Avalanche

St. Regis Basin

Izzy DavisSilver Valley & Bitterroot Mountains
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Quick report

Travel times in the mountains are quick right now thanks to a firm and refrozen surface. Bare ground is starting to make an appearance on slopes at mid elevations. 

None observed

Weather

Cloud Cover
clear
Wind Loading
none
Rain Elevation
Not observed
Recent Snowfall
None

A thick inversion sprawled across the valley in the morning and slowly broke down by the afternoon. Temperatures in the mountains stayed below freezing, but there was ample sunshine and no clouds.

Snowpack

Under a period of high pressure with sunny days and overnight freezing temperatures, the snowpack has settled and consolidated. A surface crust ranging from thin and breakable to thick and supportable can be found on virtually every slope. Sun cups are developing in exposed terrain, and ski penetration was only about 5cm at best where I travelled.

Surface hoar has developed widespread, with the largest feathers between 4500'-5500'. The ambient air temperature was cold enough today, and the low-hanging January sun didn't have a great enough influence to destroy the surface hoar or soften the surface crust too much.  

Below the firm surface, a layer of fist hard facets is developing. On an east-facing slope just below 6400', the whole snowpack was showing some amount of faceting throughout. I was able to find evidence of a brittle crust from a brief rain event on January 3rd in that location, about 20cm down from the surface, but its continuity varied quite a bit in my snow pit.   

Avalanche

Size
D2
Count
2
Aspect
NE
Trigger
N
Elevation
6800 ft

These older avalanches look like they probably failed during the 2nd week of January as a result of multiple days of warm temperatures. A large cornice fall produced a large to very large avalanche that ran to the bottom of the runout. A crown can be seen skier's right of the cornice fall that also produced a large avalanche.