Northern New Mexico

You can trigger a persistent slab avalanche up to several feet deep today.  Cohesive slabs rest on top of extremely fragile persistent weak layers, and this recipe for avalanches is widespread across much of the North and East facing terrain in our range.  Widespread cracking and collapsing continue to indicate that conditions are ripe for human-triggered avalanches. 

Potential avalanches will be larger at higher elevations.  Avoid being on or connected to slopes steeper than 35 degrees, as the current conditions lend themselves to remotely triggering avalanches from flats below or adjacent slopes.  Watch out for small wet loose avalanches today on lower elevation slopes that are getting a lot of sun. 

A significant warming trend commences today, and temperatures will climb well into the 30s today under clear sunny skies and minimal wind.  Daily highs will continue to push higher and we'll see some downright beachy weather in the mountains come Monday/Tuesday.  The snowpack has already starting to take some heat over the last few days, but this pattern will strengthen today and continue for nearly a week ahead of some possible early March snowstorms. We're keeping the avalanche danger at Considerable for one more day, but as the heat builds over the next few days we will see a transition towards strong melt-freeze patterns on solar aspects and upper-level faceting on North aspects.  We'll see wider wet-loose avalanche cycles during this period and start baking out or breaking down our slabs on the surface, which will decrease the danger but also create miserably sticky travel conditions.  Keep globstopper wax close at hand if you're heading into the backcountry at any point over the next few days, and keep an eye out for pinwheels or roller balls on slopes that are getting a lot of solar exposure.  These are signs that the snow is getting wet and could produce small wet snow avalanches.  These avalanches will be small today but could catch you off guard and carry you downslope as they entrain more snow.

The snowpack in Northern New Mexico remains well set up for human-triggered persistent slab avalanches, even with a week having passed since the last significant storm on Valentine's Day.  Our persistent weak layers are obviously still stuggling with the weight of new snow from that storm, which laid down cohesive slabs on the surface at all elevations.  Some additional light snowfall on Tuesday and sustained moderate SW winds throughout the week have continued to build out these slabs in terrain near and above treeline, incrementally loading our weak layers and helping propel incidences of human-triggered avalanches throughout the week.  Cracking and collapsing continues to be widespread in travels, and stability tests are failing with easy force on our persistent weak layers.  The weak layers we're most concerned about are the ones we've been talking about all season: very well developed depth hoar as well as faceted crusts that formed over the November to January drought period.  Between our northerly and easterly terrain, these weak layers are simply widespread and can also be found on some West-facing terrain near treeline.  In sheltered northerly terrain, buried near surface facets lie beneath the upper-level slabs and could pose a further issue, but the persistent slab problem remains the same.  Below treeline, slabs averaging 6 inches to a foot deep now sit on top of the weak snow, and have settled and stiffened a bit over the last several days.  Moving up in elevation to places where the winds continually loaded slopes over the last week, larger slabs up to several feet deep overlie the weak snow.  This strong-over-weak setup has been giving us tremendous evidence that it's primed to react over the past week, and this pattern will continue today.

We easily triggered this avalanche (size D2) several days ago while walking along the nearby ridgeline.  The slope is an East aspect near treeline at around 11,500 feet, and the slab failed on depth hoar. 

It's been an active week for avalanches in the region.  Natural avalanches (D Size 1 - 2) during the Valentine's Day storm - when we issued an avalanche warning - were mainly confined to below treeline terrain on northerly aspects above 35 degrees, where the fragile depth hoar below couldn't handle the added load.  On east and west aspects that had connected snow on them prior to the storm, melt-freeze crusts from the record-breaking warm temperatures to begin February fared a bit better at handling the added weight for natural activity. The same can be said at upper elevations, where strong winds for almost a week prior to the storm pressed the snow into hard slabs that new snow was loaded onto.  However, over the last few days we've seen and heard of multiple human-triggered avalanches, some of which occurred higher in elevation on slopes that didn't slide naturally during the storm.  The largest avalanche reported was triggered in East-facing above treeline terrain and was bordering on a size 3.  These events support an overall message that all it could take is you as a rider to get a persistent weak layer to collapse and lead to a dangerous avalanche, and the size of avalanches triggered will be larger as you move up in elevation.  If we had a larger user base here in our backcountry, we would be seeing and hearing many additional reports of human-triggered avalanches.

If you've stepped off the skin track or well-packed in trails, it should be readily obvious that a strong-over-weak structure is everywhere.  Widespread collapsing and cracking remains utterly constant on most slopes that face North and East.  Take the time to dig a quick pit or probe down into the snow and see if the slope you're planning to travel on has this strong over weak snowpack structure -- I'll be surprised if you can't find it.  The imminent warmup might make it tempting to go ride something big and exciting this morning before the melting commences, but you need to fight that urge and treat our snowpack with significant caution.  Please stick to terrain below 35 degrees and give large steep slopes a wide berth, as these conditions can also cause remotely-triggered avalanches.  Stay safe out there and break out those shorts and sandals if you haven't already!