Post Storm Avalanche Observations

Location Name: 
Recent Avalanche Activity
Williams Lake Area
Date and time of observation: 
Sat, 01/18/2020 - 11:00

Red Flags: 
Recent avalanche activity

Observation made by: Professional Observer
Snowpit Observations
More detailed information about the snowpack: 

Went for a tour to check out the recent avalanche activity. Observing these naturals was tricky, as continued snow and strong winds Friday afternoon quickly re-covered many of the slide paths. Avalanches on East aspects were fairly easy to spot, as they were widespread above treeline. Avalanches running in the new storm snow, as well as ones running in the old snow were observed. Several slides on eastern slopes initiated above treeline, and ran down into terrain near treeline. North aspects near and above treeline held clues of naturals occuring as well. These were much more localized to shallower terrain on steeper slopes which had been heavily impacted by the recent winds. Western slopes were stripped and scoured with only cross loaded gullies holding snow. Several of these gullies showed signs of inverted tracks. Smaller, isolated mid-path slides were observed on western aspects. Southern ridgelines above treeline were heavily wind effected, with small cornices appearing for the first time.        

Branches and small blowdowns in the skin track at lower elevations were obvious indications of the recently strong winds. A cohesive surface slab was prevalent throughout the tour. It was soft and breakable below treeline. In open areas above treeline, the slab was hard and made for very difficult skinning. Our previous skin track was heavily inverted at higher elevations.    

As the day progressed, solar aspects formed significant crusts on the surface.

Photo 1: Here, new snow instabilities ran as storm slabs. 300 foot initial crown.  

Photo 2: Western slopes stripped at higher elevations. 

Photo 3: Inverted skin track from previous day. Hard surface slab formed in open areas at higher elevations. 

Snowpack photos: 
Weather Observations
Blowing Snow: 
Cloud Cover: 
Air temperature: 
Below Freezing
Wind Speed: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
More detailed information about the weather: 

An all around pleasant day. Clear skies with temperatures in the high 20's all day. Light winds out of the southwest, with an occasional moderate gust.