Northern New Mexico

Dangerous avalanche conditions continue to exist as strong winds and recent snow, have created 4 to 6-foot cohesive slabs. These slabs will be stiffer and deeper at upper elevations on the leeward sides of ridgelines and cross-loaded terrain features. Triggering an avalanche near the surface can be large and dangerous on its own, but could also step down into deeper weak layers near the ground and in the middle of the snowpack.  These deep persistent slab avalanches would be very large and most likely unsurvivable. Avoid slopes where you notice obvious signs of instability like shooting cracks or loud audible collapses. Sticking to wind-sheltered, lower-angle terrain without steep slopes overhead will provide safer and better riding conditions. 

It's a cold start to the morning for this time of year with temperatures mainly in the single digits.  Winds overnight and yesterday have been in the teens with gusts in the 20's.  Today will see a series of shortwave troughs crossing through central NM which will bring increasing clouds and stronger winds by mid-day and a better chance of snow this evening.  Over the last week, we've picked up snow every day from a series of Atmospheric River (AR) events that have brought 40 + inches of snow and about 4.7 - 6" of snow water equivalent (SWE). 

Moderate to strong westerly winds over the last couple of days, have been transporting and drifting snow into stiff slabs. The strong winds and dense heavier snow with the second AR event have led to a mostly upside-down set-up within the storm snow. Stiffer, firmer snow on the surface rests on top of lower-density snow from earlier in the week.  With such strong winds, you may encounter more loading than you might expect further down the slopes.  At upper elevations, these slabs will be hard and may feel supportable on the surface, which can lead to avalanches breaking in unexpected ways, oftentimes well above you.  Most avalanches triggered will take place within the new snow but could create a one-two-punch scenario where a large avalanche within the storm snow, steps down to create a very large avalanche on deeper weak layers. 

The persistent weak layers near the ground that has plagued us much of the season are facing a significant test from the wet heavy snow, and will need time to adjust to this significant loading event. SWE totals over the last week from the two AR events are at 5 - 6" . For context, we had less than 5" of SWE for the water year on January 1st at the Snotel Powderhorn site. This has been a significant amount of loading as the SWE from the last week of storms accounts for a little under a third of the water we've received this year.    Near and below treeline terrain is where depth hoar near the ground continues to linger and remain reactive in a relatively shallow snowpack (< 1.5 m) prior to last week's storm.  At upper elevations, there's still a threat of triggering an avalanche near the ground, but most slopes have a deeper snowpack where impacting these layers would be more difficult but may not be impossible with such a significant amount of loading. In the middle of the snowpack, small-grained facets sandwiched between harder slabs and faceted crusts have been observed but are not widespread.  Most of these layers have been found on north and easterly aspects near and above treeline.  These storms over a week period will be the biggest snowfall events of the season and may push us to a tipping point where we see deep persistent slab avalanches releasing naturally.