Avalanche Advisory for 2015-03-22 07:12:31

Observations made yesterday at elevations near and slightly above treeline were consistent with the melt/freeze cycle meaning good corn snow and some softening in the early to mid afternoon making for great skiing conditions. The snow pack is well bonded and isothermal. No loose wet instabilities were observed.  That being said, a cold front has begun to push onshore bringing with it light preciptiation that has started to fall early today.  Temperatures will fall as the storm moves through with snow levels as low as 4000-5000 feet by tonight into early Monday. 

By 4 a.m. this morning  .05 inches of water was recorded at Old Ski Bowl weather station.  Precipitation amounts will increase through out the day with the heaviest periods of rain and snow falling late afternoon into this evening.  New snow totals of up to 10-12 inches are possible near and above tree line by Monday morning.  New snow will be accumulating on a firm old snow surface that could make for a good bed surface for new snow instabilities.  

Current avalanche danger is low, however, new snow and wind slabs will be our avalanche problems for Monday and Tuesday.  Higher winds of 35 to 40 mph out of the west-southwest with stronger gusts are forecast to accompany this storm.  This means that wind slab developement is possible on NW-N-NE-E-SE aspects.  Considering new snow totals, wind slabs that develop could be 2+ feet thick in some spots.  By Monday morning avalanche danger above tree line could rise to MODERATE depending on new snow totals and wind slab development.  Be cautious with route decision making, avoiding leeward apects, known avalanche paths, and run out zones.  

Photos:
Top - Casaval Ridge 3-18-15 [Bob Hutcheson]

Bottom - Wet/loose point releases, photo taken on 3-18 however slides occured earlier in the week, late Sunday/Monday. [Bob Hutcheson]

The snowpack is currently in a transitional phase: From 7,000 to about 8,500/9,000 feet, smooth, supportable melt/freeze snow can be found on warmer aspects, east and south. From +/- 8,500 feet and above, the snowpack is still transitioning. The danger is currently low, however keep your awareness up as we get new snow and increased wind today and tonight.  Below treeline, tree wells are showing and dirt patches exists, but will soon be covered by new snow amounts. 

Continue to always use safe travel methods: carry situational awareness on your skin up the mountain, choose safe routes and watch for what others are doing, ski one at a time, stop in safe zones!

For folks that plan on climbing Mt. Shasta:  Route conditions on Casaval Ridge, Sargents Ridge, and Avalanche Gulch are currently good.  That being said, the firm old snow surface will start to collect snow, and by tomorrow morning could be cover by up to a foot of new.  Should one slip and fall and are unable to self-arrest, a long tumble is a possibility.  Ice fall from rime ice that still partially covers the Red Banks and other rock outcroppings is happening, even in the early morning hours.  A helmet, crampons, and a mountain axe are necessary equipment and should be used. 

Castle Lake and Mt Eddy zones are still hosting a shallow snowpack. All areas below about 6,000 feet in the forecast area are hosting patchy snow with dirt showing around trees and in sunny spots.  For Castle Lake, skiing is out of the question at this point due to lack of snow.

Report your observations to the MSAC! A photo, a few words... send them in! (nimeyers@fs.fed.us or 530-926-9614)

Sand Flat Winter Trails: OPEN, however snow depths are meager and the Lower Sand Flat road is exposed dirt. We recommend heading up to Bunny Flat and touring up the road or anywhere higher in elevation!

Pilgrim Creek Snowmobile Park: CLOSED due to lack of snow

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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.

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