Northern New Mexico

You can trigger a small wind slab avalanche in wind drifted areas above treeline. Slabs on the leeward side of ridgelines and in cross-loaded terrain could be upwards of a foot thick and resting on top of firm surfaces or buried near-surface facets. Avoid obvious wind-drifted pillows and pay attention to clues of stiffening snow, like shooting cracks on the surface. Evaluate snow and terrain carefully, identifying features of concern.

Warm temperatures and sunny skies today will increase the chances of loose snow avalanches in steep terrain on slopes that are directly in the sun.  These avalanches will be small but could knock you off your feet and be dangerous in consequential terrain.

Over the last week, we've had three quick-moving systems bringing a little bit of snow with each pulse of weather. All added up and snow totals are 6 - 12 inches over the last week.  This combined with moderate winds during this last system have created soft slabs that are a foot plus thick on the leeward sides of ridgelines and in cross-loaded gullies above treeline.  Use caution when approaching wind exposed terrain as these types of avalanches have the ability to propagate across terrain features.     

Wind sheltered northerly aspects are where the top 20 - 30 cm of snow before these last couple of storms has turned into weak facets. In steep terrain it was easy to push the top foot of snow to create a small loose snow avalanche. Recent low-density snow on top could make these sluffs bigger and problematic in high consequence terrain above cliffs. 

A warming trend is forecasted today with temperatures climbing above freezing under sunny skies and light winds.  Slopes that are directly in the sun should see the upper portions of the snow surface becoming wet, pinwheels and rollerballs are indications that the snow surface is becoming wet. These aspects are also where there are firm melt-freeze crusts that formed prior to these last storms from the mid-January warm spell.   These avalanches will be small but could push you around dragging you down the slope. You can avoid this avalanche concern by heading to a shadier aspect and colder snow. 

 The three weeks of high pressure to begin January has done a lot to transform the old snow surface before these last couple of storms.  These last couple of storms have fallen on a variety of different surfaces ranging from melt-freeze/sun crusts on solar aspects and lower elevation terrain, to old decomposing wind slabs in the alpine and weak faceted snow on wind-sheltered northerly aspects. All of these combinations of the old snow surface are making for a good sliding surface for any potential new snow avalanche.       

So what happened with the persistent slab problem of facets and depth hoar on or near the ground on northerly upper elevation terrain? In recent snowpits these layers continue to remain present in shallow snowpacks that are less than 4 feet deep but are taking hard force to fail and propagate or are not failing at all.  These persistent weak layers will continue to remain dormant for now until we wait for a significant load, where they may become more reactive.