THIS AVALANCHE FORECAST EXPIRED ON April 14, 2020 @ 6:58 am
Avalanche Forecast published on April 13, 2020 @ 6:58 am
Issued by Andy Anderson - Tahoe National Forest - Sierra Avalanche Center

Firm snow surfaces this morning should melt to soft wet snow in response to strong April sun despite today's cooler temperatures. Sluffs of wet snow could become possible on steep sunny slopes. In addition to these loose wet avalanches, wet slab avalanches also warrant consideration. The avalanche danger is LOW this morning and will increase to MODERATE this afternoon.

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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Clear weather and below-freezing temperatures during the night should have allowed for a better refreeze. The strong April sun should provide enough warming for the firm refrozen conditions to become wet and unsupportable by this afternoon even though the forecast calls for cooler temperatures today. Loose wet avalanches could become possible on steep sunny slopes. Some of these loose wet avalanches could involve enough wet snow to bury a person especially on larger slopes or in areas where the loose wet avalanche flows into a terrain trap like a gully. 

Safety margins based on timing and terrain can help manage potential wet snow instabilities. Recreating while the snowpack remains supportable and returning before the refreeze melts into deep wet snow or avoiding steep slopes and using lower angle terrain both represent strategies to avoid wet snow instabilities.

Avalanche Problem 2: Wet Slab
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Forecasting wet slab avalanches is notoriously difficult and too much uncertainty exists to put a likelihood on this problem. The current snowpack structure may allow for the possibility of wet slab avalanches when water percolates down to the surface hoar layer buried on March 24. If a wet slab avalanche does occur it could involve enough snow to bury or injure a person.

Using timing and terrain to avoid wet snow and/or steep terrain can help avoid wet slabs. 

recent observations
Submit Observations

Observations indicated little to no refreeze occurred on Yuba Pass yesterday and wet snow existed on all aspects before 10 am. Ski kicks and cuts triggered roller balls and pinwheels on steep sunny slopes.

Snowpit data on Yuba Pass yesterday indicated that fractures may still be able to travel along the surface hoar layer buried on March 24 especially if water collects near that layer. 

Weather and CURRENT CONDITIONS
weather summary

Yesterday's afternoon cloud cover and thunderstorms dissipated in the evening leaving clear skies and light winds during the night. Overnight lows dropped below freezing in most places. Expect clear sunny weather today with slightly cooler temperatures. A warming trend should start again tomorrow.

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
Weather Station Map
Weather Station Table
6am temperature: 27 to 31 deg. F.
Max. temperature: 42 to 49 deg. F.
Average ridgetop wind direction: NE
Average ridgetop wind speed: 5 to 15 mph
Maximum ridgetop wind gust: 23 mph with one sensor showing 44 mph
New snowfall: 0 inches
Total snow depth: 62 to 81 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 sunny. Slight chance of snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 5%. Clear. Snow levels below 7000 feet. Chance of precipitation is 0%. Sunny. Snow levels below 7000 feet. Chance of precipitation is 0%.
Temperatures: 40 to 46 deg. F. 19 to 25 deg. F. 45 to 51 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.
Monday Monday Night Tuesday
Weather: Mostly sunny. Slight chance of snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 10%. Clear. Snow levels below 7000 feet. Chance of precipitation is 0%. Sunny. Snow levels below 7000 feet. Chance of precipitation is 0%.
Temperatures: 34 to 40 deg. F. 16 to 22 deg. F. 39 to 45 deg. F.
Ridge Top Winds: Light winds. Northeast 15 to 20 mph with gusts to 30 mph. East around 15 mph with gusts to 25 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