Sunburst parking lot to 2,800’ on westerly ridge. Boot pack/ Hiking recommended to ~1400′.
SNOW!!! 32 degrees in the parking lot and light snow showers through the pass today. Rain/ snow line
dropped to around 500’ overnight. Light to moderate easterly winds at ridge tops.
Obvious Signs of Instability:
Recent Avalanches – Several natural mid-storm avalanches observed throughout the region. Many were
initiated in alpine terrain (>3,000) and ran quite far into the mid-elevations in channeled terrain. (See
12/17 observation from Matt Murphy) Larger avalanche observed on Lipps (tail end of storm or mid-day
today?) that appears to have propagated quite wide.
Collapsing – Yes. One small, localized collapse @ ~2,700’ on West ridge of Sunburst.
Cracking – No
1,000- 1,500’: 1-2” of very moist, heavy snow on ground.
1,500-2,500′: 4-6″ of dry snow on the surface over mostly wet snow to the ground. Total height of
snowpack increases with elevation. 24-28” total snow depth at 2,000’.
2,500′-2,800′: 6-16” of dry snow on the surface. 34-40” total snow depth at 2,800’.
Several quick pits dug on our way up to the ridge. Focused question of the day was: Where is the surface
hoar? How is it reacting?
Pit at 2,400’ (HS = 33”): Surface hoar is present though not easy to find on crust at this mid-elevation.
Still relatively wet snow above the surface hoar. ECT failed on 6th tap from the elbow (ECTP16) at surface
*Given relatively warm temps and settlement rates, this slab (above sh) appears to be gaining strength
Pits @ 2,800’ (HS= 48”): Three of us dug three separate pits at 2,800’ with very similar results.
ECTP10 – 19 (repeated several times). All propagating on 3-6mm buried surface hoar resting on a
crust (Dec. 7-9 rain crust) approximately 15” down from the surface.
PST20/100 Arr and PST20/100 End.
We noticed the mid snowpack drying out substantially around 2,700’. Below this elevation band I suspect
the slab to heal rather quickly with warmish temperatures and generally moist snow. In this mid to upper
elevation band where the Dec. 7-9 rain crust/ surface hoar combo is present, all bets are off! This is a very
dangerous set up (persistent weak layer buried in-tact on a stout crust) that we haven’t seen in our region
for several years. Keep slope angles low, avoid run out zones and you can have a lot of fun in the
backcountry. Cautious route finding and conservative terrain choices are key right now.