Observation: Brighton Perimeter 1/21/2012

Observer Name:

Greg Gagne

Observation Date:

01/21/2012

Region:

Salt Lake
Big Cottonwood Canyon
Brighton Perimeter

Location or Route:

Brighton Periphery

Weather

Sky:

Obscured

Precipitation:

Heavy Snowfall

Wind Direction:

West

Wind Speed:

Moderate

Weather Comments:

Intense snowfall - both pre-frontal as well as post-frontal. Some graupel mixed in during frontal passage. 3"/hr estimated at times.

Snow Characteristics

New Snow Depth:

New Snow Density:

Medium

Snow Surface Conditions:

Powder

Snow Characteristic Comments:

Total storm snow approaching 1 meter (~3')

Red Flags

Recent Avalanches

Heavy Snowfall

Wind Loading

Cracking

Collapsing

Red Flag Comments:

I felt like the snowpack was hitting me aside the head with a 4"x4" while screaming at me. Really.

Primary Concern

Primary Concern:

Deep Slabs

Probability:

High

Aspect:

North

Northeast

East

Southeast

South

Southwest

West

Northwest

Elevation:

High

Mid

Trend:

More Dangerous

Primary Concern Comments:

Instabilities are now both within storm snow as well as deeper-layer instabilities in our faceted snow now buried about 1 meter deeply, even deeper in wind-loaded areas or areas that have received substantial new snow.

snow_profile_location:

Comments - Photos - Videos (group 1)

Probably the diciest day I've experienced in many years - lots of cracking, collapsing, (branches & trees shaking from collapses in meadows), and remotely triggered slides. Was finding the new snow to be super sensitive during intense precipitation periods. Got several small slides to release remotely. Did not see any natural activity (poor visibility) but imagine the hazard was Extreme. This will take awhile to heal. Would avoid slopes approaching anywhere 30 degrees in steepness. Ver dangerous conditions.

Observed Danger Rating:

Extreme

Forecast Danger Rating:

Extreme