THIS SNOWPACK SUMMARY EXPIRED ON March 6, 2017 @ 8:00 am
Snowpack Summary published on March 4, 2017 @ 8:00 am
Issued by Kyle Van Peursem - Bridgeport Avalanche Center

bottom line:

With the onset our next storm system, avalanche danger in the BWRA will rapidly rise Saturday night through Sunday, peaking around noon on Sunday.  Natural avalanches will be possible and human triggered avalanches will be likely on all slopes steeper than 35 degrees through Monday morning.

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 will begin to ramp up on Saturday with gusts reaching up to 80 mph on Sunday.  These winds, combined with heavy new snow, will rapidly load W-NW-N-NE-SE facing slopes, especially above treeline.  Natural and human wind slab avalanches will be likely on slopes steeper than 35 degrees through Monday morning.

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.

18-24" of new snow is expected in the BWRA Saturday night through Monday morning and will fall on a variety of snow surfaces formed during this past week's high pressure.  The most problematic surface will be a melt-freeze crust on E-SE-S-SW facing slopes that formed due to strong solar inputs on the slope.  New snow will not bond well to this surface and will likely avalanche naturally on typical steep southerly facing slopes (ie; the slide path above lower Leavitt Lake Road).  On shaded northerly slopes that were not sun effected, storm slabs should stabilize quickly as the storm snow will come in right side up and bond to the underlying snow surface.

Snowpack Discussion

Our short 5-day period of high pressure was a welcome relief to the constant stream of storms this past winter.  The snowpack has generally set-up quite nicely with the exception of lingering wind slabs and we saw fantastic (and safe) riding conditions over the later half of the week.  We will go through another avalanche cycle Sunday/Monday before the snowpack stabilizes again for the later part of the week.

recent observations

Numerous wind slab avalanches were observed earlier this week due to 6-12" of new snow and strong SW winds Sunday and Monday.  Since then, the snowpack stailized and no new activity was obsereved.

weather

This week's high pressure brought very warm temperatures (mid-upper 40's) with calm winds and abundant sunshine; it was starting to feel like spring out there!  This will quickly come to an end as a moderate winter storm system moves into our area Saturday with strong SW winds ramping up through the day and snow starting Saturday evening.  Snow intensity will peak Sunday morning before tapering off through the day into Monday morning.  Colder temps will move in behind the storm Monday night and Tuesday before high pressure builds in again for the later part of next week with partly cloudy skies and temps into the 40's.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Saturday Saturday Night Sunday
Weather: Cloudy. Snow developing in the afternoon Cloudy. Snow. Cloudy. Snow.
Temperatures: 30 to 36 deg. F. 25 to 30 deg. F. 10 to 24 deg. F.
Wind direction: SW SW SW
Wind speed: 25 to 35 mph with gusts to 55 mph 20 to 30 mph with gusts to 45 mph 20 to 30 mph with gusts to 40 mph
Expected snowfall: 0 in. 6-10 in. 8-16 in.
For above 10000 ft.
  Saturday Saturday Night Sunday
Weather: Cloudy. Snow developing in the afternoon Cloudy. Snow. Cloudy. Snow.
Temperatures: 25 to 29 deg. F. 22-26 deg. F. 8 to 15 deg. F.
Wind direction: SW SW SW
Wind speed: 40 to 50 mph with gusts to 75 mph 45 to 55 mph with gusts to 80 mph 45 to 55 with gusts to 85 mph
Expected snowfall: 0 in. 6-10 in. 8-16 in.
Disclaimer

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.