Northwest Mountains

Stick to low-angle terrain — slopes consistently under 30 degrees — if you want to enjoy the feet of recent snow without rolling the dice. Last week's storm load has overwhelmed our weak snowpack, and the slabs are often thick enough that you won't get clear warning signs before triggering a large, deadly avalanche. The steady drumbeat of large remote triggers locally, and fatalities in neighboring regions, is all the feedback we need.  The most dangerous terrain remains west, north, east, and high-elevation southeast aspects. Wind-sheltered southerly slopes offer lower hazard, but once the snow surface gets wet, expect small wet-loose avalanches to enter the picture.

Although we're a few days past the loading event, our travel advice has largely remained the same.  The Elk Mountains continue to see large to very large remote triggers from mellow terrain adjacent to slopes steeper than 30 degrees. The most recent examples: Elk Creek yesterday (photos), 1000-foot remote trigger(s) from Ashcroft yesterday (video), amazing remote on Carbon on Sunday (video), and a long remote trigger on Saturday (video).  Our fieldwork supports a common pattern we often see following big loading events on bad weak layers:  on average, sensitivity is more stubborn where slabs are thickest and hardest in the snow-favored Ruby Range. The softer, thinner slabs are still highly reactive near and east of town, with a gradual transition between these two setups near our forecast boundaries.  The natural flush also appears to be more extensive along the higher elevations of the Ruby Range. Using the Russian Roulette analogy, the number of bullets in the chamber varies depending on where you are in the zone, but all of those bullets are deadly.  Two more avalanche fatalities on Sunday (Idaho, Utah) underscore the seriousness of conditions as much of the West faces a similar setup: an unusually shallow and weak snowpack finally loaded by a significant storm last week.  This video from yesterday highlights that even in the snow-favored parts of our forecast area, slabs are thin enough for human-triggered avalanches, and the snowpack below is still quite weak.  Another example I'll point to is from our fieldwork near Daisy Pass on February 11th, the day that our drought layers started getting buried.  Some northerly facing start zones in the Ruby Range held a 12" snowpack composed of large, fragile depth hoar - a terrible pre-storm setup that I can't recall ever seeing in the Ruby Range in mid February.  Because of the potential size (D2 to D3) and poor snowpack structures, conservative travel is recommended across our entire forecast area.  

The potential for large, natural releases has diminished significantly, but we can't completely rule them out yet.  Today starts warm and sunny, and we could see wet loose activity develop again before cloud cover increases later today.  Tomorrow's snowfall looks to be rather minor, but with increasing winds, there's isolated potential for a large to very large natural release, given our weak layer behavior patterns.