Rock Creek

Half Moon Pass
Submission Info
Thursday, April 5, 2018 - 5:45pm
Red Flags: 
37° 27' 5.4" N, 118° 45' 26.28" W
Snowpit Observations
More detailed information about the snowpack: 

Toured up to 10,800' in the cirque below Half Moon Pass in Rock Creek to see if there was winter snow in the alpine and to get a general impression of the snowpack further south before the upcoming storm.

-From the East Fork parking area at 8800' we had to walk up the road a few hundred feet to almost 9000' before putting on our skis (see trailhead photo).

-No new avalanche activity observed today. Small steep rollovers and test slopes had unreactive or stubborn loose wet/rollerball results after noon on E and SE aspects. All observed avalanches were from at least 24hrs ago and were all loose wet (the remains of debris, snapped trees, and just the hint of crowns from the last storm cycle). All the more recent loose wet slides were small (D1) and were above 10,000' and were on all aspects.

-The snowpack is thin to non-existent below about 9800' in Rock Creek except on isolated N facing areas. Above there coverage becomes pretty good. Everywhere we traveled today (left the trailhead at 9am) the snowpack was moist top to bottom and isothermal, even up to 10,800' on N aspects.

-Two sets of snowpack tests: 1 at 10,100' on a N aspect where snow depth was 70cm - CTM SC down 65cm in moist rounding depth hoar that was F hard. This result was unrepeatable at the site. 2nd test pit at 10,883' on an E aspect near treeline in the cirque (see attached profile) - this site had the depth hoar at the bottom also under very hard layers of densely packed rounds. CTM SC down 105cm in the rounding depth hoar was unrepeatable again after one test. The snowpack above the depth hoar was a strata of melt forms and hard melt-freeze crusts (see snowpack photo). It seemed possible that these crusts could become a bed surface for wet slabs in the up-coming rain/snow event.

-Weather today was overcast almost all day with occasional brief breaks of sunlight. Winds were light from the S-SW, Temps between 7 and 9 deg C. Surface and -20 temps were 0 deg C and all locations.

Snowpit or crown profile photo or graph: 
Snowpack photos: 
Weather Observations
Blowing Snow: 
Air temperature: 
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