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Avalanche Advisory for 2018-02-09 05:55

  • EXPIRED ON February 10, 2018 @ 5:55 am
    Published on February 9, 2018 @ 5:55 am
  • Issued by Nick Meyers - Shasta-Trinity National Forest
  • February 9, 2018 @ 5:55 am

    Advisory Hotline: (530) 926-9613

  • Avalanche danger is LOW. Avalanches are unlikely and NORMAL CAUTION is advised. Shallow snowpack hazards exist. Beware of falling rime ice above 9500 ft.

  • 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

Advisory Discussion

Falling rime ice is a concern above 9500 ft. Firm snow surfaces exist. Wear a helmet and bring an ice axe, crampons, and the knowledge to use them if traveling on steep terrain. 

Recent Observations

A wide array of snow surface conditions were observed during a jaunt up to 11,000 feet in Avalanche Gulch yesterday (see observation for photos). Favorable corn skiing conditions can be found in select swaths of terrain above treeline on E-SE-S and some SW facing slopes. Overall, expect to encounter the full nine yards... rough, wind eroded features; smooth, glazed and icy snow; softer melt-freeze surfaces and various sastrugi formations. Falling rime ice was not observed but many rocks still have chunks of rime stuck to them. Winds were light out of the southeast with highs near 50 deg F.

Upper Sand Flat cross-country ski trails are still usable. 

All other areas within the forecast area, aside from Mount Shasta itself, are not in play due to lack of snow. Below treeline, snow is melting fast and shallow snowpack hazards are an increasing concern.

 

Weather and Current Conditions

Weather Summary

Through Saturday night, high pressure remains and will bring dry weather and near normal temperatures. A system will arrive Sunday morning from the north, pushing light precipitation and cooler air into the region. Overall, this system is not expected to bring significant rainfall and/or snow to the area.

Expect windy conditions in exposed areas above treeline on Mount Shasta today.

 

Season Precipitation for Mount Shasta City

Period Measured Normal Percent of Normal
From Oct 1, 2017 (the wet season) 10.11 24.22 42
Month to Date (since Feb 1, 2018) 0.00 1.95 0
Year to Date (since Jan 1, 2018) 4.28 9.01 48

24 Hour Weather Station Data @ 4:00 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) 35 34 68 48.5 4 N
Sand Flat (6750 ft) 41 36 54 45 19 0 0 1
Ski Bowl (7600 ft) 42.5 42.5 53 47.5 39 0 0 1.5
Grey Butte (8000 ft) 42.5 42.5 53 47.5 8 43 NNW
Castle Lake (5870 ft) 44.5 44.5 54 48.5 8 0 .5
Mount Eddy (6509 ft) 44 42.5 52.5 46.5 2 12 SSE 20 0 .5
Ash Creek Bowl (7250 ft) 0 0 0 0 0 0 0 station down
Ash Creek Ridge (7895 ft) 0 0 0 0 0 0 station down

Two Day Mountain Weather Forecast

Produced in partnership with the Medford NWS

For 7000 ft to 9000 ft
  Friday Friday Night Saturday
Weather Mostly sunny Clear and breezy Sunny and breezy
Temperatures 49 deg. F. 26 deg. F. 39 deg. F.
Wind direction NW NW N
Wind speed 10-15 mi/hr 10-15 mi/hr 10-15 mi/hr
Expected snowfall 0 in. 0 in. 0 in.
For 9000 ft to 11000 ft
  Friday Friday Night Saturday
Weather Sunny and windy Clear and windy. Sunny and windy
Temperatures 32 deg. F. 22 deg. F. 28 deg. F.
Wind direction NW NW NW
Wind speed 25-35 mi/hr 25-35 mi/hr 30-40 mi/hr
Expected snowfall 0 in. 0 in. 0 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.