Avalanche Advisory for 2014-12-21 06:55:34

Snow sliders and riders stomachs are plum full from a steady diet of pea soup in the recent days. All were busy wiping the goggles off their foggles to retain visibility as the snow levels fluctuated and the precip fell in the form of mist/rain/ice and/or snow pellets. The mountain received a couple inches of new snow yesterday at Bunny Flat (6,950 feet) and a bit more up higher. The downright deep conditions experienced on Friday settled out yesterday and provided more supportable powder. In general, warmer temps had the snow on the sticky/heavy side... though I still didn't hear any complaints! 

Below treeline avalanche danger remains low. That said, a lack of observations has created a lot of uncertainty for all areas above treeline and folks need to take note of this. The mountain is hosting a couple variables that are favorable for wind slab development and an unstable snowpack. These are: a steady stream of new snow over the past several days, moderate to strong west/northwest winds, warming temps. We've got snow to transport and winds to do so and thus wind slab avalanches will be of most concern for the next couple days. Warming temps could also further contribute to instability. As always, one will to need to bring out their 'A' game when the skies begin to part and adventures begin on the upper mountain.

This morning, the Bunny Flat area was seeing a massive tree drip event and likely a several inch snowpack consolidation due to the temperature rise. This will continue into today. Wind slabs will be most sensitive to trigger in the next 24-48 hours. Warming temps today could also contribute to increased sensitvity to triggering of said slabs.

Total snow depth observed at 7,900 feet at the top of T-Bar was 240cm on 12-19-14. A 157cm deep, East facing snow pit revealed an isothermal snow mass with no temperature gradients. Stability test scores (extended column tests) were all in the 20-30 range with poor shear (ECTN26@105cm/ECTN21@105cm). This "weak" layer consisted of a density change in the snowpack.  

Report your observations to the MSAC! A photo, a few words... send them in! (nimeyers@fs.fed.us or 530-926-9614)

Castle Lake area still has very little snow and no skiing is being had yet.

Mt Eddy area is hosting about 2-3 feet of snow in Wagon Bowl. I have not been up into that area yet and have received no reports.

Sand Flat Winter Trails: OPEN and in good shape!

Pilgrim Creek Snowmobile Park: OPEN, however due to lack of low elevation snow, one must drive up the road a few miles before enough snow is encountered.

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Terrain:  Remember most of the terrain that we like to play on is greater than 30 degrees.  Avalanches are possible on anything steeper than 30 degrees.  Avoid cornices, rock bands, terrain traps and runout zones of avalanche paths.

Weather:  Most of our areas avalanche danger will occur 24-48 hours after a storm. We still can see persistent weak layers from time to time and we always will be sure to let you know about that!  Heed the basic signs: Wind (significant snow transport and depositions), Temperature (rain/snow/rain/snow, which in turn weakens the snowpack), and Precipitation (Snow or rain add weight and stress to the current snowpack).

Snowpack:  If snow accumulates, give the snowpack a chance to adjust to the new snow load before you play on or near steep slopes (greater than 30 degrees).  Most direct action avalanches occur within 24-48 hours of recent snowfall.  Watch for obvious signs of snowpack instability such as recent natural avalanche activity, collapsing of the snowpack (often associated with a “whumphing” sound), and shooting cracks. If you see these signs of instability, limit your recreation to lower angle slopes.

Human Factor: Don’t forget to carry and know how to use avalanche rescue gear. You should NOT be skiing or climbing potential avalanche slopes without having beacons, shovels, and probes.  Only one person in a group should be exposed to potential avalanche danger at a time.  Remember, climbing, skiing, and riding down the edge of slopes is safer than being in the center.  Just because another person is on a slope doesn’t mean that it is safe.  Be an individual!  Make your own decisions.  Heed the signs of instability: rapid warming, “whumphing” noises, shooting cracks, snowing an inch an hour or more, rain, roller balls, wind loading, recent avalanche activity.

The Five Red Flags of Avalanche Danger any time of year include:  1) Recent/current avalanche activity  2) Whumpfing sounds or shooting cracks  3) Recent/current heavy snowfall  4) Strong winds transporting snow  5) Rapid warming or rain on snow.