Gorgeous day, horrible riding conditions at Blue Lakes

Location Name: 
Polaris Bowl
Region: 
Carson Pass Area
Observation Date & Time: 
Thursday, March 16, 2023 - 13:00
Location: 
38.655998, -119.929841
Is this an Avalanche Observation?: 
Yes


Conditions Alerts:


Terrain Alerts: 
Slopes Steeper than 30 degrees
Terrain Matches the Advisory

Observation made by: Professional Observer

Tabs

Observation
Description of Snow, Weather, and Avalanche Conditions: 

I made a late start at Blue Lakes today, hoping for some afternoon warming to soften the firm surfaces. Even on south aspects at 1pm, the snow remained very firm. I had to chainsaw my track constantly to keep my sled from overheating. Sidehills and steep ups and downs were sketchy. But the weather was gorgeous, with mild temps, a clear sky, and no wind. Instead of looking for good riding conditions, I went along routes that provided views of the surrounding avalanche terrain to look for evidence of recent avalanches. Almost every path that I've seen slide in this area over the past several years had recent crowns and debris, covered by some additional snowfall from the end of the most recent storm. None of the individual avalanches were particularly large, though many of them ran farther downhill than typical. One of the reasons I came here today was to look at an avalanche at the headwaters of Forestdale Creek that I could barely see from HWY 88 yesterday. What looked like a big avalanche yesterday turned out to be several small ones, with crowns at roughly the same elevations, but not connected to each other. 

I went to a few places with similar elevations and aspects to the recent avalanches, with the intention of doing Extended Column Tests to check for lingering instability. But at each location, there was a thick and supportable crust(s) that required cutting with my saw prior to digging, and crusts within the slab are known to produce questionable ECT results. However, while digging, I did observe planar failures on density changes within the top two feet of the snow.

Most of the cornices in the area were quite large today. Some had already partially broken, but still had enough size and mass remaining to be concerning.

Hide Avalanche Details
Avalanche Type: 
Wind Slab
Failure Plane/Weak Layer: 
Storm Snow
Additional number of similar avalanches: 
5-10
Hide Trigger
Trigger: 
Natural
Hide Terrain
Start Zone Slope Angle: 
40degrees
Aspect: 
Northeast
Starting Elevation: 
above-treeline
Hide Size
Destructive Size: 
D2 Could bury, injure, or kill a person.
Relative Size: 
R3 Medium
Crown Height: 
1 ft
Avalanche Width (Average width): 
200ft.
Avalanche Length (Vertical Run): 
600ft.
BESbswy