THIS AVALANCHE FORECAST EXPIRED ON April 18, 2019 @ 6:52 am
Avalanche Forecast published on April 17, 2019 @ 6:52 am
Issued by Steve Reynaud - Tahoe National Forest

LOW avalanche danger will transition to MODERATE avalanche danger as solar radiation and warming quickly increase this morning.  Loose wet avalanches will be likely at all elevations today.

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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    Very Likely
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Below freezing air temperatures along with mostly clear overnight skies should provide a good refreeze of the snow surface.  As solar radiation and warming temperatures increase quickly this morning, loose wet avalanche activity will become likely on all aspects and elevations.  Most loose wet avalanches will involve the recent storm snow and be D1 in size with the possibility of up to size D2 in isolated areas.  Loose wet avalanches are expected to run efficiently on the previous surface crust below the recent storm snow.

Monitor snow surface and warming conditions.  Roller balls and pinwheels will be an indication that the snow surface is losing strength and larger loose wet avalanches could occur.  Terrain traps will increase the consequences of being caught in even a small loose wet avalanche.    

recent observations

*  Widespread loose wet avalanches occurred yesterday on Hidden Peak, West Shore area.  These were both natural and human triggered up to size D1.5.  While most of these were small in size involving only the recent 3-4'' of storm snow, they ran fast and efficiently on slopes 35 degrees and steeper.  Little to no refreeze of the snow surface occurred below 8000'.

*  Observations from Powderhouse Peak, Luther Pass area, showed mostly dust of crust conditions.  1'' of new storm snow existed below 8500' with mostly wet unfrozen surface snow and up to 3'' above 8500' with firm refrozen surface crusts below the storm snow.

Weather and CURRENT CONDITIONS
weather summary

Clear skies, warming temperatures, and decreasing winds are forecasted for the next couple days.  A good refreeze of the snow surface is expected as below freezing temperatures and mostly clear skies were present overnight.  Warmer and dryer air did begin to move into our region overnight increasing temperatures in some areas into the early morning hours.  Continued warming is expected through Thursday.  Unsettled weather returns briefly on Friday afternoon through Saturday with increasing winds and the chance of light rain. 

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 28 to 35 deg. F.
Max. temperature in the last 24 hours: 35 to 41 deg. F.
Average wind direction during the last 24 hours: NE
Average wind speed during the last 24 hours: 15 to 25 mph
Maximum wind gust in the last 24 hours: 42 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 102 to 152 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Wednesday Wednesday Night Thursday
Weather: Sunny. Snow levels below 7000 feet increasing to 8000 feet in the afternoon. Chance of precipitation is 0%. Clear. Snow levels 9000 feet. Chance of precipitation is 0%. Sunny. Snow levels 9000 feet. Chance of precipitation is 0%.
Temperatures: 52 to 57. deg. F. 30 to 35. deg. F. 58 to 63. deg. F.
Mid Slope Winds: Light winds. Light winds. Light winds.
Expected snowfall: No accumulation. | SWE = none. No accumulation. | SWE = none. No accumulation. | SWE = none.
For 8000 ft. to 9000 ft.
Wednesday Wednesday Night Thursday
Weather: Sunny. Snow levels below 7000 feet increasing to 8000 feet in the afternoon. Chance of precipitation is 0%. Clear. Snow levels 9000 feet. Chance of precipitation is 0%. Sunny. Snow levels 9000 feet. Chance of precipitation is 0%.
Temperatures: 47 to 53. deg. F. 31 to 36. deg. F. 53 to 59. deg. F.
Ridge Top Winds: North 15 to 20 mph. Gusts up to 40 mph decreasing to 25 mph in the afternoon. Northeast around 15 mph with gusts to 25 mph. East around 15 mph in the morning becoming light.
Expected snowfall: No accumulation. | SWE = none. 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