Quick report
- Red Flags
- Rapid Warming
Local avalanche hunter (UDOT and now PCMR) Mark Saurer's 2012 ISSW paper on stream flow correlation with wet slabs suggests that wet slabs may be more likely 24 hours on either side of a stream-flow spike. See East Canyon stream flows HERE. See screen capture below.
Snowpack
- Instability Comment
- <p>In the Central Wasatch, the south end of the Park City ridgeline is often the canary in the coalmine for wet activity, particularly wet slab activity. It's been a difficult winter with a fairly complex snowpack structure and I wouldn't be surprised to see that continue on into spring. Wet slabs are *more likely* when these conditions (highly structured) exist and then we start to look for pooling of free water at these interfaces. They generally pool adjacent to crusts or just below a 'cohesive slab' at a layer of more coarse grains (often facets or depth hoar). </p> <p> </p> <p><strong>Interfaces we may expect to see pooling:</strong></p> <p> </p> <p><strong>New/old interface</strong> 1-2' down (see artificial pooling in first photo below). </p> <p> </p> <p><strong>Early March dust/crust/facet layer</strong> - this did not look as suspect today at 8880' ENE; not really much of a structural interface. (second photo) I imagine it would in other areas. Remains suspect this week.</p> <p> </p> <p><strong>Repeater or thinner areas</strong> - I did not look at this today. I did look at northeast at 7800' and found loose mf grains at the bottom of the snowpack (HS 60cm) but artificial pooling found other interfaces (third photo).</p> <p> </p> <p><strong>Bottom Line</strong>: we triggered some wet loose sluffs (photo 4) up to size 1.5 in steep solar terrain. Wet slab activity cannot be ruled out over the next several days with skyrocketing temps. Last note: fracture mechanics are poorly understood in an isothermal snowpack. Not sure what to make of repeated ECTPV at ESE at 8900' at the ground interface (not depth hoar). Reminded me of Japan - poor interface with bamboo at the ground level.</p> <p> </p> <p></p> <p> </p>
Thanks much to the hospitality from PCMR avalanche teams today.