Front Range
AvalancheAnonymous · Jan 5, 2014 · Front Range
Weather
Mostly overcast with limited visibility above treeline, periods of very light snowfall. Very cold with windchill well below 0F. Light/Mod winds below treeline (though strong at higher elevations), increasing significantly by mid afternoon.
Snowpack
In tighter trees mostly faceted with several inches of very light storm snow. In open glades, the storm snow is denser though with 4F/F still fluffy. Very few signs of wind affects at these elevations except when directly exposed from the strong winds coming down the valleys. Around treeline, some windloading observed but less than expected. Mix of soft storm and wind slabs 1-2ft deep. A pit at an open glade at 11,000ft on a 31dgr E facing slope showed multiple small stacks of older windslabs (1F-4F) commonly separated by a very thin layer of small sfc/nsfc facets, an old melt layer crust in the lower snowpack was completely faceted, the entire snow structure rested on 2-3mm depth hoar. Moderate CT with Q1/Q2 showed the new windslab was somewhat reactive while DT and ECT showed that the persistent slab on the depth hoar near the ground is still reactive but harder to trigger. These results jibed well with the avalanche obs below. Morale: the snowpack at RMNP seems to be a little less reactive than other areas in the FR zone. However, the snow structure is weak with the main issue being the persistent slab - and currently the new windslab as well. It would be unwise to push steep lines (greater than upper-30dgr) above treeline such as Dragontail or Elevator.
Avalanche
I was able to trigger a small windslab on a very steep (est. 39dgr) very sparsely treed E facing windloaded slope directly below a small ridge with some trees (AS-SS-R1D1-I, about 6m wide 40cm deep running to top runout; the weak layer was a thin faceted layer between the new/old snow interface. I triggered it at its flank but would I have entered its ZS I'm convinced I would have taken out most of this feature (est. 50m wide, max runout 150m).