THIS SNOWPACK SUMMARY EXPIRED ON February 26, 2017 @ 8:58 pm
Snowpack Summary published on February 24, 2017 @ 8:58 am
Issued by Kyle Van Peursem - Bridgeport Avalanche Center

bottom line:

The avalanche danger this weekend will be on the lower end of the spectrum due to a lack of recent snowfall and the continued settlement and strengthening of the storm snow from earlier this week.  Though, due to persistent SW winds loading leeward slopes, it will still be possible for a human to trigger a wind slab avalanche in upper-elevation slopes with a NW-N-NE-SE aspect throughout the weekend.

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.

SW winds continue to load leeward slopes leading to the formation of wind slabs on exposed upper-elevation slopes.  Though winds have subsisded since earlier this week, making these features stubborn and more difficult to trigger, it will still be possible to trigger a wind slab under the weight of a snowmobile in the right place.  We are expected to get some more snow this weekend into Monday with SW winds gusting up to 30-40 mph.  This will produce fragile wind slabs near ridgelines on NW-N-NE-E-SE facing slopes.  Look for blowing snow, cornices, pillows on the upper parts of leeward slopes to help identify possible wind slabs and avoid these areas.  

Snowpack Discussion

Our most recent storm system brought us between 3-4' of new snow with about 6-9" of water.  This brings out storm total since last Friday to 4-5' of snow and 7-10" of water.  Since going through an intense storm slab avalanche cycle, the new snow has become much more cohesive and has bonded to the underlying snowpack, greatly decrasing the overall avalanche danger in the BWRA.  The main concern over the next 3 days will be wind slabs and cornices in upper elevation slopes.

recent observations

During the storm on Monday and Tuesday, multiple natural storm and wind slab avalanches were observed, including a historic avalanche above lower Leavitt Lake Road that ran across the road, down into the ravine, and 50' up the other side.  This slide took out mature trees and left a huge debris pile across the road.  The avalanche likely occured during the storm on Monday or Tuesday due to heavy wet snow on top of lighted drier snow combined with heavy wind loading.  On Wednesday, observations above the Sardine Meadows area showed a rapid increase in new snow settlement and bonding with no signs of instability or avalanche activity within the previous 24 hours.


Cold air has settled over the BWRA today, with temps in the single digits.  We will warm up into the teens and then 20's over the weekend.  Clouds will increase this afternoon and Saturday before clearing some Sunday morning.  Clouds will again increase Sunday afternoon into Monday.  Light snow showers are expected Sat afternoon, Sun afternoon and Monday, with 6-12" of light dry snow expected through the end of the day Monday.  High pressure and warming temps will build into our area beginning Tuesday and should persist well into the following week.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Friday Friday Night Saturday
Weather: Sunny then becoming partly cloudy. Partly cloudy. Partly cloudy then becoming mostly cloudy. Slight chance of snow in the morning. Chance of snow in the afternoon.
Temperatures: 23 to 29 deg. F. 9 to 15 deg. F. 21 to 27 deg. F.
Wind direction: SW SW SW
Wind speed: Light winds. Gusts up to 35 mph in the afternoon 10 to 15 mph. Gusts up to 30 mph increasing to 40 mph after midnight. 10 to 15 mph with gusts to 35 mph in the morning becoming light
Expected snowfall: 0 in. 0 in. 2 in.
For above 10000 ft.
  Friday Friday Night Saturday
Weather: Sunny then becoming partly cloudy. Partly cloudy. Partly cloudy then becoming mostly cloudy. Slight chance of snow in the morning. Chance of snow in the afternoon.
Temperatures: 17 to 23 deg. F. 5 to 11 deg. F. 14 to 20 deg. F.
Wind direction: W SW W
Wind speed: 15 to 20 mph with gusts to 35 mph 20 to 30 mph with gusts to 45 mph 20 to 30 mph. Gusts up to 60 mph decreasing to 40 mph in the afternoon
Expected snowfall: 0 in. 0 in. 2 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.