Snowpack Summary published on March 1, 2017 @ 8:30 am
Issued by Kyle Van Peursem - Bridgeport Avalanche Center

bottom line:

Human triggered wind slab avalanches will be possible on wind loaded slopes steeper than 35 degrees over the next couple of days. Additionally, sunny skies and warm temperatures will lead to the potential of wet loose avalanches on solar slopes through Friday.

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.

Strong SW winds accompanied the foot of new snow that fell in the upper portions of the BWRA since Sunday. Upper elevation leeward slopes have been loaded and cornices have formed on ridgetops. Wind slabs will be gaining strength through the week and will be more stubborn but it will still be possible for a human to trigger one on slopes steeper than 35 degrees. Also be aware of large overhanging cornices that are above where you are riding. Though it is nearly impossible to predict when these will break naturally, being caught below one can be dangerous as these can trigger a larger slab avalanche. Do not approach any cornices and give them a wide berth.

Avalanche Character 2: 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.

It is March now and the sun angle is becoming higher and higher each day increasing the amount of solar radiation received in the mountains. Skies are expected to remain clear this week and temperatures are expected to rise well above freezing leading to likely loose wet avalanches on southerly facing slopes in the afternoon. These avalanches typically start near rock bands and trees and fan out into larger slides once they gain momentum down slope. Though these may be small in size and relatively harmless, these can be dangerous in high consequence terrain. Pay attention to the snow surface on southerly facing slopes in the afternoon and avoid slopes steeper than 35 degrees where roller balls start to form.

recent observations

Yesterday, several previous wind slab avalanches and cornice failures were observed in the field, including a large natural avalanche that started on a west facing slope below Ski Lake and ran across Leavitt Creek. These likely occurred during the storm on Sunday/Monday as very strong winds loaded new snow onto leeward slopes.


Since Sunday, upper portions of the BWRA received between 6-12" of low density snow, which was accompanied by strong SW winds. High pressure will build in over our area and persist through the rest of the week with steadily warming temperatures and sunny skies. The next system approaches our area on Sunday morning bringing another round of snow to the BWRA.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Wednesday Wednesday Night Thursday
Weather: Sunny Clear Sunny
Temperatures: 37 to 42 deg. F. 9 to 19 deg. F. 41 to 46 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.
  Wednesday Wednesday Night Thursday
Weather: Sunny Clear Sunny
Temperatures: 32 to 38 deg. F. 11 to 19 deg. F. 35 to 41 deg. F.
Wind direction: NW N/A N/A
Wind speed: 10 to 15 mph in the morning becoming light Light 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.