Obs-Snow Profile: Grizzly Gulch -> Wolverine -> Catherine's Pass 1/18/2011

Observer Name: 
Greg Gagne
Observation Date: 
01/18/2011
Region: 
Salt Lake
Location or Route: 
Grizzly Gulch -> Wolverine -> Catherine's Pass
Weather
Sky: 
Broken
Wind Direction: 
Northwest
Wind Speed: 
Moderate
Weather Comments: 

 Sky began to cloud up late morning with gusty, though moderate, winds out of the NW. Very little loose snow available for transport. -7 C in the shade at 10000'

Snow Characteristics

Snow Surface Conditions: 
Rain-Rime Crust
Snow Characteristic Comments: 

 For the most part, the snow surface is a very supportable, stout rain/frozen snow crust up to 5 cm thick in some places. (Perhaps even thicker at lower elevations.) There are some "islands" where dense graupel stuck to the old snow surface making for very nice travel conditions. Most everywhere I looked today the snow surface has a buffed look to it making for easy travel - and dare I say it? - fun skiing on low angled graupel islands. Ski crampons would have been ideal on steeper aspects.

Primary Concern

Primary Concern: 
Persistent Slabs
Probability: 
Moderate
Aspect: 
North
Northeast
East
Northwest
Elevation: 
High
Mid
Trend: 
Same
Primary Concern Comments: 

 I found quite variability in several pits I had dug today looking for the preserved surface hoar layer. It ranged from 10-35 cm down from the snow surface with crystals up to about 5 mm. Stability tests could get at best resistant planar fractures. One pit had a CT 15/Q1 score, but ECTN 25. Due to spatial variability, I am feeling one needs to be very diligent searching for this buried weak layer.  

Secondary Concern

Secondary Concern: 
Persistent Slabs
Aspect: 
North
Northeast
East
Southeast
South
Southwest
West
Northwest
Elevation: 
High
Mid
Trend: 
Same
Secondary Concern Comments: 

 Was finding several crust sandwiches in the top 5-20 cm of snow with weaker snow between the crusts. I was able to get Moderate, Q1 shears in several of these weak layers.

Elevation: 
10400'
Aspect: 
North
Slope Angle: 
25
profile.png
snow_profile_location: 
United States
40° 35' 9.2292" N, 111° 36' 4.4064" W
Comments - Photos - Videos (group 1)

 I was curious how the snowpack (and our preserved surface hoar layer) looked after the recent rain/wind/graupel. Pits showed spatial variability as we might expect with such unusual weather conditions. Although I was able to identify the surface hoar in most pits, for the most part I was not getting easy shears at the interface and an ECT would not propagate across the 35 cm, 1F slab above it.  For now, I still don't think we have enough of a slab above the surface hoar layer and the layer seemed to be breaking down somewhat as many of my pits did not always get clean shears. Also, some pits showed a very stout slab that is bridging the buried weak layer. I was away when the surface hoar looked at its worst, so have actually been expecting a more reactive weak layer.  However, when skiing out, I talked to a party that got a 200' wide avalanche in Catherine's Area that failed at the surface hoar layer. Am hoping the leader of this group reports the details of the slide. That said, unusual conditions (buried SH & NSF, stout rain crusts, water weight) warrant cautious travel. Am thinking any new snow will make for very fun skiing on lower-angled terrain on Wednesday.

 

Photos of (1) water channeling at lower elevations, (2) out Wasatch looking more coastal range (3) slide on S face of Superior (4)  5 cm rain crust (5) pit (6) buried surface hoar layer.

IMG_1177.JPG
IMG_1179.JPG
IMG_1181.JPG
IMG_1185.JPG
IMG_1190.JPG
IMG_1202.JPG
Printer-friendly version
Observed Danger Rating: 
Moderate
Forecast Danger Rating: 
Moderate
Snow Profile Location
Javascript is required to view this map.

Site Built by Dharmatech
Site Refresh by Flint Creative