Frog Lake

We snowmobiled to the avalanche that occurred 4 days ago on 2/26. I wanted to give this avalanche a few days, then check out what stable weather was doing with our 2/14 weak layer. We also wanted to answer whether this was a step-down avalanche to weaker snow from 2/8. Given the reported depth, we suspected as such. 

With stable weather, our 2/14 weak layer has adjusted to the weight of snow that fell since 2/23, and is likely producing hard propagating scores (ECTP20+) or ECTN scores wherever you travel. My tests along the flank and crown of this avalanche showed moderate-to-hard failure (ECTP13-21, PST 40/100 End) about 2-2.5 feet deep in surface hoar (2/14 layer). 2/14 is not being compressed mechanically very well, and remains thickly preserved. It looked like fish scales on the bottom of the failure plane of the slab. Neat—but creepy.  My tests also showed easy ECTN scores at the old snow/new snow interface (composed of surface hoar and graupel) about a foot deep. I did not observe any stepdown activity to 2/8, and given the mass of snow that moved in this avalanche and the fact that 2/8 is now buried over a meter deep, my assessment of this layer is that it is dormant. 

We're not out of the woods yet with 2/14. It will linger in a sporadic nature on some slopes. Carefully assess any steep terrain traps or well-connected upper-elevation features, especially on the north half of the compass. 

Snow surface stayed soft up to 8,000 feet. Widespread cracking on steep rollovers on all aspects while approaching the saddle above Frog. Very neat to see cracking along almost every surface due to the slight rain crust from last evening.