Snowpack Summary published on January 28, 2017 @ 8:25 am
Issued by Kyle Van Peursem - Bridgeport Avalanche Center

bottom line:

The snowpack in most places is well consolidated and strong, with no observed weak layers or signs of instability.  Wind slabs will still be an issue on upper elevation and exposed S-SW-W facing slopes but these will be gaining strength over the weekend as winds die down today.  As temperatures warm up well above freezing this weekend, loose wet point releases on solar aspects may also pose a problem to riders, especially in high consequence terrain.

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 northeasterly winds were blowing hard Thursday and Friday, stripping upper elevation exposed NE facing slopes and loading S-SW-W facing slopes.  Luckily the winds did not effect snow just below the crest and snow remained soft.  Though these wind slabs will be more difficult over the weekend as the winds die down, the weight from a snowmobiler or skier could still trigger these features.  Blowing snow, cornices, wind scoured surfaces, ripples, and other wind created textures can help identify where wind slabs may exist. The hard wind slabs that exist on some aspects may also sound hollow due to the soft snow underneath them. It is recommended to stay off of windloaded slopes steeper than 35 degrees Saturday and Sunday until these wind slabs strengthen and bond to the underlying snowpack.

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.

Temperatures in the BWRA are expected to rise well above the freezing mark in the BWRA this weekend.  Combined with clear skies, wet loose avalanches will be likely on all solar aspects, especially near the bottom of exposed cliff bands.  Though these will generall be small and harmless, they could push a person off their sled or skis and be dangerous in high consequence terrain.

recent observations

We rode up to Sonora Pass and the PCT crossing area and found a strong snowpack but blowing snow from strong NE winds on exposed ridgetops.  We saw very little signs of instability in our stability tests and none from other riders in the area.

weather

Currently (8 am Saturday), a strong inversion is present with below zero temps in Bridgeport, 18 F at the Leavitt Lake Road junction, and 28 F up at Leavitt Lake.  A large area of high pressure will donimate our weather through Tuesday with sunny skies, light winds, and warm above freezing upper elevation temperatures.  The ridge begins to break down Wednesday as the next storm takes aim at the Sierras Thursday through Friday.  Right now, 12-18 in of snow is expected at Sonora Pass by Friday afternoon.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Saturday Saturday Night Sunday
Weather: SUNNY THEN BECOMING PARTLY CLOUDY PARTLY CLOUDY THEN BECOMING CLEAR SUNNY
Temperatures: 36-41 deg. F. 13-23 deg. F. 40-45 deg. F.
Wind direction:
Wind speed: LIGHT LIGHT LIGHT
Expected snowfall: 0 in. 0 in. 0 in.
For above 10000 ft.
  Saturday Saturday Night Sunday
Weather: SUNNY PARTLY CLOUDY THEN BECOMING CLEAR SUNNY
Temperatures: 32-38 deg. F. 20-26 deg. F. 38-43 deg. F.
Wind direction:
Wind speed: NORTHEAST 15 TO 25 MPH. GUSTS UP TO 40 MPH DECREASING TO 30 MPH IN THE AFTERNOON LIGHT WINDS BECOMING NORTHEAST 10 TO 15 MPH WITH GUSTS TO 25 MPH AFTER MIDNIGHT NORTH 10 TO 15 MPH WITH GUSTS TO 30 MPH IN THE MORNING BECOMING LIGHT
Expected snowfall: 0 in. 0 in. 0 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.