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Avalanche Advisory for 2017-04-04 06:54:59

  • EXPIRED ON April 5, 2017 @ 6:54 am
    Published on April 4, 2017 @ 6:54 am
  • Issued by Andrew Kiefer - Mt Shasta Avalanche Center
  • April 4, 2017 @ 6:54 am

    Advisory Hotline: (530) 926-9613

  • Falling rime ice continues to be the primary concern for skiers and climbers venturing into high alpine terrain on Mount Shasta. Natural and human triggered avalanches are unlikely, and the avalanche danger is LOW at all elevations. NORMAL CAUTION is advised. A potent storm is set to begin on Thursday.  Expect a return to winter conditions in the backcountry by the weekend.

  • 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

A large and destructive icefall/rockfall event occurred in Avalanche Gulch recently.  There is plenty of rime ice still in the alpine that will continue to shed this spring. Daytime warming and solar radiation may not be as intense today, as mostly cloudy skies and gusty westerly winds are expected. Regardless, continue to monitor snow surface conditions as the upper snowpack thaws throughout the day. If you see rollers balls, or if you find the surface snow to be wet and very unconsolidated, it’s time to change aspects or to move to lower angle terrain. If you venture into the alpine, work to minimize your exposure to icefall with your terrain selection and your timing, and plan to avoid being underneath rime ice formations during peak heating hours.

Recent Observations

Yesterday brought clear and sunny weather with gusty and variable winds to the advisory area. High temperatures reached the upper 40’s F, with overnight lows dropping just below freezing at most locations.

The aftermath of a large icefall/rockfall event was observed yesterday high in Avalanche Gulch off of Casaval Ridge. See photo in Observations below. The exact timing of the event is unknown, but likely occurred sometime overnight on Sunday, or in the early morning hours yesterday. The falling ice and rock event gouged the southeast slopes of Casaval Ridge, leaving a large dark streak on the snow surface that is visible from town. The debris ran for close to 1000ft. It is likely that the event started as an icefall, and entrained rocks and snow during the slide downhill.    

Weather and Current Conditions

Weather Summary

Skies will be mostly cloudy throughout the day with periods of sunshine possible in the afternoon. High temperatures should reach the lower 50’s F at 6000ft, and high level winds will shift to the west with steadily increasing speeds over the next 48 hours. Tomorrow looks to bring a similar story with slightly more sunshine possible. A strong and dynamic storm series looks to begin Thursday night, bringing gusty winds, plenty of precipitation, and cold air. The advisory area could pick up over 2 inches of water by Saturday, and freezing levels may drop to as low 4000ft. The wintery storm pattern should last into next week.

In Mt Shasta City at 0500, we have a current temperature of 42 F

On Mt Shasta (South Side) in the last 24 hours...

Sand Flat - 6,750 ft, the current temperture is 33 degrees F. Temperatures have ranged from 28 F to 43 F. Snow on the ground totals 102 inches no new snow and 2 inches of settlement.

Old Ski Bowl - 7,600ft, the current temperature is 35 degrees F. Temperatures have ranged from 29 F to 44 F.  Snow on the ground totals 183 inches with no new snow and 1 inch of settlement.  

Grey Butte - 8,000 feet, the current temperature is 34 degrees F. Temperatures have ranged from 29 F to 39 F. Winds have averaged 5-20 mph with gusts to 35 mph, and have been variable in direction, blowing from the NW, N, E, SE, and S.

Mt Eddy Range (West side of Interstate-5)... 

Castle Lake - 5,800 feet, the current temperature is 40 degrees F. Temperatures have ranged from 27 F to 47 F. Snow on the ground totals 92 inches with no new snow and 1 inch of settlement.

Mt Eddy - 6,500 feet, the current temperature is 37 degrees F. Temperatures have ranged from 26 F to 43 F. Snow on the ground measures 86 inches with no new snow and little settlement. Winds have averaged 2-4 mph with gusts up to 14 mph,  and have been variable blowing SW, S, and SE.

THIS SEASON PRECIPITATION for MT SHASTA CITY: Since October 1st (the wet season), we have received 49.46 inches of water, normal is 35.81 inches, putting us at 138% of normal. For the month of April, we have received 0 inches of water, normal is .35 inches, which is 0% of normal. And finally for the year of 2017, we received 28.30 inches of water, normal is 20.60 inches, putting us at 137% 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.


CURRENT CONDITIONS at Bunny Flat (6950 ft)
0600 temperature: 33
Max. temperature in the last 24 hours: 43
Average wind direction during the last 24 hours: variable
Average wind speed during the last 24 hours: 5-10 mi/hr
Maximum wind gust in the last 24 hours: 15 mi/hr
New snowfall in the last 24 hours: 0 inches
Total snow depth: 102 inches

Two Day Mountain Weather Forecast

Produced in partnership with the Medford NWS

For 7000 ft to 9000 ft
  Tuesday Tuesday Night Wednesday
Weather Mostly Cloudy Mostly Cloudy Partly Sunny
Temperature (°F) 48 34 49
Wind Direction east becoming south/southwest in the afternoon south south/southeast
Wind Speed (mi/hr) 10-13 mph 11-20 mph 21-31 mph
Expected Snowfall (in) 0 0 0
For 9000 ft to 11000 ft
  Tuesday Tuesday Night Wednesday
Weather Mostly cloudy and windy Mostly cloudy and windy Partly sunny and windy
Temperature (°F) 26 24 27
Wind Direction west west/southwest south/southwest
Wind Speed (mi/hr) 32-41 mph, gusting to 60 mph 45-50 mph, gusting 70 mph 60-70 mph, gusting 100 mph
Expected Snowfall (in) 0 0 0


This advisory 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 advisory expires on midnight of the date it was posted unless otherwise noted.