Avalanche Advisory published on December 15, 2017 @ 6:50 am
This advisory is valid for 24 hours
Issued by Brandon Schwartz - Tahoe National Forest
bottom line

How to read the advisory

Avalanche danger is LOW for all elevations. On a regional scale, triggering an avalanche is unlikely. Signs of isolated, difficult to trigger instability linger near and above treeline. Normal caution is advised.


  • Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
  • Natural and human-triggered avalanches unlikely.
  • Small avalanches in isolated areas or extreme terrain.
weather

A mostly dry weather system will pass through the forecast area tonight. Ahead of this system, ridgetop winds have shifted to the SW this morning. Little in the way of snowfall is expected. A short lived break down of air temperature inversion conditions is the major expected outcome. A strong NE wind event will occur on Saturday with ridgetop gusts to 75 mph or more. High pressure will rebuild over the forecast area. A strong cold front is likely to impact the region mid week.

recent observations

* Snowpit test results targeting the isolated hard wind slabs that linger on a few WNW to NW aspects are highly variable. Isolated indications of stubborn to trigger instability remain.

* Widespread firm, wind scoured snow surfaces exist on most aspects near and above treeline.

* Variable snow surfaces with some areas of softer snow exist near and below treeline in shaded, wind protected areas.

* Areas north of Emerald Bay above 8,000', hold decent snow coverage. Below 8,000' snow coverage remains patchy and shallow.

* South of Emerald Bay, less snow exists. Areas below 8,500' hold very little snow. A deeper but highly variable snowpack exists in areas above 8,500'.

* Snow coverage continues to decrease due to melt on southerly aspects throughout the forecast area.

Avalanche Problem #1: Normal Caution

Isolated areas of difficult to trigger (stubborn) instability do exist near and above treeline on WNW to NW aspects within the forecast area. That said, on a regional scale triggering an avalanche is an unlikely event. Use normal caution to help improve the outcome in the unlikely event of a hard wind slab avalanche.

In utilizing best travel practices for moving around and through avalanche terrain, make sure your partner is competent and in position to perform a companion rescue in the unlikely event of an avalanche. If you and your partner are exposed to hazard at the same time, your partner is not ready, or is out of position, you are "effectively solo", even though you technically have a partner.

Common mistakes include:

*Skiing/riding directly above your exposed partner even though you are technically moving one at at time. This is an easy way to create multiple burials.

*Having a partner who is too far below to get up to a burial location in a short time (transitioning to skinning is not quick for most folks). Snowmobiles have an advantage and can get uphill quickly, but the partner must be at the ready (not helmet off with engine off).

 

 

CURRENT CONDITIONS  Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 37 to 47 deg. F.
Max. temperature in the last 24 hours: 55 to 59 deg. F.
Average wind direction during the last 24 hours: E shifting to SW
Average wind speed during the last 24 hours: E 30 mph | SW 25 mph
Maximum wind gust in the last 24 hours: E 59 mph | SW 44 mph
New snowfall in the last 24 hours: 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.
  Today Tonight Saturday
Weather: Partly cloudy skies. Mostly cloudy skies with a slight chance of snow showers after midnight. Snow level 6,500' falling below 6,000' after midnight. Partly cloudy skies, becoming sunny. Slight chance of snow showers in the morning.
Temperatures: 48 to 53 deg. F. 26 to 31 deg. F. 30 to 35 deg. F.
Wind direction: SW W NE
Wind speed: Light winds increasing to 10 to 15 mph with gusts to 35 mph in the afternoon. 10 to 15 mph with gusts to 35 mph. 10 to 15 mph. Gusts to 45 mph increasing to 60 mph in the afternoon.
Expected snowfall: 0 in. Likely 0 in | Possible up to 2 in. Likely 0 in | Possible up to 1 in.
For 8000 ft. to 9000 ft.
  Today Tonight Saturday
Weather: Partly cloudy skies. Mostly cloudy skies with a slight chance of snow showers after midnight. Partly cloudy skies, becoming sunny. Slight chance of snow showers in the morning.
Temperatures: 46 to 51 deg. F. 26 to 31 deg. F. 27 to 32 deg. F.
Wind direction: SW W NE
Wind speed: 15 to 25 mph with gusts up to 45 mph. 15 to 25 mph with gusts to 45 mph. 20 to 30 mph with gusts to 60 mph, increasing to 30 to 45 mph with gusts to 75 mph in the afternoon.
Expected snowfall: 0 in. Likely 0 in | Possible up to 2 in. Likely 0 in | Possible up to 1 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