Snowpack Summary published on March 15, 2015 @ 6:59 pm
Issued by Adam Babcock - Bridgeport Avalanche Center
Avalanche Character 1: Loose Wet
Loose Wet avalanches occur when water is running through the snowpack, and release at or below the trigger point. Avoid very steep slopes and terrain traps such as cliffs, gullies, or tree wells. Exit avalanche terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.
Avalanche Character 2: Wet Slab
Wet Slab avalanches occur when there is liquid water in the snowpack, and can release during the first few days of a warming period. Travel early in the day and avoid avalanche terrain when you see pinwheels, roller balls, loose wet avalanches, or during rain-on-snow events.
Snowpack Discussion

Special Announcement - Wet Snow instabilities:  Over the past two days, snowpack conditions in the BWRA have "turned the corner" for wet snow instabilities.  On a ski tour to Big Easy Peak today (Leavitt Creek Drainage), we triggered multiple D1 Loose Wet and Wet Slab avalanches in steep rocky terrain on northerly aspects.  These avalanches were shallow - they ran on hard, smooth melt freeze crusts near the surface - and occurred Near Treeline; they were not big enough to bury a person, but could sweep you off your feet and carry you through rocks/cliffbands.  

Touring across flat, semi-shaded terrain Near Treeline in mid-afternoon, our skis repeatedly broke through the surface snow and sunk to basal layers of the snowpack - a sign of more significant wet snow instability than I have previously seen in the BWRA.  Deeper snowpack failures may be possible in steep ravines, creekbanks, and rock outcrops Near and Below Treeline where melt/freeze crusts are less well developed on shaded aspects and shaded snow cover.

The snow that we encountered on North and East aspects Above Treeline did not show the same level of wet snow instability - it may have been cooled enough by moderate to high winds to limit melting.

On Saturday, the surface snow on a South aspect Above Treeline at the PCT Xing area had warmed up enough to be able to squeeze water out of a snowball - a clear sign of instability for that layer.  The saturation only penetrated about 10cm into the snowpack, and deep instabilities did not appear to be of concern. 

Cooler nighttime temps tonight, and a hard freeze may mitigate these wet snow instabilities.  


Above normal temps, cloud cover, and lighter winds are expected for the next couple days.  Cloud cover in this case may actually exacerbate snowpack warming as the clouds re-radiate longwave energy back into the snowpack and ground surfaces, aka "Greenhouse Effect".  This effect, combined with above average temps and lighter winds, will likely allow the snowpack to continue melting, and wet snow instabilities to persist.

Cooler nighttime temps tonight - expected to drop below freezing - may help mitigate these wet snow instabilities.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Sunday Sunday Night Monday
Weather: Mostly Cloudy Mostly Cloudy Mostly Cloudy
Temperatures: 52-60 deg. F. 30-37 deg. F. 51-59 deg. F.
Wind direction: SW SW SW
Wind speed: 20-30mph, gusts to 45mph 20-25mph, gusts to 40mph 10-15mph, gusts to 25mph
Expected snowfall: 0 in. 0 in. 0 in.
For above 10000 ft.
  Sunday Sunday Night Monday
Weather: Mostly Cloudy Mostly Cloudy Mostly Cloudy
Temperatures: 44-52 deg. F. 27-34 deg. F. 44-50 deg. F.
Wind direction: SW SW SW
Wind speed: 40-50mph, gusts to 70mph 40-45mph, gusts to 60mph decreasing to 25-30mph, gusts to 50mph after midnight. 15-25mph, gusts to 40 decreasing to 30mph in the afternoon.
Expected snowfall: 0 in. 0 in. 0 in.

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.