Avalanche Advisory for 2015-02-27 06:53:52

Our old, firm snowpack waited patiently for a refresh, and it got it! While we are not seeing impressive new snow totals, I will refer to the well used saying... "It's better than nothing!"

Up until the new snow we received over the last 24 hours, we sat in an idle period of clear weather with great corn skiing at times. Our snowpack below this new snow is, bomber. That means it's very strong, isothermal, equitemperature, no persistent weak layers of concern. Observations over the week found overall smooth and firm snow surface conditions with south and southeast aspects, low to mid elevations softening at times. Upper elevations stayed mostly firm. Ice fall (rime ice) off exposed rocks is an ongoing issue for climbers and skiers venturing onto the upper mountain. Wear a helmet and stay out of the fall line of exposed rocks/ice above. Smooth, firm snow surface conditions also mean that a slip and fall can result in a long slide for life. Self arrest skills with said conditions are an important asset to have should one choose to climb.

Concern for today and the weekend will lie within the wind slab avalanche problem. Cooler temperatures during this storm has deposited a couple inches of new, light density snow on the mountain. The Old Ski Bowl station recorded about 2.5 inches new snow. Gray Butte station has shown northwest winds blowing steadily during the storm, 20-30 mph with gusts 50+ mph. This new snow is ripe for transport and we will see some wind loading in isolated areas. Spacial variability will be the name of the game: some areas will likely see scouring down to the old snow surface while adjacent slopes will host shallow, small to medium size wind slabs. Smooth, round slabs will have formed on top of the old snow surface and could be triggered by a skier or rider. Leeward areas above treeline, near ridgelines and extreme terrain should be most suspect. 

Castle Lake and Mt Eddy zones are still hosting shallow snowpacks. All areas below about 6,000 feet in the forecast area are hosting patchy snow with dirt showing around trees and in sunny spots.

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

Castle Lake area has a shallow snowpack. Skiing is out of the question at this point due to lack of snow. 

Sand Flat Winter Trails: OPEN, trail conditions are firm and getting thin with some tree debris on snow surface. 

Pilgrim Creek Snowmobile Park: OPEN, however due to lack of low elevation snow, one must drive up the road several miles before enough snow is encountered. One CANNOT DRIVE over Military Pass. Snowmobiling is not recommended due to low snow depths.

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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.