Avalanche Advisory for 2015-03-21 06:10:24

Observations on the mountain have indicated strong snow surface refreeze and an isothermal snowpack. Lower elevations currently are holding melt/freeze conditions, however as the cold front enters the area this weekend, the melt part of melt/freeze will be limited. Upper elevations are still in a transitional phase and will remain that way until sun returns. Northerly aspects are still holding dryer, wind packed snow at upper elevations.

Four to eight inches of new snow is in the forecast for Sunday and Monday with westerly winds and snow levels dropping to as low as 4,000 feet by Monday. This will cause the avalanche danger to rise. Folks traveling in avalanche terrain on Mt Shasta in the next few days should take note of this and use careful route decision making and snow observations.

Over the past week, we saw fairly widespread natural and some human triggered wet loose point releases on many east, south and west aspects. Knowbody was caught or injured that we heard of. Snow levels with the past weekends storm rose to almost 11,000 feet at times, thus all areas below, near and above treeline received rain on snow. Top layers of the snowpack were very saturated and wet loose point releases occured within new snow layers on top of old snow during the beginning of the week.   Only a couple inches was recorded from the storm with 3-4 inches of settlement over the week.

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 and thus skiing conditions are a little funky, but not bad. Cooling temperatures over the week will prevent any wet loose activity. The danger is currently low, however keep your antennas up as we get new snow and wind this weekend. 

Below treeline, tree wells are showing and dirty snow exists. On the upper mountain, a report from mid-week noted 6 to 12 inches of dryer powder on the old, firm snow on a north facing slope. "Conditions were exhausting..." the report noted. The Catwalk on Casaval ridge is narrow with one short section of exposed ice.

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, there are some objective hazards to be noted.  Snow surfaces will be firm and smooth in the early morning hours and will make for "slide for life" conditions.  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

-------------------------------------------------------------------------------------------------------------------------------

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.