Observation: Summit

Location: Manitoba

Date:
Observer:
Route & General Observations

Manitoba to 3400′ on the standard uptrack

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Observer Comments

Occasional moderate snow transport on neighboring peaks, generally just at the highest elevations in the area.
No other red flags, and no recent avalanche activity observed from the highway in the Summit Lake zone north of Manitoba.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.
Weather

Clear and COLD! Temps in the single digits.
Occasional light winds from the SW to N above treeline to 3400'
Snow transport off nearby peaks indicated that there was stronger winds at peak level.

Snow surface

Soft snow from two smaller storms in the past week!
A wind skin -> up to 1" thick soft and very carvable wind slabs above 2700' - 3300'.
At our high point (3400') winds had created some small areas of wind slab, 1-2" thick.

Snowpack

Storms from November have left a very consistent height of snow from parking lot to ridgeline: 80 - 100cm in total snowpack depth, with the exception of some wind redistribution of snow above 2500'. The pit at 3300' was dug after probing for several hundred yards on the skin track between 3200' and 3300', with height of snow only varying from 80-120cm in an area that looked quite wind affected on the surface. This probing between 3200' and 3300' revealed a melt freeze crust over facets at the ground structure at this elevation, as pictured in the pit; probing and quick hand digging couldn't find that older snow layer below 3000', similar to recent observations on Turnagain Pass.

Structure wise, the 11/8 - 11/9 mega storm has settled to roughly 50-60 cm thick along the entire route, and at the pit location had hardened to 4 finger+ at the top. 6-8mm buried surface hoar (BSH) sat on that mega-storm layer, and was covered by the 11/13 storm. The BSH was obvious in the pit wall to the naked eye here and reactive in stability tests, but wasn't as obvious or always found at lower elevations, where there wasn't also a noticeable hardness change between the mega-storm and new snow this week.

Interestingly, the melt freeze layer that formed during the middle of the 11/8 to 11/9 storm - as observed in Turnagain and Chugach State Park - was NOT found on Manitoba, even at the lowest elevations (~1200') on the route.

Photos & Video
Please upload photos below. Maximum of 5 megabytes per image. Click here for help on resizing images. If you are having trouble uploading please email images separately to staff.