Whumphing and Collapsing off East Ridge of Relay Peak

Location Name: 
East Ridge Relay Peak
Region: 
Mount Rose Area
Date and time of observation: 
Tue, 01/15/2013 - 09:00
Location Map: 
United States
39° 18' 41.202" N, 119° 56' 32.208" W
See map: Google Maps
US


Red Flags: 
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Observation made by: Professional Observer
Snowpit Observations
More detailed information about the snowpack: 

Several large whumps and collapses felt today while skinning up into this area.  Snowpits and stability tests were done where the 2 largest whumphs were felt, both areas had ECT's failing while isolating the column.  Both had a buried melt freeze crust that had facets growing below the crust that was the failure layer.  Aspects of concern were E-SE, from 9500'-10,000', with HS 195-210cm.  On North aspects the buried melt freeze crust was not found and on South aspects the crust was much thicker and stronger, 4-6'' thick.

All exposed terrain to the recent N-NE-E winds are hammered and highly variable.

 

Photo#1:  Small wind slab off ridgeline, 8'' deep, 10,000', South aspect.

Video#1:  Tests done on slope after large whump was felt while skiing up a 25 degree slope.  ECTPV on facets below a melt freeze crust..  Dense wind slab ranged from 1'-2.5' deep.  9800', East aspect, 25 degree slope, GPS coordinates provided above.

Video#2:  ECTPV failing on facets below a 3'' melt freeze crust.  Slab 1' deep.  SE aspect, 9950', 25 degree slope.  N 39.31274 W 119.94339  

Video#3:  Strong N winds on ridgelines at 10,000'.  Very little snow available for transport with little snow movement.

Snowpack photos: 
Snowpit videos (tests, etc): 

Mt Rose2013 1 15 003

Mt Rose2013 1 15 008

Mt Rose2013 1 15 006

Weather Observations
Blowing Snow: 
Air temperature: 
Below Freezing
Wind Speed: 
Strong
Precipitation: 
Air temperature trend: 
Warming
Wind Direction: 
North
Accumulation rate: 
More detailed information about the weather: