Snowpack Summary published on April 7, 2017 @ 11:29 am
Issued by Ryan Lewthwaite -

bottom line:

New snow & strong winds will increase the likelihood of avalanches through the weekend.  The forecast calls for 3-4' of higher density snow being moved by gusting winds around 100mph, above 8000'. Wind slabs have formed on leeward slopes from the North through Southeast aspects & could likely be triggered lower on the terrain than expected. Avoid travel on or below terrain traps, where snow has been deposited & crossloaded, on ridgelines & around rocks. Expect natural avalanches to occur & for them to be very large in scale. Human triggered avalanche will result in poor outcomes, make good decisions or choose another activity, like bowling. 

Avalanche Character 1: Wind Slab
Wind Slab avalanches release naturally during wind events and can be triggered for up to a week after a wind event. They form in lee and cross-loaded terrain features. Avoid them by sticking to wind sheltered or wind scoured areas.

A ferocious precipitation event is underway with strong winds from the Southwest. This storm snow is blowing hard & depositing on North though Southeast aspects creating wind slabs. Wind slabs will be tender for several days & with these storm totals will be very thick & highly variable. Expect cornices, crossloading, irregular deposition pockets, & natural avalanches to occur in widespread fashion.

Avalanche Character 2: Storm Slab
Storm Slab avalanches release naturally during snow storms and can be triggered for a few days after a storm. They often release at or below the trigger point. They exist throughout the terrain. Avoid them by waiting for the storm snow to stabilize.

New snow totals will be around 3-4' throughout the storms duration with winds strong out of the Southwest. If you travel in the higher elevations, where more has accumulated, your probability of triggering large scale avalanches increases. It will take time & slow subtle atmospheric changes to allow stability of the new snow.

Avalanche Character 3: Loose Dry
Loose Dry avalanches exist throughout the terrain, release at or below the trigger point, and can run in densely-treed areas. Avoid very steep slopes and terrain traps such as cliffs, gullies, or tree wells.

Deposited snow that has been protected by trees from the wind will be a concern. Precipitation that has fallen on Northerly aspects, with this wind protection, are suspect to human triggered avalanches. Don't be lured by untracked powder.

Snowpack Discussion

Warm & springlike conditions had begun to shape the snowpack until yesterdays winter storm rolled into the BWRA. Surface corn snow was variable in density but able to be penetrated with a boot up to 12". 6cm of new snow was being blown around by strong winds out of the West but seemed to bond well to the corn surface. When temperatures remain above freezing at night & the snowpack warms to a constant Zero degrees celsius, isothermal snowpack conditions exist. An isothermal snowpack contains available moisture to create & destroy bonds as the temperature permits. Strong, homogenous bonds usually mean a more stable snowpack overall when it is this deep & cold. Although, rapid precipitation & strong winds will make the new surface snow unstable.

recent observations

Avalanches were hard to see with low visibility & blowing snow, coving any indicators that they have happened. Anticipate that they have occured & will still hold the possibility of failure.


Strong wind will continue today with multiple rounds of heavy rain and higher elevation snow. Snow, snow pellet showers, and potentially some isolated thunderstorms will bring additional accumulations Saturday as low as western Nevada valley floors. A drier pattern is likely for early next week with another moderate storm possible for the end of next week.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Friday Friday Night Saturday
Weather: Cloudy with snow & rain Cloudy with rain in the evening & snow through the night. Cloudy. Snow likely in the morning, then snow showers likely in the afternoon.
Temperatures: 36-44 deg. F. 18-24 deg. F. 25-31 deg. F.
Wind direction: Southwest Southwest Southwest
Wind speed: Winds 20 to 35 mph with gusts to 95 mph Winds 20 to 35 mph, gusts up to 95 mph decreasing to 80 mph after midnight Winds 20 to 30 mph with gusts to 70 mph
Expected snowfall: 6-14 in. 4-10 in. 3-7 in.
For above 10000 ft.
  Friday Friday Night Saturday
Weather: Cloudy with snow Cloudy with snow Cloudy. Snow in the morning, then chance of snow showers in the afternoon
Temperatures: 30-38 deg. F. 10-18 deg. F. 16-24 deg. F.
Wind direction: Southwest Southwest Southwest
Wind speed: Winds 50 to 70 mph with gusts to 110 mph Winds 45 to 65 mph. Gusts up to 110 mph increasing to 120 mph after midnight. Winds 40 to 60 mph decreasing to 30 to 50 mph in the afternoon. Gusts up to 95 mph
Expected snowfall: 8-15 in. 6-14 in. 4-8 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.