Snowpack Summary published on March 9, 2017 @ 9:22 am
Issued by Kyle Van Peursem - Bridgeport Avalanche Center

bottom line:

Avalanche danger will increase during the afternoon on E-SE-S-SW facing slopes due to the potential for loose wet avalanches.  Natural and human triggered avalanches will be possible on these aspects.  Look for rollerballs and pinwheels and avoid these slopes in the afternoon.

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.

Persistent warm temperatures and sunny skies will cause the snow surface on solar aspects to melt and lose cohesion leading to likely loose-wet avalanches during the afternoon.  These slides will generally be small but could entrain enough snow to knock a rider off their sled and/or bury them.  It is recommended to avoid E-SE-S-SW facing slopes, especially as things warm up in the afternoon.  Precursors to loose wet avalanches include roller balls or pinwheels coming down slope and sinking deep past your boots in wet snow. 

Avalanche Character 2: Normal Caution
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. Use normal caution when travelling in the backcountry.

Another potential hazard to be aware of this time of year are areas of ice and slick crusts that have refrozen overnight.  These can be tricky to spot and can be dangerous as they can cause riders to quickly lose control of their sleds on steep slopes.  Always look ahead of where you plan to ride to make sure these features don't exist on your route.

Snowpack Discussion

As we head into a period of persistent high pressure with warm temps and sunny skies, the snow will begin its transition to a spring time snowpack, where the diurnal melt/freeze will make the snowpack more uniform.  Generally, the avalanche danger is higher during the first week or so as the mountains begin to shed their seasonal snowpack.  Afterwards, the potential for wet avalanches begins to decrease and the snowpack becomes much more stable and safe. 

recent observations

Ryan was up in the BWRA on Sunday and Monday during and after our most recent storm and found about 2' of new snow with heavy wind loading and large wind drifts.  Kyle went up on Tuesday and found punchy but stubborn wind slabs but did not observed any recent avalanche activity.  The snow surface consisted of a mix of wind boards, crusts, and wet snow with some dry snow persisting on the most shaded northerly slopes.


Our last storm on Sunday brought us 18-24" of new snow with about 1.5-2" of water.  This was most likely our last significant snow event for a while as an area of high pressure builds in over the CA coast diverting the main storm track well to our north and looks to persist at least for the next two weeks.  This means warming temps with highs in the upper 40's to low-mid 50's and temps above 9000' remaining above freezing overnight.  Wind should remain relatively light through the next two weeks as well.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Thursday Thursday Night Friday
Weather: Sunny Clear Partly cloudy then becoming mostly cloudy.
Temperatures: 44 to 54 deg. F. 26 to 36 deg. F. 45 to 55 deg. F.
Wind direction: N/A N/A N/A
Wind speed: Light Light Light
Expected snowfall: 0 in. 0 in. 0 in.
For above 10000 ft.
  Thursday Thursday Night Friday
Weather: Sunny Clear Partly cloudy then becoming mostly cloudy.
Temperatures: 34 to 44 deg. F. 26 to 36 deg. F. 34 to 44 deg. F.
Wind direction: N/A W W
Wind speed: Light Light winds becoming west 10 to 15 mph with gusts to 25 mph after midnight West 10 to 15 mph with gusts to 30 mph in the morning becoming light
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.