THIS AVALANCHE ADVISORY EXPIRED ON January 7, 2015 @ 6:50 am
Avalanche Advisory published on January 6, 2015 @ 6:50 am
Issued by Brandon Schwartz - Tahoe National Forest

Avalanche danger remains LOW for all elevations and aspects. Small wet snow instabilities may form in isolated areas of direct sun exposure in response to daytime warming. 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
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  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
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    Very Large
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Air temperatures were well above freezing last night at the mid and upper elevations. A decent overnight snow surface refreeze is expected to have occurred despite the warm air temperatures. This is due to radiational cooling under partly cloudy skies and aided by the longer night this time of year. As daytime warming progresses, isolated areas of minor wet snow instability may form on SE-S-SW aspects that receive fairly direct sun exposure. On northerly aspects, slab avalanche activity remains unlikely today. Weak snow that exists near the snow surface in many areas generally lacks a sufficient overlying slab. Exercise normal caution and keep an eye out for potential isolated areas of localized instability.

recent observations

Observations made yesterday on Castle Peak (Donner Summit area) revealed areas of wet surface snow up to 2 inches deep forming on S aspects at 8,100' by late morning. Overall solar input remains limited by the low sun angles of early January. E and W aspects that had received fairly indirect sun angles by mid day remained mostly frozen. The low sun angle is also allowing for N aspects to remain shaded and colder. Below the variable snow surface conditions, a generally well bonded and stable mid and basal snowpack exists. Near crust facets associated with the uppermost rain crust in the snowpack continue to develop and weaken, but are not an instability concern at this time.

Weather and CURRENT CONDITIONS
weather summary

High pressure firmly in place over the forecast area will expand to the north and east today. This will allow for a decrease in high level cloud cover, continued above average air temperatures, and light winds. An air temperature inversion remains over the region. Remote sensors are reporting 8,000' to 9,000' air temperatures this morning in the low to mid 40s. Maximum daytime air temperatures are forecast to reach the mid 40s to low 50s again today for areas above 7,000'. Light to moderate speed ridgetop winds out of the north are expected to shift to the southeast for a few hours this morning before becoming light and variable.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 39 to 44 deg. F.
Max. temperature in the last 24 hours: 46 to 53 deg. F.
Average wind direction during the last 24 hours: North
Average wind speed during the last 24 hours: 17 mph
Maximum wind gust in the last 24 hours: 34 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 25 to 36 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: 46 to 53 deg. F. 26 to 34 deg. F. 51 to 57 deg. F.
Wind Direction: Variable Variable Variable
Wind Speed: Light winds Light winds 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: 44 to 51 deg. F. 29 to 35 deg. F. 43 to 50 deg. F.
Wind Direction: SE Variable Variable
Wind Speed: 10 to 15 mph with gusts to 25 mph in the morning, becoming light. Light winds 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.