THIS AVALANCHE ADVISORY EXPIRED ON March 3, 2016 @ 6:50 am
Avalanche Advisory published on March 2, 2016 @ 6:50 am
Issued by Steve Reynaud - Tahoe National Forest

Through the morning hours, avalanche danger will be Low on all aspects and elevations.  As daytime warming occurs, avalanche danger will rise to Moderate on E-SE-S-SW-W aspects on slopes steeper than 35 degrees due to the possibility of loose wet avalanches.  Isolated areas of loose wet instabilities may also form on NW-N-NE aspects

2. Moderate

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Above Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

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Near Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

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Below Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Loose Wet
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  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

A stronger snow surface refreeze is expected to have occurred overnight with slightly colder overnight temperatures and reduced cloud cover as compared with yesterday.  Strong SW winds could delay snow surface warming in the most wind exposed areas near and above treeline although little to no delay will occur in more wind protected areas.  Wet snow instabilities are expected to form on E-SE-S-SW-W aspects on slopes steeper than 35 degrees during the late morning and through the afternoon hours as daytime warming occurs.  Wet snow instabilities could also occur on NW-N-NE aspects in the form of roller balls and/or pinwheels.

Timing is critical to avoid loose wet instabilities and find supportable snow with the best travel conditions.  Recent roller balls or pinwheels are an indication that the snow surface is loosing strength and that loose wet avalanches are becoming possible.  Use boot penetration to constantly monitor the supportability of the snow surface.  If boot penetration exceeds 10-12 inches into wet snow, it's time to move to a less sun exposed aspect and/or terrain under 30 degrees without steeper terrain above.

recent observations

Observations from Jakes Peak (West Shore) and Mt. Judah (Donner Summit) showed similar spring type conditions.  Wet surface snow existed by the late morning hours in wind protected areas and slopes below treeline.  Melt freeze crusts existed on SE-S-SW aspects and good corn snow was found in some areas.  The SW winds only slightly delayed snow surface melt in the most wind exposed areas.  At both locations, the overnight refreeze was moderate, with SE-S slopes below 7500' becoming unsupportable by mid day.  On Jakes Peak, roller balls and pinwheels were reported on NE and E aspects in the mid day hours.  Upper elevation east aspects are still transitioning with a few inches of wet snow on top of older snow.

Weather and CURRENT CONDITIONS
weather summary

Above average temperatures will continue through Friday as high pressure rebuilds then slowly moves east.  Overnight low temperatures were slightly colder than the previous night with remote sensors showing low to mid 30's above 8000'.  Several disturbances will move past our forecast area over the next few days mainly bringing us an increase in clouds, winds, and a slight chance of light precipitation.  A major pattern change is expected to develop over the weekend and into next week.  For today, areas of high thin clouds will be possible with temperatures forecasted for the mid 40's to high 50's above 7000'.  SW winds will be strong with gusts of 50 to 60mph above 8000' in the afternoon.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 31 to 36 deg. F.
Max. temperature in the last 24 hours: 47 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 25 to 30 mph
Maximum wind gust in the last 24 hours: 57 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 54 to 83 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Wednesday Wednesday Night Thursday
Weather: Partly cloudy. Partly cloudy then becoming mostly cloudy. Mostly cloudy. Slight chance of showers.
Temperatures: 51 to 59 deg. F. 28 to 35 deg. F. 41 to 48 deg. F.
Wind Direction: SW SW SW
Wind Speed: 15 to 25mph with gusts to 35mph. 20 to 30mph with gusts to 40mph. 15 to 25mph with gusts to 35mph.
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Wednesday Wednesday Night Thursday
Weather: Partly cloudy. Partly cloudy then becoming mostly cloudy. Mostly cloudy. Slight chance of snow showers in the morning then chance of snow showers in the afternoon.
Temperatures: 46 to 52 deg. F. 27 to 34 deg. F. 37 to 44 deg. F.
Wind Direction: SW SW SW
Wind Speed: 30 to 40mph. Gusts to 50mph increasing to 60mph in the afternoon. 40 to 50mph with gusts to 80mph. 35 to 45mph with gusts to 65mph.
Expected snowfall: 0 in. 0 in. Up to 1'' 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.