Observation: Public
Observation Details
Name:
Josh HirshbergObservation Date:
February 13, 2021Submitted:
February 14, 2021Zone or Region:
Stevens PassActivity:
Skiing/SnowboardingLocation:
Lanham creekTriggered Avalanches
Did you trigger any avalanches?
YesWas it intentional?
NoAvalanche Type:
Soft SlabSize:
Size 1: Relatively harmless to peopleElevation:
5400Aspect:
NComments:
Triggered on a short convexity in open trees. 50-100ft vertical by 25cm deep , ran on Feb 11th near-surface facets.Photo:
Observed Avalanches
Did you observe any avalanches?
YesAvalanche Type:
Dry Loose (Sluff)Size:
Size 1: Relatively harmless to peopleElevation:
near and below treelineAspect:
Comments:
Natural point releases in steep to extreme terrain on a variety of aspects.Signs of Unstable Snow
Observations
Most notable were the cold air temps and very light, low-density snow (HN24 20-25cm). E winds transported snow on slopes immediate to Hwy 2 corridor and a few other prominent drainages. Where we traveled, winds were calm all day with no blowing snow.
Storm snow is was resting on the Feb 11th interface (mostly near-surface facets 0.5mm-1.0mm). We suspected buried surface hoar but couldn't confirm. We targetted the mid-Jan crust-facet matrix. At Lanham Lake height of snow was 280cm and the mid-Jan crust was down 90cm below the surface. At 5580ft, N aspect height of snow was 395cm. Test results at this site were: No results in Deep Tap on Jan 24 FCxr (0.3-05mm) down 130cm. DTM (BRK), PST 50/140 END in mid-Jan FCxr (0.5-1.0mm) down 141cm, just above Jan 13 rain crust. Facets above Jan 13th crust are punctuated with intermittent crusts and vertical ice columns.
Media
