THIS AVALANCHE ADVISORY EXPIRED ON January 14, 2015 @ 6:53 am
Avalanche Advisory published on January 13, 2015 @ 6:53 am
Issued by Brandon Schwartz - Tahoe National Forest

Avalanche danger is LOW for all elevations and aspects.

Normal caution is advised.

1. Low

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

1. Low

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

1. Low

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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

With decreasing cloud cover, greater amounts of incoming long wave solar radiation are expected to create a few inches of surface wet snow today. Any areas of wet snow instability that form are expected to remain minimal and not pose a significant threat to backcountry travelers. Areas around exposed rocks and bushes may become full depth wet snow today. These areas already have well established free water drainage and are not expected to pose much of an instability issue.

On northerly aspects a weak layer of generally poorly developed near crust facets that exist below the uppermost rain crust within the snowpack warrants continued monitoring. Finding an area where this weak layer is capped by a slab with the proper characteristics for a slab avalanche to occur remains highly unlikely. As evidenced by the recent small avalanche on Castle Peak, it is not an impossibility. Do not allow this dry spell to generate complacency for best practice travel techniques in and around avalanche terrain.

recent observations

Observations made yesterday on Rubicon Peak (West Shore Tahoe area) and on Castle Peak (Donner Summit area) revealed a mix of snowpack conditions. Snowpit tests targeting near crust facets in the upper snowpack showed further decreases in strength on northerly aspects both on Rubicon Peak and on some areas of Castle Peak. On other northerly aspects on Castle Peak, this weak layer was nonexistent. Evidence of a several day old small slab avalanche with a crown depth of 6 to 8 inches was noted on Castle Peak in a NW aspect gully at 8,500'. The trigger is unknown with a multitude of ski and snowmobile tracks in the area. Cornice collapse is also a possibility. Based on recent observations from the area, the avalanche is believed to have occurred sometime within the past seven days.

Snow surface conditions were noted to remain frozen all day on northerly aspects in most areas with minor amounts of wet snow formation on southerly aspects.

Weather and CURRENT CONDITIONS
weather summary

Clearing conditions exist this morning in the wake of a departing cold front that passed through the region yesterday. Very light rain and snow showers were noted yesterday in isolated areas. New snow amounts from the last 24 hours are minimal at 0 to trace inches. Cloud cover is decreasing and ridgetop winds have shifted to the northeast. Wind speeds increased after 8 pm last night with ridgetop gusts to 62 mph reported early this morning. Strong northeast winds lasting through sunrise are expected to decrease to moderate speed for most of today. Winds are forecast to become light and variable tonight. Air temperatures at 8,000' to 9,000' are in the mid 20s this morning with minimal inversion conditions. Maximum daytime air temperatures are forecast to reach the mid 30s to low 40s today for areas above 7,000'.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 23 to 27 deg. F.
Max. temperature in the last 24 hours: 34 to 43 deg. F.
Average wind direction during the last 24 hours: Northeast
Average wind speed during the last 24 hours: Prior to 8 pm, 10 mph | Since 8 pm 37 mph
Maximum wind gust in the last 24 hours: 62 mph
New snowfall in the last 24 hours: 0 to trace inches
Total snow depth: 24 to 34 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Tuesday Tuesday Night Wednesday
Weather: Partly cloudy skies, becoming sunny. Clear skies. Sunny skies.
Temperatures: 33 to 41 deg. F. 17 to 23 deg. F. 37 to 44 deg. F.
Wind Direction: E E Variable
Wind Speed: 15 to 20 mph with gusts to 30 mph in the morning. 10 to 15 mph in the evening becoming light. Light winds
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Tuesday Tuesday Night Wednesday
Weather: Partly cloudy skies, becoming sunny. Clear skies. Sunny skies.
Temperatures: 32 to 40 deg. F. 19 to 26 deg. F. 36 to 42 deg. F.
Wind Direction: E E Variable
Wind Speed: 15 to 20 mph with gusts to 30 mph. 15 to 20 mph with gusts to 30 mph in the evening. Light winds
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.