Continued loading of the storm slab along with warming temperatures will lead to an increasing avalanche danger through the day.
Weather Forecast
A pulse of Pacific moisture will bring rising temperatures, moderate S winds and upwards of 15cm of storm snow. Freezing level should reach 1600m today. Thursday, Friday we should expect cloudy with sunny periods a trace of snow and winds SW creeping into the moderate range at ridge top.
Snowpack Summary
Glacier Park has received over 140cm of snow in the last 2 weeks accompanied by significant wind; expect to find windslab in the alpine and exposed treeline. Warming trend with more snowfall will assist storm slab formation over the Jan 16 surface hoar. The Dec 15 layer is now buried over 1m, Jan 4th is down ~65cm and the Jan 16th is down ~50cm.
Avalanche Summary
Highway avalanche patrol observed several Natural avalanches to size 2.5 from various aspects. One of note was a natural size 3 from Jan 21st in Crossover path possibly cornice triggered. Our field team observed a size 2 slide on E aspect, 1800m on steep skiable terrain that looked to be tree bomb triggered.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.