THIS AVALANCHE ADVISORY EXPIRED ON April 9, 2014 @ 6:47 am
Avalanche Advisory published on April 8, 2014 @ 6:47 am
Issued by Brandon Schwartz - Tahoe National Forest

Early this morning, avalanche danger is LOW for all elevations and aspects. Avalanche danger will quickly increase to MODERATE danger by the late morning hours for all elevations and aspects in response to daytime warming. Small human triggered loose wet avalanches are expected today. Small naturally occurring loose wet avalanches are possible in isolated areas.

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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    Certain
    Very Likely
    Likely
    Possible
    Unlikely
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    Historic
    Very Large
    Large
    Small

Last night, overnight minimum air temperatures were well above freezing and skies were clear. Snow surface refreeze is expected to be fairly superficial again this morning, having been dependent entirely on radiational cooling. A few hours of supportable snow surface conditions are expected early this morning. By late morning, daytime warming is expected to have caused sufficient snow surface melting to allow for loose wet snow avalanches to occur. Small human triggered loose wet avalanches are expected today with small natural loose wet avalanche activity becoming possible by the afternoon hours.

recent observations

Observations made yesterday on Becker Ridge (Echo Summit area) revealed that the previous night's snow surface refreeze during above freezing air temperatures had been very superficial and dependent entirely on radiational cooling under clear skies. Southerly aspects held 4 inches of melt-freeze crust on top of 10 inches of residual wet snow from previous days melting. On N aspects steeper than about 38 degrees at 8,000', a half inch thick breakable melt-freeze crust remained on the snow surface at mid day. On most sun exposed N aspects, 4 inches of wet surface snow sat on top of stable recent storm snow, unaffected by melt-freeze. Small loose wet avalanches, roller balls, and pinwheels failing at the interface between wet and dry snow were very easily human triggered in most areas. Several small natural loose wet avalanches were observed from Hwy 89 on NE-E aspects between 7,000' and 9,000' on Flagpole Peak (Echo Summit area) and Mt. Tallac (Desolation Wilderness area).

Weather and CURRENT CONDITIONS
weather summary

High pressure currently over the forecast will peak today before shifting to the east tomorrow. Another day of clear skies and well above freezing air temperatures is expected at all elevations. Very little cooling occurred last night with remote sensors between 8,200' and 9,600' reporting overnight minimum air temperatures in the low to mid 40s. Below freezing air temperatures are limited to the mountain valley floors below about 6,500' due to air temperature inversion. Maximum daytime air temperatures are forecast to reach well into the 50s today for areas between 7,000' and 9,000'. Ridgetop winds will increase today out of the southwest, becoming moderate in speed and continuing through tomorrow in response to shifting and flattening of the high pressure ridge.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 40 to 46 deg. F.
Max. temperature in the last 24 hours: 50 to 58 deg. F.
Average wind direction during the last 24 hours: Southwest
Average wind speed during the last 24 hours: 19 mph
Maximum wind gust in the last 24 hours: 29 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 41 to 66 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Tuesday Tuesday Night Wednesday
Weather: Sunny skies. Clear skies, becoming partly cloudy. Partly cloudy skies.
Temperatures: 51 to 59 deg. F. 30 to 37 deg. F. 50 to 57 deg. F.
Wind Direction: Southwest Southwest Southwest
Wind Speed: 10 to 15 mph with gusts up to 25 mph in the afternoon. 10 to 15 mph with gusts to 25 mph. 15 to 20 mph with gusts to 30 mph.
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Tuesday Tuesday Night Wednesday
Weather: Sunny skies. Clear skies, becoming partly cloudy. Partly cloudy skies.
Temperatures: 51 to 57 deg. F. 29 to 36 deg. F. 49 to 55 deg. F.
Wind Direction: Southwest Southwest Southwest
Wind Speed: 15 to 25 mph with gusts to 35 mph. 15 to 25 mph with gusts to 35 mph. 15 to 25 mph with gusts to 40 mph.
Expected snowfall: 0 in. 0 in. 0 in.
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.