Northern New Mexico

An Avalanche Warning is in place today into Thursday. Continued heavy snowfall and strong winds will create very dangerous avalanche conditions at all elevations. Natural and human-triggered avalanches are likely.  Storm slab avalanches could break on the old snow/new snow interface and be 4 plus feet deep and able to break widely across the slope or step down into deeper weak layers in the snowpack.  Persistent slab avalanches are likely on weak layers near the ground or in the middle of the snowpack.  

Traveling in and around avalanche terrain is not recommended. Avoid being on or connected to slopes steeper than 30 degrees giving avalanche path runouts wide berths as we could see very large natural avalanches running long distances into the flats and valley bottoms below.  

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 4.55" of snow water equivalent (SWE).  Strong SW flow will bring more snow today through the evening, where we could pick up an additional 12 - 18 inches of snow.   The first storm from last Wednesday through Saturday brought low-density snow with light winds as it was a mostly right-side-up storm.  The second system from Monday through Wednesday has come with higher snow levels (9000') and heavier denser snow with strong W/SW winds.  Winds overnight have been in the 20 to 30 mph range with gusts in the 50-60s.  This has led to mostly an upside-down set-up within the storm snow over the last week.  

With an abundance of snow available for transport before this second AR event, storm slabs have been growing and stiffening over the last couple of days and may now be 4 + feet deep on the leeward sides of ridgelines and cross-loaded terrain features.  Natural avalanche activity within the storm snow is likely today and there's the real possibility of storm slab avalanches stepping down into deeper weak layers as they travel down the slope.  This one-two punch could produce very large and unsurvivable avalanches, If you are feeling the need to get out, be sure to give avalanche path runout zones wide berths as we could see avalanches running well into the flats below.  

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 most likely will struggle to handle this significant loading event. SWE totals so far over the last week are at 4.55" and an additional foot of snow and strong winds are forecasted through the evening that could push us close to 6" of SWE for the week. For context, we had less than 5" of SWE for the water year on January 1st at the Snotel Powderhorn site.  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 not 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.

It might be best, to let mother nature run its course over the next several days, or head inbounds at a resort to make some powder turns. Traveling in and around avalanche terrain is not recommended as we may see very large natural avalanches that are capable of running long distances well into the flats and valley bottoms below.