Snowpack Summary published on April 3, 2018 @ 8:07 am
Issued by Ryan Lewthwaite -

bottom line:

Loose Wet avalanches are possible in the warm afternoon hours today & tomorrow. Barely freezing temperatures at night has kept our snowpack soft, saturated, & melting. An atmospheric river will impact our region on Friday bringing with it a deluge of precipitation, likely rain, to near treeline areas. Do not rule out Wet slab avalanche activity as this storm puts rain on our snow. Caltrans has begun blowing Hwy 108, so far they are at the Leavitt Falls Vista. Condense parking along the roadway allowing for Marine & plow vehicles to pass.

Avalanche Character 1: 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.

Afternoon warming has melted snow at a rate of 2-3" per day & more on aspects that receive intense sun. The suns progression across the landscape is turning the snow to liquid & vapor quickly. Darker objects like rocks & trees hold heat energy & can create point-releases & hollow areas. Rollerballs & loose sluffs indicate unstable snow. Be cautious of melting out creeks & Cornices falling from above.

Snowpack Discussion

Inversions this week have kept most areas near & above treeline with above freezing temperatures at night. Thin unsupportable crusts exist where firm wind scoured areas do not. The riding has been decent lately but you can dig your track deep in places where unsupportable crusts remain. Obvious signs of rapid melting can be seen, making creek beds unpredictable. Slabs do exist on leeward features but are stubborn to react. Wet loose avalanche activity is likely during the afternoon hours while  lastnights refreeze will make it icy in the morning.

recent observations

We are still exploring places & finding evidence of large avalanches that came with the last storm cycle. Wind slabs have released on N-NE-E aspects with R2D3 size & force. Winds continue to move small amounts of available snow to lee slopes. Cornices have fallen & stepped into old weak layers, especially around Leavitt Lake. Be cautious of the upcoming storm bringing with it rain to higher elevations. 

CURRENT CONDITIONS Weather observations from Sonora Pass
0600 temperature: 28 deg. F.
Max. temperature in the last 24 hours: 48 deg. F.
Average wind direction during the last 24 hours:
Average wind speed during the last 24 hours: mph
Maximum wind gust in the last 24 hours: mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 58 inches

Sun today with increasing cloudiness tomorrow & later into the week. Warm temperatures during the day, while we get below freezing at night. Thursday we can expect a light dash of precipitation, probably rain to 10,000'. Beyond that our weather looks to sour with an atmospheric river moving into the Sierra Crest Friday through the weekend. Heavy rain & flodding are a concern for low lying areas. With this storms development anticipate Loose wet & Wet slab avalanche activity to rise at all elevation bands. Keep cold thoughts!

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Tuesday Tuesday Night Wednesday
Weather: Sunny Clear with increasing clouds. Mostly cloudy.
Temperatures: 44 to 54 deg. F. 27 to 32 deg. F. 47 to 57 deg. F.
Wind direction: Light winds West Southwest
Wind speed: Light winds; gusts to 25 mph later 10 to 15 mph; gusts to 25 mph 10 to 15 mph; gusts to 30 mph
Expected snowfall: 0 in. 0 in. 0 in.
For above 10000 ft.
  Tuesday Tuesday Night Wednesday
Weather: Sunny Clear with increasing clouds. Mostly cloudy.
Temperatures: 37 to 43 deg. F. 24 to 29 deg. F. 39 to 45 deg. F.
Wind direction: West Southwest Southwest
Wind speed: 10 to 15 mph 10 to 15 mph; gusts to 25 mph 15 to 25 mph; gusts to 35 mph
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.