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Avalanche Advisory for 2015-03-08 06:39:40

  • EXPIRED ON March 9, 2015 @ 6:39 am
    Published on March 8, 2015 @ 6:39 am
  • Issued by Nick Meyers - Shasta-Trinity National Forest

The avalanche danger is LOW for most elevations and aspects.
Areas of MODERATE danger will exist for human triggered avalanches in the form of small, loose wet snow instabilities on low to mid elevation, steep, sun exposed S-SE aspects during the warmest parts of the day.  

Remember, LOW avalanche danger means that unstable snow can still exist on isolated features in steep terrain.  
Climbers should be heads up for ice fall, and "slide for life" conditions.

 

 

 

 

 

 

 

 

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Avalanche Problem 1: Loose Wet

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Very warm daytime high's and above freezing nighttime temps have created wet surface snow and this will continue today and tomorrow. Isolated features in steep terrain below, near and above treeline may see human triggered loose wet snow instabilities, roller balls, and pinwheels on mainly south and southeast aspects during the warmest parts of the day.  While usually not a hazard themselves, they could potentiall knock a person off their feet and push them into undesirable terrain.

 

Recent Observations

We have been back into a run of copius amounts of Vitamin D, Vitamin C (Corn), tanning and/or sun burns, and apres ski flip flops-n-beverages. Tree wells are beginning to show at 6,950 feet (Bunny Flat area) and 2-4 feet of snow remains on the ground at that elevation. An unfortunate sign of Spring, though we have high hopes that we'll get a few more storms before the big lady sings. At treeline, we are still looking good with 80-90 inches of rock solid snow and most, if not all of the routes accessed from Bunny Flat are in good shape.
Of focus now is a storm set to arrive late Tuesday this week bringing up to .5 inches of precip over a few days, high snow levels (beginning near 8 to 9,000 feet and lowering to 6,000 ft) and windy conditions, southwesterly. We don't like to be Debbie Downer, but overall March is not looking incredibly wet or wild... so we are feeling fortunate to get any extra snow to pad our spring skiing and climbing season.


A couple of nice photos from the upper mountain (3/1/15), Avalanche Gulch/Trinity Chutes area.  [Photo: S Rathbun]

Observations over the weekend have indicated overall low avalanche danger with Mt Shasta's strong, melt-freeze snowpack. Near record high temperatures yesterday and above freezing nighttime temps have raised concern for heat related instabilities. That said, the snowpack stability remains good and we have not observed nor been able to trigger any significant instabilities such as loose wet sluffs, roller balls and/or pinwheels on any aspect/elevation. One should not let their guard down as the chance of human triggered instabilities will only increase today and tomorrow in response to daytime warming and poor over night re-freeze. Wet avalanche activity is a bit hard to predict when it will happen, both for human triggering and naturally occuring. The main point is to be cautious on steep slopes that directly face the sun during those early to mid afternoon hours. Evaluate the snow and terrain: watch for wet snow on sunny slopes, ski one at a time, be on the lookout for terrain traps and stop in safe zones. Wet loose snow can start small and gain speed and size as they move down the slope.


The "Catwalk" and Trinity Chutes, 3/1/15.  [Photo: S Rathbun]

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. 


Upper Avalanche Gulch area, 3/1/15.  [Photo: S Rathbun]

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, 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).

SnowpackIf 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.

 


 

    Weather and Current Conditions

    Weather Summary

    In Mt Shasta City this morning at 0500, we have clear skies and a current temperature of 36 F degrees. 

    WEATHER STATION INFORMATION (0500hrs):

    On Mt Shasta (South Side) in the last 24 hours...

    Old Ski Bowl - 7,600 feet, the current temperature is 40 F. Snow on the ground totals 86 inches with 1 inch settlement. Temperatures in the last 24 hours have ranged from 39 F to 52 F.   

    Gray Butte - 8,000 feet, The current temperature is 43 F and temps have ranged from 41 F to 51 F in the last 24 hours. Winds have been easterly in direction, averaging 5-10 mph with max gusts to 28 mph ENE.

    Castle Lake and Mt Eddy (West side of Interstate-5)... 

    Castle Lake - 5,600 feet, the current temperature is 44 F. Temps have ranged from 44 F to 58 F in the last 24 hours. The Castle Lake area has a patchy 8 inches of snow on the ground. 

    Mt Eddy - 6,500 feet, the current temperature is 36 F. Temps have ranged from 34 F to 54 F in the last 24 hours. Current snow depth is 28 inches with 1 inch settlement.  Winds have averaged 3 mph WSW, with gusts to 7 mph, east.

    WEATHER SYNOPSIS: We will push forward under our current weather regime today and for the beginning of the week. Conditions today and tomorrow will be a clone of yesterday.  This means more down right WARM day and nightime temperatures and light winds. Currently of focus, however, will be a weak to moderate storm set to arrive Tuesday night. Beginning then, several days of light to moderate precip will fall with snow levels starting ridiculously high, near 8,000 to 9,000 feet and lowering to 6,000 feet by Wednesday night. This storm will also bring moderate southerly winds to the mountain with speeds at 25-35 mph with gusts into the 40-50 mph range.

    THIS SEASON PRECIPITATION: Since October 1st (the wet season) , we have received 30.16 inches of water, normal is 31.23 inches, putting us at 96% of normal. For the month of March, we sit at 0.00 inches of water, normal is 1.73, putting us at 0% of normal. For the year of 2015, we've received 10.64 inches water, normal is 16.02, equalling 66% of normal. 

    Always check the weather before you attempt to climb Mt Shasta. Further, monitor the weather as you climb. Becoming caught on the mountain in any type of weather can compromise life and limb. Be prepared.

    CURRENT CONDITIONS at Bunny Flat (6950 ft)
    0600 temperature: 40
    Max. temperature in the last 24 hours: 52
    Average wind direction during the last 24 hours: Easterly
    Average wind speed during the last 24 hours: Variable mi/hr
    Maximum wind gust in the last 24 hours: 28 mi/hr
    New snowfall in the last 24 hours: 0 inches
    Total snow depth: 86 inches

    Two Day Mountain Weather Forecast

    Produced in partnership with the Medford NWS

    For 7000 ft to 9000 ft
      Sunday
    (4 a.m. to 10 p.m.)
    Sunday Night
    (10 p.m. to 4 a.m.)
    Monday
    (4 a.m. to 10 p.m.)
    Weather Sunny Clear Sunny
    Temperature (°F) 58 35 58
    Wind (mi/hr) Northeast Light, 0-5 mph Northwest Light, 0-5 mph Northeast Light, 0-5 mph
    Precipitation SWE / Snowfall (in) / 0 / 0 / 0
    For 9000 ft to 11000 ft
      Sunday Sunday Night Monday
    Weather Sunny Clear Sunny
    Temperature (°F) 61 34 58
    Wind (mi/hr) Northwest 5-10 mph North/Northwest 0 Northwest 10-20 mph with higher gusts
    Precipitation SWE / Snowfall (in) / 0 / 0 / 0

    Disclaimer

    This advisory does not apply to Ski Areas or Highways and is for the Mt. Shasta, Castle Lake and Mt. Eddy back country. Use this information for guidance only. You may find different conditions in the back country and should travel accordingly. This advisory expires on midnight of the date it was posted unless otherwise noted.