The last avalanche forecast for this season will be published on April 18. Thank you to all who have supported this avalanche center through volunteer hours, snowpack/avalanche observations, and financial contributions.
This Avalanche Advisory was published on January 26, 2012:
|January 26, 2012 at 8:00 am|
Skies cleared some yesterday afternoon and overnight. Remote sensors indicate that temperatures remained near and above freezing again last night in most places up to at least 9000 ft. The partly cloudy skis should persist through this morning before a low pressure system north of the area pushes more clouds into the region. This system could also bring a 10-20 % chance of some minor precipitation starting later this afternoon. Both the clouds and the best chances of precip will exist north of Highway 50. The forecast only calls for about .02 inches of precipitation. Temperatures should remain warm again today keeping the snow level around 8000 ft. The westerly winds have started to increase ahead of this system and should remain moderate to strong through tonight. Early tomorrow morning they should begin to shift north and east and decrease in strength. By tomorrow mostly sunny skies should return to the forecast area with daytime highs slightly cooler than yesterday and today.
Warm temperatures and partly sunny skies made the top four to six inches of snow wet and heavy on all aspects at all elevations on Tamarack Peak yesterday. Wet surface snow instabilities like roller balls, pinwheels, and wet loose sluffs occurred on all aspects with some of these instabilities occurring naturally near exposed rocks and trees and some skier triggered ones occurring on 35-38 degree slopes (photo showing wet loose snow sluff on a north aspect). A larger wet loose snow avalanche occurred on a NE aspect on Freel Peak the previous day (photos); however, observations in the same area yesterday only showed wet surface snow and much smaller wet surface instabilities. Hand pits, snowpits, ski cuts on test slopes, and small cornice blocks dropped onto steep slopes in the Tamarack Peak area and the Freel Peak area did not show any signs of slab instabilities yesterday (snowpit from Tamarack, more info from Freel). This data also showed that the snowpack has completely incorporated the storm snow weaknesses into the stronger snow around them creating a mostly stable snowpack. These observations match the previous day's data from Carson Pass, Donner Summit, Echo Summit, and the West Shore that also pointed to a mostly stable snowpack. Other reports from the backcountry indicated a mix of breakable crusts and wet heavy snow on the snow surface across the region from Red Lake Peak to Rubicon to Castle Peak to Sunrise Bowl.
All of the recent data indicates that slab avalanche activity has become unlikely due to consolidation and settlement allowing the snowpack to strengthen since the recent storm. Unlikely does not mean impossible and very isolated and rare pockets of potential instability may still exist in steep complex terrain. Even though slab avalanches are unlikely today, wet surface snow instabilities like pinwheels, roller balls, and loose wet snow sluffs should continue to occur. Most of this activity should remain small due to warming occurring during the last two days, some continued cloud cover, the relatively low sun angles, and clear skies overnight allowing a slightly better refreeze. That being said, small sluffs and pinwheels can still knock a person off balance or push someone into an area with higher consequences. Steep open areas that face the southern half of the compass hold the best potential for this type of instability today, but these types of wet snow instabilities could continue on the northerly aspects as well. If more rain falls than forecasted, the size and distribution of wet snow instabilities will increase.
The bottom line:
Weather Observations from along the Sierra Crest between 8200 ft and 8800 ft:
|0600 temperature:||32-36 deg. F.|
|Max. temperature in the last 24 hours:||38-45 deg. F.|
|Average wind direction during the last 24 hours:||West|
|Average wind speed during the last 24 hours:||10 mph increasing overnight to 30-35 mph|
|Maximum wind gust in the last 24 hours:||51 mph|
|New snowfall in the last 24 hours:||O inches|
|Total snow depth:||22-41 inches|
Two-Day Mountain Weather Forecast - Produced in partnership with the Reno NWS
For 7000-8000 ft:
|Weather:||Partly cloudy with isolated showers developing after 1 pm.||Mostly cloudy with scattered snow showers||Partly cloudy in the morning then sunny in the afternoon|
|Temperatures:||42-48 deg. F.||23-30 deg. F.||33-40 deg. F.|
|Wind direction:||West||Southwest shifting to the north after midnight||East|
|Wind speed:||20-30 mph with gusts to 40 mph||20-25 mph with gusts to 40 mph||15-20 mph with gusts to 30 mph|
|Expected snowfall:||O in.||O in.||O in.|
For 8000-9000 ft:
|Weather:||Partly cloudy with isolated snow showers developing after 1 pm.||Mostly cloudy with scattered snow showers||Partly cloudy in the morning then sunny in the afternoon|
|Temperatures:||34-42 deg. F.||21-28 deg. F.||33-39 deg. F.|
|Wind direction:||West||West shifting to the north after midnight||East|
|Wind speed:||35-45 mph with gusts to 65 mph||35-40 mph with gusts to 60 mph decreasing to 25-30 mph with gusts to 40 mph after midnight||15-25 mph with gusts to 35 mph|
|Expected snowfall:||O in.||O in.||O in.|