THIS SNOWPACK SUMMARY EXPIRED ON April 4, 2021 @ 7:29 am
Snowpack Summary published on April 3, 2021 @ 7:29 am
Issued by Arden Feldman - Bridgeport Avalanche Center

bottom line:

Loose wet avalanches will quickly become possible today as the strong spring sunshine melts last night’s thin refreeze. Look out for signs of wet snow instability like unsupportable wet snow and rollerballs. Once the snow gets too wet, it’s time to turn around and avoid the hazard.  

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.

With a marginal refreeze overnight, today’s strong spring sunshine and warm temperatures will quickly heat up snow surfaces. As the thin refreeze melts, loose wet avalanches will become possible on southerly slopes at all elevations and lower elevation northerly slopes. These avalanches will be largest on sustained steep slopes and especially hazardous in extreme terrain and around terrain traps. The hazard will be most pronounced during the heat of the day in the afternoon, but will be possible anytime you encounter loose, unconsolidated wet snow. Today you could encounter areas that didn’t refreeze at all last night and will be wet and unsupportable first thing in the morning. Rollerballs and ankle deep or deeper wet snow are signs that the slope is getting too wet. There may only be a short window to ride today before that happens. Get out early to avoid unsupportable wet snow and the loose wet avalanche hazard.  

Snowpack Discussion

This time of year overnight temperatures become very important. Even though last night’s air temperatures generally bottomed out in the mid to upper 30s and did not go below freezing, long wave radiation loss to the clear skies should have allowed for snow surfaces to refreeze in most areas. This will likely only be a thin refreeze that will break down quickly under today’s strong sunshine. Some areas, like those protected from the clear skies by tree cover, may have not frozen at all last night. They could be wet and unsupportable first thing in the morning. Considering this variability and uncertainty in the overnight refreeze, it is especially important to do your own localized snowpack assessments. Poke around in the snow and see how thick the overnight freeze actually was. This will give you some insight into how much time you have before the slope becomes fully wet and unsupportable. Safe travel in the backcountry this time of year requires getting out early to avoid the hazard. Timing is key. 

With similar temperatures and weather forecasted for tonight and tomorrow, avalanche conditions should be similar tomorrow. However, continue to do your own snowpack assessments. If the overnight temperatures are just a couple of degrees warmer, the snowpack may not refreeze at all. Be aware of other hazards in the backcountry this time of year as well. Long sliding falls are possible in the mornings before snow surfaces heat up. Along with loose wet avalanches, rockfall is also a serious hazard, especially in the afternoons.  

CURRENT CONDITIONS Weather observations from Sonora Pass
0600 temperature: 40 deg. F.
Max. temperature in the last 24 hours: 48 deg. F.
Average wind direction during the last 24 hours: South
Average wind speed during the last 24 hours: 10-20 mph
Maximum wind gust in the last 24 hours: 34 mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 94 inches
weather

Warm and sunny spring weather is forecasted for the weekend. Light to moderate winds will be strongest in the afternoons. Sunday night winds pick up ahead of a dry cold front Monday morning. Cooler temperatures and stronger winds are forecasted for Monday.  

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Saturday Saturday Night Sunday
Weather: Sunny. Partly cloudy. Sunny.
Temperatures: 48 to 58 deg. F. 33 to 38 deg. F. 49 to 59 deg. F.
Wind direction: Southwest Southwest Southwest
Wind speed: 10 to 20 mph with gusts to 35 mph. 10 to 20 mph with gusts to 30 mph. 15 to 20 mph with gusts to 40 mph.
Expected snowfall: 0 in. 0 in. 0 in.
For above 10000 ft.
  Saturday Saturday Night Sunday
Weather: Sunny. Partly cloudy. Sunny.
Temperatures: 39 to 45 deg. F. 31 to 37 deg. F. 42 to 47 deg. F.
Wind direction: Southwest Southwest Southwest
Wind speed: 20 to 35 mph with gusts to 45 mph. 20 to 30 mph. Gusts up to 40 mph. 20 to 35 mph with gusts to 55 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.