THIS AVALANCHE ADVISORY EXPIRED ON February 24, 2016 @ 6:52 am
Avalanche Advisory published on February 23, 2016 @ 6:52 am
Issued by Steve Reynaud - Tahoe National Forest

Avalanche danger will be Low during the early morning hours.  As daytime warming occurs, Moderate avalanche danger could become possible on E-SE-S-SW-W aspects on slopes steeper than 35 degrees due to loose wet avalanches.  Small wind slabs may form on SE-S-SW-W-NW aspects near and above treeline due to recent N-NE winds.

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

E-SE-S-SW-W aspects are slowly transitioning from recent storm snow towards future melt freeze conditions.  On most solar aspects by midday, there are 3-4'' of wet surface snow on top of colder more winter like snow below.  Until an established melt freeze crust is formed, loose wet avalanches will be possible.  Most of these loose wet avalanches will be in the form of human triggered roller balls or pinwheels.  Although as temperatures continue to warm throughout the week and winds decrease, larger loose wet avalanches could become possible.

Use quick hand pits to identify surface wet snow on top of colder recent storm snow that has yet to undergo melt freeze.  Avoid solar aspects steeper than 35 degrees once the snow surface has more than a few inches of wet snow on top of the transitional recent storm snow.  Current roller balls and pinwheels indicate that the snow surface is loosing strength and that loose wet avalanches are possible.

Avalanche Problem 2: Wind Slab
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Moderate N-NE winds overnight with continuing winds throughout today could create small wind slabs on SE-S-SW-W-NW aspects near and above treeline.  These wind slabs are expected to be small in size and limited to the most efficient wind loading locations near peaks and ridges above 8000'.  Look for areas of active wind loading and signs of previous wind loading.  These small wind slabs could be most problematic in steep, complex terrain.

 

recent observations

Observations from Armstrong Pass (Luther Pass area) and Meiss Meadow (Carson Pass area) showed similar snowpack conditions.  Unconsolidated soft snow exists on shaded north aspects in wind protected areas.  In wind exposed areas a mix of wind scoured crusts, supportable wind board and breakable crusts existed.  Solar aspects by mid day are transitioning with 3-4'' of wet snow on top of colder recent storm snow.  Small roller balls could be skier triggered on South aspects below 8800' by mid day at Meiss Meadow.  The N-NE winds were keeping both locations cool at the higher elevations with minimal loose wet activity observed.

 

Weather and CURRENT CONDITIONS
weather summary

High pressure will continue through the forecast area this week with mostly sunny skies.  Warming at the upper elevations with temperatures at 6am in the 30's to low 40's above 8000'.  NE winds are forecasted to be 15 to 30mph with gusts to 40mph before switching to the west later in the day.  Forecasted high temperatures jump considerably for Wednesday and Thursday with light winds. 

 

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 37 to 43 deg. F.
Max. temperature in the last 24 hours: 46 deg. F.
Average wind direction during the last 24 hours: NE
Average wind speed during the last 24 hours: 15 to 25 mph
Maximum wind gust in the last 24 hours: 34 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 60 to 90 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 Clear, then becoming partly cloudy. Sunny
Temperatures: 45 to 51 deg. F. 26 to 31 deg. F. 50 to 58 deg. F.
Wind Direction:
Wind Speed: Light winds. Light winds. Light winds.
Expected snowfall: 0 in. 0 in. 0 in.
For 8000 ft. to 9000 ft.
Tuesday Tuesday Night Wednesday
Weather: Sunny. Clear then becoming partly cloudy. Sunny.
Temperatures: 38 to 45 deg. F. 31 to 35 deg. F. 43 to 50 deg. F.
Wind Direction: NE switching to W in the afternoon. W SW
Wind Speed: 15 to 30mph with gusts to 40mph becoming West 10 to 20mph in the afternoon. 10 to 15mph. 10 to 15mph.
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.