Avalanche Advisory for 2015-04-05 06:33:12

Conditions have not changed significantly over the weekend. Firm, smooth snow surfaces with limited softening continue today. This will change soon as several storm systems pass over the area beginning this afternoon (see weather section below). These systems are forecasted to give us up to 1.75 inches of precipitation by mid week with snow levels down to Mt Shasta City limits at times. This could mean 1-2 feet of new snow accumulation on the mountain over the next few days. West/Southwest winds will accompany these systems with the highest wind speeds near and above treeline. Wind and storm slab development will take place and the avalanche danger will rise. 

We will have to wait and see how new snow bonding to old snow goes... based on predicted temperatures, models are showing this first wave of snow to be cooler, followed by a brief break, and then heavier, warmer snow close behind. This could mean the "upside down cake effect", or heavier (dense) snow on top of lighter (less dense) snow. This is not favorable for good snow stability. Temps are going to warm up a few degrees after the storm, mid-week. Any avalanche danger will likely be during or 24-48 hours after these storm systems.

For folks that plan on climbing Mt. Shasta:  All routes on the mountain are currently in great shape, however with incoming new snow, climbing is not advised for the next several days. The avalanche danger is expected to rise with the formation of wind and storm slab avalanches. Post holing will also be a problem where significant accumulation occurs. WInd, extreme wind chill and winter weather will be encountered this week and if one still chooses to make a trip up or on Mt Shasta, be prepared!

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, if any 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’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.