Northern New Mexico

Generally safe avalanche conditions exist for most of the day, as snow is expected to start falling around mid-day.  Loose snow avalanches in steep terrain on northerly aspects will remain the primary concern as it's possible for these sluffs to gouge near the ground in very weak faceted snow, potentially running for long distances.  Expect changing and rising avalanche danger overnight and into the weekend as snow starts to stack up from the first of several systems that impact our mountains.

The seemingly never ending mid-winter drought finally came to an end yesterday with the first inch of new snow we've seen in exactly 18 days!  Looking ahead, the first in a series of moderate snowstorms will start up around mid-day today, and is expected to bring around 5-9 inches of higher density snow (0.4-0.7" SWE) through tomorrow morning.  This will be the first storm in what's shaping up to be an overall more active weather pattern that persists for the next 10+ days, where we'll see subsequent snowstorms and stronger wind events without an extended drought in between.  None of these individual systems look really big, but in totality we expect these snowfall and wind events to add significant stress and potentially reach a big tipping point for our exceptionally weak snowpack.  Expect the avalanche danger to start rising overnight and into the weekend once we add the first in this series of incremental loads to our widespread weak layers.

The snowpack at this point in the season is relatively straightforward: it's shallow and extremely weak.  There's a lot of weak snow all throughout the snowpack that's been developing over the last three extended drought periods that occurred in December, mid-January, and late January/early February.  Near surface faceting has been widespread on all aspects from W-N-E that hold snow.  Solar slopes at mid elevations and below have formed a crust up to 5cm thick, but well-developed facets sit just below those crusts and in all honesty the crusts we've been seeing aren't all that robust and tend to be easily breakable.  Depth hoar is also prevalent on all of these aspects, and we're finding some of the weakest depth hoar to be the early December snow, which is generally located in the upper sections of the snowpack where you can visibly see depth hoar cups with a naked eye.  On northerly aspects, especially below treeline, all this faceting has led to a completely cohesionless snowpack that's capable of sluffing in really steep terrain and gouging all the way to the ground.  These dry loose sluffs are be your only real concern today, but if you're getting out take note of all the weak snow that pervades our mountains.  As we start to build slabs on top of all this weak snow over the next week or more, the avalanche danger will rise accordingly.  It'll be an incremental loading pattern, where at first we might see avalanches breaking at the old snow interface or just below a crust, and eventually see more avlanches stepping down or breaking directly on the depth hoar near the ground once we reach enough of a load. 

As we enter a more active weather pattern that will finally start to feel like a few weeks of winter, the take-home message is pretty simple.  Ours is really not a snowpack to be trusted, so as we start to reintroduce slabs into the picture, be ready to take significant steps back in your travels.  Perhaps the best way to frame this is to realize that even once there's a hypothetical slab on top, it will be almost impossible to avoid impacting our weak layers as a human.  Keep this in the back of your mind today and enjoy one more day of generally safe conditions if you make it out.  Hopefully there's at least an inch if not a few to add to the smiles by late afternoon!