-traditional westerly aspects forming generally shallow but potentially touchy windslab. New wind loading should primarily occur in the near and above treeline elevation bands, but may still be possible below treeline depending on local loading patterns.  

Watch for new or previous firmer wind transported snow on a variety of aspects Tuesday: Don't let the combination of Moderate avalanche danger with non-traditional lee aspects/cross-loaded slopes catch you by surprise!  

A secondary avalanche concern on Tuesday will be loose wet avalanches on solar slopes. Despite cool freezing levels, late February sunshine should activate steeper solar slopes as the day progresses. Watch for pinwheeling and rollerballs as precursors to more significant loose wet activity and especially be wary of loose wet avalanches around terrain traps. 

Weather and Snowpack

Dry weather with the warmest temperatures of the winter occurred February 7-10th with temperatures climbing into the 50's in most areas east of the crest. Snow in the northeast zone buried the crust with about 2-3 feet of snowfall starting February 11th through Saturday morning.

Rain and mild temperatures were seen in the central east and southeast zones last week forming a newer crust further south and outside the Washington Pass zone. An active and cooler pattern buried the crust in the central and southeast zones starting February 17th with about 6-10 inches of storm in the near and above treeline Wednesday through Saturday morning.

A weak front on Sunday only brought up to a few inches of additional snowfall through Monday morning.

Recent Observations

The North Cascades Mountain Guides sent a report Friday for the Washington Pass area and report that the February 11th crust is found at about 65-80 cm down. Some but not all tests give hard sudden collapses with sudden propagation. Also some stiff pencil hard wind slab gave easy shears near or below ridgelines with some sensitive wind slab avalanches observed on NE aspects during the middle of last week.

The pro-patrol at Mission Ridge Saturday reported pockets of ski triggered 6-14 inch wind slab during avalanche control on northeast to southeast slopes above about 5800 feet. These slab were releasing on the February 17th crust. Later today a skier triggered a 6-10 inch wind slab and was caught and carried but not injured in a northeast facing chute at about 6300 feet.

Large avalanches that are sensitive to skier triggering continue to be noted north of the border releasing down to the Feb 11th crust. Although nearby, avalanche activity either natural or skier triggered have not been observed in the Washington Pass zone down to this crust, but this is still relevant information to keep in the back of your mind if traveling around the NE Cascades.