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Avalanche Advisory for 2015-04-03 06:56:35

  • EXPIRED ON April 4, 2015 @ 6:56 am
    Published on April 3, 2015 @ 6:56 am
  • Issued by Jon Dove - Shasta-Trinity National Forest

The avalanche danger will continue to be LOW for all elevations and aspects.  The possibility for loose wet snow instabilities, roller balls, and pin wheels on steeper S-SE-E aspects is low due to cool temperatures.  Firm and smooth snow conditions exist and present "slide for life" potential if one were to fall and are unable to self-arrest.  Normal caution is advised.

Carry a beacon shovel and probe. Wear a helmet. Know how to use your ice axe and crampons.

 

 

 

 

 

 

 

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: Normal Caution

  • Character ?
  • Aspect/Elevation ?

A surface cold front has brought cold air to the area keeping the snow from softening much during the week.  Firm and smooth snow conditions will exist on all elevations and aspects.  For climbers this presents "slide for life" conditions if one were to fall and are unable to self-arrest.  An ice axe, crampons, and helmet are necessary equipment.  Know how to use them! 

Recent Observations

The weather patterns this winter will always keep you guessing.  For long stretches of January and February mild temperatures and sunny days brought corn snow and spring-like conditions to Mount Shasta.  Now, April has begun and cooler, more winter-like conditions are set to return later this weekend.  Weather over the course of the week brought cooler, more seasonal, early spring temperatures to Mount Shasta with a few scattered snow showers on Tuesday and Wednesday.  No significant amount of snow fell during these showers, and accompanying winds were moderate.  General conditions on the mountain are consistent with the typical melt-freeze, isothermic snow pack found during spring time.  Snow surfaces at most elevations and aspects are firm and smooth with some softening in the afternoon.  The cooler temperatures during the week prevented any softening at higher elevations limiting the opportunity to enjoy good corn snow.

A report from an individual who did an early afternoon tour to the top of Powder Bowl yesterday (Thursday) coincides with above stated conditions.  The snow surface at 9,000 feet was just starting to soften by about 1:30, but did not provide ideal corn.  Those who ride, slide and glide will be most happy during the later half of the weekend with the several inches of snow that is forecast to fall.  This will mean, however, that the avalanche conditions will rise as new snow amounts stack up.  We'll have to see what happens as the weekend progresses.

Something unique to note is a lunar eclipse happening early tomorrow morning starting at 3:16 am.  If clouds permit, those who are willing to get up at that hour might get to enjoy the shortest lunar eclipse of the century! 

Photos:
Top Left- Forrest and Alyssa below Shastarama chute on ascent 3/27/2015 - Photo: Jon Dove

Top Right- Shay and Alyssa climbing up into the Shastarama chute proper 3/27/2015 - Photo: Jon Dove

Bottom- Forrest dropping in and slaying the corn, top of Shastarama chute 3/27/2015 - Photo: Jon Dove

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.  Snow conditions have made the melt/freeze transition into supportable firm snow at most elevations and aspects.  Snow on more northerly facing aspects may host snow that has not fully transitioned yet, and may be a little punchy.  This means that boot penetration of a few inches is possible.  Firm snow on W-SW-S-SE-E aspects will not soften much during the day making good corn snow harder to find.  Climbers should be advised that the presence of firm, smooth snow means the possibility for a long fall is present.  "Slide for life" conditions exist if self-arrest is not achieved immediately!   The potential for ice fall and rock fall exists and will be 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

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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’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 fair skies and a current temperature of 26 F degrees.  Winds are calm.

    WEATHER STATION INFORMATION (0500hrs):

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

    Old Ski Bowl - 7,600 feet, the current temperature is 25 F. Snow on the ground totals 78 inches with 2 inches settlement since Sunday.  Temperatures have ranged from 18 F to 34 F.

    Gray Butte - 8,000 feet, the current temperature is 27 F. Temps have ranged from 17 F to 36 F. Winds have been variable in direction, averaging 7 mph with gusts to 28 mph, E.

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

    Castle Lake - 5,600 feet, the current temperature is 33 F. Temps have ranged from 21 F to 43 F. The Castle Lake area has very little snow left on the ground.

    Mt Eddy - 6,500 feet, the current temperature is 26 F. Temps have ranged from 19 F to 36 F in the last 24 hours. Current snow depth is 17 inches with no settlement since Sunday.  Winds have been variable, averaging 2 mph with gusts to 11 mph, ESE.

    WEATHER SYNOPSIS: A weak ridge has moved over the area bringing cold air with it as it moves to the east pushing temperatures in valley bottoms to the upper 20's.  Clouds will increase in the afternoon leading to mostly cloudy skies overnight.  Winds will be light at mid to lower elevations (10,000 feet and below), 5-15 mph coming primarily out of the SW.  Upper elevations (above 10,000 feet) will have slightly higher winds of 20-30 mph with occasional higher gusts.  Saturday will provide a short break with partly cloudy skies, then trending to a slight chance (20%) of snow Saturday evening.  Models generally agree on an upper level low moving southward across the region later in the weekend bringing rain and snow to area.  Winds will increase as weather approaches on Sunday.  We'll see how those systems develop.

    THIS SEASON PRECIPITATION: Since October 1st (the wet season) , we have received 31.43 inches of water, normal is 35.69 inches, putting us at 88% of normal. For the month of April, we sit at 0 inches of water, normal is 0.23, putting us at 0% of normal. For the year of 2015, we've received 11.91 inches water, normal is 20.48, equalling 58% of normal. 

     
    Snow Survey Results for March 2015 for the Sacramento, Shasta and Trinity Watersheds: 49% of normal with at average depth of 37 inches. Historic average for snow is 76.8 inches. Last year at this time we were 36% of normal. Similar years to this year are 1936, 1977, 1988, 1994.

    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: 25
    Max. temperature in the last 24 hours: 34
    Average wind direction during the last 24 hours: Variable
    Average wind speed during the last 24 hours: 7 mph mi/hr
    Maximum wind gust in the last 24 hours: 28 mph mi/hr
    New snowfall in the last 24 hours: 0 inches
    Total snow depth: 78 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 Mostly sunny with increasing clouds Mostly cloudy Partly cloudy
    Temperature (°F) 48 26 45
    Wind (mi/hr) East shifting to Southwest in the afternoon Around 5 mph West shifting to Northwest after midnight 10-15 mph lowering to around 5 mph North shifting to Southwest in the afternoon 5-10 mph
    Precipitation SWE / Snowfall (in) / 0 / 0 / 0
    For 9000 ft to 11000 ft
      Friday Friday Night Saturday
    Weather Mostly sunny with increasing clouds Mostly cloudy Partly cloudy
    Temperature (°F) 25 7 with wind chill to -18 23 with wind chill to -15
    Wind (mi/hr) Southwest 10-15 mph Southwest 0 West-Southwest 25-35 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.