Northern New Mexico

It continues to remain possible to trigger a large wind slab avalanche at upper elevations as strong winds over the last several days have drifted snow into stiffer harder slabs. You're most likely to encounter these wind slabs on the leeward sides of ridgelines and cross-loaded terrain features where you find smooth lens-like surfaces or obvious wind drifted pillows. Watch for obvious signs of instability like shooting cracks on the surface.  A wind slab avalanche could break close to 4 feet deep and be dangerous on its own, but could also step down into deeper weak layers creating a larger and more destructive avalanche. 

It definitely feels like spring here in northern NM as we're about to flip the calendar to April.  The birds are chirping, temperatures are warm and the winds have been cranking over the last several days. W/SW winds have been in the sustained 20 - 40 mph range with gusts in the 50's.  Today's going to be another carbon copy of the last several days but with stronger winds forecasted this afternoon ahead of the next system that arrives tonight bringing the next shot of snow. 

The main concern over the last several days has been wind slabs near and above treeline.  After last week's impressive 45-inch storm there was a lot of snow available for transport and strong winds have transported snow into stiffer hard slabs at upper elevations. We've had a couple of natural wind slab avalanches over the last several days.   These hard slabs will be supportable in spots and could feel hollow or drummy.  Hard slabs tend to break in unexpected ways oftentimes well above you. These wind slabs have failed on density changes, a graupel layer that formed during last weeks storm or in some cases the full depth of the storm snow on crusts.  

Temperatures have been climbing into the mid and upper 40's over the last two days, but strong winds have kept surfaces cool enough that we haven't seen a widespread loose wet snow cycle in the recent storm snow.  Temperatures today are expected to get into the low 40's with continued strong winds so decided to drop loose wet snow avalanches from the problem list, but you may find slopes at lower elevations that are slightly more protective from the wind that warms up quickly. Watch for signs of the surface warming, like rollerballs and pinwheeling or wet snow on the surface.  These avalanches would be small but could be difficult to maneuver out of in steep terrain. 

Deeper down in the snowpack faceted crusts and buried near surface facets from our late February and early March dry periods remained in the top meter of the snowpack before this latest round snow. This last storm was the first significant loading event since these layers formed and they seemed to hold up well. That said, avalanche control teams got a result the other day in uncompacted terrain where a new snow avalanche stepped down into deeper weak layers. Today, you're unlikely to impact these weak layers on your own, but if you triggered a wind slab avalanche or a wet loose avalanche, it could step down to these older weak layers as it moves downhill and picks up momentum.  

On some slopes before this last storm, the snowpack was shallow and depth hoar and basal facets continued to linger near the ground. Near and below treeline slopes on northerly aspects are where you're most likely to find these shallow snowpacks with lingering deeper persistent weak layers.  We haven't seen avalanches on these layers since end of February, but they continue to remain reactive with hard force in long column stability tests.  Before committing to a slope, try to identify what avalanche problems exist and what the consequences could be if you were to trigger an avalanche.  

Our last daily scheduled forecast for the season will be today.  We'll put out a General Spring Avalanche Statement and update the forecast if needed for big avalanche events if they warrant through April 21st.