THIS AVALANCHE FORECAST EXPIRED ON March 5, 2019 @ 6:46 am
Avalanche Forecast published on March 4, 2019 @ 6:46 am
Issued by Brandon Schwartz - Tahoe National Forest

MODERATE avalanche danger continues at all elevations due to lingering wind slab and expected loose wet avalanche problems today.

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: Wind Slab
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A wind slab avalanche problem lingers due to recent new snow and SW winds. The vast majority of wind slabs exist near treeline and above treeline on NW-N-NE-E-SE aspects. Avalanche size up to D2 is possible. Some of these wind slabs may take on some wet slab characteristics, especially on SE aspects.

Identify the specific terrain features where unstable wind slabs may exist. Ridgetop areas below cornice features and wind pillows are the most suspect. Approach travel near these features with caution, opting for more conservative terrain choices if signs of instability exist.

Avalanche Problem 2: Loose Wet
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Today is expected to be one of the first days when the higher sun angle and higher levels of incoming solar radiation associated with March affect stability. Natural roller balls are expected as snow falls off of rocks and trees in sun exposed areas. Some of these roller balls may trigger loose wet avalanches. Human triggered loose wet avalanches are likely today in steeper, sun exposed areas. The majority of loose wet instability is expected on E-SE-S-SW-W aspects at nearly all elevations. Loose wet avalanches are expected to a much lesser extent on NW-N-NE aspects but may also occur in areas of sun exposure. Avalanche size is expected at D1 with the isolated possibility to size D2.

If roller balls are present, this avalanche problem may soon follow. Avoid complex terrain and long steep pitches where this instability is present. Downslope hazards such as cliffs and terrain traps could greatly magnify the consequences of being pushed around by a small loose wet avalanche.

recent observations

* Small (size D1) wind slabs were reported yesterday from Incline Lake Peak (Mount Rose area) and from Elephant's Hump (Carson Pass area). Some larger avalanches in the size D2-D3 range were reported from near Blue Lakes (Carson Pass area) but details as to time/day of occurrence are unclear.

* Small (size D1) loose wet avalanches were intentionally skier triggered yesterday on a N aspect at ~9,200' on Incline Lake Peak (Mount Rose area). These were on the drier end of the loose wet spectrum.

* Snow level was in the 6,800' to 7,100' elevation range for much of the day on Sunday.

Weather and CURRENT CONDITIONS
weather summary

A short lived break in the weather will occur today with weak high pressure over the region. Any lingering fog is expected to dissipate quickly for partly cloudy skies and light to moderate speed SW winds today. Maximum daytime air temperatures are forecast to climb above freeze today in most locations. The next in a series of storm systems will begin on Tuesday. Expect increasing cloud cover, increasing winds, and light precipitation tomorrow with the storm intensity increasing Tuesday night through Wednesday. For the latest info on this upcoming storm cycle, check with NWS Reno.

Weather observations from along the Sierra Crest between 8200 ft. and 8800 ft.
0600 temperature: 22 to 26 deg. F.
Max. temperature in the last 24 hours: 31 to 33 deg. F.
Average wind direction during the last 24 hours: SW
Average wind speed during the last 24 hours: 42 mph
Maximum wind gust in the last 24 hours: 76 mph
New snowfall in the last 24 hours: 3 to 8 inches
Total snow depth: 121 to 168 inches
Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 7000 ft. to 8000 ft.
Monday Monday Night Tuesday
Weather: Mostly cloudy then becoming partly cloudy. Patchy fog in the morning. Slight chance of snow showers in the morning. Snow levels below 7000 feet. Chance of precipitation is 15%. Mostly cloudy. Snow levels below 7000 feet. Chance of precipitation is 5%. Cloudy. Slight chance of snow in the morning, then snow likely in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 70%.
Temperatures: 35 to 40 deg. F. 22 to 27 deg. F. 35 to 40 deg. F.
Mid Slope Winds: Southwest around 15 mph with gusts to 25 mph in the morning becoming light. Light winds. Gusts up to 35 mph after midnight. Light winds becoming south around 15 mph with gusts to 50 mph in the afternoon.
Expected snowfall: No accumulation. | SWE = trace amounts. No accumulation. | SWE = none. 60% probability 1 to 2 inches. 40% probability no accumulation. | SWE = up to 0.20 inch.
For 8000 ft. to 9000 ft.
Monday Monday Night Tuesday
Weather: Partly cloudy. Patchy fog in the morning. Slight chance of snow showers in the morning. Snow levels below 7000 feet. Chance of precipitation is 15%. Mostly cloudy. Snow levels below 7000 feet. Chance of precipitation is 5%. Cloudy. Slight chance of snow in the morning, then snow in the afternoon. Snow levels below 7000 feet. Chance of precipitation is 75%.
Temperatures: 31 to 36 deg. F. 20 to 25 deg. F. 31 to 36 deg. F.
Ridge Top Winds: Southwest 15 to 25 mph with gusts to 40 mph. South 15 to 25 mph. Gusts up to 30 mph increasing to 50 mph after midnight. South 15 to 30 mph with gusts to 55 mph increasing to 30 to 45 mph with gusts to 75 mph in the afternoon.
Expected snowfall: No accumulation. | SWE = trace amounts. No accumulation. | SWE = none. 70% probability of 1 to 3 inches. 30% probability no accumulation. | SWE = up to 0.20 inch.
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