Wet snow on Tallac - Corkscrew Avy Path.

Location Name: 
Mt. Tallac
Desolation Wilderness Area (including Emerald Bay)
Date and time of observation: 
Sat, 04/02/2016 - 11:40
Location Map: 
United States
38° 54' 56.6712" N, 120° 6' 5.3028" W

Red Flags: 
Rapid warming
Obvious avalanche path

Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

A decent snow surface refreeze occurred in this area last night despite above freezing air temperatures due to radiational cooling under clear skies. By 9:45 am below 7,400', areas around trees where forest canopy had limited radiational cooling were marginally skier supportable. Open areas and areas at higher elevation remain skier supportable through the morning hours. Descending into the E aspect Corkscrew avalanche path (noted lat/long) at 11:40 am revealed a mix of deep wet snow on SE micro aspect features, supportable conditions on micro E aspect features, and wet transitional snow on micro NE aspect features. On the NE aspect features off the summit ridge around 9,000', large skier triggered roller balls and pinwheels up to 45 cm in diameter were observed. Sticking to the supportable E aspect portions of the slope yielded supportable wet snow conditions from 9,000' down to 7,000' between 11:40 am and noon. Below 7,000' at noon, wet snow on open E aspects became unsupportable. Slope angle in the path at that elevation was insufficient to show signs of instability. Heavily treed areas at the same elevation held little to no snow on the ground.

Photo 1: Ski cut off summit ridge on E aspect feature at the top of Corkscrew (near noted lat/long) producing minor loose wet instability in the form of roller balls less than 30 cm in diameter and tiny sluff.

Photo 2: Boot pen knee deep into unsupportable wet snow at 6,900' on an E aspect in the lower portion of Corkscrew path at noon.

Snowpack photos: 
Weather Observations
Blowing Snow: 
Cloud Cover: 
Air temperature: 
Above Freezing
Wind Speed: 
Air temperature trend: 
Wind Direction: 
More detailed information about the weather: 

Some increasing cumulus clouds, but insufficient to slow snow surface warming at mid day.