Support the forecast! Support the forecast!

Give to Friends of the Chugach National Forest Avalanche Info Center.

Observation: Hatcher Pass

Location: IMB Area

Date:
Observer:
Route & General Observations

Below A Frames > IMB > Marmot Test Slopes > Microdot South > Airbag Ally

Road to upper lot was deep and not plowed.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Observer Comments

New snow and wind may have covered up signs of recent avalanches.
While visibility was generally poor today due to cloud cover and low light, some openings in the clouds allowed for hard light to migrate across the landscape.
One new, recent avalanche crown was visible at the top of Martin Mine. Approximately 1-2 feet deep, 200 feet wide. Debris was covered in new snow and wind blown snow.
New snow totals appear to be around 12" at 3500'. This new snow is upside down, with wind pressed and wind effected snow on the surface, 4"/10cm, thick. This layer produced localized shooting cracks, no longer than 6 feet.
No collapsing or whumphing was observed today.
Only one test slope, NW, 4000', 35deg, produced an small skier cut avalanche, 4" deep x 10 feet wide x 20 feet vertical run, failing within the storm snow.

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

This afternoon:
Skies Overcast to Broken
3000' 26-29F, winds gusting 11-18 mph, generally SE. Snow was being actively transported, lightly, throughout the day. High of 29F.
At upper elevation ridgelines we observed active wind loading all day, moderate. Marmot 4500' weather station indicated SE 12-18 mph, consistently gusting 19-32 mph. High of 21F.
No precipitation.

Snow surface

Settled storm snow total appears to be 12" at 3200'
Widespread, upside down, with 4" of 4F wind slab sitting on F new snow.
Patchy wind pillows on leeward features 3000-4600', 6"-18" deep, stubborn localized cracking, no collapsing (other than one small avalanche triggered, "red flags"
Scoured areas, down to old melt-freeze crust

Snowpack

Snow Pit 1:
Rae Wallace Bowl
NW, 3400', 20 deg slope
ECTN13 down 20cm in storm snow
ECTN 24, 25 down 40cm on 2/8 old thin weak layer, mixed forms, facets with strong rounding
ECTN 25, PST 95,98 END, down 75 cm under very old, thin 1F MF crust on 4F rounding facets. (Persistent Slab)

Snow Pit 2:
Microdot
W, 4200', 32 deg slope
ECTN14, CT14RP, wind blown snow 0.5mm/rounding facets 1.0mm (Persistent Slab)

For the areas we traveled the avalanche problems were stubborn to unreactive to trigger and we rated the avalanche hazard for today as moderate for low to mid elevation.
We speculate that the upper elevations are considerable for large avalanches in specific areas. We speculate that human triggered avalanches would be likely on leeward aspects, at upper elevations, where recent, consistent, wind loading has likely resulted in 30cm thick wind slabs in upside down snow.