Avalanche Advisory for 2016-01-28 06:57:25

Sunny skies and relatively warm temperatures for a January day made for an enjoyable ski tour yesterday.  A variety of snow conditions were observed as I set out to find wind slab formations, and any evidence of avalanche activity.  Below treeline, the ample amount of snow that had collected in the tree canopy has made for a sizable stockpile of tree bombs.  A halo of wet and disturbed snow surrounds each Red Fir breaking up the surface of the snowpack.  A sun/melt freeze crust was found on south to southwest aspects below, near, and above treeline.  The snow on southeast facing aspects was saturated, heavy, and supportable with all the solar heat gain during the day.  There was some evidence found of recent snow instabilities in the form of roller balls and a two small wind slab avalanches, both on southerly facing aspects above treeline.  A snow study pit was dug on a west facing aspect with a 30 degree slope at 8,200 ft.  The snowpack at this location had a layer of slightly less dense snow laying between more dense layers approximately 32 cm deep.  The layer of less dense snow was composed of decomposing stellars and dendrites with the layers both above and below composed of rounded grains.  An extended column test was performed resulting in a score of ECTN27 Q2 at 33 cm deep.  The evidence of failure during the ECT was simply the appearance of a crease at the layer of slightly less dense snow highlighting its presence.  

For today, avalanche danger for wind slabs above treeline had been decreased due to the effects of the weather over the last couple days.  Warm daytime temperatures and abundant sunshine have helped to round snow grains and encourage bonding of wind slabs to the snow below.  There still may be pockets of wind slab instability at higher elevations in the usual suspect spots just below ridge tops, the tops of chutes and couloirs, around rock outcroppings, etc. The snowpack near and below treeline has been settling and consolidating well with a the past few days of pleasant weather.  Avalanche danger for these elevations will remain low with the next storm systems due to snow levels around 8,000 feet.  Avalanche danger above treeline, however, will rise due to newly developing wind slabs and storm slabs over the next 36 hours.

Quick Pit Profile from West aspect in Sun Bowl on 1-27-2016 by Jon Dove:

View across Sun Bowl to SE aspect. Note the two small naturally triggered wind slab avalanches with starting zones directly below cornice formations:

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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.