Avalanche Advisory for 2014-02-23 06:54:50

Overall, it's a mix between hard, firm conditions, isolated wind slabs and pockets of powder. Southerly, sun affected slopes with decent coverage are moving toward melt/freeze and some decent corn skiing was found in Powder Bowl yesterday, mid afternoon. Powder Bowl is south facing and gets very good sun and is protected from northwest winds.

A look up into the Old Ski Bowl, with Casaval Ridge and the Trinity Chutes in background, and Green Butte Ridge slicing left to right up to Sargents Ridge.  [Photo: 2-21-14  N Meyers]

Northerly facing, cooler slopes are variable and host poor skiing. The old snow from weeks past is completely bombproof and difficult to penetrate with shovel, boot and even probe. Some areas of old snow has an icy sheen to it and is very, very slick. For climbers, a slip and fall on this smooth, icy snow could prove disastrous as self arrest would be difficult as many rocks still stick out of the snow like jagged teeth.  The wind slabs we found were 10 to 30 cm thick. About the bottom 2/3 of any given wind slab hosted partial faceting and in general, sugary snow sitting on the firm, old snow. The top 1/3 of the slab hosted sun/wind crusts 5 to 10 cm thick. While compression tests scores were low, bridging from crusts and only partially developed facets are keeping things intact at this point and full slab propagation is not likely with the current conditions. Our weather leading up to next weeks storms will dictate the development of these weak layers. We have potentially two up coming avalanche problems: new snow on top of wind slabs with underlying weak layers, and/or new snow on top of icy, old snow. At this point, triggering any avalanche activity will be difficult.  Overall, our pit was 120cm deep on the north facing aspect of Green Butte, one of the deepest areas we could find.

For now, snow conditions are still slim and shallow! Any recent pictures you might have seen of Shasta make it look like conditions are pretty good. I suppose it IS good considering our winter, however in reality, there is only about 1-3 feet of snow on the mountain. Many of the rocks are white and look covered, but this is rime ice and not snow. Anybody wishing to climb this weekend is cautioned: rock and rime ice fall will be a hazard, especially during the warmest portions of the day. A slip and fall on any existing frim and icy snow, as mentioned above, will likely prove disastrous if unable to self arrest. 

Snow is melting and patchy below 6,000 feet and many shallow buried object exists below treeline.

---------------------------------------------------------------------------------------------------------------------------------------------------------------

Some trailheads are still accessible by 4 x 4 vehicle. Be cautious of any overnight trips on the mountain with snow involved. Storms can easily dump large amounts of snow to the area and make it difficult to drive off the mountain! While Northgate, Brewer Ck and Clear Ck trailheads are officially closed, the bathrooms are still open with packout bags inside, and one can still access the Mt Shasta Wilderness. However, your summit pass and wilderness permits must be purchased at McCloud or Mt Shasta Ranger Stations. NO DOGS are allowed in the Mt Shasta Wilderness OR Sierra Club Property. Thanks!

---------------------------------------------------------------------------------------------------------------------------------------------------------------

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.