THIS SNOWPACK SUMMARY EXPIRED ON March 13, 2018 @ 8:54 am
Snowpack Summary published on March 11, 2018 @ 8:54 am
Issued by Ryan Lewthwaite -

bottom line:

Snowmobiling in the BWRA has been good for the past week, but we are in need of a Refresh. We have observed a robust snowpack from last week melt out very quickly. Our concern from the next 48 hours is the sun directly influencing loose wet avalanche activity in the afternoon.

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.

There is a possibility of small loose wet avalanche activity in the afternoon hours. Without cloud coverage we can expect rapid warming of snow surfaces leading to unstable steep slopes. There is spring corn riding to be had out there today.

Snowpack Discussion

The large snow accumulations we received over a week ago has shrink-wrapped itself to our slopes. Rapid melting is occurring daily & temps are just below freezing at night giving us an unsupportable crust before noon. Corny surface snow is available in the afternoon hours & loose wet avalanche activity is also possible. There are wind slabs on Northeast aspects from strong winds on Thursday that will require caution.

recent observations

This weeks observations come from all over our region including: Stanislaus NF, Virginia Lakes, Hoover Wilderness, the BWRA, & Twin Lakes. The avalanche activity from early in the week had settled down & we are experiencing spring-like conditions. We had our first Public Observation of the season from the other side of Sonora Pass. The snowpilot graph shows us a problematic layer of Graupel mid-pack. Graupel can be a serious layer of concern soon after a storm. The large grain size & unconsolidated structure can act like ball-bearings within a snowpack. Thank you very much for the info! Other observations key us into wind slabs that have formed & rapid melting is taking place. Numerous Large Old growth trees were toppled by the snowload & strong winds from our recent storm.

CURRENT CONDITIONS Weather observations from Sonora Pass
0600 temperature: 29 deg. F.
Max. temperature in the last 24 hours: 40 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: 2.5 inches
Total snow depth: 45 inches
weather

Clear to partly cloudy skies are looming for the next couple days. We are barely reaching freezing at night & daytime temps are in the high 30's to 40's. Winds are going to be light & from the South. Rapid melting due to intense sun can be expected.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Sunday Sunday Night Monday
Weather: Sunny Partly cloudy Partly cloudy
Temperatures: 41 - 47 deg. F. 25 - 30 deg. F. 43 - 49 deg. F.
Wind direction: Light winds Light winds South
Wind speed: Light winds Light winds 10 to 15 mph; gusts to 25 mph later
Expected snowfall: 0 in. 0 in. 0 in.
For above 10000 ft.
  Sunday Sunday Night Monday
Weather: Sunny Partly cloudy Partly cloudy
Temperatures: 35 - 40 deg. F. 22 - 28 deg. F. 36 - 41 deg. F.
Wind direction: Light winds South South
Wind speed: Light winds 10 to 15 mph; gusts to 25 mph late 15 to 20 mph; gusts to 30 mph
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.