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Paulina Peak D2 R2 slide

Location Name
Paulina Peak
Newberry Crater Area
Adam Craig
Email Address
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Date and time of avalanche (best estimate if unknown)
Red Flags
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Avalanche Type
Trigger type
Wind Speed
Wind Direction
Air temperature
Above Freezing
Air temperature trend
Bed Surface
Old Snow
Weak Layer
Old Snow
Crown Height
3 ft
Avalanche Width
Avalanche Length
Near Treeline
More detailed information about the weather

 Lingering storm clouds broke as we approached the Peak around 10am, starting the solar warming trend, which didn't effect this true NE slope, nor had it seen any solar influence during the long high pressure we've experienced since Dec 22.  Light West wind flowing downslope was keeping this shaded slope even cooler.  

More detailed information about the avalanche

Although, on account of missing most of the rain in the Cascade Crest on Sunday, the skiing was quite good at Paulina Peak, there is a very thin, weak snowpack currently.    Our group recieved a positive report about the East Side terrain from a Sunday group and elected to head out on Monday to see what the situation was like.  This was our first trip to this area this season, and was mostly chalked up to Reconnaisance.  Seeing their multiple tracks down through the Playground area, we elected to go to Penis Bowl.  I dug an Extended Column on the breakover at the ridgeline on an East aspect. It failed on ECT23 SC Q3 at 70cm down.  90cm total snow depth, the bottom 20cm was comprised of rounding facets with a thin sun/rain crust on top.  Concerned with this result, but unsure if a layer buried that deeply would be reactive to a skier on small terrain features,  we discussed options for skiing the slope safely and did a ski cut down the ridgeline to see if there was any result.  Both skiers felt strong settlements.  Then a snowboarder walked down the ridgeline, causing a settlement that send cracks shooting down the edge of the slope, between the skier's feet.  Oops.  We dug into the cracks and found them penetrating the crust layer into the depth hoar.  Noting this Persistent Slab setup, we chose to follow the ridge down and through the lower-angle forested run option, recording more settlements and cracking on a small convex ridge in the more north-facing forest as well.  Ah, human factors.  Instead of leaving, we elected to test and ski the NE aspect, sheltered from sun, but exposed to downslope wind, a combo we hoped would have kept the depth hoar at bay somehow.  To the  Green Room run, the other normal "safety" run at Paulina.  A smaller settlement on the ridgeline above the run was discounted as we would be in old growth forest, therefore, "safe" for the run.  The upper run went well, wind buffed powder.  The lower part of the run is in an avalanche path, which means through small tight trees and large boulders with the current thin snowpack.  The most obvious path involves traversing under a 20-30' cliffband to gain the old growth forest again.  Below the cliff is a 30' slope of open snow to more tight small trees.  Skier 1 (me) crossed the slope quickly and stopped amongst  lower-angle old growth at the base of the cliff for the rest of the group.  Skier 2 crossed 30 seconds later and triggered a D2 R2 Deep Slab.  Skier 2 was going quickly and kept it up, skiing off the edge of the slab while it was still cracking, essentially under his feet.   The slab maintained cohesion and was moving quite slowly due to the tree support immediately below, which caused it to break apart and slow down quickly.  The crown was frowning from multiple shallow rocky and shrubby start zones and approximately 60' across.  The toe was 150' below, still in tight trees.  Start zone was at a breakover in the slope, approximately 37-39 degrees.  The path was largely on a 32-34 degree slope.  Skier 3 was called off and stopped above the crown, eventually making his way over it for inspection and to travel to our safe(er) area.  We inspected the crown, but did not conduct a full profile on account of feeling an intense need to go home promptly.  The failure appeared to have happened at the base of the new snow, which on this downslope-loaded rollover was approximately 95cm deep(!), it then stepped through the old melt/freeze crust into the near crust facets and depth hoar below.  All of the buried facets were rounding and almost wet looking.  The bed surface was very planar and hard.  Entire height of snow on this slope was 160cm on average, but with many rocks and shurbs buried.  Of note is the primary snow surface on non-solar aspects doesn't have the rain crust the Crest recieved on Sunday.  With another few storm loads, this persistent depth hoar may continue rounding and settling out.  Or not.  As always, be careful at Paulina, if you go at all.  This place has complicated weather and terrain that we will never completely understand, in my case after eight years of regular skiing .  I have experienced similar "storm day" success with new loose snow on a weak crust before the slabs really form, then a day or two later when it warms a touch and the snow begins to settle, a buried issue becomes reactive.  Sometimes without a skier trigger.