Avalanche: Chugach State Park

Location: Harp Area

Route & General Observations

Skinned east of harp and dug a few pits. Hoped to get on bigger N facing terrain but ended up sticking to S and W aspects.

Avalanche Details
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Trigger NaturalRemote Trigger Unknown
Avalanche Type Soft SlabAspect West
Elevation 4000ftSlope Angleunknown
Crown DepthunknownWidthunknown
Vertical Rununknown  
Avalanche Details

Steep W facing dry loose stepped down to 30 to 50 cm (estimated from a distance) soft slab. Maybe 50 ft wide, vertical run of the slab 200 ft? A few days old at least, maybe a week. Recent activity limited to lots of solar wet loose, with a few of those becoming very small wet slabs that only entrained surface snow.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

Warm. Nearly every S face had roller balls below 4000'. Snow squall moved through at 3 pm and dropped half inch of snow. Not much wind throughout the day.

Snow surface

Soft snow, less wind affected than anticipated. 10 to 20 cm newish snow on a variety of old surfaces including soft settled snow, wind crust, and ice crusts. Cold and dry everywhere except solar aspects.


Pit details on NNW at 3100':
Calm winds
HS 170
Slope angle 25

Dug down almost to the ground since we hoped to get on bigger N facing terrain but didn't have much beta for the snow here.

Ice crusts noted approx 50 cm down and 120 cm down

ECTX, but propagated across entire column on 2nd overdrive tap. See pic. 120 cm deep on layer of facets above pencil ice crust.

Conducted a deep tap test ECT, removing the top 60 cm of snow. ECTP28. Felt like a low probability high consequence situation. Have seen a lot more ski traffic on W and S facing so unsure how much this set up has been tested. Did not want to find it in a wind scoured area so went to S facing slopes.

Pit details on SSW at 3400':
Calm winds
HS 240, but in an area that receives lots of loose snow avalanche debris below steep terrain. HS on flat aspect in nearby area 130 to 160.
Slope angle 30.

Dug down 110 cm and found same crusts as N facing, just slightly shallower. Very strong supportive upper snowpack. Pencil crust 40 and 110 cm deep. ECTX. Couldn't get propagation with overdrive taps, but could get the block to shear off cleanly on same facet/ice crust combo, prying behind it with shovel with hard force. Deep tap ECTX removing top 50 cm of snow. No propagation in PST. No concerning instabilities noted riding S and W facing terrain.

Photos & Video
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