Avalanche Advisory for 2016-04-15 06:36:20

What felt like a well hyped storm did not result in much new snow for the Mt Shasta area. Storm totals at treeline on Mt Shasta totaled 2-4 inches at best. It might be easy to scoff at the idea of any avalanche danger from such a small amount of snow, but combined with very high winds, we did see and could continue to get some small to medium size instabilities... mostly confined to near and above treeline areas.

While the visibility was not great, a local observer was able to snap this shot below yesterday. This shot was taken just above treeline on Green Butte ridge and does a great job illustrating the high winds that have been occuring, transporting new snow onto those south, southeast, east facing slopes. We've actually had wind loading occuring on numerous aspects. The storm arrived with southwest/west winds and now have switched to north/northwest. Thus, one can expect perhaps all aspects to potentially host small to medium size cornices, wind pillows, wind slabs. These wind loaded areas could host pillows/slabs/cornices up to 8" to 12" inches deep. Snow depth totals of up to 8" were noted yesterday, particularly in gully bottoms and more protected areas, but could have grown in depth due to sustained winds continuing to load these areas.. Ridge lines were scoured, which is standard for Mt Shasta during these wind events.

Yesterday, cornice build up was rapid and a skier observed a cornice failure along the southeast facing Green Butte ridgeline. The cornice did not seem like it triggered a slab as no crown was visible, but it did propagate down about 40 feet wide and ran three quarters of the way down Sun Bowl. "Cornice build up was rapid from the nuking (north) winds yesterday and while I didn't see much wind slab activity, very weak cornices were observed", said the skier. He went on to say further, "I wouldn't be dropping in off Casaval or any of the bowls today!" 

Good call. The bottom line here is that, even though we received only a scant couple inches of snow, it has been light enough for wind to transport it onto leeward aspects and form some instabilities.  Cornice failure and wind slabs represent the two main avalanche problems. Loose wet activity is not expected to be much of a problem today, but with a rapid warming trend tomorrow, we'll need to be aware that his warming could create some loose wet snow point releases over the weekend.

Treeline, Green Butte Ridge, approximately 8,000 feet, Mt Shasta on 4.15.16 - Photo: J Koster

Photo taken just below Lake Helen in Avalanche Gulch on 4.13.16 - Photo: C Carr / Shasta Mtn Guides

Climbing Conditions: Current climbing conditions are good to great. Below are some things to think about when planning your trip this Spring:

1. Avalanche Danger & Weather: You may encounter a variety of snow conditions during the spring time.  Late season storms can bring fresh snow and high winds to the mountains. Avalanche danger can quickly spike due to new wind and storm slabs on top of icy, firm melt/freeze snow. Further, warm and sometimes downright hot days can create loose wet avalanches. Low danger in the cool morning hours may rise rapidly to higher danger during the afternoon hours on sunny aspects. These are two different avalanche problems associated with different weather patterns with both being possible during the same week, or even the same day. A beacon, shovel and probe continue to be essential, even during Spring time. Always check the avalanche advisory before starting your climb, and call the ranger station for the latest in weather and conditions. Spring time weather patterns can bring it all.  The point is... you need to bring the appropriate attire to accommodate all weather conditions. Snow, rain, sun, wind... you can count on all of it on Shasta at some point during Spring time. Further, Mt Shasta can often host a cloud cap creating poor visibility conditions. DO NO climb into a white-out. It is very easy to wander off the WRONG side of Mt Shasta when on the upper mountain, >12,500 feet. This can create a long day and perhaps night for climber, party members, rescue resources and family. Play it safe. 
2. Firm and smooth snow (slide for life conditions): Snow conditions on Mount Shasta are great right now. That being said, the snow in the morning hours is very firm and very smooth. These types of conditions have caused serious injury in the past to those who slip, trip, or fall and fail to self-arrest as they slide.  You MUST know how to self-arrest with an ice axe. This is one of your best defenses for a safe trip on Mt Shasta. Practice this and other climbing skills on small, short slopes in soft snow. If you fall, you must immediately self-arrest or you will take a long, sliding, tumbling fall resulting in serious injury or death. Along with your solid ice axe skills, know how to walk/climb with crampons on.  It is easy to catch the front points of the crampon on the cuff of your pant leg resulting in a fall if you are not careful with each step.
3. Rime Ice:  What is rime ice? Rime ice forms on rocks, towers, etc. as super cooled water droplets freeze upon contact with a solid object. The ice grows into the wind taking on a cauliflower like appearance. The exposed rocks on Mt Shasta at higher elevations are currently plastered in rime ice. This hazard will diminish as the ice flakes off on warm days, but until then... HEADS UP! You absolutely should wear a helmet if climbing. As the days warm, chances increase of getting hit by falling ice until all of it falls off.

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LOCAL AREA ROAD, NORDIC, AND SNOWMOBILE PARK STATUS:

The Sand Flat cross country ski trails are  still covered in snow. A little bit of fresh snow has them in better shape currently, though they have been a little crusty before this last storm. 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 season. http://www.mtshastanordic.org

The Pilgrim Creek & Deer Mountain Snowmobile Parks are open, however there is currently no snow at these locations. One had to drive down the 19 road (Military Pass) 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.