Avalanche Advisory for 2016-12-01 06:59:14

On the mountain, winter is in full stride. West/Northwest winds have been blowing on the mountain over the month of November with several wind events transporting a lot of snow on to south and east aspects. Two good sized wind slab avalanches started off the season right around November 21st off of Green Butte in the Old Ski Bowl. This certainly got my attention and was a great reminder that as long as there is snow on the ground, avalanches can occur, regardless of time of year. 



One natural and one human triggered (snowmobile) wind slab avalanches in mid/late November. Top: This is the north facing aspect off Green Butte, approx. 9,000 feet. Bottom: East aspect of Green Butte, approx 8,800 feet.

Yesterday, backcountry travels below, near, and above treeline on the south side of Mt Shasta noted a largely wind affected snowpack.  A widespread, variable thickness, breakable sun crust was observed on most aspects and elevations. Bunny Flat is hosting a couple feet of snow, whereas above treeline snow depths from 250 to 300 cm (98-118 in.) were observed above Lake Helen (10,500 ft). In Avalanche Gulch, the skiing was generally poor with an overall firm snowpack. A couple compression tests in The Gulch by a local ski guide resulted in CT25-27/Q2-3 at 60cm deep. In the Old Ski Bowl area, just under Green Butte on a northerly aspect (9,050 ft), snow depths were 120-130 cm (47-51 in). Several extended column tests resulted in nothing spectacular, ECTN15@12cm and ECTN25@32cm, both poor shear quality (Q3). Overall at this location, the bottom 3/4 of the snowpack was rock solid with the top 1/4 wind affected and firm. Softer snow, absent of the sun crust, could be found mostly near treeline in protected, shady aspects. 

Observations are limited thus far this season. We encourage you to submit your backcountry findings through our NEW big, blue 'submit observations' button, located under the 'advisory' tab on our website.

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LOCAL AREA ROAD, NORDIC, AND SNOWMOBILE PARK STATUS:

The Sand Flat cross country ski trails are in good shape still and ready for your cross country skis and snow shoes.  These are backcountry routes 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 CLOSED for the time being but will be opening soon! The trails are covered in snow and they are working on getting things going this month. http://www.mtshastanordic.org

The Pilgrim Creek & Deer Mountain Snowmobile Parks are open, however there is no snow at these locations currently. One must drive down the 19 road (Military Pass) for an unknown distance to get to consistent snow before unloading. 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 OPEN. The Everett Memorial Highway is OPEN. The Castle Lake and Everett Hwy are plowed year round to the trailheads. The roads are not always first priority, so your dawn patrol powder mission might be ceased if the plow has not made it up yet. Siskiyou County does a great job keeping the roads clear. Be respectful of the plow drivers if you encounter them. If you get to Bunny Flat before or during when the plow is there, please park on the uphill, LEFT side of the parking lot as you drive in. This is uphill and lookers right of the bathrooms. Thank You!

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.