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.


This Avalanche Advisory was published on March 31, 2008:


March 31, 2008 at 0:00 am

Forecast Discussion:


This advisory was posted on March 31, 2008 7:00 AM

A map of the SAC forecast area is available on our home page.

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Today's Advisory:

Today, avalanche danger should remain LOW at all elevations and aspects. If slopes see significant sunshine or more than forecast warming occurs some very small and isolated areas of MODERATE danger could form on exposed slopes steeper than 40 degrees.

Skies should continue to clear today as a high pressure ridge builds over the forecast area. This high pressure should also cause the winds to decrease allowing the cold air mass to remain over the area. Tomorrow cloud cover and winds should start to increase again as another small low pressure system approaches the forecast area.

Snow surface conditions vary from hard melt/freeze crusts to 1 to 2 inches of snow sitting on top of these crusts across the forecast area. Yesterday observations from Jake's Peak (west shore of Lake Tahoe), Talking Mountain, and Huckleberry Canyon (both in the Echo Summit area) continued to show a strengthening trend in the bonds between the new snow and the old snow surfaces. They also showed that the snowpack below the old snow surfaces remains frozen, strong and well bonded on all aspects.

Today more sun and slightly warmer daytime temperatures could cause some instabilities to form due to daytime warming. The most likely places for these instabilities should be southerly aspects near and above treeline and lower elevation slopes that are exposed to the sun. There is very little new snow in either of these areas due to less snow accumulation at lower elevations and wind scouring of the southerly aspects during this storm. This lack of new snow and the strong, refrozen old snow below the new snow should keep any instabilities that do form today very small and very isolated in distribution. If these instabilities do form, they should be limited to point-release slides or other surface instabilities like pinwheels, and they should not pose much of a threat to backcountry travelers. Natural avalanche activity is unlikely again today.

The bottom line: Today, avalanche danger should remain LOW at all elevations and aspects. If slopes see significant sunshine or more than forecast warming occurs some very small and isolated areas of MODERATE danger could form on exposed slopes steeper than 40 degrees.

Andy Anderson, Avalanche Forecaster

Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 13-16 deg. F
Max. temperature at Sierra Crest past 24 hours: 22-26 deg. F.
Average wind direction at Sierra Crest past 24 hours: Southwest shifting to the southeast this morning
Average wind speed at Sierra Crest past 24 hours: 35 mph becoming light after 2am last night.
Maximum wind gust at Sierra Crest past 24 hours: 68 mph
New snowfall at 8,200 feet past 24 hours: 0 to 1 inch
Total snow depth at 8,200 feet: 80 inches
Mountain Weather Forecast For Today:
Partly cloudy.
Temperature forecast for 8,000 to 9,000 feet: 30 to 36 deg. F
Ridgetop winds forecast for the Sierra Crest: Southwest at 10 mph.
Snowfall expected in the next 24 hours: 0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet:
Today, partly cloudy skies with daytime highs 38 to 44 deg. F. Southeast winds at 10 mph.

Tonight, partly cloudy skies with overnight lows around 22 deg. F. Winds out of the east at 10 mph.

For Tuesday, mostly cloudy skies with daytime highs 43 to 49 deg. F. and light southwest winds at 10 to 15 mph.

Above 8000 Feet:
Today, partly cloudy skies with daytime highs 30 to 36 deg. F. Southwest winds at 10 mph.

Tonight, partly cloudy skies with overnight lows around 22 deg. F. Winds out of the southeast at 10 mph shifting to the south after midnight.

For Tuesday, mostly cloudy skies with daytime highs 33 to 41 deg. F. and southwest winds at 10 to 15 mph.


The bottom line:


Andy Anderson - Avalanche Forecaster, Tahoe National Forest


Weather Observations from along the Sierra Crest between 8200 ft and 8800 ft:

0600 temperature: deg. F.
Max. temperature in the last 24 hours: deg. F.
Average wind direction during the last 24 hours:
Average wind speed during the last 24 hours: mph
Maximum wind gust in the last 24 hours: mph
New snowfall in the last 24 hours: O inches
Total snow depth: inches

Two-Day Mountain Weather Forecast - Produced in partnership with the Reno NWS

For 7000-8000 ft:

  Monday: Monday Night: Tuesday:
Weather:
Temperatures: deg. F. deg. F. deg. F.
Wind direction:
Wind speed:
Expected snowfall: O in. O in. O in.

For 8000-9000 ft:

  Monday: Monday Night: Tuesday:
Weather:
Temperatures: deg. F. deg. F. deg. F.
Wind direction:
Wind speed:
Expected snowfall: O in. O in. O in.