|Skiing down to Warm Lake Road - The last rays of sun for year 2012.|
|Ponderosa Forest Skiing at Big Creek Summit - The Last rays of sun for year 2012.|
|Warm Lake Road Valley, with the West Mountains in the background.|
During the evening radiation cooling of the top surface makes is considerably cooler than the crystals deeper in the snowpack (20-30 cm), and the faceting process continues unabated during the evening. Since the direction of the faceting changes twice per day (day & evening), this type of snow is called diurnal recrystallized snow. These are many words to describe good skiing snow, even when we have not seen precipitation in a week! The next clip shows my dear friend John enjoying himself while skiing diurnal recrystallized snow..
At northerly and shaded aspects the snow surface was mostly "near surface facets" (NSF) above precipitation particles. These type of snow is more dense, but is a close second to recrystallized snow in terms of ski quality. below a clip of John skiing NSF in top of old snow.
The snowpit+ and stability tests for our Big Creek Summit snowpack are summarized next.
|Snowpit for Big Creek Summit WWS Slope at 7300 feet - December 31st 2012|
Monday BC Skiing was a great closure to a fantastic weekend of ski touring and avalanche instruction at Mores Creek Summit and Copper Mountain. Sunday evening avalanche students as well as instructors for SnowGeek and NSP wrapped up an Avalanche Level 1 course with a delicious dinner at the Longhorn Restaurant at Crouch in Garden Valley.
The classroom session was completed Friday at Boise. After 10 hours of sitting in a classroom, the next day we were happy to be skinning up Pilot Peak road.
|Pedro with AVI L1 students at a Boise - Practicing Beacon Functional & Compatibility Test|
|Upper Mores Creek EES Meadow. Freeman Peak is in the background.|
By the way - we are grateful to Greg's nice grooming, it felt like skiing the cat track of a ski resort. Greg is the Boise Snowmobile Association trail groomer. This is a great example where skiers greatly benefit from snowmobile initiatives. The return of BC skiers to the parking area is made safer by the grooming, allowing intermediate and beginners skiers to enjoy Pilot Peak. Most years it is possible to ski lower angles slopes back to the road, but the lack of snow below 7000 feet has force skiers to use the Pilot Peak road as the main route up to Pilot Peak higher elevation slopes.
Below a the snowpit+ profile with stability test results for a west aspect slope at 7600 feet.
The principal reason for sharing the SnowPit+ results (profile, test results, and stability test scores) of three popular backcountry skiing areas is to illustrate how much variability exists in snowpack structures in our area. However, it is surprising that the concerning layer for every one of these areas (MCS, Banner Summit, Big Creek) are buried close to the 60 cm depth, and that localized steep temperature gradients are present near the weak facet layer. In other words facetting continues, as well as its capacity to alter (weaken?) the snowpack.
During periods of high pressure, such as the one we are experiencing in South West Idaho, we start exploring new terrain and venturing into steeper terrain as the snowpack instabilities subsides. But we need to remind the reader of this blog that this season highly variable and complex snowpack structure will demand of us to carefully evaluate all steep slopes before we commit. The consequences of triggering 60 cm slabs can be severe.