THIS AVALANCHE FORECAST EXPIRED ON April 11, 2020 @ 7:00 am
Avalanche Forecast published on April 10, 2020 @ 7:00 am
Issued by Steve Reynaud - Tahoe National Forest

Sunny skies and warmer temperatures are expected for today.  Human triggered avalanches are possible due to wind slab, persistent slab, and loose wet avalanche problems.  MODERATE avalanche danger continues 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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Strong NE/E winds have continued overnight and are forecasted to remain strong through today.  Wind slab avalanches will remain possible in near and above treeline areas.  Areas that received the most snow yesterday could have larger and more problematic wind slabs today. 

Look for blowing snow, cornice formation, and wind pillows.  Avoid steep wind loaded terrain.  Rapid warming could further decrease the strength of these wind slabs today.

Avalanche Problem 2: Persistent Slab
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Persistent slab avalanches remain a concern throughout the forecast region.  Some snowpack tests continue to show weakness on the old snow crust layer buried 1 to 3’ deep.  While this problem is isolated, there may still be some areas that remain unstable enough for human triggered avalanches today.  The last known avalanche on this weak layer was 2 days ago on Wednesday.  This problem seems to be lingering in higher elevation terrain like the Mt. Rose area, although it has been previously found in other areas.  Avalanches associated with this weak layer could be large ( 1 to 3' deep), propagate wide, and be remotely triggered.    

Avalanche Problem 3: Loose Wet
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Intense April sunshine and warming temperatures will make loose wet avalanches likely on all aspects and elevations.  New snow from yesterday will warm and become wet quickly this morning.  Widespread loose wet activity will begin with this new snow this morning and then could involve the older snow as crusts soften and weaken with daytime warming.  Rapid warming today could also cause large cornices to become weaker and break off. 

Roller balls and pinwheels will be indicators that the snow surface is rapidly warming and losing strength.  Once the snow becomes wet and sticky, it’s time to change aspects or call it a day.  Avoid terrain below large cornices and avalanche paths as daytime warming occurs.  Loose wet avalanches could be large enough to injure or bury a backcountry user.

recent observations
Submit Observations

Observations were done on Relay Peak yesterday to gather more details about the skier-triggered avalanche that occurred there Wednesday, April 8.  They found that the deepest spot of the avalanche had failed on a thin layer of weak snow below the new snow.  The crust at the base of the recent snow was barely discernable.  Several snowpit tests at the crown all yielded unstable results on that weak layer.

Homewood Ski Patrol reported an avalanche from uncontrolled terrain on Qual Face.  A loose wet avalanche from a ski cut stepped down to a deeper weak layer causing a large D2 avalanche.

Weather and CURRENT CONDITIONS
weather summary

We received up to 3 to 8'' of snow over the last 24 hours, mostly focused on the southern portion of the forecast region.  Snow levels fluctuated in the 7500-8500' range before lowering overnight with .10 to .40'' of rain recorded at some stations.  High pressure will begin to build into our area with sunny skies, warming temperatures, and slightly decreasing winds.  High temperatures today should be in the low 40's to 50's above 7000'.    Winds and clouds will increase for Sunday as a cold front moves through our area.

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
Weather Station Map
Weather Station Table
6am temperature: 23 to 25 deg. F.
Max. temperature: 29 to 41 deg. F.
Average ridgetop wind direction: NE/E
Average ridgetop wind speed: 15 to 30 mph
Maximum ridgetop wind gust: 66 mph
New snowfall: 3 to 5 inches
Total snow depth: 68 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. Snow levels below 7000 feet increasing to 7500 feet in the afternoon. Chance of precipitation is 0%. Clear. Snow levels 8000 feet. Chance of precipitation is 0%. Sunny. Snow levels 8500 feet. Chance of precipitation is 5%.
Temperatures: 45 to 51. deg. F. 28 to 33. deg. F. 51 to 57. deg. F.
Mid Slope Winds: Northeast 10-15 mph. Light winds. Northwest around 15 mph. Gusts up to 25 mph in the afternoon.
Expected snowfall: No accumulation. | SWE = none. No accumulation. | SWE = none. No accumulation. | SWE = none.
For 8000 ft. to 9000 ft.
Friday Friday Night Saturday
Weather: Sunny. Snow levels below 7000 feet increasing to 7500 feet in the afternoon. Chance of precipitation is 0%. Clear. Snow levels 8000 feet. Chance of precipitation is 0%. Sunny. Snow levels 8500 feet. Chance of precipitation is 5%.
Temperatures: 39 to 45. deg. F. 25 to 30. deg. F. 45 to 51. deg. F.
Ridge Top Winds: Northeast 15 to 25 mph. Gusts up to 40 mph decreasing to 30 mph in the afternoon. Northwest around 15 mph with gusts to 25 mph. West around 15 mph with gusts to 30 mph.
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