Observation: NWAC Forecaster
Observation Details
Name:
Josh HirshbergObservation Date:
March 1, 2021Submitted:
March 1, 2021Zone or Region:
East CentralActivity:
Skiing/SnowboardingLocation:
Marion LakeObserved Avalanches
Did you observe any avalanches?
YesAvalanche Type:
Wet LooseSize:
Size 1: Relatively harmless to peopleElevation:
6200Aspect:
EComments:
Small point releases originating from rocks near the Bomber Chutes, just outside of the Mission Ridge ski area boundary. These likely ran on the 27th or 28th.Photo:
Signs of Unstable Snow
Observations
We found sun-softened surfaces on steep E aspects around 5,800ft and fresh rollerballs on west aspects below 4,500ft. In the shade, surfaces stayed cool and dry above 5,000ft. Near treeline, recent wind slabs were difficult to trigger, except in isolated areas where they had underlying surface hoar.
At 5620ft, NE, above Marion Lake we found variable height of snow, 110-200cm. In a relatively sheltered slope w height of 178cm, we found 2 layers of concern: buried surface hoar (3-4mm) @ 160cm, and rounding facets (0.5-1mm) @ 90cm, beneath the Jan 13th crust. Both produced sudden but variable results in compression test. A Propagation Saw Test on the rounding facets @ 90cm indicates potential for propagation: PST 42/100 END. PST, CT, and Deep Tap on layers above and sandwiched between mid-Jan crusts, as well as Dec 9th facets @ 46cm all yielded no results. Pushing DT well-beyond the limits of the test, we got a sudden collapse on facets and melt forms (3-4mm) near the ground @ 22cm. Notable was a well-preserved layer of graupel @128cm that produced no results in tests.
Media
