Lawine

Pyramid Peak area

Ben VandenBosSeeley Lake
Auf der Karte ansehen

Quick report

Cracking
Observed
Collapsing
Observed

I went into the Swan to see how our persistent slab problems were behaving. My goals were to look for surface hoar in terrain where it may/may not have been destroyed, look for recent natural avalanches, and continue to investigate how these layers were presenting on solar aspects. 

I dug a handful of pits on N-NW-WNW aspects at middle elevations looking for SH in terrain where it may have been either wilted by sun or knocked over by wind. I did not find it in these places and my snowpack tests returned mostly ECTN and ECTX results. I also looked for facets+crusts on middle elevation slopes and found reactive facets sitting on the 2/14 crust. This layer was buried relatively shallowly on these aspects, about 8-10 inches down. In wind-loaded terrain, I  experienced collapsing and associated cracking involving this combo and had propagating test results in my ECTs. A bit further up, I remotely triggered a D1.5 slab on this layer on a S/SW aspect at 7,500'. The slide entrained wet snow as it moved downhill, running an estimated 800 vertical feet. More details in the avalanche section below.

A minor natural wet loose problem turned on today, in very steep, rocky ovens facing S-SW. I observed a handful of D1 wet loose slides here, and the snow felt like it would have been relatively easy to push in this terrain during peak heat and melt of the day. Slides quickly stopped moving as they ran into lower elevation terrain where the snow was drier. 

I experienced cracking and collapsing in wind-loaded terrain on S-SW aspects. This was happening on a thin layer of facets sitting on a crust which was buried around 2/14. I experienced no signs of instability on shaded slopes, but my travel here was limited.

Weather

Cloud Cover
clear
Wind Loading
none

Lots of sun today and mild temperatures. Southerly winds were intermittently blowing lightly, but less than forecast.

Avalanche

Size
D1.5
Type
WS
Aspect
SW
Trigger
AS
Elevation
7500 ft

In addition to the remotely triggered slide, I also observed a handful of small wet loose avalanches that came out of rocky ovens on solar slopes. None of these was larger than a D1. I could see evidence of a few slightly older slabs that may have failed on 2/14 crust+facet combos on solar aspects in heavily wind loaded terrain.