THIS SNOWPACK SUMMARY EXPIRED ON April 16, 2019 @ 7:40 am
Snowpack Summary published on April 14, 2019 @ 7:40 am
Issued by Ryan Lewthwaite -

bottom line:

Changing weather today & warm overnight temperatures will keep us vigilant to the dynamic conditions. Sun & Loose Wet snow surfaces early today will give-way to strong SW winds, increased cloud cover, & mixed precipitation tonight. Adjust your travel plans as the expected front approaches & winds grow with intensity. Snowmobiles are deploying from the Pickel Meadow Pack station.

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 was not an overnight refreeze in the mountains, leaving behind a creeping snowpack. Unconsolidated surface snow will be easily penetrated by track & ski with the potential to cause Loose Wet avalanches. Changing atmospheric conditions today could superficially firm-up the surface snow creating an unsupportable melt-freeze crust with wet snow underneath.

Avalanche Character 2: 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.

As high pressure dissipates today a front will encroach bringing with it strong SW winds & wet snow accumulations. The Sierra Crest will see the lion's-share of precipitation but confidence is waivering on the total amount we will receive.(3-6" up to 10") If the sun & rapid warming post-storm comes to fruition, we are looking it another potential Wet Slab scenario for Lee aspects N-E, near & above treeline.

Snowpack Discussion

New avalanche activity around the BWRA has been nil. The diurnal refreezing has been substantial enough to keep surface snow firm late in to the afternoon. Wind Slabs have been very difficult to trigger with non-standard slope tests. The loosest snow has been in the lower elevations on slopes that get long duration sun effect. A low pressure system today will increase clouds & SW winds bringing with it snow showers for the Crest. Rain is more likely in low valley elevations below 7500' with wet snow showers above. Wind Slabs should form with the strong SW flow on aspects N-E. These slabs could become wet & unstable if rapid warming & sun impact the new snow after deposition.

CURRENT CONDITIONS Weather observations from Sonora Pass
0600 temperature: 36 deg. F.
Max. temperature in the last 24 hours: 53 deg. F.
Average wind direction during the last 24 hours: West
Average wind speed during the last 24 hours: Light mph
Maximum wind gust in the last 24 hours: Moderate mph
New snowfall in the last 24 hours: 0 inches
Total snow depth: 89 inches
weather

This mornings sunshine will be interupted by increasing clouds & Southwest winds. Overnight temperatures did not reach freezing last night at either Snotel site. Expect to start the day with Loose Wet snow conditions on all aspects & elevations. Tonight a low pressure air mass will bring us rain to areas below 7500' & light snow showers above. There is increasing confidence that snow totals for the Sierra Crest could grow to accumulations around 10" by Tuesday morning. Models are favoring a wetter scenario at the start of this system & temperatures dropping as it receedes. Winds from the SW will be gusting to Strong speeds, transporting snow to Lee aspect Wind Slabs. Aligning with spring conditions, the post storm warming will be rapid, losening the newly fallen snow & increasing the avalanche danger for Wet Slabs.

Two-Day Mountain Weather Forecast Produced in partnership with the Reno NWS
For 8000 ft. to 10000 ft.
  Sunday Sunday Night Monday
Weather: Sunny then becoming partly cloudy. Mostly cloudy with a chance of snow showers. Snow Level 8500' Clouds decreasing with a chance for snow showers. Snow Level 8500'
Temperatures: 43 to 53 deg. F. 28 to 34 deg. F. 39 to 49 deg. F.
Wind direction: Southwest Southwest Southwest
Wind speed: 15 to 25 mph; gusts 45 to 60 mph later 15 to 25 mph; gusts to 60 mph 15 to 25 mph; gusts to 60 mph
Expected snowfall: 0 in. 1 in. 1 in.
For above 10000 ft.
  Sunday Sunday Night Monday
Weather: Sunny then becoming partly cloudy. Mostly cloudy with a chance of snow showers. Snow Level 8500' Clouds decreasing with a chance for snow showers. Snow Level 9000'
Temperatures: 35 to 43 deg. F. 22 to 28 deg. F. 31 to 39 deg. F.
Wind direction: Southwest Southwest Southwest
Wind speed: 25 to 40 mph; gusts to 60 mph 30 to 45 mph; gusts to 65 mph 30 to 45 mph; gusts to 65 mph
Expected snowfall: 0 in. 1 in. 1 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.