THIS AVALANCHE FORECAST EXPIRED ON December 8, 2018 @ 6:50 am
Avalanche Forecast published on December 7, 2018 @ 6:50 am
Issued by Brandon Schwartz - Tahoe National Forest

LOW avalanche danger exists for all elevations. Normal caution is advised.

1. Low

?

Above Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

?

Near Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

1. Low

?

Below Treeline
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
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Recent new snow buried and preserved the Dec 4 surface hoar layer under just a few inches of new snow. Generally, the snow above the surface hoar weak layer is too shallow and lacks sufficient cohesiveness to present a problematic slab. Avalanche concerns are minimal at this time until another loading event occurs. Exercise normal caution while traveling in the backcountry to keep a margin of safety against the unexpected isolated pocket of unstable snow.

Ridgetop winds are expected to pick up a little bit tonight from the SW. There is plenty of unconsolidated snow along the ridgetops available for wind transport. It is possible that a few small and isolated wind slabs could form tonight. This added load on top of the buried 12/4 surface hoar layer may create areas of unstable snow.

recent observations

* The Dec 4 buried surface hoar layer has been noted within the top 6 inches of the snowpack in many but not all locations around the forecast area. It is often difficult to find when present. Grain size ranges from 4 to 15 mm (about 1/8 to 1/2 inch).

* The deeper snowpack is well consolidated and without problematic weak layers.

* No new avalanche activity has been reported since Dec 2.

* Decent snow coverage exists above 7,000' to 7,500' along the Sierra Crest with the best coverage in the northern and far southern Sierra Crest portions of the forecast area.  Snow coverage declines to the east.  Early season conditions exist.

Weather and CURRENT CONDITIONS
weather summary

Low level cloud cover continues to provide foggy conditions down low with sunny skies above the fog. Cloud cover and fog are expected to dissipate in most areas by this afternoon. Light winds are forecast for today with a brief increase in SW winds tonight. High pressure will build in for a warming trend over the weekend. Cloud cover and chances of precipitation are expected to return next week.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 20 to 29 deg. F.
Max. temperature in the last 24 hours: 30 to 34 deg. F.
Average wind direction during the last 24 hours: ENE
Average wind speed during the last 24 hours: 5 mph
Maximum wind gust in the last 24 hours: 20 mph
New snowfall in the last 24 hours: 0 to trace inches
Total snow depth: 30 to 38 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Friday Friday Night Saturday
Weather: Mostly sunny above 7000 feet. Snow levels below 7000 feet. Chance of precipitation is 0%. Clear. Snow levels below 7000 feet. Chance of precipitation is 0%. Sunny. Snow levels below 7000 feet. Chance of precipitation is 0%.
Temperatures: 34 to 39. deg. F. 16 to 22. deg. F. 36 to 41. deg. F.
Mid Slope Winds: Light winds. Light winds. Light winds.
Expected snowfall: No accumulation. | SWE = none. in. No accumulation. | SWE = none. in. No accumulation. | SWE = none. in.
For 8000 ft. to 9000 ft.
Friday Friday Night Saturday
Weather: Mostly sunny above 7000 feet. Snow levels below 7000 feet. Chance of precipitation is 0%. Clear. Snow levels below 7000 feet. Chance of precipitation is 0%. Sunny. Snow levels below 7000 feet. Chance of precipitation is 0%.
Temperatures: 31 to 36. deg. F. 15 to 20. deg. F. 32 to 37. deg. F.
Ridge Top Winds: Light winds. Southwest 10 to 15 mph. Gusts up to 30 mph after midnight. Northwest 10 to 15 mph with gusts to 25 mph in the morning becoming light.
Expected snowfall: No accumulation. | SWE = none. in. No accumulation. | SWE = none. in. No accumulation. | SWE = none. in.
Disclaimer

This avalanche advisory is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This advisory covers the Central Sierra Nevada Mountains between Yuba Pass on the north and Ebbetts Pass on the south. Click here for a map of the forecast area. This advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

For a recorded version of the Avalanche Advisory call (530) 587-3558 x258