The last avalanche forecast for the 2023-2024 season posted on April 21st. Thank you to all who contributed to the avalanche center this season through observations, volunteer time, and/or financial contributions.
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The last avalanche forecast for the 2023-2024 season posted on April 21st. Thank you to all who contributed to the avalanche center this season through observations, volunteer time, and/or financial contributions.
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December 21, 2008 at 7:54 am |
This morning, avalanche danger is LOW for all elevations and aspects. After the onset of snowfall, expect some pockets of MODERATE danger to develop late this afternoon near and above treeline on N-NE-E aspects that are 35 degrees and steeper. |
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The next storm system to affect the forecast area is expected to arrive this afternoon. Ridgetop winds are shifting from west to southwest ahead of the approaching storm. Air temperatures are on the rise this morning as warmer air is pushed through the forecast area prior to the expected cold front passage. Increasing ridgetop winds and increasing snowfall are expected late today through the overnight hours.
Yesterday, observations made on Relay Peak (Mount Rose area) and on Castle Peak (Donner Summit area) both indicated a mix of conditions in wind exposed and winds sheltered areas. Wind exposed areas were heavily scoured by the 12/19 storm event with conditions ranging from bare ground or ice to high density supportable wind slabs. In more wind protected areas, enjoyable unconsolidated snow surface conditions were found. Snowpits dug near treeline on a 32 degree east aspect at 9,600' on Relay and near treeline on an north aspect at 8,300' on Castle both gave indications of a stable snowpack.
Today, a stable snowpack exists in most areas. However, human triggered avalanches are unlikely but not impossible. The right combination of buried weak layer (surface hoar or faceted snow) combined with the right trigger point on the slope could cause an avalanche of significant size. This will be difficult but not impossible to accomplish today.
Gale force SW winds during and after the 12/19 storm event scoured any available snow for wind transport. As a result, new wind loading in lee areas will not occur until late this afternoon and after the onset of snowfall. Expect some shallow slabs to form near and above treeline in wind loaded areas, mainly on N-NE-E aspects.
The bottom line:
This morning, avalanche danger is LOW for all elevations and aspects. After the onset of snowfall, expect some pockets of MODERATE danger to develop late this afternoon near and above treeline on N-NE-E aspects that are 35 degrees and steeper.
This morning, avalanche danger is LOW for all elevations and aspects. After the onset of snowfall, expect some pockets of MODERATE danger to develop late this afternoon near and above treeline on N-NE-E aspects that are 35 degrees and steeper.
0600 temperature: | 27 deg. F. |
Max. temperature in the last 24 hours: | 27 deg. F. |
Average wind direction during the last 24 hours: | West Southwest |
Average wind speed during the last 24 hours: | 25 mph |
Maximum wind gust in the last 24 hours: | 40 mph |
New snowfall in the last 24 hours: | 0 to Trace inches |
Total snow depth: | 31 inches |
For 7000-8000 ft: |
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Sunday: | Sunday Night: | Monday: | |
Weather: | Scattered snow showers in the morning. Snow likely in the afternoon. | Snow | Snow in the morning. Scattered snow showers in the afternoon. |
Temperatures: | 26 to 33 deg. F. | 16 to 23 deg. F. | 19 to 26 deg. F. |
Wind direction: | Southwest | Southwest | Southwest |
Wind speed: | 10 mph increasing to 15 to 25 mph with gusts to 35 mph in the afternoon. | 20 to 30 mph with gusts to 50 mph | 15 to 25 mph with gusts to 40 mph |
Expected snowfall: | Trace to 2 in. | 4 to 8 in. | 1 to 3 in. |
For 8000-9000 ft: |
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Sunday: | Sunday Night: | Monday: | |
Weather: | Scattered snow showers in the morning. Snow likely in the afternoon. | Snow | Snow in the morning. Scattered snow showers in the afternoon. |
Temperatures: | 23 to 30 deg. F. | 14 to 21 deg. F. | 15 to 22 deg. F. |
Wind direction: | Southwest | Southwest | Southwest |
Wind speed: | 25 to 35 mph with gusts to 45 mph, increasing to 35 to 45 mph with gusts to 75 mph in the afternoon. | 40 to 60 mph with gusts to 100 mph | 35 to 45 mph with gusts to 65 mph |
Expected snowfall: | Trace to 2 in. | 5 to 10 in. | 1 to 4 in. |
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