THIS AVALANCHE FORECAST EXPIRED ON April 10, 2018 @ 6:52 am
Avalanche Forecast published on April 9, 2018 @ 6:52 am
Issued by Brandon Schwartz - Tahoe National Forest

Areas of MODERATE avalanche danger will exist today at all elevations. As last night's snow surface refreeze melts away, loose wet avalanches will become possible. When snow surface conditions become marginally unsupportable to unsupportable, avoid travel in or below avalanche terrain.

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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Air temperature inversion conditions had air temperatures above 7,000' at or above freezing last night for most locations. Despite the above freezing air temperatures, a decent snow surface refreeze is expected to have occurred last night from radiational cooling under clear skies.  Expect a better snow surface refreeze to have occurred on open slopes and a comparatively weaker refreeze to have occurred under forest canopy. The supportable snow surface could melt away quickly today with warmer air at the mid and upper elevations this morning and maximum daytime air temperatures forecast in the 50s and 60s. Once the supportable surface has melted away, feet of residual wet snow deeper in the snowpack that did not refreeze last night will become exposed. Once last night's snow surface refreeze has melted away, loose wet avalanches are possible.

Areas of loose wet avalanche problems will form first on E-SE-S-SW-W aspects at all elevations. Wet snow instability will eventually spread to NW-N-NE aspects as the day progresses and to a lesser extent on the highest elevation N aspects. Avalanche size up to D2 is possible (large enough to bury or injure a person). Monitor snow surface supportability. When last night's snow surface refreeze melts away and conditions become marginally unsupportable to unsupportable, avoid travel in or below avalanche terrain.

recent observations
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* Observations made and received yesterday from Rubicon Peak (West Shore Tahoe area), Pyramid Peak (Desolation Wilderness area), and Carpenter Ridge (Independence Lake area) reported firm rain crust on the snow surface during the early to mid morning hours on all aspects. Snow surface melt lead to softening on all but upper elevation N aspects. Conditions on E-SE-S-SW-W-aspects remained supportable through the mid day hours with some areas becoming unsupportable by early afternoon.

* Numerous recently opened glide cracks were observed in areas where the snowpack overlies granite slabs in the Desolation Wilderness.

Weather and CURRENT CONDITIONS
weather summary

Sunny skies and a continued warming trend is forecast for today. Moderate speed ridgetop winds shifted from SW to E yesterday evening. Winds are forecast to become light to moderate in speed today. Cloud cover and winds increase tonight as the next weather disturbance approaches the region. Increasing cloud cover and increasing S winds are forecast for Tuesday with a slight chance of light precipitation during the afternoon hours. The next storm system with a good chance for measurable snowfall is expected Wednesday night into Thursday.

CONDITIONS ALONG THE SIERRA CREST BETWEEN 8200 FT. AND 9200 FT. IN THE LAST 24 HOURS
Weather Station Map
Weather Station Table
6am temperature: 31 to 38 deg. F.
Max. temperature: 43 to 48 deg. F.
Average ridgetop wind direction: SW shifting to E
Average ridgetop wind speed: 24 mph
Maximum ridgetop wind gust: 37 mph
New snowfall: 0 inches
Total snow depth: 53 to 91 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Monday Monday Night Tuesday
Weather: Sunny skies. Partly cloudy skies. Mostly cloudy skies. A slight chance of rain showers in the afternoon. Snow level 8,500'.
Temperatures: 57 to 63 deg. F. 37 to 42 deg. F. 50 to 56 deg. F.
Mid Slope Winds: E S S
Wind Speed: Generally light winds. Gusts up to 20 mph in the morning. Light winds increasing to 10 to 15 mph with gusts to 35 mph after midnight. 15 to 20 mph with gusts to 55 mph, increasing to 25 to 35 mph with gusts to 65 mph in the afternoon.
Expected snowfall: 0 0 0
For 8000 ft. to 9000 ft.
Monday Monday Night Tuesday
Weather: Sunny skies. Partly cloudy skies. Mostly cloudy skies. A slight chance of rain and snow showers in the afternoon. Snow level 8,500'.
Temperatures: 51 to 59 deg. F. 37 to 42 deg. F. 45 to 51 deg. F.
Ridge Top Winds: E S S to SW
Wind Speed: 10 to 15 mph. Gusts up to 30 mph in the morning. 10 to 15 mph with gusts to 35 mph, increasing to 20 to 30 mph with gusts to 60 mph after midnight. 30 to 45 mph with gusts to 80 mph, increasing to 45 to 60 mph with gusts to 95 mph in the afternoon.
Expected snowfall: 0 0 0 to 1
Disclaimer

This avalanche advisory is provided through a partnership between the Tahoe National Forest and the Sierra Avalanche Center. This advisory 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 advisory applies only to backcountry areas outside established ski area boundaries. This advisory describes general avalanche conditions and local variations always occur. This advisory expires 24 hours after the posted time unless otherwise noted. The information in this advisory is provided by the USDA Forest Service who is solely responsible for its content.

For a recorded version of the Avalanche Advisory call (530) 587-3558 x258