THIS AVALANCHE FORECAST EXPIRED ON March 21, 2020 @ 7:01 am
Avalanche Forecast published on March 20, 2020 @ 7:01 am
Issued by Steve Reynaud - Tahoe National Forest

Areas of unstable snow continue to exist throughout the forecast region.  Human triggered avalanches will remain possible today at all elevations due to wind slab, deep slab, and loose wet avalanche problems.  MODERATE avalanche danger will exist.

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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Wind slabs could still be reactive in near and above treeline areas throughout the forecast area.  Periods of moderate SW to NE winds since the storm has ended could have built out wind slabs in wind exposed areas.  Large amounts of low density snow exists along ridges that can be easily wind transported.

Look for blowing snow today or evidence of previous blowing snow.  New cornice formation or wind pillows may also be clues to where the wind has been transporting snow.  Slight changes in wind directions may build small wind slabs in unexpected locations.  Complex terrain may harbor these wind slabs on multiple aspects.

Avalanche Problem 2: Deep Slab
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Recent reports have come in that a deep slab avalanche cycle occurred on the buried facet/crust combination.  The majority of these reported avalanches are thought to have happened during the main loading event of the storm cycle on Sunday.  A human triggered deep slab avalanche was reported yesterday in the Ebbetts Pass area.  Details are very limited at this point.  Informal observations along with some snowpack test results have been trending towards this layer gaining strength, but more uncertainty now exists after this recent avalanche incident.

This deep slab problem exists in near and below treeline areas on NW-N-NE aspects.  It is now buried anywhere from 3 to 6+ feet deep.  While these deep slab avalanches are becoming more unlikely, any avalanche associated with this layer would be large and destructive. 

Avalanche Problem 3: Loose Wet
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Increasing solar radiation from strong March sunshine will make loose wet avalanches likely today.  Loose wet avalanches are expected to start mid to late morning as daytime warming and strong solar radiation warm the snow surface.  Roller balls and pinwheels may be an indication of larger loose wet avalanches becoming possible.  Many of these wet instabilities will occur around rocks, cliffs, and trees, as they heat up throughout the day.

Avoid travel on solar aspects as the day begins to warm up in the mid to late morning.  Travel conditions will deteriorate as the snow surface becomes wet and sticky. 

recent observations
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A D2 deep slab avalanche was reported from Kinney Reservoir (Ebbetts Pass area) yesterday.  The avalanche occurred on a N aspect and failed on the old snow facets.  Limited details are available.

A natural avalanche was reported from the Fireplug in the Mt. Rose area.  This slab avalanche was around 1' deep on a N aspect.  There remains questions about this avalanche as it had wide propagation with shooting cracks off to the side and below the avalanche.  Some deeper instability or a potential deep slab may be associated with these avalanche characteristics.

Many reports of limited instabilities have been reported throughout the forecast region with greatly increased user traffic.  Snowpack tests targeting the deep slab problem continue to vary from location to location.

Weather and CURRENT CONDITIONS
weather summary

Sunny skies, light winds, and warmer temperatures are forecasted for today.  Increasing clouds with isolated convective snow showers will become possible with afternoon heating.  Graupel type snow could fall in some higher elevation areas with little accumulation expected.  Temperatures continue to warm through the weekend with continued springtime afternoon convective type storms possible.  Monday through Wednesday is expected to be more active with a potential storm and below average temperatures.

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
Weather Station Map
Weather Station Table
6am temperature: 12 to 20 deg. F.
Max. temperature: 28 to 34 deg. F.
Average ridgetop wind direction: SW shifting to NE
Average ridgetop wind speed: 10 to 25 mph
Maximum ridgetop wind gust: 33 mph
New snowfall: 0 to trace inches
Total snow depth: 61 to 89 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Friday Friday Night Saturday
Weather: Sunny then becoming partly cloudy. Isolated snow showers in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 20%. Clear. Snow levels below 7000 feet. Chance of precipitation is 0%. Sunny then becoming partly cloudy. Slight chance of snow showers in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 20%.
Temperatures: 33 to 38. deg. F. 16 to 22. deg. F. 37 to 42. deg. F.
Mid Slope Winds: Light winds. Light winds. Light winds.
Expected snowfall: No accumulation. | SWE = trace amounts. No accumulation. | SWE = none. No accumulation. | SWE = trace amounts.
For 8000 ft. to 9000 ft.
Friday Friday Night Saturday
Weather: Sunny then becoming partly cloudy. Isolated snow showers in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 20%. Clear. Snow levels below 7000 feet. Chance of precipitation is 0%. Sunny then becoming partly cloudy. Slight chance of snow showers in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 25%.
Temperatures: 27 to 33. deg. F. 14 to 20. deg. F. 31 to 37. deg. F.
Ridge Top Winds: Light winds. Light winds. East around 15 mph in the morning becoming light.
Expected snowfall: No accumulation. | SWE = trace amounts. No accumulation. | SWE = none. No accumulation. | SWE = less than 0.10 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