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Avalanche Forecast for 2020-12-30 06:00

  • EXPIRED ON December 31, 2020 @ 6:00 am
    Published on December 30, 2020 @ 6:00 am
  • Issued by Aaron Beverly - Mount Shasta Avalanche Center

Overall avalanche danger is low. Hidden rocks will continue to present a hazard to sliders and riders. A small storm should bring 2-4 inches of snow this evening. Combined with moderate winds, small wind slabs may form. Some remote, cold areas on the fringes of our forecast area show signs of a persistent weak layer. The first week of the new year is looking good for precipitation.

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

Overall avalanche danger is low. But low danger does not mean no danger. Continue to watch for unstable snow on isolated terrain features.

Pay attention on steep leeward slopes. New snow and wind may combine to create small wind slabs. Cracking snow indicates wind slabs are forming.

A persistent weak layer exists in some of our colder, north facing, remote zones. If you find yourself venturing far out into the boonies, take some extra time to do some sleuthing. Whumphing sounds indicate the snowpack is collapsing within a weak layer and is one of our obvious signs of avalanche danger. Don't ignore it.

Forecast Discussion

Join us for our second virtual Avalanche Awareness Presentation this Friday, January 1st at 7:00 p.m. With incoming snow expected after New Year's, this is a good time to refresh your knowledge and skills.

Recent Observations

Up to 30 inches of snow exists throughout our forecast area. Northwest winds have been moderate. Temperatures were above freezing during the daytime hours yesterday.

Near and above treeline you'll find variable snow surfaces, with chalky, wind-affected snow dominating the above treeline zone and crusts forming near treeline.  Tread lightly as there are hidden rocks lurking. It is best to avoid the sides of ridges and moraines if you are skiing. Stay in gullies for the deepest snow. Snowmobiles should be extra careful everywhere off the roads.

A persistent weak layer does exist in some of our cold, north facing areas. Wumphing sounds and column tests have exposed its sensitivity to weight and force. This problem has not been seen on Mount Shasta.

Weather and Current Conditions

Weather Summary

Fair weather will gradually diminish today as a front moves in. Expect increasing winds, dropping temperatures, and snow above 3,500 ft after 4 p.m. We should get 2-4 inches of snow this evening and up to an inch early Thursday morning. Southwest and west winds will be moderate to strong near and above treeline.

This weekend, wet weather will resume with close to 1.5 inches of precipitable water expected. Stay tuned for snow levels. The first week of the new year looks promising for precipitation.

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) 32 20 41 31.5 1 N
Sand Flat (6750 ft) 31 15 33 27 0 0 Depth sensor not working.
Ski Bowl (7600 ft) 29 27 39.5 32.5 27.8 0 0 0.3
Gray Butte (8000 ft) 28 28 36 32 10 37 WNW
Castle Lake (5870 ft) 34 25.5 39 34 12.8 0 0.5
Mount Eddy (6509 ft) 31.5 25 41 32.5 2 4 WSW 26.6 0 0.5
Ash Creek Bowl (7250 ft) 29.5 22.5 34 29.5 28.2 0 0.7
Ash Creek Ridge (7895 ft) 25 23 31 28

Two Day Mountain Weather Forecast

Produced in partnership with the Medford NWS

For 7000 ft to 9000 ft
  Wednesday
(4 a.m. to 10 p.m.)
Wednesday Night
(10 p.m. to 4 a.m.)
Thursday
(4 a.m. to 10 p.m.)
Weather Snow, mainly after 4 p.m. Areas of blowing snow after 1 p.m. Dropping temperatures. Breezy. Chance of precipitation is 80%. Snow. Areas of blowing snow before 7 p.m. Breezy. Chance of precipitation is 100%. A 20 percent chance of snow showers before 10 a.m. Partly sunny.
Temperature (°F) 24 22 31
Wind (mi/hr) Southwest 15-20 Northwest 5-10 North 5-10
Precipitation SWE / Snowfall (in) 0.23 / 2-4 0.05 / 0-1 0.00 / 0
For 9000 ft to 11000 ft
  Wednesday Wednesday Night Thursday
Weather Snow, mainly after 4 p.m. Areas of blowing snow after 10 a.m. Falling temperatures. Windy. Low wind chills. Chance of precipitation is 80%. Snow. Areas of blowing snow. Windy. Low wind chills. Chance of precipitation is 100%. A 20 percent chance of snow showers before 10 a.m. Mostly sunny. Windy. Low wind chills.
Temperature (°F) 25 15 25
Wind (mi/hr) West 30-40 Northwest 25-30 North 25-30
Precipitation SWE / Snowfall (in) 0.23 / 2-4 0.05 / 0-1 0.00 / 0

Season Precipitation for Mount Shasta City

Period Measured (in) Normal (in) Percent of Normal (%)
From Oct 1, 2020 (the wet season) 3.49 14.70 24
Month to Date (since May 1, 2021) 1.79 7.34 24
Year to Date (since Jan 1, 2021) 16.40 42.70 38

Disclaimer

This forecast does not apply to Ski Areas or Highways and is for the Mt. Shasta, Castle Lake and Mt. Eddy backcountry. Use this information for guidance only. You may find different conditions in the backcountry and should travel accordingly. This forecast expires 24 hours after the posted time unless otherwise noted.