Observation Date: 12/01/2011

Route/Location:
St. Mary’s Basin in the Bitterroot Mtns

Weather:
Skies were clear. Temperatures in the low 20′s. Wind out of the Northwest at 8-10mph at elevation. Trace of new snow.

Wind:
The wind was blowing moderately hard for most of the day out of the North and West. This was causing some light snow loadingThe addition of weight on top of a snowpack, usually from precipitation, wind drifting, or a person. on lee aspects as well as some cross-loadingThe addition of weight on top of a snowpack, usually from precipitation, wind drifting, or a person. of gullies creating small pockets of wind drifted snow at upper elevations.

New Snow: 0-3″

Snow DensityThe mass of snow per unit volume, but often expressed as a percent water content. New fallen powder has a low densityThe mass of snow per unit volume, but often expressed as a percent water content. New fallen powder has a low density (3-10%), while heavy or wet snow is more dense (10-20%). (3-10%), while heavy or wet snow is more dense (10-20%).: Light

Avalanche Activity:
Some evidence of old avalanche debris below steep, rocky face. This slideA mass of snow sliding, tumbling, or flowing down an inclined surface. Same as avalanche. looks to have occurred a couple of weeks ago when we received all of our new snow in a short amount of time, not allowing it to consolidate and bond to the underlying surfaces.

Observed Danger Rating:

Other Comments:
Now that the snow has had time to settle and strengthen, we found snow stabilityThe chance that an avalanche will not occur, relative to a given trigger (usually the weight of a human). to be very good on all aspects and elevations. The one thing to look out for is recent snow drifts and shallow areas around rock outcrops in the higher elevations. The snow coverage is good at elevation for this time of year. Skiing was very good on Northerly facing slopes that had not been affected by solar radiation. Traveling was excellent with only 5-10cm of ski penetration.

Observer: t laroche