THIS AVALANCHE ADVISORY EXPIRED ON February 16, 2017 @ 6:51 am
Avalanche Advisory published on February 15, 2017 @ 6:51 am
Issued by Brandon Schwartz - Tahoe National Forest

LOW avalanche danger early this morning will increase to MODERATE danger for all elevations as daytime warming progresses. Wet loose avalanches are possible today. Timing of travel in or below sun exposed avalanche terrain is important.

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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    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Wet loose avalanches will become possible today in sun exposed areas once overnight melt-freeze crusts melt away. The vast majority of wet loose instability is expected to occur on E-SE-S-SW-W aspects on slopes 37 degrees and steeper. Expected size for most avalanche activity is small. In isolated areas a wet loose avalanche with size sufficient to bury a person could occur, especially if a terrain trap is involved.

Air temperatures this morning are about 10 degrees warmer at the mid and upper elevations than 24 hours ago. Areas of wet snow are expected to form faster today than yesterday. Human triggered roller balls and pinwheels reaching 1 foot or more in diameter will give indication of slopes to avoid. Areas around exposed rock features will heat up more quickly than open snow covered slopes.

recent observations

Observations made yesterday on Rose Knob Peak (Mount Rose area) noted that human triggered roller balls up to 18 inches in diameter started to occur on E aspects around 8,000' by 10 am. By noon wet snow deeper than boot top height existed on sun-exposed E-SE-S-SW aspects up to 9,600'. Some small natural loose wet point releases were noted to have occurred between 10 am and noon on sun exposed SW-W aspects below 8,500.  At the upper elevations, widespread evidence of wind scouring existed. On northerly aspects above 7,800', areas sheltered from E and NE winds held pockets of unconsolidated snow.

Weather and CURRENT CONDITIONS
weather summary

Sunny skies and above freezing air temperatures will continue today ahead of an approaching storm system. Ridgetop winds made the shift yesterday evening from NE to SW. Expect cloud cover to increase this afternoon along with increasing ridgetop winds. SW ridgetop winds will become gale force tonight. Precipitation is expected to begin during the pre dawn hours tomorrow. Snow level is forecast to begin around 6,500' to 7,000' and slowly lower during the day. This first storm is expected to taper off by tomorrow evening. The next storm system is right behind it for Friday.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 36 to 43 deg. F.
Max. temperature in the last 24 hours: 45 to 48 deg. F.
Average wind direction during the last 24 hours: NE shifting to SW
Average wind speed during the last 24 hours: 20 mph
Maximum wind gust in the last 24 hours: 47 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 118 to 140 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 skies, becoming mostly cloudy. Mostly cloudy skies. A chance of rain and snow after midnight. Cloudy skies with snow and rain.
Temperatures: 47 to 52 deg. F. 32 to 37 deg. F. 36 to 42 deg. F.
Wind Direction: SW SW SW
Wind Speed: 10 to 15 mph. Gusts to 25 mph increasing to 35 mph in the afternoon. 15 to 20 mph with gusts to 50 mph, increasing to 20 to 30 mph with gusts to 70 mph after midnight. 20 to 35 mph with gusts to 85 mph.
Expected snowfall: 0 in. 0 to 2 in. 3 to 8 in.
For 8000 ft. to 9000 ft.
Wednesday Wednesday Night Thursday
Weather: Partly cloudy skies, becoming mostly cloudy. Mostly cloudy skies. A chance of rain and snow after midnight. Cloudy skies with snow.
Temperatures: 43 to 49 deg. F. 29 to 34 deg. F. 30 to 36 deg. F.
Wind Direction: SW SW SW
Wind Speed: 15 to 25 mph. Gusts up to 35 mph increasing to 45 mph in the afternoon. 20 to 30 mph with gusts to 60 mph, increasing to 30 to 50 mph with gusts to 100 mph after midnight. 40 to 60 mph decreasing to 30 to 50 mph in the afternoon. Gusts up to 110 mph.
Expected snowfall: 0 in. 0 to 3 in. 4 to 8 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