Variable surface conditions, New snow and lots of wind in the Lakes Basin

TJ Lake
Submission Info
Saturday, March 7, 2020 - 12:30pm
Red Flags: 
Recent loading by new snow, wind, or rain
37° 34' 57.6552" N, 119° 0' 21.8268" W
Snowpit Observations
More detailed information about the snowpack: 

This past week of unseasonable warm temperatures had a large effect on the snowpack at mid and lower elevations in the Mammoth area. The difference was obvious both in overall coverage as well as in surface conditions as I made my way into the Lakes basin this morning. My last visit to the area was at the end of last week, and since then, many rocks and berms of dirt have become exposed. More notable was the very hard surface conditions we encountered today. 

We skied to 10200’ above TJ lake and encountered temperature crusts of varying thickness on all aspects below and near tree line even in shaded and protected areas. Thickness ranged from a thin zipper crust that was easy enough to slide through, to 1-2 cm trapdoor crust that was quite challenging to ski through, to 20+cm thick fully supportable crust that made for fast traversing. In many areas, the ground had a blue tinge to it, indicating the high water content of the refrozen surface. While I suspect shaded and protected N-NE-E terrain may still hold cold soft snow, that was not in our cards today. 

Flurries of new snow began around 10 Am today, and by Noon consistent (S1) snowfall was starting to accumulate. As we returned to the car a little after 1 pm, there was 1-1.5 cm on the ground. Winds were strong and gusty at all elevations today. While the prevailing direction seemed to be out of the SW, local topography led to very erratic wind direction, and it seemed to be blowing from all directions at some point this morning. Temperatures remained well below freezing throughout the day. 

NO signs of instability were observed on my tour, but there was a lot of snow blowing around today. Despite the small amounts of precipitation, I did observe some areas with fresh drifting BTL. Nothing too concerning 5-15 cm at the most, but I suspect if the snow continues to accumulate this afternoon, there will be some fresh wind slab development at mid and upper elevations today.

Snowpack photos: 
Weather Observations
Blowing Snow: 
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Air temperature trend: 
Wind Direction: 
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

1000 @8900' 26°F Moderate SW winds, obscured, S-1 

1200@10200' 19°F, Strong/Very strong NW winds, Obscured. S1

110@8700' 22°F, Strong SW, Obscured, S1

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