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Avalanche Advisory for 2013-03-03 07:00:21

  • EXPIRED ON March 4, 2013 @ 7:00 am
    Published on March 3, 2013 @ 7:00 am
  • Issued by Nick Meyers - Shasta-Trinity National Forest

For today, the overall avalanche danger remains LOW for all aspects and elevations. We received a trace of new snow over the past 12 hours with light to moderate NW winds. Instabilities are unlikely today. Most other areas have been scoured down to the old, firm snow surface and/or entered a melt/freeze cycle. Normal caution advised.

We are expecting the avalanche danger to rise on late Tuesday and Wednesday, 3-5 and 3-6. Up to 1" inch of water and moderate to strong Southwest winds are expected for this storm. This could mean several inches of snow in town and more above 6,000 feet. A firm snowpack in place will provide a great bed surface for this new snow to potentially slide on. Stay tuned for potential advisory updates as the week progresses.

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 ?
  • Likelihood ?
    Very Likely
  • Size ?
    Very Large

Recent Observations

In general, warmer temperatures have kept lower elevation snow soft and sticky in most areas. Higher elevation snow hosts a mix-mash of conditions from scoured firm snow, melt/freeze corn, and wind affected sastrugi features. Variability all depends on the aspect and elevation you choose to adventure to. Stability tests have indicated a strong snowpack overall. Yesterday's temperatures at 11:00 am climbed to 63 F degrees out past McCloud near Ask Creek, 58 F degrees in Mt. Shasta City and 40 F on Gray Butte. This softened the snow up to approx. 10,000ft, though no temperature induced instabilities were observed.


    Weather and Current Conditions

    Weather Summary

    A welcomed change in the weather should freshen up our current snowpack this coming week and make things feel like winter again. For today and tomorrow we'll get a short break as the storm approaches and hits coastal areas first...Exact arrival of the storm is conflicting amongst models, however we should begin to see some action beginning Tuesday night and Wednesday. Decent Southwest flow and water amounts up to 1" are expected and should give us several inches of new snow in town and potentially more above 6,000 feet by Wednesday evening. Warmer temperatures that we've had lately will keep snow levels at 6,000 to 7,000 feet in the beginning, but cold air drops down Tuesday and will drop freezing levels to town or lower. Areas west of Mt. Shasta may see potentially more precip amounts, but with some South flow, periods of heavy precip are likely for the Mt. Shasta area. Further, Southwest winds look moderate to strong (30-40 mph with gusts higher) for near and above treeline areas beginning Tuesday and lasting through Wednesday.

    WEATHER STATIONS - (last 24 hours):
    In Mt. Shasta City at 0500, we have cloudy skies and a current temperature of 41 F.
    On Mt. Shasta:  In the Old Ski Bowl (7,600') on the south side of Mt. Shasta, we have a current temperature of 27 F. Snow on the ground totals 96"  inches with .5-1" new snow and little settlement. Temperatures have ranged from 27 F to 41F.  At Grey Butte (8,000') on the south side of Mt. Shasta winds averaged 12 mph from the NW with a max gust of 35 mph from the NW. The current temperature is 27 F and temps have ranged 27 F to 40 F.
    Castle/Mt. Eddy:   Castle Lake - Castle Lake is hosting a current temp of 30 F. In the last 24 hours temperatures have ranged from 30 F to 47 F. Snow depth measures 44" inches with a trace of new snow.  On Mt Eddy, we have 60" inches of snow on the ground with a trace of new snow and little settlement. The current temperature reads 30 F with temps ranging from 30 F to 47 F. Winds have been SE, averaging 1 mph and gusting to 6 mph from the SE.

    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. A disturbance this next week could bring up to an inch of water to the area with higher snow levels. 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 73% of normal, 22.55" recorded; normal 30.70". For 2013, we sit at 12% of normal with 1.85" recorded and 14.82" normal.

    CURRENT CONDITIONS at Bunny Flat (6950 ft)
    0600 temperature: 30
    Max. temperature in the last 24 hours: 43
    Average wind direction during the last 24 hours: NW
    Average wind speed during the last 24 hours: 13 mi/hr
    Maximum wind gust in the last 24 hours: 35 mi/hr
    New snowfall in the last 24 hours: trace inches
    Total snow depth: 55-95 inches

    Two Day Mountain Weather Forecast

    Produced in partnership with the Medford NWS

    For 7000 ft to 9000 ft
    (4 a.m. to 10 p.m.)
    Sunday Night
    (10 p.m. to 4 a.m.)
    (4 a.m. to 10 p.m.)
    Weather Slight chance of snow before 10am, clearing otherwise, sunny Mostly clear Mostly sunny
    Temperature (°F) 40 24 44
    Wind (mi/hr) North 5-10 mph NW becoming SSE after midnight 5-10 SE 10-15 mph with gusts higher
    Precipitation SWE / Snowfall (in) / trace to none / 0 / 0
    For 9000 ft to 11000 ft
      Sunday Sunday Night Monday
    Weather Slight chance of snow before 10am, clearing otherwise, sunny, blustery Mostly clear Sunny, windy
    Temperature (°F) 28 17 34
    Wind (mi/hr) NW in the morning and increasing in the afternoon. 20-30 mph with gusts higher NW trace to none SW 30-40 mph with gusts higher
    Precipitation SWE / Snowfall (in) / trace to none / 0 / 0


    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.