THIS AVALANCHE ADVISORY EXPIRED ON December 14, 2017 @ 6:47 am
Avalanche Advisory published on December 13, 2017 @ 6:47 am
Issued by Andy Anderson - Tahoe National Forest

LOW avalanche danger exists at all elevations today. Triggering an avalanche is unlikely but not impossible. Continue to assess the snowpack and terrain, and travel carefully in the backcountry. Watch for lingering unstable snow on isolated terrain features.

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

Triggering an avalanche has become unlikely. Unlikely does not mean impossible and some unstable snow may still remain in a few isolated areas especially in steep complex terrain or on unsupported near and above treeline NW aspects where hard wind slabs linger. Very large triggers like several people on a slope or large cornice pieces dropped onto a slope may still be able to trigger some of these isolated hard slabs. While the avalanche danger may have decreased, other hazards like numerous exposed obstacles and widespread firm icy surfaces still remain. Travelling in sheltered non-wind-affected terrain where softer snow still exists or on snow-covered sun-exposed terrain where spring-like conditions exist should provide safer and more enjoyable conditions today. 

recent observations

* Snow coverage is deepest above 8000' in areas north of Emerald Bay.  Minimal snow coverage exists below 8000'.  In the southern part of the forecast area, less snow exists. Below 8500' snow coverage remains patchy in the southern part of the forecast area. Above 8500 ft. a deeper but highly variable snowpack exists.  Snow coverage is decreasing on southerly aspects at higher elevations. 

* Spring-like snow conditions prevail on southerly sun-exposed terrain where snow coverage exists.

* Widespread firm, wind scoured snow surfaces remain on most near and above treeline terrain.

* Variable snow surfaces ranging from softer snow to firm surfaces exist on sheltered near and below treeline northerly terrain.

* Tests targetting the isolated hard wind slabs lingering on a few NW aspects started to yield inconsistent results this week.

Weather and CURRENT CONDITIONS
weather summary

Inversion conditions continue with another night of well above freezing temperatures along ridges and above 8000 ft. and below freezing temperatures at lower elevations and even colder temperatures in the valleys. While the weather remains calm and clear, these inversion conditions will continue. The strong high-pressure ridge over the forecast area will bring another sunny warm day to the mountains with daytime highs above 7000 ft. expected to top out in the mid 50's. Expect the sunny dry weather to continue as long as the high-pressure ridge remains in place.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 33 to 46 deg. F.
Max. temperature in the last 24 hours: 52 to 56 deg. F.
Average wind direction during the last 24 hours: East and North
Average wind speed during the last 24 hours: 10 to 15 mph
Maximum wind gust in the last 24 hours: 36 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 15 to 32 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Wednesday Wednesday Night Thursday
Weather: Sunny Clear Sunny
Temperatures: 49 to 55 deg. F. 25 to 35 deg. F. 48 to 53 deg. F.
Wind Direction: Variable Variable Variable
Wind Speed: Light Light Light with some gusts up to 25 mph in the morning
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Wednesday Wednesday Night Thursday
Weather: Sunny Clear Sunny
Temperatures: 49 to 54 deg. F. 29 to 39 deg. F. 47 to 52 deg. F.
Wind Direction: Variable Variable becoming east after midnight East
Wind Speed: Light Light increasing to 10 to 15 mph with gusts to 25 mph after midnight 10 to 15 mph with gusts to 25 mph in the morning becoming light in the afternoon
Expected snowfall: 0 in. 0 in. 0 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