Northern New Mexico

Dangerous avalanche conditions persist in mountains today where cohesive slabs up to several feet thick sit on top of a weak, faceted snowpack. The most dangerous slopes are northerly, East-facing, or cross-loaded terrain near and above treeline, but you can still trigger a slab avalanche below treeline primarily in open or exposed steep terrain.  Loose snow avalanche activity will increase today on steep northerly terrain at lower elevations or any areas that are seeing a lot of direct sunlight.  These smaller surface level avalanches aren't all that consequential on their own, but in our situation they could step down into deeper weak layers.  Sheltered, lower-angled terrain will provide the safest riding and travel conditions today. 

It'll be another beautiful, calm day to finish out the weekend.  Snowfall over the last week (19-25" since Valentine's Day) has done wonders for travel in the mountains and there's a lot of enticing turns to be made out there, at least for the moment.  Unfortunately, a lot of the enticing terrain that's steep enough to slide harbors strong potential for persistent slab avalanches, and these are the kinds of avalanches you do not want to be involved in.  As you head to enjoy the improved conditions on this nice sunny Sunday, stick to a conservative plan and resist the temptation to ride big lines.  In travels yesterday, we spotted about 8 different natural avalanches in our small zone, many of which were size 2 (large enough to bury or fatally injure a person).  These avalanches likely occurred on Friday during the heaviest snowing and loading, but today marks only the second day since this last storm, and many similar slopes remain primed for a human to trigger them. 

The most dangerous slopes at the moment are near and above treeline, where the slabs are larger (up to 2 or 3 ft thick) and more consistent across the slope.  A faceted weak layer that formed during the early February dry period got buried during the Valentines Day storm.  In some cases these facets sit underneath a crust, but regardless the issue is that they remain close to the surface and easy to impact as a traveler.  We've had easy propagating test results on this layer as well as very short PST cuts, indicating that the facets are extremely weak and the slabs that cap them are intact.  While persistent slab avalanches would be easiest to trigger on this particular layer, they could also gouge down into depth hoar near the ground and send most of the season's snowpack downhill.  Loose snow sluffing will start to occur more readily today thanks to the warmer temps, late-February sun angles, and light winds.  It wouldn't be difficult for any smaller loose snow avalanche to step down to one of these layers of weak facets and cause a big destructive slide.  So to keep things simple, it's best to stay off and a decent distance away from the avalanche terrain at these upper elevations.

Below treeline, it's a little bit of a different story as these cohesive slabs are a still harder to find but the snow just below them is awfully weak.  The strong winds last week stripped many areas in the woods and deposited the storm snow in others, making the slab component more variable.  However, the clear weather and warming this weekend has already caused some settling and stiffening of the existing slabs, and this can cause the slab to become more reactive.  This setup can still lead to avalanches, particularly in open and exposed areas that were loaded rather than stripped.  Avalanche mitigation teams had a few significant results yesterday in these kinds of places, where the avalanches triggered ran close to the ground.  Since below treeline areas offer some of the safest riding overall, continue to do your due diligence and look for this strong-over-weak setup as you approach steeper areas before hopping into them.  Any obvious red flags like big shooting cracks or collapses are strong suggestions to stick to lower-angle, more sheltered terrain.

This upcoming week, we delve head-first into a late winter drought.  Conditions will evolve in the coming days as the snowpack takes on large daily temperature swings and the slabs change.  Some of the best soft powder conditions we may see this winter are currently out there, but take our advice to heart and be conservative today so that you can come home safe.