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Avalanche Advisory for 2013-03-09 06:57:48

  • EXPIRED ON March 10, 2013 @ 7:57 am
    Published on March 9, 2013 @ 6:57 am
  • Issued by Adam Teel - Mt. Shasta Avalanche Center

For today, the avalanche danger is LOW for low and mid elevations and  MODERATE on the upper elevations. The new snow has bonded well to the old snow and no avalanche activity has been observed or reported.

 

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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 Last night the winds picked up some and were gusting 35 mph from the East. There is plenty of new snow available for transport and we may still see wind slabs forming from the recent storm snow.

Avalanche Problem 2: Storm Slab

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 It is unlikely that this sluff could bury someone but sluff managment may be necessary on steeper slopes.

Recent Observations

So far the new snow seems stable, there has been no avalanches observed or reported and stability tests near Castle Lake, Sun Bowl, and Grey Butte have had stable results. The weakness within the new storm snow seems to be on the mend and the snowpack has adjusted well. We may still see wind slabs form from the 2-4 inches of light snow we had on top which hadn't had much wind effect. The sun caused a light 'zipper' type crust on South facing slopes yesterday and I expect that to be more noticeable today. The Northerly slopes are still holding Excellent riding conditions.

 

    Weather and Current Conditions

    Weather Summary

    We can expect a warming trend through the weekend and into next week. Highs reaching the mid 50's on Sunday through Tuesday then we should  get some clouds mid-week and a chance of precip on friday. The light winds we've been experiencing will increase some today and tomorrow coming from the North initially and switching to the Northeast by tonight.

    WEATHER STATIONS - (last 24 hours):
    In Mt. Shasta City at 0500, we have clear skies and a current temperature of 31 F.
    On Mt. Shasta:  In the Old Ski Bowl (7,600') on the south side of Mt. Shasta, we have a current temperature of 20 F. Snow on the ground totals 115 inches with 1 inch of settlement. Temperatures have ranged from 16 F to 32F.  At Grey Butte (8,000') on the south side of Mt. Shasta winds averaged 11 mph from the ENE with a max gust of 35 mph from the E. The current temperature is 23 F and temps have ranged 18 F to 28 F.
    Castle/Mt. Eddy:   Castle Lake - Castle Lake is hosting a current temp of 24 F. In the last 24 hours temperatures have ranged from 22 F to 42 F. Snow depth measures 55" inches with 2 inches of settlement.  On Mt Eddy, we have 73 inches of snow on the ground. The current temperature reads 25 F with temps ranging from 19 F to 32 F. Winds have been averaging 2 mph from the SW and gusting to 11 mph from the Southeast.

    THIS SEASON:  September and October were warm and dry with September recording exactly zero precipitation. November remained warmer than normal with precipitation almost double normal values, 9.16" vs. 5.08". A local weather COOP observed the 2nd wettest November on record. December started out wet and warm, but temperatures cooled and brought snow to very low elevations. Since our avalanche cycle near Christmas, we've had a few small storms that brought some amounts of snow to the area, but did not produced any notable avalanches. January was below normal for precipitation with a long period of high pressure and sun that kept skiing conditions somewhat meager. We've had a few storms in the past few weeks that have brought a pittance of wintery weather, but nothing to write home about!  The area has been under siege by high pressure overall and giving us blue bird days for the most part. California and the Sierra Nevada have recorded the driest January and February on record. We currently have 6-10 feet of snow above 6,500 ft. Since September 1st, Mt Shasta sits at 76% of normal, 24.37" recorded; normal 32.13". For 2013, we sit at 23% of normal with 3.67" recorded and 16.25" normal. Since Tuesday our pre-settlement storm totals are: Old Ski Bowl 24 inches, Castle Lake 19 inches, and 17 inches at Mount Eddy.

    CURRENT CONDITIONS at Bunny Flat (6950 ft)
    0600 temperature: 36
    Max. temperature in the last 24 hours: 42
    Average wind direction during the last 24 hours: NE
    Average wind speed during the last 24 hours: 9 mi/hr
    Maximum wind gust in the last 24 hours: 35 mi/hr
    New snowfall in the last 24 hours: 0 inches
    Total snow depth: 74-115 inches

    Two Day Mountain Weather Forecast

    Produced in partnership with the Medford NWS

    For 7000 ft to 9000 ft
      Saturday
    (4 a.m. to 10 p.m.)
    Saturday Night
    (10 p.m. to 4 a.m.)
    Sunday
    (4 a.m. to 10 p.m.)
    Weather Sunny Clear Sunny
    Temperature (°F) 36 22 45
    Wind (mi/hr) N 5-10 NE 5-10 NE 5-10
    Precipitation SWE / Snowfall (in) / 0 / 0 / 0
    For 9000 ft to 11000 ft
      Saturday Saturday Night Sunday
    Weather Sunny Clear Sunny
    Temperature (°F) 30 19 36
    Wind (mi/hr) N 15-20 NE 0 NE 10-15
    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.