Route today was Catherine's Pass down Dry Fork to Ant Knolls; returning back through Alta. As is often the case in this area, generally thinner snowpack than in tri-canyons. Was finding anywhere from 60-120 cms (2-4') between 8500' and 10000'. What I found interesting today follows up on Drew's excellent coverage of spatial variability and the strength/energy/structure cycle. While skinning up Ant Knolls at about 8500' on a NW aspect I was finding some of the weakest snow I have seen in many weeks. Thin snowpack (60 cms at most) consisting of mostly facets and depth hoar, capped by the 20 cms of new snow over the weekend. Difficult skinning where your skis would crash down through the weak snow to the ground. Quick hand pits showed it was difficult to even isolate a column of snow. 1000' higher on the same aspect I was finding a 120 cm snowpack that didn't look much different than what others have been finding elsewhere in the range - early and mid-January facets are found in the upper 60 cms of the snowpack, but no energy in the slab - ECTX.

I have become a disciple of the strength/energy/structure model as it helps objectively describe and evaluate what we see in the field.

Lower elevation profile shows:

• Low strength as it is even difficult to isolate a column.
• No energy in the slab on top (really not much of a slab apart from the new snow over the weekend.
• Poor structure - entire snowpack consists of weak facets and depth hoar.

Upper Elevation profile shows:

• High strength as no fractures in the early and mid-January faceted layers.
• No energy in the slab (no propagation on ECT.)
• Poor structure (4 lemons, possibly 5 but I didn't measure grain size.)

Over time I am expecting the upper elevation snowpack in this area to continue strengthening as the moderately deep snowpack likely has a small temperature gradient and by most accounts the two layers from the January faceting events are gradually transitioning to stronger layers (i.e. F -> 4F -> 1F). [Note - I did not take temperature profiles nor did I examine the facets under a scope - just raw observations.] These layers of course may become active, but it will require a more substantial load.

The low elevation snowpack will continue to weaken as it is thinner and likely has a steeper temperature gradient. It too lacks a slab on top to become active.

I didn't travel all that widely in this drainage today, so it is possible that the weak lower elevation snowpack was an outlier. But my concern in the future would be the lower elevation wouldn't take much of a load to become active, whereas the upper elevation snowpack is likely to require a more substantial load. The weaker snow at the lower elevations also concerns me somewhat as this area is popular with snow machiners who are likely to spend more time sledding where the snowpack is weaker. (Tracks from sledders in this area show lots of high marking at similar elevations and aspects where I was finding weaker snow.)