You are here

Avalanche Advisory for 2018-01-03 06:12:52

  • EXPIRED ON January 4, 2018 @ 6:12 am
    Published on January 3, 2018 @ 6:12 am
  • Issued by Aaron Beverly - Mount Shasta Avalanche Center
  • January 3, 2018 @ 6:12 am

    Advisory Hotline: (530) 926-9613

  • LOW avalanche danger and generally safe avalanche conditions exist. Sparse coverage and icy slopes present significant travel hazards in the backcountry. Monitor changing conditions Thursday and Friday with rain and snow expected.

  • 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

We will see a break in our stagnant weather pattern as a warm front moves in after 4 pm. Snow levels will drop from 8000 to 6000 feet over the next three days. Expect rain or wet snow near and below treeline through Friday night. This could reduce the thin snowpack in these elevations bands. Since no significant precipitation will be received today or tonight, avalanche danger will remain unchanged until at least tomorrow.

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 had two small storm events in December totaling 10 inches of snow and less than 1 inch of SWE. December 2017 was the second driest December in the past 107 years in Mount Shasta. 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 rideable snowpack.

Recent Observations

Temperatures ranged from 39 to 49 degrees F yesterday at the Old Ski Bowl, though thin clouds reduced the heating effect of the sun on snow surfaces. Ridgelines have little snow and the tops of moraines are rocky. You can still find decent coverage in gullies. Snowpack stability is very good at all elevations. Expect thin snow below 8000 feet.

Weather and Current Conditions

Weather Summary

A low pressure system offshore from Southern California is spinning gradually closer to the forecast area. The trajectory of the low favors Northern California and the Southern Oregon Coast. Effects of this system should begin after 4 pm, with the bulk of precipitation coming Thursday and Thursday night.

As much as 1.5 inches of water is likely through Sunday, with a full inch expected by early Friday morning. Expected snow levels:

  • Today: 8000 feet
  • Thursday: 7000 feet
  • Friday: 6000 feet
  • Saturday: 4000 feet

We may see a few inches of snow at lower elevations over the weekend.  Wet conditions should prevail through next Wednesday.

-------------------------

THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 5.83 inches of water, normal is 15.69 inches, putting us at 37% of normal. For the month of December, we have received 0.0 inches of water, normal is .48 inches, which is 0% of normal. And finally for the year of 2018, we received 0 inches of water, normal is .48 inches, putting us at 0% 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 (mph) Snow (in) Comments
Cur Min Max Avg Avg Max Gust Dir Depth New Water Equivalent Settlement
Mt. Shasta City (3540') 36 30 50 40 2 N
Sand Flat (6750') 38 34 49 40 14 0 0 0
Ski Bowl (7600') 42 40 47 43 18 0 0 0
Grey Butte (8000') 41 40 46 43 6 31 WNW
Castle Lake (5870') 46 42 49 46 0 0 0 0
Mount Eddy (6509') 42 38 49 44 1 4 WSW 0 0 0
Ash Creek Bowl (7250') Station down
Ash Creek Ridge (7895') Station down

Two Day Mountain Weather Forecast

For 7000 ft. to 9000 ft.
  Wednesday Wednesday Night Thursday
Weather Mostly cloudy A chance of rain and snow. Cloudy. Chance of precipitation is 50%. Little or no snow accumulation expected. Rain likely, mainly after 4pm. Mostly cloudy. Chance of precipitation is 70%.
Temperatures 50 deg. F. 37 deg. F. 42 deg. F.
Wind direction Southeast South South
Wind speed 5-10 mph 5-10 mph 10-15 mph
Expected snowfall 0 in. <1 in. <1 in.
For 9000 ft. to 11000 ft.
  Wednesday Wednesday Night Thursday
Weather Mostly cloudy, with a temperature falling to around 28 by 5pm A 50 percent chance of snow. Mostly cloudy. Windy. Snow likely, mainly after 4pm. Mostly cloudy. Wind chill values as low as -1. Windy. Chance of precipitation is 60%.
Temperatures 35 deg. F. 26 deg. F. 27 deg. F.
Wind direction South South Southwest
Wind speed 10-15 then 25-30 mph, gusting 40 35-45 mph, gusting 50 35-45 mph, gusting 50
Expected snowfall 0 in. <1 in. 1-2 in.

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.