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 April 15, 2008:


April 15, 2008 at 0:00 am

Forecast Discussion:


This advisory was posted on April 15, 2008 6:15 AM

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

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Today's Advisory:

Avalanche danger is LOW for all elevations and aspects. Normal caution is advised.

The cold front that passed through the forecast area yesterday afternoon and overnight has decreased air temperatures significantly across the forecast area this morning. Remote sensors are reporting air temperatures below freezing at all locations within the forecast area. Air temperatures above 8,000' are in the teens and single digits. Strong southwest ridgetop winds that occurred yesterday are decreasing this morning, but are expected to remain moderate in speed through today.

Yesterday, the very weak surface refreeze that was created by radiational cooling melted very quickly. Observations made on Mt. Tallac (Desolation Wilderness area) revealed that once the thin surface crust had melted on E-SE-S aspects, 1 to 2 feet of wet snow that had formed over the past two days was exposed at the surface at all elevations. Despite significant wet snow forming each of the past three days, no significant avalanches beyond small human triggered surface sluffs were observed or reported during the recent warm spell. A solid refreeze of wet surface snow is expected to have occurred overnight.

Today, cold air temperatures will continue the process of wet snow refreeze in many areas. Some minor melting of surface snow will occur on SE-S-SW aspects, mainly below 8,000'. The snow surface in most other areas is expected to remain frozen today. Natural and human triggered avalanches are unlikely at this time.

The bottom line: Avalanche danger is LOW for all elevations and aspects. Normal caution is advised.

Brandon Schwartz, Avalanche Forecaster

Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet): 13 deg. F
Max. temperature at Sierra Crest past 24 hours: 36 to 43 deg. F.
Average wind direction at Sierra Crest past 24 hours: Southwest
Average wind speed at Sierra Crest past 24 hours: 45 mph
Maximum wind gust at Sierra Crest past 24 hours: 84 mph
New snowfall at 8,200 feet past 24 hours: 0 to trace inches
Total snow depth at 8,200 feet: 68 inches

Mountain Weather Forecast For Today:
Sunny and cool.
Temperature forecast for 8,000 to 9,000 feet: 22 to 27 deg. F
Ridgetop winds forecast for the Sierra Crest: Southwest at 20 to 25 mph with gusts to 50 mph. Winds decreasing to 15 to 20 mph with gusts to 40 mph in the afternoon.
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 28 to 36 deg. F. West winds at 10 to 20 mph with gusts to 35 mph. Winds shifting to northwest by late morning.

Tonight, partly cloudy skies in the evening, then clearing. Overnight lows 18 to 24 deg. F. North winds at 10 to 15 mph with gusts to 25 mph in the evening.

For Wednesday, sunny skies with daytime highs 41 to 48 deg. F. Northeast winds at 10 to 15 mph.

Above 8000 Feet:

Today, partly cloudy skies with daytime highs 22 to 27 deg. F. Southwest winds at 20 to 25 mph with gusts to 50 mph. Winds decreasing to 15 to 20 mph with gusts to 40 mph in the afternoon.

Tonight, partly cloudy skies in the evening, then clearing. Overnight lows 20 to 25 deg. F. North winds at 15 to 20 mph with gusts to 40 mph. Winds shifting to northeast at 10 to 20 mph with gusts to 35 mph after midnight.

For Wednesday, sunny skies with daytime highs 35 to 41 deg. F. Northeast winds at 15 to 25 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:

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

For 8000-9000 ft:

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