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 February 16, 2007:


February 16, 2007 at 1:00 am

Forecast Discussion:


The bottom line: Near and above treeline, the avalanche danger is LOW. Below treeline, avalanche danger is LOW. Low danger does not mean no danger. Normal safe travel techniques are advised for traveling in the backcountry.

A high pressure ridge building off the west coast of California will continues to keep temperatures above normal. Yesterday temperatures along the crest rose into the mid 30's and today they should reach into the low 40's. This warming trend should continue through Saturday before a cold front reaches the forecast area on Sunday. The northwest flow accompanying this ridge will continue to promote gusty northeast winds along the Sierra crest through Saturday.

The strengthening trend that has been observed in the snowpack over the last few days is continuing across the forecast area. Layer bonding tests from the last several days show that the weaknesses created in the most recent snow during the storm are rapidly consolidating. These tests and other observations also indicate that the bond between the old snow surfaces and the storm snow is gaining strength as are the layer interfaces deeper in the snowpack. Warm air temperatures throughout the forecast area will help this trend to continue over the next few days. As these conditions continue we should start to see some of the more persistent weak layers slowly begin to gain strength. Moderate northeast winds should result in some more minor snow transport to the W-SW-S aspects today. It is unlikely that this will add enough additional load to cause avalanche activity on these slopes.

Yesterday most of the aspects below 9000 feet exhibited some softening as the temperatures climbed above freezing. Some "roller balls" and "pin wheels" were observed as the snow surface warmed up. Expect to see more of those small surface instabilities on all aspects today as temperatures are forecasted to climb even higher. Remember that even though the avalanche danger has decreased it is always a good idea to use safe travel techniques when traveling in the backcountry.

No avalanches were reported yesterday.

The bottom line: Near and above treeline, the avalanche danger is LOW. Below treeline, avalanche danger is LOW. Low danger does not mean no danger. Normal safe travel techniques are advised for traveling in the backcountry.

At this time, we have not raised enough money to meet our operating budget for this year. If you use this service with any regularity and would like to continue to do so, please show your support for the Sierra Avalanche Center. You may make a tax deductible donation directly to us via Paypal or by sending a check to our address listed above, c/o the Truckee Ranger Station. A financial graph showing the current fundraising and budget numbers is available by clicking here. The financial support already received this winter from a variety of users is greatly appreciated.

Andy Anderson , Avalanche Forecaster
Today's Central Sierra Weather Observations:
0600 temperature at Sierra Crest (8,700 feet):
29 deg. F
Max. temperature at Sierra Crest past 24 hours:
33-38 deg. F
Average wind direction at Sierra Crest past 24 hours:
northeast
Average wind speed at Sierra Crest past 24 hours:
20 mph
Maximum wind gust at Sierra Crest past 24 hours:
57 mph
New snow fall at 8,200 feet past 24 hours:
0 inches
Total snow depth at 8,200 feet:
55 inches
Mountain Weather Forecast For Today:
Sunny and warm.
Temperature forecast for 8,000 to 9,000 feet:
40 - 45 deg. F
Ridgetop winds forecast for the Sierra Crest:
Northeast 25 - 35 mph, gusting to 50 mph
Snowfall expected in the next 24 hours:
0 inches
2 Day Mountain Weather Forecast:

7000 to 8000 Feet
Today, sunny skies with daytime highs 46 to 51 degrees F. North winds at 20 to 30 mph in the morning and decreasing to 10 to 15 mph in the afternoon. Tonight, clear with lows 27 to 32 degrees F. Northeast winds at 15 to 20 mph. Saturday, sunny skies with daytime highs 48 to 53 degrees F. East winds at 10 to 20 mph are expected.

Above 8000 Feet
Today, sunny skies with daytime highs 40 to 45 degrees F. Northeast winds at 25 to 35 mph in the morning and decreasing to 15 to 25 mph in the afternoon with gusts reaching 50 mph. Tonight, clear with lows 32 to 37 degrees F. Northeast winds at 25 to 35 mph with gusts to 50 mph. Saturday, sunny skies with daytime highs 43 to 48 degrees F. Northeast winds at 20 to 30 mph with gusts to 50 mph are expected in the morning. By the afternoon they are forecasted to shift more to the east and decrease to 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:

  Friday: Friday Night: Saturday:
Weather:
Temperatures: deg. F. deg. F. deg. F.
Wind direction:
Wind speed:
Expected snowfall: O in. O in. O in.

For 8000-9000 ft:

  Friday: Friday Night: Saturday:
Weather:
Temperatures: deg. F. deg. F. deg. F.
Wind direction:
Wind speed:
Expected snowfall: O in. O in. O in.