THIS AVALANCHE ADVISORY EXPIRED ON March 31, 2017 @ 7:00 am
Avalanche Advisory published on March 30, 2017 @ 7:00 am
Issued by Andy Anderson - Tahoe National Forest

Some areas of minor loose wet instabilities may exist in areas that are receiving rain this morning, but these concerns should diminish as the day cools off. The avalanche danger should remain LOW today due to the small amount of new snow accumulation expected out of this storm. LOW danger does not mean no danger and some small wind slabs could still form on isolated terrain features. If more snow falls than forecasted larger wind slabs could exist.  

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 ?
    Historic
    Very Large
    Large
    Small

Some small wet snow instabilities like roller balls, pinwheels, and small point releases may remain possible this morning in areas where rain is still occurring. These wet snow instabilities should become unlikely as the day cools off and snow levels fall to Lake level. At higher elevations, the 1 to 2 inches of snow from last night combined with the 1 to 3 inches of new snow today should not provide enough accumulation to create significant widespread avalanche problems. Some small wind slabs may form on wind-loaded terrain. In some isolated areas that receive the most snow or in areas where more snow falls than forecasted some isolated and slightly larger wind slabs may form. If the storm disobey's the forecast and provides more snow to more widespread areas, then these wind slabs could also be more widespread and more significant human-triggered avalanches would become possible. 

recent observations

Yesterday observations on Rose Knob Peak, Mt. Rose, and Castle Peak all found wet snow on a supportable crust early in the day. The snowpack became unsupportable between 11 am and noon in those areas leaving deep wet snow on the sun-exposed slopes. Some minor natural and skier triggered loose wet instabilities including small roller balls and pinwheels occurred on all but the due north aspects in the Fireplug and Mt. Rose areas.

Weather and CURRENT CONDITIONS
weather summary

A fast-moving storm brought strong west and southwest winds and some precipitation to the forecast area starting last night. So far about .3 to .9 inches of water has fallen from the sky. Most of this has fallen as rain below 8000 ft. with 1 to 2 inches of new snow above 8000 ft. The forecast calls for snow level to quickly fall to Lake level or below by mid-morning. Precipitation should continue today with another 1 to 3 inches of snow in the forecast. Most of the precipitation should end by this evening. The winds should also remain strong and shift more to the west and northwest by this afternoon. Sustained wind speeds in the 35 to 55 mph range with gusts over 85 mph are expected today. The forecast calls for the winds to shift to the north and northeast tonight and tomorrow and remain strong. Expect a cooler and windy day for tomorrow. 

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: 52 to 57 deg. F.
Average wind direction during the last 24 hours: Southwest
Average wind speed during the last 24 hours: 20 to 40 mph
Maximum wind gust in the last 24 hours: 114 mph
New snowfall in the last 24 hours: 1 to 2 inches
Total snow depth: 119 to 175 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Thursday Thursday Night Friday
Weather: Cloudy becoming mostly cloudy this afternoon. Snow showers and isolated thunderstorms this morning with scattered snow showers this afternoon. Mostly cloudy becoming partly cloudy with isolated snow showers in the evening Partly cloudy becoming sunny
Temperatures: 36 to 41 deg. F. 18 to 23 deg. F. 42 to 47 deg. F.
Wind Direction: Northwest North Northeast
Wind Speed: 20 to 30 mph with gusts to 65 mph decreasing to 45 mph in the afternoon 15 to 25 mph with gusts to 50 mph 15 to 25 mph with gusts to 45 mph
Expected snowfall: 1 to 3 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Thursday Thursday Night Friday
Weather: Cloudy becoming mostly cloudy this afternoon. Snow showers and isolated thunderstorms this morning with scattered snow showers this afternoon. Mostly cloudy becoming partly cloudy with isolated snow showers in the evening Partly cloudy becoming sunny
Temperatures: 32 to 38 deg. F. 16 to 21 deg. F. 36 to 42 deg. F.
Wind Direction: West shifting to the northwest in the afternoon North Northeast
Wind Speed: 35 to 55 mph with gusts to 95 mph decreasing to 20 to 35 mph with gusts to 60 mph in the afternoon 25 to 35 mph with gusts to 70 mph increasing to 80 mph after midnight 25 to 40 mph with gusts to 95 mph decreasing to 80 mph in the afternoon
Expected snowfall: 1 to 3 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.

For a recorded version of the Avalanche Advisory call (530) 587-3558 x258