Avalanche Advisory for 2015-01-02 07:07:12

Happy New Year! Hope everyone has been keeping the rubber side down and hairy side up. Local roads and skiing conditions have remained downright icy. It's safe to say that it's becoming harder and harder to find softer snow in the forecast area! A few, true powder sniffers (no, NOT drugs) have reported some areas of brilliance, but these "powder stashes" are far and few between.

Adventures over the week brought in observations from Mt Shasta, Castle Lake, the Mt Eddy area, and Ash Creek Butte. Clear and cold weather has the snowpack in all these areas much the same....firm and variable. One will find the full 9 yards on any given piece of terrain: bullet proof ice, breakable crust, firm and chalky pack powder, melt runnels, and if your lucky or just good, a brief pocket of old powder. Snow depths are looking good however and we definitely have a solid base for the remaining winter. Mt Shasta and Ash Creek Butte are seeing average depths of 5 to 6 feet. In the Eddy Mountains, average snow depths are 3-4 feet in the Upper Deadfall Lakes area. Castle Lake and Cliff Lake snow depths are less, with an average of 1-3 feet. 

Snow stability overall has been very good. It's been tough to even get a shovel in the snow in some areas. Lingering, small, hard wind slabs have been unreactive to trigger. Shallow snow on cold, northerly facing slopes is seeing some depth hoar (sugary, poorly bonded snow grains) form below a widespread, thick crust. Further loading from future snow could pose a threat for deep slab instability on these slopes, but not likely due to the thick crust layer(s). Elsewhere, cold, clear nights has formed well developed surface hoar crystals in lower elevation, protected areas. This could be our next weak layer if surface hoar persists and becomes buried....but with a week of sunny weather in the forecast, I suspect the surface hoar will be destroyed by sun and wind before our next storm. Icy surface conditions with new snow on top, whenever that may be, will pose the greatest threat for rising avalanche danger in the future. Avalanche danger will likely be in the form of storm and wind slabs on top of the icy bed surface and maybe, buried surface hoar.

Below: East Bowl of Ash Creek Butte. A well known and large avalanche path and producer of frequent slides during storms and wind events. This slide observed on 1-1-15. It appeared to be a heat induced, wet sluff that probably occured during our rapid warming event on 12/20-12/21. Photo: Meyers

Above: Ash Creek Butte, 1-1-15 / Skier: Malee / Photo: Meyers

Above: East Side, 1.1.15 / Photo: Meyers

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 has a shallow snowpack, but a few folks have been making some turns up there. Be careful of shallow buried objects. Ice skating was reported as "game on"... Cliff Lake is hosting poor skiing, but decent ice skating (back, lookers left portion of the lake is best) as well.

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 several miles before enough snow is encountered. One CANNOT DRIVE over Military Pass. Don't try it, it just tears up the road for OSV users.

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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.