Avalanche Conditions

3 photos

Marriot Basin Conditions - Dec 17-20

Marriot Basin - Duffey Lake Road

Avalanche Conditions

Myself and a small group spent 4 days camped in Marriot Basin.

Weather: Stormy conditions persisted throughout the trip with incremental new snow (5-10cm at a time) and we received approximately a cumulative 30cm of new snow.

Winds in the basin ranged from NW to SW and were gusty. A few days had pronounced winds and lots of wind transport was apparent.

Temperatures ranged from about -2 to -4 during the daytime with warming to near 0 deg Friday.

Avalanche conditions: We skied a range of aspects, elevation and angles but mostly sticking to conservative terrain and stepping out a bit towards the end of the trip. We did only slightly touched upon venturing into the alpine. Angles skied never surpassed 35-40 degrees. Ski penetration into the snow ranged from 30-50cm in areas not wind affected and closer to 10-15cm in areas with wind redistribution.

We observed no natural avalanches during the duration of our stay nor did we ever see any signs of instability (shooting cracks, whumphing, etc.).

The December 9th crust was evident on steep south up as a suncrust to near alpine or as a pronounced temperature crust below 1650m.

A test profile Saturday on a west-southwest aspect treeline feature with a snowpack depth of 140cm and some cross loading provided no significant compression test results. Soft slab formation 20-30cm deep had 4F-1F resistance near the surface and overlay 4F snow. The suncrust was apparent with no evidence of faceting down 55cm with 1F resistance snow above.

Overall great skiing conditions with few evident concerns other than wind transport and potential windslab in specific lee treeline/alpine features. We were rating the hazard for our little area at Low (BTL)/ Moderate (TL)/ Considerable (TL) based on our observations.

On The Map

These observations and opinions are those of the person who submitted them. The ACMG and its members take no responsibility for errors, omissions, or lapses in continuity. Conditions differ greatly over time and space due to the variable nature of mountain weather and terrain. Application of this information provides no guarantee of increased safety. Do not use the Mountain Conditions Report as the sole factor in planning trips or making decisions in the field.