THIS SNOWPACK SUMMARY EXPIRED ON January 6, 2019 @ 7:26 am
Snowpack Summary published on January 4, 2019 @ 7:26 am
Issued by Ryan Lewthwaite -

bottom line:

The snowpack has endured a long lapse without precipitation but has maintained adequate depth due to low sun angle & shadows. The anticipation of a winter storm Saturday has us attuned to radar, weather forecasts, & the potential for elevated avalanche activity for the weekend. Although winds have firmly scoured the alpine, near & below treeline still holds decent soft snow deposits. Hwy 108 is surprisingly covered from People's Gate, with the S facing "Carbide Hill" as the only continuously bare section of road.

Avalanche Character 1: Normal Caution
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. Use normal caution when travelling in the backcountry.

Use heightened awareness while traveling in avalanche terrain & always carry the Trifecta of rescue equipment & bring a savvy partner. Be hesitant of overhanging cornices on slopes above you, they can trigger large avalanches. Some Southerly aspects may have loose wet snow which has been effected by sun. Many subsurface objects & streams are reappearing.

Snowpack Discussion

Surface hoar has been typically found in the mornings & degraded by afternoon sun, with the largest feathers found in riparian cavities & lower elevations. At treeline & below the SH, near surface facetting has occurred & in some locations creating a plyable surface skin with loose grains underneath. Although higher in the alpine a supportable surface windpack has a similar NSF layer. The BWRA & VLakes areas both had a facet layer 20-30cm deep that was acting as an interface that could fail with MOD to HARD forces. 

recent observations

Yesterdays observations yielded adequate but dwindling coverage & a mostly stable snowpack for the BWRA & Virginia Lakes. An avalanche above Leavitt Lake in the Cirque was noticed to have possibly released sometime on Tueasday. The origin of the slide was from a break in the looming cornice on the most NW portion of the feature. The cornice mass collapsed onto a previously wind loaded slab sending a R1D2 avalanche almost 600' towards the lake edge. NC-O-R1-D2 Chunks the size of rerigerators are still in tacts throughout the debris.

CURRENT CONDITIONS Weather observations from Sonora Pass
0600 temperature: 32 deg. F.
Max. temperature in the last 24 hours: 46 deg. F.
Average wind direction during the last 24 hours: South
Average wind speed during the last 24 hours: Calm mph
Maximum wind gust in the last 24 hours: Light mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 26 inches
weather

A pleasant day in the mountains yesterday with abundant sun & no wind. Temperatures are inverted this morning with both Snotels reading above freezing. Unseasonably warm temperatures & a lack of precipitation for over a week is about to end as a low pressure system enters Saturday morning. Mountain snowfall could be heavy at times & visibility will be shallow due to strong South winds & gale force gusts. A robust line-up of Pacific storms may inundate us with precipitation of many forms throughout the next 7-10 days.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Friday Friday Night Saturday
Weather: Mostly cloudy Mostly cloudy then becoming partly cloudy Increasing clouds with snow throughout the day Snow Level Below 7000'
Temperatures: 38 to 44 deg. F. 18 to 24 deg. F. 26 to 32 deg. F.
Wind direction: Southwest Southwest South
Wind speed: 10 to 15 mph; gusts to 35 mph later 15 to 25 mph; gusts to 45 mph increasing to 55 mph late 15 to 30 mph; gusts to 80 mph
Expected snowfall: 0 in. 0 in. 3 to 6 in.
For above 10000 ft.
  Friday Friday Night Saturday
Weather: Mostly cloudy Mostly cloudy then becoming partly cloudy Increasing clouds with snow throughout the day Snow Level Below 7000'
Temperatures: 32 to 37 deg. F. 14 to 19 deg. F. 20 to 26 deg. F.
Wind direction: Southwest Southwest South
Wind speed: 15 to 25 mph; gusts to 25 mph increasing to 45 mph later 25 to 35 mph increasing 30 to 45 mph; gusts to 70 mph late 35 to 50 mph; gusts to 100 mph!
Expected snowfall: 0 in. 0 in. 3 to 6 in.
Disclaimer

This snowpack summary applies only to backcountry areas in the Bridgeport Winter Recreation Area. Click here for a map of the area. This snowpack summary describes general avalanche conditions and local variations always occur. This snowpack summary expires in 48 hours unless otherwise noted. The information in this snowpack summary is provided by the USDA Forest Service who is solely responsible for its content.