Observation: NWAC Observer
Basic Information
Observation Details
Observation Date:
March 26, 2023Submitted:
March 26, 2023Observer:
NWAC Observer - Willie WebsterZone or Region:
East NorthLocation:
Rock Mountain (West North and East 5500' to 7000' )Signs of Unstable Snow
Recent Avalanches?
None ObservedCracking?
None ExperiencedCollapsing?
None ExperiencedMedia/Attachments
Advanced Information
Weather Summary
Cloud Cover:
OvercastTemperature:
25°FWind:
CalmNew/Recent Snowfall:
3"While the Valley bottom was feeling warm, wintry conditions are found up high. Very little wind and occasional snow showers under overcast skies made up the weather conditions today.
The crown lines of small wind slabs were seen on a NE aspect of Rock Mountain at about 7300'. These may have occurred over a week ago at the beginning of this recent warm up, but that timing is a guess.
Snowpack Observations
Things are melting out fast in the low country and there were a few patches of asphalt on the ride up. Above 5500' the snowpack gets more substantial. Even so, the height of snow varies impressively in this part of the zone. In wind scoured areas there is 1-3' and in wind loaded areas closer to 4-6'. Four inches of new snow covers a two inch thick crust in most places, but deeper soft snow is preserved on North aspects and above tree line. The bottom of the snowpack is made up of large basal facets aka depth hoar. These large coarse grains are not a great foundation for the rest of the snowpack. The mid snowpack is a mix of crusts and facets. The upper snowpack of rounded grains fell with the storms of early March plus a little bonus on top. I didn't see any signs of avalanches releasing down on those lower crusts or basal facets. In two extended column tests there were signs of 'fracture propensity' (ECTP 12 @68cm & ECTP 10 @68cm). These failures were on top of the old X-mas crust. The snowpack in this part of the zone is dramatically different from the Washington Pass zone; it is shallower and more faceted. Cornices haven't started to fall yet in this area, but there are some sizeable ones to watch out for.
Avalanche Problems
| Problem | Location | Distribution | Sensitivity | Size | Comments |
|---|---|---|---|---|---|
Persistent Slab
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Layer Depth/Date: 68 cm Weak Layer(s): Dec 25, 2022 (MF) |
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Cornice
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This persistent slab problem is probably unique to the Tiffany area, and without more observations it's actual sensitivity to triggers is pretty uncertain.