Observation: Public
Observation Details
Name:
Mike RolfsObservation Date:
February 4, 2021Submitted:
February 4, 2021Zone or Region:
East CentralActivity:
Skiing/SnowboardingLocation:
In Bounds Mission RidgeTriggered Avalanches
Did you trigger any avalanches?
YesWas it intentional?
NoAvalanche Type:
Soft SlabSize:
Size 1: Relatively harmless to peopleElevation:
Near treelineAspect:
NWComments:
6" soft slab triggered by first turn on wind deposited snow in a chute that accesses bowl 4 in the Mission Ridge Ski area. Snowboarder caught and carried a short distance but escaped uphill. Avalanche ran 100 feet resulting in a 12" soft fanned out debris pileObserved Avalanches
Did you observe any avalanches?
YesAvalanche Type:
Soft SlabSize:
Size 2: Could bury, injure, or kill a personElevation:
NTLAspect:
NComments:
Since Saturday, there have been 4 in-bounds avalanches at Mission Ridge. I got personal accounts for three of them, and 2nd hand info on the fourth. These have occurred at all aspects and include:Saturday, Jan30, chute 4, ntl, skier triggered, caught and carried. East aspect
Sunday, Jan 31, bowl 5, ntl, skier triggered, 18" crown. East aspect (See obs report of 1/31 titled Mission Ridge - https://nwac.us/public-obs/20210131_mission-ridge/)
Tuesday, Feb 2, Chair 2 Chair line, ntl, N aspect, 48" crown, skier triggered, bystander caught and carried. No injury. Soft debris
Thursday, Feb 4, Bowl 4 entry chute, NW aspect, 6" crown, skier triggered but escaped. Soft debris - the subject of this report
Photo:
Signs of Unstable Snow
Observations
I believe these avalanches are occurring in locations where the wind deposits snow gently over a slippery surface. (similar to my 1/9 avalanche report -https://nwac.us/public-obs/20210109_east-of-mission-ridge/). Without lift access to the top of Mission Ridge this year, Mission Ridge's upper mountain snow-pack is natural and mostly undisturbed for the first time in 55 years. Our institutional memory about which spots are dangerous and which are safe is faulty because we don't have experience in this terrain with a natural snow-pack. Avalanches are occurring in surprising locations. If touring in bounds at Mission Ridge, we should adjust our alert level, and treat the terrain as if it is our first visit ever and evaluate every slope with a critical eye.
Media
