THIS SNOWPACK SUMMARY EXPIRED ON April 26, 2018 @ 7:45 am
Snowpack Summary published on April 24, 2018 @ 7:45 am
Issued by Ryan Lewthwaite -

bottom line:

Isolated spring thundersnows are possible in the afternoon for the next couple days. If accompanied by rain expect increased natural Loose Wet avalanche activity. Observing cumulus clouds building should trigger a flight response to seek shelter. A snowmobile, high-marking a bowl, may be one of the best lightning conductors ever. Soft corn snow that hasn't refrozen at night can be dicey on steep terrain. Sunday the 29th is the last day of snowmobiling.

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.

Loose wet avalanche activity may persist through the closing weekend. The sun & warm air temps are contributing to the rapid melting of surface snow. Liquid is percolating through the snowpack & can be seen running along the ground in some areas. The expected rain & thunderstorms will loosen snow grains exponentially, making avalanches almost a certainty. It has been three nights without a refreeze!

Snowpack Discussion

An isothermal snowpack exists. A fairly homogenous snowpack around 0C & daytime temperatures reaching near 60F degrees has us in springmode. The excellent corn sliding in the morning turns to a slush soon after, constraining backcountry plans. Crusts are deteriorating within the snowpack as melt-water percolates towards the ground. The snow is going fast! Please submit any snowy observations you see, it only takes a moment & you can help spread the knowledge by helping me.

recent observations

The mountains are shedding Loose Wet avalanches at a constant rate. Many of the avalanches are originating from the hot exposed rocks on steep terrain. Travelers can easily trigger wet sluffs on slopes steeper than 30 degrees. The push-a-lanche phenomenon has been witnessed while splitboarding in the afternoon heat. Large areas around rocks, trees & bushes are hollow from radiant heat. Be cautious of these tree-wells as they can alter your travel, quickly sucking you into a hole. Some looming cornices are looking as though they want to peel off the ridges.

CURRENT CONDITIONS Weather observations from Sonora Pass
0600 temperature: 34 deg. F.
Max. temperature in the last 24 hours: 56 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: 41 inches
weather

Warm temps & light winds. There is an increasing chance for afternoon thundersnows through Thursday. Beyond Thursday the forecast gets crazy again with snow & colder temperatures on the horizon. Small accumulations are expected at higher elevations & winds will increasing with the cumulus build-up.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Tuesday Tuesday Night Wednesday
Weather: Sunny. Isolated thunderstorms in the afternoon. Partly cloudy. Isolated showers & thunderstorms late. Partly cloudy. Slight chance of showers & thunderstorms in the afternoon.
Temperatures: 56 to 66 deg. F. 36 to 41 deg. F. 59 to 67 deg. F.
Wind direction: Light winds Light winds Light winds
Wind speed: Light winds Light winds Light winds
Expected snowfall: 0 in. 0 in. 0 in.
For above 10000 ft.
  Tuesday Tuesday Night Wednesday
Weather: Sunny. Isolated thunderstorms & snow showers in the afternoon. Partly cloudy. Isolated showers & thunderstorms late. Partly cloudy. Slight chance of thunderstorms & snow showers in the afternoon.
Temperatures: 49 to 55 deg. F. 32 to 38 deg. F. 51 to 57 deg. F.
Wind direction: Light winds Light winds Light winds
Wind speed: Light winds Light winds Light winds
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.