Northern New Mexico

The dust has finally settled and we're on the tail end of a rampage of February snowstorms that have heavily built out the snowpack in the Northern Sangre de Cristo mountains. With the most recent storm coming in a bit lighter than expected yesterday, avalanches occuring in the new snow are still possible today but less of a concern than the persistent slab problem. We now have between 3 and 6 feet of snow sitting atop our early season weak layers all across the map and those weak layers are not well-adjusted to all of the recent new additions. This is evidenced by some of the large and very large natural avalanches we observed that failed near the ground during some of the stronger storm pulses last week. It's clear that you can still impact those persistent weak layers in your travels today, and if you do it's possible to trigger a very destructive avalanche. Please be diligent in your travels: cautious route-finding and conservative tour plans are key to staying safe out there right now.

We've survived this early February gauntlet of storms, and the numbers are pretty impressive: 58+ inches of snow and over 5" of snow water equivalent (SWE). We're getting a little break from the crazines as we enter nearly a week of high pressure weather today. All of this new snow will start to settle over the next couple of days and we'll be very actively engaged with the state of our weak layers, seeing as we still have a very active persistent slab problem for the moment.

Over the last few days, we have observed some large to very large avalanches that have run well into the flats below.  One of them was the Peace Sign, which ran and put a large amount of debris across the "old" Williams Lake Trail that people frequent. This west-facing slope gets cross-loaded and most likely started higher up with a slab on the surface stepping down into deeper weak layers.  This path had already ran this year during the mid-January storms, so we may continue to see avalanche paths that already ran as repeat offenders. Another notable slide was a large D2 avalanche on a north aspect below treeline early in the morning.  We had been at the top of the start zone the day before, where we had a weak snowpack and shallow overall snowpack, but no results in extended column tests. This was a factor of not having enough of a slab for propagation. Some of our recent storms came in with a lot of wind unlike the Feb. 2-3 storm, so slab formation has been more widespread even in open and exposed areas below treeline. We still have a setup for avalanches to start within the recent storm snow and step down into deeper weak layers.

There are several prominent weak layers in the snowpack, depending aspect and elevation. Most of the weak layers lie deeper down the snowpack and were formed during the dry periods earlier this season. Depth hoar and the early January drought facet layer continue to remain reactive in many of our pits. On solar aspects you may also find faceted crusts that formed during the late January warming event, and we were even finding a buried near surface facet layer from in between the Feb. 2-3 storm and the Feb. 7 storm. Since February 2nd we've doubled or even tripled our snowpack, and weak layers are struggling to adjust to this added weight. This makes for complex and challening conditions where you may not be getting the advance feedback that we sometimes get from widespread weak layers. However, if you dig around our snowpack you'll realize that if you do trigger a persistent slab avalanche, it's likely to be catastrophic. You can always avoid these avalanche problems by staying off and beneath terrain over 30 degrees. Wind-sheltered low-angle terrain has great skiing and riding conditions right now.

Near and below treeline continue to exhibit the shallowest and weakest snowpack, even though on average these areas are showing less of a reactive slab at the present moment. It's definitely still possible to trigger a destructive avalanche in these zones if you find the right setup. Above treeline, the snowpack is extremely variable but really deep now in certain spots. We're still finding incredibly weak snow at the base of all that, which means we have a recipe for triggering a very large persistent slab avalanche up there, just like the one we saw run at the Peace Sign. It's going to take hitting a shallow spot on the margins of the slab or triggering a smaller avalanche in the newer snow that steps down to those deeper weak layers.

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