Avalanche Forecast

A weak dissipating front should move through an upper ridge and across the Northwest on Thursday. This should cause some light rain or snow in most areas west of the crest with a minor drop in snow levels. Offshore surface flow should cause cool east winds in the lower Cascade passes. A light wintry mix of precipitation seems possible at the lower Cascade passes mainly Snoqualmie.

This weather should have limited effects on snow conditions.

Mainly watch for lingering areas of firmer wind transported snow and wind slab on previous lee slopes from the back end of the storm early this week.

New snow amounts should be limited on Thursday and any new wind slab should be unlikely, shallow and small if any.

Loose wet avalanches will not be indicated due to the cloud cover and cooling. Storm slab will also not be listed due to the expected limited amounts of new snow. 

Strong southwest flow carried a wet front across the Cascades Saturday night. The front tapped subtropical moisture which pushed snow levels high and resulted in 2-3 inches of rain for most NWAC sites west of the crest Saturday night. Exceptions were in the passes were Stevens which stayed snow and Snoqualmie which saw freezing rain. Stevens had skier and natural activity Saturday night and Sunday morning.

Snow on the back end of this storm Sunday and Monday was mostly in the 8-15 inch range except Stevens Pass where the extra from Saturday night caused a total of about 25 inches. This storm snow generally bonded well to the wet grains and rain crusts west of the crest. No significant avalanche activity was reported west of the crest by professionals Monday or Tuesday except at Stevens Pass. Both Monday and Tuesday mornings the patrol at Stevens triggered 15-20" soft wind slabs on N-NE aspects of Cowboy Ridge, releasing down to the wet grains from early Sunday.

Here is a video from Monday by NWAC pro-observer Dallas Glass at Stevens Pass via our YouTube Channel. 

A gaggle of NWAC pro-observers in Moonlight Bowl/Skyline area Tuesday at Stevens Pass found wind transport on N-NE aspects near treeline but no wind or storm slab. Storm layers reported by observers and on our observation page that failed in column tests were not propagating.

Some sun with mild temperatures is being seen west of the crest on Wednesday. Small loose wet avalanches might be possible on steep solar slopes. East winds are causing cooler temperatures in the Cascades passes.

Below the most recent storm snow, the middle and lower snowpack should consist predominately of melt-freeze grains and crusts from warm periods this winter.