Observation: Steep Hollow

Observation Date
12/16/2013
Observer Name
Weed
Region
Logan » Franklin Basin » Steep Hollow
Location Name or Route
Steep Hollow
Weather
Sky
Few
Wind Direction
West
Wind Speed
Moderate
Weather Comments
Nice day, westerly winds kept things cool at upper elevations.
Snow Characteristics
Snow Surface Conditions
Powder
Faceted Loose
Wind Crust
Snow Characteristics Comments

I found meadows with some nice fast recrystallized surface snow and surface hoar. Low angled slopes rode well. In many areas i would sink through weak sugary snow all the way to the ground. I did not dare leave the packed trail for fear of dropping into the structureless faceted snow or hitting shallowly buried rocks.

Red Flags
Red Flags
Cracking
Collapsing
Poor Snowpack Structure
Red Flags Comments
I triggered several audible collapses today, and it's been over a week since our last storm. These were in drifted low angled areas where a variable slab exists capping very weak sugary snow or facets. Most of these also cracked with barely visible hair-line shooting cracks up to around a foot deep (25cm). One wumpf shot cracks around 5 meters in radius around me in the center.
Avalanche Problem #1
Problem
New Snow
Trend
Same
Problem #1 Comments

The wumpfing and cracking indicate some potential for triggering an old wind slab, now a persistent slab, in steep terrain. i was in an area that appears not to have been traveled and tracked yet this season, but I was still surprised by the frequency of the collapses so long after the most recent storm.

Comments

The December snow cracked easily and failed as a slab when disturbed by a sled.

I triggered several audible collapses today. Most also cracked with super thin, barely visible cracks around a foot deep. Old wind slabs in lower angled terrain on very weak faceted snow.

Here are a couple views of Double Top Mountain in upper Steep Hollow from the East. The starting zones are well "primed;" the anchors are buried and smoothed in by very weak faceted snow, and we are set up for large avalanches when a good storm or two lays down a cohesive slab layer.

Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate