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Avalanche Advisory for 2018-01-01 06:43:58

  • EXPIRED ON January 2, 2018 @ 6:43 am
    Published on January 1, 2018 @ 6:43 am
  • Issued by Andrew Kiefer - Mt Shasta Avalanche Center

LOW avalanche danger and generally safe avalanche conditions exist. Sparse coverage and icy slopes present significant travel hazards in the backcountry. 

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 ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Normal caution is advised. The icy, thin snowpack continues to create backcountry travel hazards. Steep terrain above treeline is challenging and dangerous. Arresting a fall in these conditions is difficult. Watch out for rocks. Low angle slopes with smooth ground cover offer the best skiing and riding.

  • Ski and ride one at a time in avalanche terrain.
  • Don’t regroup in run-out zones.
  • Avalanche rescue skills are essential when in avalanche terrain.

Advisory Discussion

For several days, clear and warm weather conditions have remained steady, and our snowpack has experienced very little change. A re-cap of our season: October and November storms laid a shallow snowpack at high elevations on Mount Shasta. During Thanksgiving week, it rained up to 10,000ft. This rain event capped the snow surface with a crust at 7,000ft and above, and eliminated any snow below. We have had two small storm events this December totaling 10 inches of snow and less than 1 inch of SWE. High pressure has dominated our weather pattern. Precipitation is well below average, and a large portion of our advisory area is free of snow. Mount Shasta and Ash Creek Butte are the only areas with a (barely) rideable snowpack. 

Recent Observations

The snowline slowly creeps upward. Very little coverage exists below 6,500ft. The height of snow ranges from 30-100cm between 6,500-9,500ft. The slick icy rain crust formed on Thanksgiving is the primary snow surface near and above treeline. On some north and east aspects below treeline,  dry recycled powder (the December 3rd and December 20th storms) still may exist at the snow surface.  South and some west aspects, near and above treeline, have patches of corn snow. Snowpack stability is very good throughout the advisory area. Rocks, down trees, small tree tops and bushes are widespread.

Weather and Current Conditions

Weather Summary

December finished with a fizzle as far as precipitation was concerned. Mount Shasta City had the 2nd driest December in the past 107 years. The start of 2018 will continue with inactive weather as high pressure is set for today and tomorrow. Expect partly cloudy skies with highs in the mid 40s and light and variable winds. Be sure to check out the “Super Moon” tonight. Beginning tomorrow night, a series of weak disturbances will bring slight chances for precipitation and high freezing levels. A stronger system will approach from the southwest Wednesday night into Thursday. This system will break down the ridge of high pressure giving a better chance for later storms to deliver more precipitation to the region. A cooler weather system will follow by this weekend.



CLICK HERE for information from the NOAA Climate Prediction Center

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THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 5.83 inches of water, normal is 15.21 inches, putting us at 38% of normal. For the month of December, we have received .29 inches of water, normal is 7.85 inches, which is 4% of normal. And finally for the year of 2017, we received 44.82 inches of water, normal is 43.21 inches, putting us at 104% 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.

24 Hour Weather Station Data @ 5:00 AM

Weather Station Temp (°F) Wind (mi/hr) Snow (in) Comments
Cur Min Max Avg Avg Max Gust Dir Depth New Water Equivalent Settlement
Mt. Shasta City (3540 ft) 33 31 55 38 1 N
Sand Flat (6750 ft) 34 33 45 37 14 0 0 0
Ski Bowl (7600 ft) 38 34 45 38 18 0 0 0
Gray Butte (8000 ft) 38 35 43 38 9 18 W
Castle Lake (5870 ft) 44 38 48 43 8 0 0
Mount Eddy (6509 ft) 35 35 47 40 1 5 WSW 10 0 0
Ash Creek Bowl (7250 ft) station down
Ash Creek Ridge (7895 ft) station down

Two Day Mountain Weather Forecast

Produced in partnership with the Medford NWS

For 7000 ft to 9000 ft
  Monday Monday Night Tuesday
Weather Partly Sunny Mostly Cloudy Mostly cloudy then slight chance of showers.
Temperature (°F) 47 44 48
Wind Direction East/Southeast East Southeast
Wind Speed (mi/hr) 5-10 mph 5 mph 5-10 mph
Expected Snowfall (in) 0 0 0
For 9000 ft to 11000 ft
  Monday Monday Night Tuesday
Weather Partly Sunny Mostly Cloudy Mostly cloudy then slight chance of snow showers.
Temperature (°F) 30 30 33
Wind Direction West South South/Southwest
Wind Speed (mi/hr) 10-15 mph, gusting 25 mph 10-15 mph, gusting 20 mph 15-20 mph, gusting 30 mph
Expected Snowfall (in) 0 0 0

Disclaimer

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