Northern San Juan
SnowpackKrista Beyer · Mar 3, 2024 · Northern San Juan
Weather
Another storm full of wind and dust and weather model disagreement has got my mind on 'Dune.' In Frank Herbert's novel he explores the limits of foresight, "Maud'Dib could indeed, see the Future, but you must understand the limits of this power. Think of sight. You have eyes, yet cannot see without light. If you are on the floor of a valley, you cannot see beyond the valley." Just so, you cannot expect to anticipate avalanche danger without a reliable weather forecast, and it is mighty tough to have a reliable weather forecast with misalignment in models. Today's forecast discussion explores this uncertainty and highlights the need to recognize the limitations of our tools. While forecasted snow totals were uncertain across the southern mountains, the winds were not, and reports suggest that the dust that came with them is a widespread phenomenon. Observed winds averaged 25-30 mph from the southwest. Snowstakes were blown clean, but it appeared as though Red Mountain Pass picked up 4-5 inches before noon.
Snowpack
The dust has arrived. This is our second storm with visible dust; the visual results are dramatic. What we can hope for now is this layer gets buried deep. 4-5 inches of new snow observed before noon. Drifted north and northeast slopes carried boot top powder and isolated drifts up to 40 cm at ridgeline. A pit dug on a northeast slope near treeline indicated that instability is limited to near-surface layers. Pit tests highlighted failures on three different layers. 1) the dust layer with a CT11 and ECTN11 @ 14cm from the surface. 2) Beneath a pencil-hard wind slab CT15 and ECTP 15 @ 25cm from the surface. 3) What is likely the 2/27 interface CT25 and ECTN 25 @ 35 cm from the surface. Notably, the propagating result failed on progressive loading steps.