Sunday, November 28, 2010

Pilot Peak - Top of the World - November 28th

Today (Sunday) Mores Creek Summit was uncharacteristically quiet considering the new snow! By mid morning there was only one vehicle at Freeman, and two vehicles at Mores Creek Summit. Based on the tracks I spotted at Pilot Peak, very likely there were two parties enjoying backcountry skiing; a party of two and a single individual.

It was cold day (consistent -7 Deg  C during the day) with moderate strength north winds. At ridge tops the wind compacted the snow, and made trail breaking less painful. Mores Creek Summit Snotel recorded 4 inches (10 cm) of new snow, and as the snowpack continues to settle this Sunday promised to be a spectacular day. Above 7000 feet the new snow depth varied between 20 to 30 cm depending on aspect and wind. Trail breaking was not too bad, and it beginning to feel more like consolidated snow with the occasional bottomless sections.

No evidence of instability was observed as I skinned to "Top of The World". However, considering the significant amount of snow movement at the top of "Top of The World" I choose to ski a conservative line with 30-32 degrees of steepness. The skiing was FANTASTIC! These are the best conditions I have seen early in the winter at Mores Creek Summit in a very LONG time!

During the day I kept an eye for areas where the NSF buried by the new snow could pose problems. After climbing back up for more, I decided to dig a snow pit in a wind loaded area to evaluate how the snowpack was reacting to the stiffening and loading of the slab.

The above profile was recorded for a snowpit at 7800 feet at an East aspect on a slope with 30 degrees steepness. I was surprised to find the NSF buried between 40-45 cm. This weak layer had the following results:
  • Propagation Propensity at the 45 cm (ECTP)
  • Moderate trigger likelhood (CT17)
  • And clean but sluggish slip fracture response: Q2 (for both ECT and CT)
Inspection of the Pit profile (and structural weaknesses -Lemons) clearly show a layer of concern at the 40-45 cm depth. Thus, I abandon my plan to ski a line in the 36 degree, and instead I skied a less steep line with 32-33 degrees steepness.

By the way, it is difficult to estimate slope steepness without a sight through clinometer. Clinometers are COOL devices, and it is an essential tool for the serious and competent winter backcountry traveler. An example of a supplier is:

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As I skied down I noticed a party of two climbing up on the uphill track I put in earlier. I skied to a safe spot at the bottom of the slope, and had some chicken soup and a quick snack. As I prepared to snap a picture of my track (rightmost), I noticed the two skiers skiing together the slope. The skier in the middle skied the 36 degree slope, with her partner below. 

Remember, ALWAYS ski one at a time in the backcountry! Avalanche accidents triggered by multiple skiers are NOT rare!

These two skiers used my uphill track, thus it was not difficult to spot the transition between the snowpack and windslab. In addition, the skin track skirted some rocky and shallow areas next to the wind slab close to the top of the slope. The uphill track I layout at the top was meant to get as close as possible to the "dragon", since I wanted to understand how the "starting zones" are getting configured this winter.

The skiers should have noticed conditions requiring care. Besides, this a highly variable early season snowpack. I am still bedazzled by their choice to both ski the slope simultaneously!

At the end of the day I skied the "Knob Ridge". The coverage was good, the snow was GREAT. The brush required good planing  below the 6500 feet elevation. As I navigated slopes with more East orientation below the 6500 level, I noticed a "thin" zipper sun crust, but very ski-able still. It must had been warmer at lower elevations today!

At the bottom (Summit Creek) I was very lucky to follow the downhill tracks of a VERY wise skier. He was incredibly adept at finding the only few open slots through the dense brush. There is another storm for Tuesday that will affect our area, I only hope that this storm buries some of the troublesome brush between 5800 and 6200 feet of elevation.

I have to say that the skiing at the 7000-8000 is superb, and it is worth having to deal with the brush at lower elevations.


PS: A day like today is some of the BEST birthday present I ever received from nature!