Look for scattered snow showers today with another 1-2" of snow possible throughout the day as the center of a low-pressure system passes through the AZ/NM border. Yesterday's storm resulted in 5" of new snow (0.5" SWE) with NNE winds, 20-35 mph that picked up last night and will continue until mid-day when they will diminish and shift towards the NW. Clearing skies by late-afternoon and high temps at 10,000' will be around 33F. A transient ridge will then push this system east and yet another system enters our area mid-day tomorrow. This system will favor the southern mountains and looks likely to bring a good-dose of moisture with conservative estimates of 1-foot of snow to the high country of the 4 Corners Region by the end of Friday.
Snowpack Discussion
3-5" of new snow yesterday with moderate NNE winds overnight has likely resulted in numerous shallow wind slabs in wind-exposed terrain at higher elevations. Yesterday in the La Sals in more wind-sheltered areas, I observed a variety of surfaces that the new snow has fallen-on. On southerly aspects, I encountered a supportive-crust and on well-shaded, northerly aspects, I observed soft snow containing some graupel in the uppermost layers. A couple of shovel-tilt-tests informed me that some of these layers are not bonding very well and it will be interesting to see how new snow and/or wind-drifted snow will bond with these surfaces.
On Monday, Snowpack tests revealed that we still have a poor snowpack structure, but suspect weak layers are far-enough down in the snowpack that it will be difficult to affect them. Last week's storm appears to be bonding well to the old snow. Time and warm temperatures have helped stabilize the snowpack but it is still possible to trigger a deep and dangerous avalanche on a buried persistent weak layer of sugary, faceted snow. This weak layer exists on slopes that face NW-N-E, and thin snowpack areas consisting of steep, rocky terrain are the most likely trigger points. Here is a snapshot of the snowpack near Cooley Pass.
