THIS AVALANCHE FORECAST EXPIRED ON April 11, 2019 @ 6:58 am
Avalanche Forecast published on April 10, 2019 @ 6:58 am
Issued by Steve Reynaud - Tahoe National Forest

Sunny conditions are expected for today.  LOW avalanche danger this morning will increase to MODERATE avalanche danger as daytime warming occurs due to a loose wet avalanche problem. 

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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    Possible
    Unlikely
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    Large
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Well below freezing temperatures with clear skies will have provided a good overnight refreeze of the snow surface.  As these surface crusts warm up and lose strength throughout the day, loose wet avalanche activity will become possible on all aspects and elevations.  Monday nights rain storm wetted the upper snowpack up to 1 to 2 feet deep with this layer slowly refreezing over time.  This wet snow will be of concern as the firm surface crusts warm and lose strength today.  Many areas will have firm exposed rain crusts that will pose travel concerns, especially this morning.  Higher elevation terrain exposed to the NE winds may not soften today at all.  In areas that lose supportability, loose wet avalanches could involve most of the wet snow beneath the surface crusts and be large in size.

Monitor snow surface conditions.  Use slope angle to reduce loose wet avalanche hazards.

recent observations

*  Several natural large cornice failures, loose wet avalanches, and a slab avalanche were observed yesterday on Donner Peak and Mt. Judah (Donner Summit area).  These looked to fail during Monday night's rain event and were all size D2 avalanchesCornice fall was also observed on Elephants Hump in the Carson Pass area.

*  Substantial rain on Monday night wetted the top 1-2' of the upper snowpack in the Donner Summit area.  This wet snow was capped by a surface crust that ranged from supportable to non-supportable.  Unsupportable crusts also existed in the Carson Pass area.  Small loose wet avalanches were easy to trigger on test slopes on E aspects in the late morning in the Donner Summit area.

Weather and CURRENT CONDITIONS
weather summary

Sunny skies with below normal temperatures and cool northerly winds are expected today.  Mostly clear skies overnight with temperatures in the teens to low 20's with NE winds 20-30mph along the Sierra Crest.  Unsettled weather is forecasted for Thursday and Friday with milder conditions for the weekend.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 16 to 20 deg. F.
Max. temperature in the last 24 hours: 27 to 34 deg. F.
Average wind direction during the last 24 hours: NE
Average wind speed during the last 24 hours: 20 to 35 mph
Maximum wind gust in the last 24 hours: 49 mph
New snowfall in the last 24 hours: 0 to trace inches
Total snow depth: 105 to 156 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. Chance of precipitation is 0%. Clear then becoming partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 0%. Cloudy. Isolated snow showers in the morning, then widespread snow showers in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 60%.
Temperatures: 39 to 45. deg. F. 24 to 29. deg. F. 34 to 40. deg. F.
Mid Slope Winds: North 10 to 20 mph with gusts to 30 mph. North around 15 mph with gusts to 30 mph. Northwest 10 to 15 mph with gusts to 25 mph.
Expected snowfall: No accumulation. | SWE = none. No accumulation. | SWE = none. 60% probability up to 1 inch. 40% probability of 1 to 2 inches. | SWE = less than 0.15 inch.
For 8000 ft. to 9000 ft.
Wednesday Wednesday Night Thursday
Weather: Sunny. Snow levels below 7000 feet. Chance of precipitation is 0%. Clear then becoming partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 0%. Cloudy. Isolated snow showers in the morning, then widespread snow showers in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 60%.
Temperatures: 31 to 39. deg. F. 20 to 25. deg. F. 27 to 35. deg. F.
Ridge Top Winds: Northeast 20 to 35 mph with gusts to 50 mph shifting to the north 15 to 25 mph with gusts to 40 mph in the afternoon. North 15 to 25 mph with gusts to 40 mph. Northwest 15 to 20 mph with gusts to 30 mph.
Expected snowfall: No accumulation. | SWE = none. No accumulation. | SWE = none. 60% probability up to 1 inch. 40% probability of 1 to 3 inches. | SWE = less than 0.20 inch.
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