Quick report
- Cracking
- isolated
- Collapsing
- isolated
The tour objective was to assess the rate of new snow, the reactivity of new snow in areas of wind deposition and the bonding of the new snow/old snow interface. We departed from the Yuba Pass Sno Park at approximately 10:00 AM and were greeted with a trace of snow on the ground and snow rates of approximately S-1. High winds from the SW were already transporting new snow in the lot, making for cold and blustery conditions. We were just above the rain snow level at 6,700 feet and new snow was melting on contact with the parking lot asphalt. Moving south on the Webber Lake Rd. snow was accumulating on the leeward side of snow mobile tracks and consisted of a moist and dense mixture of graupel, rimed particles and fresh stellars and plates. Ascending Lincoln ridge we found drifted mounds of newly wind transported snow. Wind deposited new snow was approximately only 2" in depth and was accumulating on well established drifts. These drifts were ski tested but accumulation amounts were too minimal to show any reactive results. Upon reaching the ridge we encountered strong winds with gusts of approximately 35-40 mph with significant amounts of snow being transported by the strong winds. On the leeward side of this ridge we found a location of deeper newly wind drifted snow of approximately 4". Travel in these deposition areas produced cracks of 2-4' and showed signs of shearing between spaced tracks. A test pit at this location produced repeatable results of ECTP1 on a 4F slab 4" from the top. The fracture plane was just above the old snow/new snow interface on top of the solar crust on a layer of graupel deposited by the incoming storm. Snow on top of the ridge at approximately 7600 ft. was slightly drier than near the lot and rates increased to almost S-2. One small collapse was heard on the ascent. Conditions heading down the north side of Lincoln Ridge varied from 10-20 cm of soft unconsolidated snow to 4-8 cms of new snow on top of supportable and breakable crust. On the return we ascended the SW ridge of point 7127 and descended north slopes to near the Yuba Pass Sno lot. Upon returning to the lot at around 12:30 PM about 3" of snow had accumulated on the ground, while the radiant heat from the lot continued to melt falling snow. Cracking occurred in an isolated area where wind transported snow had drifted into approximately 4" of steeply deposited accumulation. Cracking was 2-4' in length.
Weather
- Air Temp
- 32
- Cloud Cover
- overcast
- Wind Loading
- moderate
- Rain Elevation
- 6,700
- Recent Snowfall
- 7
- Snow Avail For Transport
- moderate amounts
Moderate snow was falling at about .5" per hour upon arrival with moderate winds below tree line. Winds increased to strong with very strong gusts at near tree line. Temperatures were near freezing at the lot and a few degrees colder near tree line.
Snowpack
A variable 2-4 cm melt/freeze crust of pencil to knife hardness dominated solar aspects with 4F consolidated snow beneath. This increased to pencil hard rounds beneath. North facing slopes held 10-20 cm of unconsolidated snow with 4-6 cm of new snow.