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Avalanche Advisory for 2014-04-04 06:50:54

  • EXPIRED ON April 5, 2014 @ 6:50 am
    Published on April 4, 2014 @ 6:50 am
  • Issued by Nick Meyers - Shasta-Trinity National Forest

The avalanche danger for all aspects and elevations is LOW. Isolated areas of MODERATE wind slab instability may exist, especially in complex or extreme terrain on N - NE - E - SE aspects.

Normal caution is advised.

Carry a beacon, shovel and probe and know how to use them!

Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

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: Wind Slab

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Lingering wind slabs have gained strength and have become very difficult to trigger. Any instability is most likely to be encountered above treeline, especially in complex or extreme terrain on N - NE - E - SE aspects, but not limited to.

 


 

Avalanche Problem 2: Cornice

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Small to medium size cornices have formed near ridgetops and bowls over the past weeks. Stay on terra firma when scoping your line or climbing ridge routes!

Recent Observations

The storm cycles of the past two weeks have added precious inches of snow to our low snowpack, extending our season of good climbing and skiing conditions by hopefully a few weeks. We saw a short lived spike in the avalanche danger on Monday of this past week. Numerous, small storm slab avalanches were easily triggered on many aspects steeper than 35 degrees near and above treeline on Gray Butte and one reported slide on the north aspect of Green Butte. Tuesday, our snowpack seemed to adjust well to the new snow (6-8 inches over 48 hours) and no further instability was observed over the week. Wednesday and Thursday the sun came out during the day cooked the new snow to a crisp. Which brings us to our current snow status: generally crispy (read: breakable crust) at lower and mid elevation slopes with pockets of old powder in shaded, cold and protected areas in the trees. Everything above treeline is generally wind blown in exposed areas and packed powder/powder in more protected areas. Southerly winds in the recent days has transported snow onto N - NE slopes and small to medium size, isolated wind slabs could be encountered above treeline on said aspects, albeit difficult to trigger. Overall, the snowpack sits in a transitional phase, working towards melt/freeze, but not their yet. With the weather clearing and temps warming in the coming days, we should see Shasta's famed spring skiing return, hopefully by next week.

For climbers, conditions have been excellent on all routes. With the recent new snow however, be sure to thoroughly read this avalanche advisory. Over snow travel with the new snow will be difficult (i.e. post-holing) without snowshoes/skis/splitboard at this time. The season for climbing Mt Shasta is going to be shifted forward this year. On a normal year with ample snow on the ground, good climing conditions usually start in April and can go all the way into July sometimes. This year is not the case...the best conditions to climb Shasta this year will be NOW through April and potentially May. The extent of good climbing conditions will hinge on our Spring weather. More snow could potentially extend the season and warm days with shining sun will shorten it. While the mountain looks like it's got a thick blanket of snow on it, in reality there is only about 2-5 feet of snow on the ground, depending on aspect and elevation. Good climbing conditions, in general, means snow on the mountain. As the snow melts, rockfall increases and a climb of Shasta becomes more dangerous. All in all, sooner than later will be best for climbing Shasta. Check the climbing advisory on our webpage also!

PLEASE NOTE: Snow conditions on most routes are smooth and firm, especially in the AM hours. Conditions as such have lead to accidents due to slip/falls and failure to self arrest. A slip and fall on smooth, firm and sometimes icy snow can result in a slide for life on the steeper slopes of Mt Shasta. Self arrest skills with an ice axe and proper crampon use are essential for a safe climb. Do not under estimate the importance of proper knowledge and skills with your ice axe/crampons/self arrest techniques. Further, an avalanche beacon, shovel and probe are recommended for any climbers attempting Shasta currently. Lastly, with snow on  mountain, the rockfall danger has been low. However, rime ice can plaster exposed rocks on Shasta this time of year. As the days warm, the rime ice will flake off and fall onto climbers below, especially on the Avalanche Gulch route. Ice is like a rock and a HELMET should always be worn.

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While Northgate, Brewer Ck and Clear Ck trailheads are officially closed, the bathrooms are still open with packout bags inside, and one can still access the Mt Shasta Wilderness. However, your summit pass and wilderness permits must be purchased at McCloud or Mt Shasta Ranger Stations. NO DOGS are allowed in the Mt Shasta Wilderness OR Sierra Club Property. Thanks!

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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.

 


 

    Weather and Current Conditions

    Weather Summary

    In Mt Shasta City this morning at 0500, we have cloudy skies with a current temperature of 39F.

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

    Old Ski Bowl - 7,600 feet. The Old Ski Bowl weather station has 4-6 inches new snow in the last 24 hours. The current temperature is 23F with a low of 19F and a high of 28F. Total snow depth is 73 inches.

    Gray Butte - 8,000 feet - The current temperature is 22F. Temps have ranged from a low of 22F to a high 25F.  Winds have been blowing out of the southwest, averaging 9 mph with max gusts topping out at 21 mph from the southwest also.

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

    Castle Lake - 5,600 feet, the current temperature is 29F with a low of 29F and a high of 33F. Castle Lake has received 2-4 inches of new snow and hosts a current snowpack of 8 inches at best.

    Mt Eddy - 6,500 feet, the current temperature is 26F with a low of 26F and a high of 31F. Mt Eddy has received 2-4 inches of new snow and the current snow depth total is 33 inches. Winds have averaged 1-2 mph, with gusts to 13 mph all southerly in direction.

    THIS SEASON: Since September 1st , we have received 13.57 inches of water, normal is 36.48 inches, putting us at 37% of normal. For the year of 2014, Mt Shasta has received 10.75 inches of water with normal being 20.60 inches which puts us at 52% of normal. And lastly, for April we sit at 97% of normal, receiving .34 inches of water, normal is .35 inches. Mt Shasta finished off March at 73% of normal, accumulating 4.37 inches of water with normal being 5.96 inches.

    WEATHER SYNOPSIS:

    All in all, look for a gradual warming and drying trend as we move through the weekend. Today and into this evening, the area will see light, scattered showers with no significant accumulation expected. Tomorrow should host lingering clouds and begin to clear as Sunday rolls along. Temperatures will also gradually warm as next week approaches. Next week looks to be mostly clear with highs in the upper 50s to lower 60s. Our famous Northwest winds wil begin to blow today. While not exceedingly strong, expect 20-30 mph winds on the upper mountain with gusts possible higher.

    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.

    CURRENT CONDITIONS at Bunny Flat (6950 ft)
    0600 temperature: 19
    Max. temperature in the last 24 hours: 28
    Average wind direction during the last 24 hours: Southwest
    Average wind speed during the last 24 hours: 9 mi/hr
    Maximum wind gust in the last 24 hours: 21 mi/hr
    New snowfall in the last 24 hours: 2-4 inches
    Total snow depth: 73 inches

    Two Day Mountain Weather Forecast

    Produced in partnership with the Medford NWS

    For 7000 ft to 9000 ft
      Friday
    (4 a.m. to 10 p.m.)
    Friday Night
    (10 p.m. to 4 a.m.)
    Saturday
    (4 a.m. to 10 p.m.)
    Weather Scattered snow showers, mostly cloudy Slight chance of snow showers, otherwise, partly cloudy, clearing Partly sunny
    Temperature (°F) 37 25 45
    Wind (mi/hr) South / Southwest, becoming Northwest later in the day. 5-15 mph Northwest 10-15 mph Northwest 10-20 mph
    Precipitation SWE / Snowfall (in) / .5-1 / > .5 / 0
    For 9000 ft to 11000 ft
      Friday Friday Night Saturday
    Weather Snow showers mainly before 11am, mostly cloudy Mostly cloudy, chance of snow showers mainly before 11pm, clearing Partly sunny
    Temperature (°F) 20 13 28
    Wind (mi/hr) West / Northwest 20-30 mph West/Northwest 1-2 Northwest 25-35 mph, increasing
    Precipitation SWE / Snowfall (in) / 1-2 / > .5 / 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.