Forecaster Observation - Marion/Essex Creeks, Flathead Range

Location Name: 
Forecaster Observation - Marion/Essex Creeks, Flathead Range
Region: 
Flathead Range - Middle Fork Corridor
Date and time of observation: 
Tue, 02/09/2016 - 12:00
Location Map: 

Red Flags: 
Rapid warming
Observation made by: Forecaster
Snowpit Observations
More detailed information about the snowpack: 

Moist surface snow (and down about 15cm from the surface) existed on sunny aspects. Rollerballs and small point releases occurred throughout the day. Lingering wind slabs existed on shaded north, northeast, and east aspects. These wind slabs fractured in stability tests but did not propagate across the entire column. Thin, high, spotty cloud cover inhibited solar warming on sunny aspects for the first part of the day, but as the sky completely cleared in the mid-afternoon wet looose sluffs began in earnest on sunny aspects. Wet snow avalanches were the main concern today. The lower elevations stayed relatively cool due a temperature inversion. The most noticeable layer in our snowpits today was the Jan. 28 rain crust. In a pit on an east-southeast aspect it was about 35 cm (14 inches) from the surface and on a previously wind loaded north aspect pit it was located about 78 cm (30 inches) from the surface. There is some weak, faceted snow above and below this layer but it did not fracture and the break did not propagate in our stability tests.

We also observed 3 old natural avalanches (wind slabs) from last weekend. These were all north and east facing aspects near ridgelines and because they were almost completely filled in from prior wind loading it was difficult to assess the depth and width of the crowns (see images below). Last weekend's strong to extreme winds produced wind crust about 10-15 cm thick at the snow surface at many elevations in open areas. Soft (and somewhat moist due to warming temps) snow exists in protected areas. All sunny aspects developed a melt-freeze (sun) crust last night. 

Pit 1: East-Southeast aspect, 34 degree slope, 6950 ft. Sky=3/8

Total Snow Depth (HS) = 207 cm

ECTN 27 @ 180 cm from the ground

CT 21 Q1 @ 155 cm from the ground that released on 4mm graupel 

Pit 2: North aspect, 34 degree slope, 7200 ft. Sky=0/8

Total Snow Depth (HS) = 280 cm

ECTN 12 @ 255 cm from the ground that released at bottom of hard (1F+) wind slab

ECTN 29 @ 245 cm from the ground

CT 5 @ 255 cm from the ground that released at bottom of hard (1F+) wind slab

 





 

Snowpack photos: 
Weather Observations
Blowing Snow: 
No
Cloud Cover: 
Clear
Air temperature: 
Above Freezing
Wind Speed: 
Light (Twigs in motion)
Precipitation: 
None
Air temperature trend: 
Warming
Wind Direction: 
Southwest
Accumulation rate: 
None
More detailed information about the weather: 

Thin high clouds earlier in the day gave way to mostly clear skies in the early afternoon. Temperature inversion with the transition to warmer temperatures around 4500 ft. 

Activity: 
Skiing
High Temp. (C): 
5.0
Low Temp. (C): 
-4