THIS AVALANCHE FORECAST EXPIRED ON February 19, 2019 @ 6:55 am
Avalanche Forecast published on February 18, 2019 @ 6:55 am
Issued by Steve Reynaud - Tahoe National Forest

MODERATE avalanche danger will exist due to wind slab and storm slab avalanche problems.  Human triggered avalanches remain possible at all elevations.

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: Wind Slab
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Large existing wind slabs and cornices, that may still be sensitive to human triggering, exist on NW-N-NE-E-SE aspects in near and above treeline terrain.  Yesterday afternoon, winds shifted to the NE and have been consistent in the moderate range overnight.  These NE winds are forecasted to continue and will easily transport our recent low density storm snow.  New and reactive wind slabs will be possible on SE-S-SW-W-NW aspects in near and above treeline areas.

Look for blowing snow, cornice formation, wind pillows, and snow surface clues as to where wind slabs are located or are forming.  Large cornices exist around the forecast region and should be given a wide margin of safety.

Avalanche Problem 2: Storm Slab
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The recent storm snow continues to gain strength over time with limited signs of instabilities in many areas.  In other locations, avalanche activity and signs of instabilities have been reported.  Continued cold temperatures along with a variety of layers in the recent storm snow will take additional time to settle and gain strength.  Human triggered storm slab avalanches remain possible in wind protected near and below treeline areas.

Look for cracking and/or any signs of cohesion in the recent storm snow.  In areas where storm slabs do not exist, loose dry sluffing may be encountered on steep slopes.  Some of these loose dry avalanches could be large enough to take a backcountry user for a ride into potential hazards.   

recent observations

*  A storm slab avalanche was reported on Trestle Peak, in the Donner Summit area, that looked to occur sometime late Saturday night/early Sunday.  Other signs of storm slab instabilities existed yesterday with cracking around skis in below treeline terrain.

*  Shooting cracks reported on Jakes Peak (West Shore area) in below treeline terrain along the skin track.  Also reports of shooting cracks while down skiing.

*  Observations from Andesite Peak and Johnson Canyon (Donner Summit area) and Tamarack Peak (Mt. Rose area) all showed a right side up snowpack with little signs of instabilities observed.

Weather and CURRENT CONDITIONS
weather summary

Cold northerly flow will be with us for most of this week with temperatures 10 to 20 degrees below normal.  For today, mostly dry conditions are expected except for some lake effect snow possible along the SW shore of Lake Tahoe and around Hwy. 50.  Any snow showers should be light and wrap up sometime today.  Partly cloudy with the potential for some sun forecasted for today.  Tuesday will be a break before an inside slider storm drops down from the north on Wednesday/Thursday, with generally light snow accumulations expected.  Chance of another storm is possible for the weekend. 

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 5 to 11 deg. F.
Max. temperature in the last 24 hours: 22 deg. F.
Average wind direction during the last 24 hours: SW shifting to NE
Average wind speed during the last 24 hours: 20 to 30 mph
Maximum wind gust in the last 24 hours: 39 mph
New snowfall in the last 24 hours: 0 to 4 inches
Total snow depth: 119 to 133 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Monday Monday Night Tuesday
Weather: Mostly cloudy then becoming partly cloudy. Isolated snow showers. Snow levels below 7000 feet. Chance of precipitation is 20%. Partly cloudy then becoming clear. Snow levels below 7000 feet. Chance of precipitation is 0%. Sunny. Snow levels below 7000 feet. Chance of precipitation is 0%.
Temperatures: 18 to 23. deg. F. Zero to 8 above zero. deg. F. 25 to 30. deg. F.
Mid Slope Winds: East winds 10 to 15 mph. East winds 10 to 15 mph. East winds around 10 mph becoming light.
Expected snowfall: Up to 1 inch. | SWE = trace amounts. No accumulation. | SWE = none. No accumulation. | SWE = none.
For 8000 ft. to 9000 ft.
Monday Monday Night Tuesday
Weather: Mostly cloudy. Isolated snow showers. Snow levels below 7000 feet. Chance of precipitation is 20%. Partly cloudy then becoming clear. Snow levels below 7000 feet. Chance of precipitation is 0%. Sunny. Snow levels below 7000 feet. Chance of precipitation is 0%.
Temperatures: 12 to 18. deg. F. 1 below to 4 above zero. deg. F. 21 to 27. deg. F.
Ridge Top Winds: Northeast 15 to 25 mph with gusts to 40 mph. Northeast 15 to 25 mph with gusts to 50 mph. Northeast 15 to 25 mph with gusts to 50 mph.
Expected snowfall: Up to 1 inch. | SWE = trace amounts. No accumulation. | SWE = none. No accumulation. | SWE = none.
Disclaimer

This avalanche forecast is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This forecast 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 forecast applies only to backcountry areas outside established ski area boundaries. This forecast describes general avalanche conditions and local variations always occur. This forecast expires 24 hours after the posted time unless otherwise noted. The information in this forecast is provided by the USDA Forest Service who is solely responsible for its content.

For a recorded version of the avalanche forecast call (530) 587-3558 x258