Observations from Fireplug

While the sun shown brightly over most of the forecast area, especially the Sierra Crest today, thick overcast was present over the Tamarack Peak area. I went into Fireplug to get more assessment on the recent wind slab avalanche that was reported from there yesterday.

The Pint Glass avalanche path where the avalanche had occurred had been fairly well tracked, leaving only a couple of places remaining where I could assess the avalanche. I was able to examine two sections of shooting cracks extending off of the climber's right flank and along the climber's right end of the crown. In all of these snowpack failure locations, the cracks did not extend below the 1 foot depth of the crown. The snowpack failed on a subtle density change of lightly wind drifted snow, 4F- hard slab over a F+ hard storm snow weak layer/bed surface.

Having a look around other nearby avalanche start zones, small D1 wind slab crowns were visible in the area. I saw three ~1 foot crowns on the top of Dick's Crack near the W end of Fireplug and two ~1 foot crowns on the Far East Ridge of Tamarack Pk.

Also of note in the area was 5 to 7 mm persisting surface hoar. This was seen in open areas and between small trees. Warming temperatures and wind ahead of the next snowfall event will likely destroy this SH, but it is worth keeping an eye on until then.

Sun crust had formed from yesterday's solar radiation despite below freezing air temperatures on E-SE-S-SW-W aspects and low angle northerly aspects. This sun crust was about 1 to 1.5 inches thick and ranged from breakable to semi-supportable.