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.

 Early winter snowfall has returned to the Sierra. Remote sensors have reported new snow amounts from the November 3 storm system as generally 6 to 9 inches of new snow along the Sierra Crest with isolated areas up to 10 to 12 inches. Around 5 to 6 inches of new snow has been reported from the Carson Range. Another small to moderate storm event is expected Saturday night follow by another storm system impacting the area sometime mid to late next week. Air temperatures above 7,000' are expected to remain near or below freezing for the next several days.

The recent new snow has fallen on bare ground in the majority of areas. In some spots this new snow has fallen on patches of older snow either held over from last winter or the remnants of the October 4-6 storm event.  These areas of old snow generally exist above 8,000' on N to NE aspects that traditionally receive large amounts of wind loading. Very limited observations made Wednesday near Tinker's Knob (Upper Cold Stream/Deep Creek area) revealed that the old snow on the ground was in a melt/freeze state and of high density. No evidence of a weak layer was observed, but the coverage of the old snow was sufficient to create pockets of efficient bed surface, much more so than the surrounding bare ground areas (photos, more info). This means that new snow will not have the early season anchoring effect of rocks and logs, but will sit on top of a high density layer of snow and/or ice in these areas.

Minimal opportunities exist at this time for any over snow travel. The best bet would be mellow touring on the graded forest roads that are near the Sierra Crest, above 7,000', and are now covered with 6 or more inches of new snow. Even then plan on hitting a few rocks during your outing. Areas directly below ridgelines as well as gully features that are subject to wind loading may exhibit slab formation despite a shallow snowpack. Wind loading can increase snow deposition rates by 2 to 10 times the rate that snow is falling from the sky. This rapid loading can create enough snowpack instability for an avalanche to occur, despite only a few inches of snow on the ground in wind protected areas. Make constant observations as you travel, looking for indications of current or recent snowpack instability. This includes recent avalanche activity, wind loading, collapse, audible whumpfing sounds, shooting cracks, and/or test slope failure.

Each person should travel with avalanche rescue equipment including a transceiver, probe, and shovel with which they are well practiced. Allow only one person at a time to travel on slopes that are steeper than 30 degrees. Many hazards such as rocks, down trees, and stumps are often hidden just beneath the snow surface. Travel cautiously and slowly as it is a very long winter after getting hurt before the season really gets started. Often the best way to satiate early season excitement is to put fresh batteries in avalanche transceivers and practice rescue skills. Check out the avalanche tutorials specifically designed for skiers and snowmobilers at the Forest Service National Avalanche Center web site.

Current remote weather station data from the NWS can be found by clicking here. A general weather forecast for the area can be found by clicking here.

The bottom line:

 Early Season Conditions Update #1

Daily avalanche advisories are planned to resume in mid November or later as conditions dictate. Occasional intermittent early season updates to this page will occur earlier as conditions warrant.

 

Brandon Schwartz - Avalanche Forecaster, Tahoe National Forest

Weather Observations from along the Sierra Crest between 8200 ft and 8800 ft:

0600 temperature:	deg. F.
Max. temperature in the last 24 hours:	deg. F.
Average wind direction during the last 24 hours:
Average wind speed during the last 24 hours:	mph
Maximum wind gust in the last 24 hours:	mph
New snowfall in the last 24 hours:	O inches
Total snow depth:	inches

Two-Day Mountain Weather Forecast - Produced in partnership with the Reno NWS

For 7000-8000 ft:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.
For 8000-9000 ft:
	Friday:	Friday Night:	Saturday:
Weather:
Temperatures:	deg. F.	deg. F.	deg. F.
Wind direction:
Wind speed:
Expected snowfall:	O in.	O in.	O in.