THIS AVALANCHE ADVISORY EXPIRED ON January 8, 2015 @ 6:42 am
Avalanche Advisory published on January 7, 2015 @ 6:42 am
Issued by Brandon Schwartz - Tahoe National Forest

Avalanche danger remains LOW for all elevations and aspects. Small isolated areas of wet snow instability may form 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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    Small

Again last night, air temperatures were well above freezing at the mid and upper elevations. A decent overnight snow surface refreeze is expected to have occurred due to radiational cooling under clear skies despite above freezing air temperatures. As daytime warming progresses, isolated areas of minor wet snow instability may form on a variety of aspects. Areas near exposed rocks that act as heat sinks and in gullies that focus parabolic reflection onto the snow surface will experience greater snow surface melting. These areas will also be the most likely places for a small human triggered wet snow instability to occur. 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 Red Vista Ridge (Carson Pass area) indicated that wet surface snow had formed in all areas of sun exposure. On shaded northerly aspects snow surface temperatures remained below freezing, but moisture in the upper snowpack increased. This caused the top 4 inches of the snowpack to become moist and heavy in many areas. Signs of wet snow instability were very isolated and limited to a single pair of skier triggered pinwheels on a heavily shaded N aspect at about 8,300' at 2:15pm. No other signs of wet snow instability were observed on surrounding above treeline peaks with full sun exposure. A report was received from Mt. Judah (Donner Summit area) where a party experienced a single isolated wet snow whumph while traversing out onto a SE aspect near large exposed rocks at mid day. No other signs of instability were observed by that party.

Weather and CURRENT CONDITIONS
weather summary

Clear skies, light winds, and above average air temperatures will continue as the ridge of high pressure moves over the forecast area today. As the ridge axis shifts east, a slight increase in cloud cover is expected tomorrow. This morning, remote sensors are reporting 8,000' to 9,000' air temperatures in the mid 30s to upper 40s. Inversion conditions have the coldest air on the mountain valley floors. Maximum daytime air temperatures are forecast to reach the mid 40s to low 50s today for areas above 7,000'. Ridgetop winds have become light and variable and are expected to remain so through tomorrow.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 35 to 47 deg. F.
Max. temperature in the last 24 hours: 54 to 60 deg. F.
Average wind direction during the last 24 hours: Variable
Average wind speed during the last 24 hours: 12 mph
Maximum wind gust in the last 24 hours: 29 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.
Wednesday Wednesday Night Thursday
Weather: Sunny skies. Clear skies, becoming partly cloudy. Partly cloudy skies.
Temperatures: 46 to 53 deg. F. 29 to 37 deg. F. 49 to 55 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.
Wednesday Wednesday Night Thursday
Weather: Sunny skies. Clear skies, becoming partly cloudy. Partly cloudy skies.
Temperatures: 46 to 53 deg. F. 32 to 40 deg. F. 45 to 51 deg. F.
Wind Direction: Variable Variable Variable
Wind Speed: Light winds 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.