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Professional Observation

Basic Information

Observation Details

Observation Date:
April 1, 2023 - April 3, 2023
Submitted:
April 4, 2023
Observer:
PAC - Studley (off duty)
Zone or Region:
Warm Lake area
Location:
Warm Lake and Big Creek

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
Isolated
This observation is from Saturday (04/01)- Monday (04/03) around Warm Lake and Big Creek Summit. Heavy snowfall and strong winds had a significant impact on the region Saturday. Storm snow was inverted (or upside down) with heavy, wind-effected snow overlying softer snow. Cracking and whumphfing was observed Saturday and Sunday. The snowpack at Big Creek is very different than Warm Lake area. The Warm Lake area has a notoriously shallow and weaker snowpack with pronounced facets near the base of the snowpack.

Snow Stability

Stability Rating: 
Fair
Confidence in Rating: 
Moderate
Stability Trend: 
Improving

Media

Two avalanches observed on Sunday (04/02) east of Warm Lake. Both on N/NW aspects between 6600'-7400'
Snowing heavily on Big Creek Summit Monday PM
Sunday was a mix of snow showers and brief sun. Deep snow found on north aspects

Advanced Information

Weather Summary

Cloud Cover:
Mostly Cloudy
Temperature:
Below freezing
Wind:
Moderate , W

Saturday, snowfall rates were S3-4 for 5-6 hours with strong W/SW winds. Clouds broke around 1630 and the sun popped out for a couple hours. Sunday, intermittent snow showers with brief periods of sunshine. Monday, cold north winds. Snowfall rates of S2-3 from 1300-1700.

Avalanche Observations

Two natural avalanches observed on Sunday (04/02) east of Warm Lake. Both were on N/NW aspects between 6600'-7400'. Both appeared large enough to bury or kill a person.

Snowpack Observations

Saturday, 50-60 cm of wind-drifted snow in pockets. Shooting cracks were observed within new storm snow. Sunday, a melt-freeze crust was observed on west aspects from 5200' to 7200'. Inverted storm snow, wind effected. North aspects had 45 cm new snow. Monday, storm snow settled but kept coming.

We dug a snow pit on a NW aspect around 6800'. HS was 185 cm. Upper Snowpack structure was somewhat similar to that of the forecast area around McCall. The lower snowpack had a thick layer of facets about 90 cm from the surface. CT 14 RP on facets in between two melt-freeze crusts. ECTN 17 on this same layer. This was our layer of concern. Although the overall snowpack structure was a concern.

ECTN 17 on facets between two MF crusts. This block did not propagate in the ECT but popped out after prying.

Avalanche Problems

Storm slabs and wind slabs were our primary avalanche concerns over the weekend. We were especially cautious of aspects that had the melt-freeze/facet sandwich.

Terrain Use

Given the intensity of the weekend storm and the weak snowpack structure around Warm Lake, the group agreed to avoid slopes over 30 degrees during and after the storm.

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