Whumpfing and collapsing.

Location Name: 
South Corner, below PPG Yurts/North Fork Lake Fork Drainage
Region: 
Lick Creek Area
Date and time of observation: 
Sun, 02/18/2018 - 13:30
Location Map: 
United States
45° 1' 29.3916" N, 115° 55' 16.1328" W
US


Red Flags: 
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain

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

Widespread collapsing of snowpack between 7400 and 7800 ft.  Crust from extended high pressure was decomposing and creating widespread collapses/whumphing on a layer of faceted snow below it but above deeper crust between 50 and 60cm.  Numerous mit pits and hasty pit showed about 20 cm of light density snow(Thursday/Friday snwo) with upside down layer of warmer, wind affected(Saturday) snow at surface all of which was poorly bonded to crust layer which was the surface prior to the Wednesday night storm.   In some areas, crust was not decomposing as fast and was still supportable. Ski cuts on steep rollovers had no effect.  No natural avalanches were observed(possibly not seen) during late afternoon breaks in the cloud cover on the steeper terain in the Lick Creek Canyon.  Wind slab formations were observed near ridgetops in exposed terrain.  

Weather Observations
Blowing Snow: 
No
Cloud Cover: 
75% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Light
Precipitation: 
Snow
Air temperature trend: 
Cooling
Wind Direction: 
Southwest
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Periods of heavy precip which turned to grauple late in the afternoon.  Sun was out for about 30 mins around 3pm.