Natural Storm Slabs Avalanches

Location Name: 
Natural Storm Slabs Avalanches
Region: 
Williams Lake Area
Date and time of observation: 
Sat, 03/14/2020 - 13:45


Red Flags: 
Recent avalanche activity
Recent loading by new snow, wind, or rain
Rapid warming
Obvious avalanche path

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

Clouds quickly cleared and it turned into a beautiful day in the mountains.  Winds died down and were in the single digits to low teens during the day at ridgetops out of the SW.  We did not observe any significant snow transport during the day.  Considering we had 95 MPH winds Friday afternoon during the storm, new snow on top seemed to be not impacted by these winds and probably fell later Friday evening when winds calmed down some.  We did observe several natural storm slab avalanches that ran probably during peak instability Friday evening.  Some of these were small others propagated long distances.  Most of these avalanches were confined to above treeline where we had the most amount of snow and the strongest winds. 

In our travels today above treeline and on ridgetops we couldn't get any shooting cracks and wind slabs did not seem to be reactive to ski cuts.  In stability tests we were getting the new snow to fail on lower density snow within the new snow. 

At least in the Williams Lake drainage we did not observe any persistent slab avalanches.  Sun and warming during the day and we observed roller balls on southerly aspects above treeline.  At lower elevations, temperatures hit the low 40's and was quickly warming up. 

Photo 1: Storm slab avalanches on N aspects from Friday's storm in the South Fork drainage

Photo 2: Extended Column Tests where we were getting the failure and propagation within the new snow

Photo 3: Natural storm slab avalanche that released sometime Friday evening

Photo 4: Roller balls on south aspects 

Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
25% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Light
Air temperature trend: 
Warming
Wind Direction: 
Southwest