THIS AVALANCHE ADVISORY EXPIRED ON February 28, 2016 @ 7:00 am
Avalanche Advisory published on February 27, 2016 @ 7:00 am
Issued by Andy Anderson - Tahoe National Forest

The avalanche danger should remain LOW today due to increased cloud cover and winds, slightly cooler temperatures, and a prolonged melt-freeze cycle. Some small loose wet avalanches could still form on isolated terrain features on any aspect where wet snow exists. If the forecasted cloud cover does not materialize, the avalanche danger could rise to MODERATE on sun exposed slopes at all elevations due to loose wet avalanche issues.

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: Loose Wet
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  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
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    Very Large
    Large
    Small

Colder overnight temperatures, increased winds, slightly cooler daytime temperatures, and forecasted cloud cover should all work to limit the wet snow that forms due to daytime warming today. In addition the snowpack has experienced several days of melt-freeze cycles, and even though it has still not fully transitioned to corn snow in many places, those melt-freeze cycles have allowed good drainage channels that prevent free water from pooling in any specific layer to form in the snowpack. Despite all the things working to limit wet snow formation today, some small isolated loose wet snow instabilities like small roller balls, pinwheels, and wet point releases may still form on some isolated terrain features especially on the E-SE-S-SW-W slopes steeper than 35 degrees where drier snow still exists under the wet surface snow. Some areas of wet snow could also form on more northerly aspects. If the forecasted cloud cover does not materialize, loose wet snow instabilities may become more widespread and larger. If more cloud cover and wind occurs, the snow surface may remain mostly frozen in many areas today.

recent observations

Yesterday on Rubicon Peak, wet snow existed on the N aspects up to about 8800 ft. Some small roller balls did occur on these aspects but no other signs of instability existed on the northerly aspects. Small human triggered roller balls also occurred in the Deep Creek area due to the presence of wet snow on N aspects. Upper elevation east facing aspects on Rubicon Peak had started to refreeze by 1 pm, and a thin frozen melt-freeze crust existed above drier snow that had not transitioned to corn on these upper elevation east aspects

Weather and CURRENT CONDITIONS
weather summary

The small system that passed north of the region did bring some increased southwest winds and and slightly cooler temperatures. Overnight lows fell into the low to mid 30's above 8000 ft. last night and the forecast call for daytime highs in the mid to upper 40's instead of upper 40's to mid 50's. Another weak system north of the region could start to deliver some medium to high level cloud cover to the area by midday today. This cloud cover may persist through tomorrow. The forecast calls for the winds to start decreasing tonight and continue to diminish tomorrow. Temperatures should remain well above normal. 

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 33 to 36 deg. F.
Max. temperature in the last 24 hours: 46 to 52 deg. F.
Average wind direction during the last 24 hours: Southwest
Average wind speed during the last 24 hours: 30 to 45 mph
Maximum wind gust in the last 24 hours: 55 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 56 to 86 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Saturday Saturday Night Sunday
Weather: Clear becoming mostly cloudy over the Sierra Crest by midday Mostly cloudy Partly cloudy becoming mostly cloudy
Temperatures: 44 to 51 deg. F. 23 to 30 deg. F. 45 to 52 deg. F.
Wind Direction: Southwest Southwest Southwest
Wind Speed: 10 to 20 mph with gusts to 30 mph 10 to 15 mph with gusts to 25 mph 10 to 15 mph with gusts to 25 mph
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Saturday Saturday Night Sunday
Weather: Clear becoming mostly cloudy over the Sierra Crest by midday Mostly cloudy Partly cloudy becoming mostly cloudy
Temperatures: 44 to 50 deg. F. 23 to 30 deg. F. 44 to 50 deg. F.
Wind Direction: Southwest Southwest West
Wind Speed: 30 to 40 mph with gusts to 60 mph decreasing to gusts to 50 mph in the afternoon 20 to 30 mph with gusts to 45 mph 15 to 25 mph with gusts to 40 mph
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.