Northwest Mountains

Parts of the Ruby Range received up to 10 inches in the past 24 hours with a couple more inches expected today.  Natural avalanches are becoming far less likely than this past weekend, but leeward features will endure continued loading today increasing that concern.  Any triggered avalanche whether on drifted terrain or sheltered slopes will be at a minimum large enough to bury, injure, or kill you if not bigger.  Exercise cautious and conservative route finding by managing overhead hazard protecting against an unexpected remote trigger or natural avalanche.  Slope angles below 30 degrees that are not connected to or below steeper terrain will be your ticket to a safe day in the mountains.  

Last night's storm did not produce as much snow as expected with totals ranging this morning from 2 to 6 inches and a couple more inches expected today.  This means the Avalanche Watch was dropped and the danger rating will remain at CONSIDERABLE (level 3 of 5) today.  Even though the danger rating remains the same, avalanche conditions have changed a bit.  There is an increased concern for natural avalanche activity on drifted, upper elevation slopes particularly in the Ruby Range (NW mountains).  Westerly winds will move the recent snow onto leeward slopes which will keep the pressure on the snowpack and elevate the possibility for natural avalanches.  Natural avalanches starting in leeward features at upper elevations have the potential to break very large and run long distances to valley bottoms.  To help illustrate this potential size take a look at a video Zach Guy produced yesterday showing numerous destructive avalanches from this past weekend.  You can trigger an avalanche of this size by playing on drifted, upper elevation slopes as well as simply crossing below steep slopes.  Remote triggering a large or very large avalanche needs to remain on your radar and should be included in your route planning so that you prevent being caught off guard.  Moving through basins with overhead hazards or directly below steep slopes is a recipe for disaster.  Slabs and weak layers are well connected across the landscape and have the ability to break wider and run farther than you would expect. 

Sheltered terrain remains a concern as well.  Snowfall from the past 24 hours has not added much weight to the snowpack, but weak layers continue to adjust to the significant burden from the past few weeks of snow.  For snow favored areas in the Northwest Mountains, slabs are several feet thick and have become dense; this means that obvious signs of instability are decreasing.  The snowpack may not alert you to the hazard prior to dropping into a steep slope.  It is more a game of discipline than assessment right now.  Consider the consequences of triggering a slab several feet thick rather than attempting to guess at the likelihood of triggering an avalanche.  The expected avalanche size remains dangerously large even in sheltered terrain.  For areas with a shallower snowpack, like in the Southeast Mountains, slabs are thinner and are expected to be easier to trigger.  Recent observations from shallower snowpacks suggest below treeline slopes remain very sensitive to the weight of a person like this observation from Brush Creek a few days ago, or this one from the eastern Aspen Zone.  Weak layers were more developed and slabs are thinner resulting in the weight of a person easily causing failure.

The simplest solution to the current avalanche conditions is simple low angle terrain without overhead hazard.  The consequences of triggering an avalanche remain very high and look to remain there for the foreseeable future.  Be patient; steeper recreation opportunities will become safer at some point later this year.