Avalanche Advisory for 2016-01-26 06:57:42

The snowpack continues to stabilize and settle in the forecast area due to a full day of sun yesterday. Another 4 inches of settlement was recorded at treeline on Mt Shasta and 2-3 inches on the west side over the past 24 hours. Snow conditions are going to depend largely on aspect and elevation. Southerly slopes for most elevations got warm yesterday and some roller balls were observed. Northerly slopes will still host supportable powder. Instabilities are going to be isolated to steep terrain and spacial variability will be the soup of the day. Todays conditions will mostly mirror yesterdays, minus southerly slopes which might have a bit of a crust this morning. Roller balls, failing cornices, small to medium size wind slabs and surface sluffing could all be encountered. Large, destructive avalanche are unlikely, however small avalanches are likely and could sweep somebody into terrain traps and/or undesireable terrain and could be enough to bury a person if in just the right spot. Lingering pockets of instability for wind loaded topography such as roll overs/convexities, steep chutes, and complex terrain with rock outcroppings will represent the best places for triggering wind slabs and surface sluffs and should be todays primary concern. Near and above treeline, keep your peepers open for overhanging cornices on wind affected ridgelines and existing wind slabs which could be triggered when on slopes steeper than 37 degrees. Be able to observe signs of wind such as cornice formations, wind pillows and snow surface texture.

Mt Shasta: Wind slab conditions near and above treeline are very close to day prior. Warming continues to help snowpack settle and wind slabs bond to old snow. Wind slabs still present on all aspects near and above treeline. Slabs stiff and better developed in Avalanche Gulch above 9,000 feet due to colder temps and consistent wind, compared to softer slabs found yesterday in Giddy Giddy Gulch (just above treeline, south side). On a S/SE aspect at 10,285 feet on Casaval Ridge (100 feet below Lake Helen), at 18cm deep, 1-2mm facets are developing from new precipitation particles on the old snow surface. However, slabs appear to be bonding well to a high friction, variable bed surface. Stability test results: ECTN12 Q3 / ECTN21 Q3 / Air temp: 28 F  / No significant temperature grandient. Despite somewhat poor structure, the hypothesis is that the snowpack is gaining strength due to counteracting processes of sintering and faceting from temperature fluctuations. Snow settlement on the high friction bed surface created by wind also assisting. Skiing above 9,000 feet was typical "Shasta variable". Scoured pockets/ridges with deposited snow in gullies and depressions. Winds were gusting 25 mph, N/NW and trasported decent amounts of snow on S/SE aspects above 9,0000 feet on ridge lines.

Photos: Left, Avalanche Gulch on 1/25/16 with Casaval Ridge in background. Right, some point release/roller ball activity off the lower portion of Casaval Ridge into Avalanche Gulch. 

Castle Lake: Great skiing was reported from the Castle Lake area yesterday with pockets of instability in the form of cornice failure, surface sluffing, and small wind/soft slabs. Spacial variability will continue to be the name of the game today. Castle Lake has complex terrain. Steep rollovers, chutes and rocky outcrops can host pockets of instability. The entire north facing ridgeline above Caslte Lake can shed cornices and trigger slides below. 

Photos: Left, ridgeline above Castle Lake, cornice failure causing slide. Right, surface hoar observed on northern ridgeline on "Right Peak". 

East Side: Observations from the east side of the forecast area, east of Mt Shasta... Upper snowpack "right side up" with density change from fist to four finger approximately 15cm deep and continuing from four finger to one finger density at approximately 40-45 cm deep. No crust layers were observed in top 100-120 cm of snow. Extended column test on a north aspect at 7,300 feet of ECTX. Recent avalanche activity included a small point release on a southeast aspect below a rock outcropping. Some afternoon roller balls observed on a south aspect near treeline. A skier triggered, small loose-dry sluff on steep terrain occurred as well as another skier triggered small, isolated wind slab on a 37 degree slope. The wind slab was on a north aspect, near treeline with an eight inch crown, approximately 15 feet wide and slid about 20 feet.

Photo: A small wind slab, mid-fracture, along ridgeline, east side
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LOCAL AREA ROAD, NORDIC and SNOWMOBILE PARK STATUS:

The Sand Flat cross country ski trails are in great shape and ready for your cross country skis or snow shoes. These are backcountry trails marked with blue diamonds on trees. Trails are not groomed.  Snow shoers, please blaze a parallel trail to cross country skiers staying out of the skin track. These trails can be accessed via the Everett Memorial Highway. Thank you, and enjoy!

The Mt Shasta Nordic Center is open! These beautiful, groomed trails can be accessed via the Ski Park Highway. http://www.mtshastanordic.org

The Pilgrim Creek & Deer Mountain Snowmobile Parks are open! Trails are being groomed currently. Head to our "Education" tab on our website and find the snowmobile section for trail information, grooming status and other sledder resources!

The Castle Lake road is plowed to the lake. The Everett Memorial Highway is plowed to Bunny Flat.

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