Northern New Mexico

Dangerous avalanche conditions exist today, especially near and above treeline where you could easily trigger a wind slab avalanche several feet deep on wind-loaded slopes.  Our snowpack is harboring widespread depth hoar and weak faceted snow that could lead to a persistent slab avalanche in steep terrain wherever a slab exists in the upper portions of the snowpack.  Be on the lookout too for loose snow avalanches during today's warm, sunny weather.

Avoid slopes that are actively loading today and pay attention to obvious signs of instability like shooting cracks or loud audible collapses, as these are indications you've come across unstable snow.  Avoid being on or underneath large steep slopes, as it's possible to remotely trigger avalanches that break well above you.  Any avalanche triggered could grow in size if it steps down into depth hoar layers deeper in the snowpack, taking with it most of the seasons' snowpack.  Any slab avalanche triggered today would lead to a nasty ride and could be big enough to injure or bury you.

Warm, springy temperatures and sunshine continue today under abnormally high pressure and will be only be kept in check by increased winds and the passage of some high cirrus clouds.  This warming trend is causing the new snow that fell several days ago to settle on cooler aspects, while more solar aspects are rapidly melting back to bare ground.  This settling will help create more supportable travel conditions for skiing and riding, but be aware that during this hot weather trend you'll likely be dealing with some glopping and sticky snow as you pass between sunny and shady snow surfaces.  

It was instructive to finally get out and observe the aftermath of this last snowstorm with excellent visibility yesterday.  We observed multiple different types of natural avalanches that occurred both during and after the storm.  In addition to lots of loose snow avalanches that occured during the heavy snowfall and during yesterday's warm-up, we laid eyes on many small storm slab avalanches that released during or directly after the storm. We were still getting some cracking and collapsing in the softer, umcompacted storm snow yesterday, but now these soft slabs have had a few days to sit and settle, and honestly lots of the storm slabs that could have released most likely did, so we are removing this problem from the forecast today.  In areas where these soft slabs have settled and stiffened up a little bit, you're most likely to collapse one of our buried persistent weak layers, so these situations now fall under the curtain of our persistent slab problem.

The big topics for today are wind slabs developing near and above treeline and the continued development of a persistent slab problem.  In our travels yesterday, we observed the low-density storm snow easily being transported over ridgelines with only moderate W/SW wind gusts, and we came upon plenty of wind-drifted areas above treeline as we suspected.  Overnight, the W/SW winds have definitely picked up and will remain sustained in the 20-30mph range with gusts in the 40s through tomorrow, so a pattern of wind-loading will continue and also spread downhill in elevation to plenty of our near treeline terrain. Two of the natural avalanches we observed yesterday were the results of a more brief but intense wind-loading event that occurred late on Thursday following the storm, and we expect wind slabs today to be simillarly reactive and your most likely setups for triggering a dangerous avalanche.  Be on the lookout for obvious wind-drifted pillows, textured snow surfaces in open areas, and suddenly stiffening or hollow sounding snow underfoot, as you are likely in the vicinity of a wind slab.  If you were to trigger a wind slab avalanche in steeper terrain today, it could break up to several feet deep and could also step down to deeper weak layers as it moves downhill.  Be very careful with this problem today and stick to wind-sheltered or wind-scoured terrain in your travels.

In this video I point out our depth hoar in a spot near treeline during the recent storm.  The new snow has settled or slid since the storm, and this buried weak snow remains close to the surface and easy to impact in your travels today.

Let's check in next on our persistent slab problem.  Throughout our snowpack, we've developed widespread weak layers below the surface in areas that held snow through the extended drought period from early November to late January.  Many slopes from NW-NE-E (plus the typical West-facing slopes along the Fraser-Wheeler ridgeline) have extremely developed depth hoar throughout a lot of the old snow, and others also harbor faceted crusts.  These persistent weak layers are incredibly weak but have predominantly lacked a slab because we didn't see any significant snowstorms for over two months.  That pattern changed overnight with this most recent snowstorm, and now we have built up slabs that are sitting atop these weak layers and driving persistent slab avalanches.  The risk of triggering a persistent slab avalanche is greater near and above treeline, where harder and more cohesive wind slabs are building up on the surface.  However, the potential also exists below treeline where the storm snow has begun to settle and subtly stiffen during the warm-up, and these slabs could be capable of propagating widely across slopes with the widespread interconnecteness of our weak layers.  The question is where these slabs are capable of overcoming friction and sliding, and my sense is that it's somewhere around 35 degrees in most places. My advice to you today is to stay off and well away from larger avalanche terrain and to look consciously for obvious signs of instability like shooting cracks and loud collapses.  Use this kind of feedback as a reminder to back off further, and if you aren't getting it do NOT use that as a justification to go ride a larger avalanche path!  We still aren't at a point where very large and destructive avalanches could happen, but the current conditions lend themselves to remote triggering and any persistent slab avalanche triggered right now would definitely be large enough to bury you. 

A final quick note on loose snow avalanches.  It's going to warm up quickly today, and the high clouds won't be enough to hide the sun from our mountains.  This will help drive the occurrence of loose snow avalanches in pockets of steeper terrain, which could start in the form of point releases in shadier spots or wet roller balls in sunnier spots.  Either way, these avalanches usually start very small and quickly entrain more and more snow as they move downhill.  They aren't particularly dangerous but could knock you off balance or into harmful objects. 

Continue to function with a conservative early season mindset if you're getting out today.  We are still learning a lot about how our persistent weak layers are responding to changes as this week's storm was the first "semi-significant" test they have faced.  Evaluate the snowpack careully and err on the side of caution if you're uncertain about the stability of any slope.  It's still very much a shallow snowpack in many places out there with lots of rocks and ground hazards present, but it's definitely getting a bit easier to move around.  Stay safe out there and keep your fingers crossed for a snowy February!