THIS AVALANCHE ADVISORY EXPIRED ON April 16, 2014 @ 6:33 am
Avalanche Advisory published on April 15, 2014 @ 6:33 am
Issued by Brandon Schwartz - Tahoe National Forest

Early this morning, avalanche danger is LOW for all elevations and aspects. Areas of MODERATE danger will form quickly today on all aspects at all elevations on slopes 37 degrees and steeper. Human triggered loose wet avalanches are possible. Natural avalanches are unlikely.

2. Moderate

?

Above Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

?

Near Treeline
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

2. Moderate

?

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
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

A weak to fairly poor snow surface refreeze is expected to have occurred last night with above freezing air temperatures and partly to mostly cloudy skies. As daytime warming progresses, snow surface melt will allow for human triggered loose wet avalanches to become possible on all aspects at all elevations. Any avalanches that occur today are expected to be small. Once last night's snow surface refreeze is fully melted and the snowpack becomes unsupportable, move to more northerly aspects or exit from in or below avalanche terrain for the remainder of the day.

recent observations

Observations made yesterday on Andesite Peak (Donner Summit area) revealed that clear skies the night before had allowed for enough radiational clooling to create a fairly strong snow surface refreeze on open slopes. Treed areas with a reduced view of the sky held a significantly weaker snow surface refreeze ranging from half of that on open slopes to areas of little to no snow surface refreeze. By 10:30 am, 1 to 2 inches of wet snow in melt phase existed on the snow surface on the NE-E-SE aspects traveled.

Weather and CURRENT CONDITIONS
weather summary

A cold front will pass to the northeast of the forecast area today. Mid to high level cloud cover increased for several hours last night along with southwest winds. Cloud cover has decreased a bit at sunrise this morning. Remote sensors between 8,000' and 8,800' are reporting overnight low air temperatures in the upper 30s. Maximum daytime air temperatures are forecast to reach the mid 40s to upper 50s today for areas above 7,000'. Moderate speed westerly ridgetop winds will increase a little more today with ridgetop gusts to 40 mph expected. A series of weather systems passing to the north of the forecast area will keep periods of mid to high level cloud cover and moderate speed winds in the forecast for the next few days. Air temperatures are expected to remain above average.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 37 to 39 deg. F.
Max. temperature in the last 24 hours: 53 to 56 deg. F.
Average wind direction during the last 24 hours: Southwest
Average wind speed during the last 24 hours: 21 mph
Maximum wind gust in the last 24 hours: 33 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 23 to 55 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Tuesday Tuesday Night Wednesday
Weather: Partly cloudy skies. Partly cloudy skies. Partly cloudy skies.
Temperatures: 54 to 60 deg. F. 32 to 37 deg. F. 54 to 60 deg. F.
Wind Direction: Southwest West Northwest
Wind Speed: 10 to 20 mph with gusts to 30 mph. 15 to 20 mph with gusts to 30 mph in the evening, decreasing to around 10 mph. 10 to 15 mph. Gusts up to 25 mph in the morning.
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Tuesday Tuesday Night Wednesday
Weather: Partly cloudy skies. Partly cloudy skies. Partly cloudy skies.
Temperatures: 45 to 53 deg. F. 29 to 34 deg. F. 48 to 54 deg. F.
Wind Direction: West West West shifting to north.
Wind Speed: 20 to 30 mph with gusts to 40 mph. 15 to 25 mph. Gusts to 40 mph decreasing to 30 mph after midnight. 20 to 25 mph with gusts to 35 mph, shifting and decreasing to 10 to 15 mph with gusts to 25 mph in the afternoon.
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.