THIS AVALANCHE FORECAST EXPIRED ON March 11, 2019 @ 6:56 am
Avalanche Forecast published on March 10, 2019 @ 6:56 am
Issued by Brandon Schwartz - Tahoe National Forest

A wind slab avalanche problem is expected to continue today in near treeline and above treeline areas. MODERATE avalanche danger exists near and above treeline. LOW avalanche danger exists below treeline.

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.

1. Low

?

Below Treeline
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
    Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
Avalanche Problem 1: Wind Slab
  • Type ?
  • Aspect/Elevation ?
  • Likelihood ?
    Certain
    Very Likely
    Likely
    Possible
    Unlikely
  • Size ?
    Historic
    Very Large
    Large
    Small

Yesterday's strong SW winds created blowing and drifting snow near and above treeline. Unstable wind slabs existed yesterday with avalanche activity reported in lee areas. A wind slab avalanche problem is expected to continue today with human triggered avalanches possible. The vast majority of wind slabs exist near treeline and above treeline on NW-N-NE-E-SE aspects. Expected avalanche size is up to D2. As winds shift to the NE tonight, new wind slabs may form on SE-S-SW-W-NW aspects.

Identify the specific features of concern where wind slabs exist and move conservatively around them. Read the terrain by identifying cornices, wind pillows, and the textured snow surfaces associated with recent wind drifted snow and wind slab formation. Softer snow and less avalanche hazard will be found in the wind protected areas below treeline, but maintain awareness of exposure to steeper slopes overhead that hold wind slabs.

recent observations

* SW ridgetop winds were much stronger than forecast yesterday, leading to more blowing snow and wind slab avalanche activity than expected.

* Natural and human triggered wind slab avalanches up to size D2 were reported yesterday from the Carson Pass, Echo Summit, and West Shore Tahoe areas. These avalanches occurred in near treeline to above treeline terrain mainly on N-NE-E aspects. Observations also indicated unstable wind slabs on Silver Peak (Pole Creek area). In the Carson Pass and Pole Creek areas, observers noted that the weak layer was lower density snow below the wind slab. 5 people were reported caught in avalanches yesterday (4 in an avalanche on Echo Peak and 1 in an avalanche on Melissa Coray Peak).

* No signs of instability were reported from wind protected areas below treeline.

 

Weather and CURRENT CONDITIONS
weather summary

Ridgetop winds out of the SW are decreasing in speed this morning and are forecast to become light today. Snow showers are expected today, becoming more widespread this afternoon and tonight. Ridgetop winds are forecast to shift to the NE tonight and become moderate in speed, possibly creating areas of blowing snow. Decreasing cloud cover and warming air temperatures are expected for tomorrow. Another weather disturbance is expected on Tuesday for more snow showers. High pressure is forecast to build over the region later this week.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 14 to 20 deg. F.
Max. temperature in the last 24 hours: 18 to 25 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 40 mph
Maximum wind gust in the last 24 hours: 73 mph
New snowfall in the last 24 hours: Trace to 2 inches
Total snow depth: 125 to 169 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Sunday Sunday Night Monday
Weather: Mostly cloudy. Slight chance of snow showers in the morning, then snow showers likely in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 60%. Mostly cloudy. Chance of snow showers through the night. Snow levels below 7000 feet. Chance of precipitation is 55%. Mostly cloudy then becoming partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 10%.
Temperatures: 27 to 32 deg. F. 16 to 21 deg. F. 31 to 36 deg. F.
Mid Slope Winds: Light winds. Northeast around 15 mph with gusts to 35 mph. Northeast around 15 mph with gusts to 30 mph.
Expected snowfall: 80% probability of 1 to 2 inches. 20% probability of 2 to 4 inches. | SWE = up to 0.15 inch. 80% probability of 1 to 2 inches. 20% probability of 2 to 3 inches. | SWE = up to 0.15 inch. No accumulation. | SWE = none.
For 8000 ft. to 9000 ft.
Sunday Sunday Night Monday
Weather: Mostly cloudy. Slight chance of snow showers in the morning, then snow showers likely in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 60%. Mostly cloudy. Chance of snow showers through the night. Snow levels below 7000 feet. Chance of precipitation is 60%. Mostly cloudy then becoming partly cloudy. Snow levels below 7000 feet. Chance of precipitation is 10%.
Temperatures: 22 to 28 deg. F. 12 to 17 deg. F. 27 to 33 deg. F.
Ridge Top Winds: Light winds. Northeast 15 to 25 mph with gusts to 35 mph. Northeast around 15 mph with gusts to 30 mph.
Expected snowfall: 80% probability of 1 to 2 inches. 20% probability of 2 to 4 inches. | SWE = less than 0.10 inch. 80% probability of 1 to 2 inches. 20% probability of 2 to 3 inches. | SWE = up to 0.25 inch. 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