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Avalanche Advisory for 2018-02-17 05:32

  • EXPIRED ON February 18, 2018 @ 5:32 am
    Published on February 17, 2018 @ 5:32 am
  • Issued by Aaron Beverly - Mount Shasta Avalanche Center

Avalanche danger is LOW and NORMAL CAUTION is advised. Firm and icy snow surfaces are widespread and shallow snowpack hazards exist. Icefall and rockfall may be encountered above 11,000 ft. Windy cold weather with a chance of snow will begin tonight. Be prepared.

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 means:

  • Watch for isolated slabs.
  • Ski and ride one at a time in avalanche terrain.
  • Don't regroup in run out zones.
  • Basic avalanche rescue skills are essential in avalanche terrain.

Isolated slabs are related to wind and terrain. Look for places where small areas of drifting have occurred and firm layers of surface snow overlie softer layers. This will occur on the lee side of ridges, in terrain depressions, on convex terrain features, and in the lee of isolated bands of trees.

Forecast Discussion

The snowpack has experienced very little change over the last several days. Expect firm and icy snow surface conditions to continue. Self-arrest on steep terrain will be difficult if not impossible. Wear crampons and carry an ice axe and know how to use them.

Don't let today's sunny weather lull you into complacency. A cold front will move in late this afternoon. It will be accompanied by strong winds, cold temperatures, and 1-2 inches of snow. Wind chills could fall well below 0 °F. Be prepared for these changing weather conditions if spending the night on Mount Shasta.

Above 11,000 ft, always be prepared for falling rock and ice. Wear a helmet.

Avalanche danger is LOW at all elevations.

Wondering if we are in a drought?  Check out the U.S. Drought Monitor for California.

Drought Monitor

Recent Observations

In the last 24 hours, temperatures near and below treeline have ranged from 25-46 °F. East/southeast winds have been light. Temperatures above treeline have been below or near freezing. Little snow settlement has occurred.

The snowpack above 7,000 ft is 1-4 ft deep and comprised mostly of hard melt-freeze crusts and ice layers. Snow surfaces are firm and icy right out of the Bunny Flat parking lot. Coverage is spotty below treeline. Snow on the road to the Old Ski Bowl is thin but usable.

The upper Sand Flat road and cross-country ski trails are rough and firm. The lower road and trails are out of service.

The Castle Lake and Mount Edddy backcountry has 8 to 12 inches of snow but coverage is inconsistent and sparse. Winter recreation is limited.

No avalanches or evidence of unstable snow have been observed this month.

Weather and Current Conditions

Weather Summary

Expect sunny skies and above freezing temperatures today. After 4 p.m., a cold front will move in, bringing cold temperatures, strong winds, and a chance of snow. Snow levels will drop to town through the night. The brunt of the storm will be Sunday. Overall, 0.16 in of water could fall producing 1-2 in of snow.

After Monday morning, partly sunny skies and cold temperatures will follow for most of the week. Models show an area of low pressure breaking into the area next weekend bringing the possibility of snow and rain.

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 30 52 41 5
Sand Flat (6750 ft) 32 28 43 36 18 0 0 0
Ski Bowl (7600 ft) 29.5 25 45.5 33.5 38.5 0 0 0
Gray Butte (8000 ft) 32.5 25.5 37 32 5 18 ESE
Castle Lake (5870 ft) 32.5 26.5 39.5 33.5 8 0 0
Mount Eddy (6509 ft) 35.5 28 39 35 2 14 SE 22 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
  Saturday
(4 a.m. to 10 p.m.)
Saturday Night
(10 p.m. to 4 a.m.)
Sunday
(4 a.m. to 10 p.m.)
Weather Mostly sunny. A 30 percent chance of showers after 5 p.m. A chance of rain and snow showers before 11 p.m., then a chance of snow showers. Chance of precipitation is 50%. Mostly cloudy. Breezy. A 50 percent chance of snow showers. Partly sunny.
Temperature (°F) 44 26 27
Wind (mi/hr) W 5-10 mi/hr SW 15 mi/hr W 15-20 mi/hr
Precipitation SWE / Snowfall (in) / 0 / <1 / 1-2
For 9000 ft to 11000 ft
  Saturday Saturday Night Sunday
Weather Mostly sunny and windy. A 50 percent chance of snow showers. Mostly cloudy and windy. Wind chill values as low as -22. A 50 percent chance of snow showers. Areas of blowing snow. Mostly cloudy and cold. Wind chill values as low as -30. Windy.
Temperature (°F) 31 6 6
Wind (mi/hr) W 25-30 mi/hr W 0 W 45-50 mi/hr
Precipitation SWE / Snowfall (in) / 0 / <1 / 1-2

Season Precipitation for Mount Shasta City

Period Measured (in) Normal (in) Percent of Normal (%)
From Oct 1, 2023 (the wet season) 10.19 26.21 39
Month to Date (since Mar 1, 2024) 0.08 3.94 2
Year to Date (since Jan 1, 2024) 4.36 11.00 40

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.