THIS SNOWPACK SUMMARY EXPIRED ON February 1, 2015 @ 7:27 pm
Snowpack Summary published on January 30, 2015 @ 7:27 pm
Issued by Adam Babcock - Bridgeport Avalanche Center
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.

Normal caution and safe travel protocols are advised in avalanche terrrain.  Moderate to strong North/Northeast winds will transport this week's light density new snow (the 2-3inches that fell Monday night/Tuesday has already been redistributed in some places by moderate winds).  Watch for windslab development on South/Southwest aspects and other lee-side features over the next 24 hours.  Windslabs should remain manageable in size due to the small amount of snow available for transport, and the high winds forecast (high winds tend to distribute light snow over a wide area and the higher winds forecast will sublimate some of the mass into the atmosphere).  The rain-glazed surfaces below fresh windslabs can still cause a slide-for-life into trees/rocks/off cliffs if you cut even a small slab loose.

Snowpack Discussion

DESCRIPTION: The BWRA received 2-3 inches of new snow Monday night through Tuesday morning.  This new snow has remained cold and light-density above 9500' despite warmer temps at lower elevations, and has been blown around by variable winds to form soft windslabs 3-6 inches deep in protected terrain pockets.  The underlying rain crust and bulletproof windslabs persist, creating classic dust-on-crust skiing conditions.  

The snowpack on northerly aspects above 9000' is largely faceted; even southerly aspects above 10,000' show a mix of crusts and facet layers.  Snowpack depths from snowpits this week range from 0.5m on south aspects to 1.0m on north aspects.  Surface hoar development is widespread on most aspects above 9,500', though the moderate and strong winds forecast this weekend may help mitigate this condition.  Faceting below the January 16 rain crust is also widespread on a variety of aspects and elevations, and this weakness may become problematic with a significant snow load.

THE BOTTOM LINE: Still no obvious signs of instability, natural and human-triggered avalanches are unlikely.  Watch for moderate to strong North and Northeasterly winds to build windslabs over the next 24 hours.

recent observations

Recent snowpits have shown a weak facet layer - prone to failure in column tests - developing immediately below the January 16 rain crust (surface rain crust prior to the new snow this week).  This layer may become problematic when slopes receive significant snow load (wind or snowfall events).  Column tests reveal the easiest failures to initiate are within 30cm of the surface of the snowpack; failures deep within the snowpack have been hard to trigger and have not shown propagation.

weather

High pressure is expected to settle over the Eastern Sierra this weekend, bringing mild/above average temperatures for the weekend.  Moderate to strong North/Northeast winds up to 75mph near the Sierra Crest are expected tonight through tomorrow.

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. Slight chance of snow showers. Mostly cloudy. Slight chance of snow showers. Partly cloudy then becoming sunny.
Temperatures: 33-40 deg. F. 19-26 deg. F. 35-42 deg. F.
Wind direction: North North North
Wind speed: 10-15mph, gusts to 25 20-30mph, gusts to 45 20-30mph, gusts to 45
Expected snowfall: Little or no accumulation in. Little or no accumulation in. No accumulation in.
For above 10000 ft.
  Friday Friday Night Saturday
Weather: Mostly cloudy. Slight chance of snow showers. Mostly cloudy. Slight chance of snow showers. Partly cloudy then becoming sunny.
Temperatures: 30-40 deg. F. 16-24 deg. F. 35-45 deg. F.
Wind direction: Northeast Northeast Northeast
Wind speed: 15-20mph, gusts to 25 30-35mph, gusts to 55 increasing to 40-50mph, gusts to 75 after midnight. 40-50mph, gusts to 75 decreasing to 65 in the afternoon.
Expected snowfall: Little or no accumulation in. Little or no accumulation in. No accumulation 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.