Observation: Moab

Observation Date
01/2/2017
Observer Name
Dave Garcia

Region:

Location Name or Route
Gold Basin
Weather
Sky
Overcast
Precipitation
Light Snowfall
Wind Direction
South
Wind Speed
Moderate
Weather Comments
Cloudy skies and light snowfall. No accumulation during the day. Winds were moderate in the basins and appeared to be strong on the ridges. Weather station indicates gusts up to 40 mph. High temperature of 19 degrees at Gold Basin.
Snow Characteristics
Snow Surface Conditions
Powder
Dense Loose
Snow Characteristics Comments
Good quality powder remains on sheltered northerly facing aspects.
Red Flags
Red Flags
Wind Loading
Red Flags Comments
Winds have picked up over the last two days, and the snow from the Christmas storm is still available for transport. A lot of this snow has settled and consolidated, but there is still enough to be blown around, especially when winds approach 30 or 40 mph. Wind slabs observed today were isolated and relatively small. We triggered a fresh windslab while skiing lone pine. This is a moderately steep north facing slope. The slab was triggered on our second lap, 7th skier on the slope. We were skiing the right side and working left with each run. I was the 7th skier (so skiing more left almost due north) and the slab broke at my feet and the crown was pretty well above me. I skied off to the right without incident. The crown was 6 to 8 inches deep and ran for maybe 180 feet. The crown was right below the rock band on the skiers left side. These fresh drifts are somewhat small and manageable right now, but the forecast is for more winds and possible snow. With more wind and a fresh load of snow they will be something to watch out for.
Avalanche Problem #1
Type
Wind Slab
Trend
Increasing Danger
Problem #1 Comments
As noted above, wind slabs are the biggest concern right now. Winds were mainly from the south and southwest. So be aware on northerly slopes. So far wind slabs are small and somewhat isolated, but they could be more of a problem with forecasted wind and snow throughout the week.
Avalanche Problem #2
Type
Persistent Slab
Trend
Same
Problem #2 Comments
We dug a pit on a 32 degree north facing slope. The pit revealed the same graupel/facet layer that Eric and I identified last Thursday on a high elevation NW slope. The snow was a bit deeper in today's location and the buried weak layer is 47cm below the surface. This layer failed on a compression test CTM17 Q2. We also performed an extended column test and the layer did not fail. See the photo below of the layer in question. This layer still exists, but like last Thursday was not super reactive to stability testing. We used this test slope to make a decision to ski lone pine. It is worth mentioning the snow was very deep where we dug (210cm) and lone pine has slid previously this season, so is of course not as deep. Heading up lone pine we probed with our poles to find some sugary snow maybe 18 inches below the surface. This was not seen in our pit with the exact same aspect. It makes sense to find near surface facets on lone pine considering that it slid already in mid December. A more shallow snowpack is typically a breeding ground for facets. There wasn't really a consolidated slab on top of the facets so we decided to ski the slope anyway. I think the little wind slab we kicked off was also a good test of these facets as it did not step down into them. If we get more snow this week, or wind continues to deposit snow on lone pine and other similar slopes I would stay off. Any of the NW through NE facing slopes that have slid previously will probably resemble the snowpack in lone pine. If it hasn't slid previously it should more closely resemble our pit which we all felt good about.
Closeup shot of the graupel/facet layer seen in today's pit 47cm below the surface. Failed CTM17 Q2, did not fail on ECT.
A shot of the small crown from the wind slab.
A shot of the small slide in relation to our tracks in lone pine.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
Snow Profile Coordinates