Support the forecast! Support the forecast!

Give to Friends of the Chugach National Forest Avalanche Info Center.

Observation: Turnagain

Location: Magnum - Sunburst

Date:
Observer:
Route & General Observations

Observed 2 natural avalanches on the SW face of Sunburst:
#1 @ 5pm on SW face of sunburst (~3,500′ West of Wx station)
Dimensions: 200-300’ wide, ran ~1,000’ (full track), estimated crown depth 2’
-start zone was ~100’ below ridge
-this was adjacent & connected to a slope that had a crown in it (from earlier
in the day)

#2 @ 5:15 pm 1/4 mi to the East of the first avalanche
This looked like a cross loaded pocket.
-start zone was 200’ below ridge
Dimensions: 50’ wide, ran ~1,000 (full track)

Winds were strong out of the East & Northeast between 4:30-5:30. Observed
plumes on Lipps and witnessed rapid loading on SW facing Sunburst. Winds were
not as strong on Magnum & Cornbiscuit. It seemed like rapid loading from wind +
slopes sitting in the sun were the main factors leading to these 2 slides.

We were not able to see any people or tracks going into the 1st avalanche, which
we witnessed after the debris had begun moving. The 2nd one we witnessed in its
entirety – confirmed natural trigger (see video).

Pit:
Dug ~100’ below the ridge in PMS bowl
30 deg slope @ 2,800’
S aspect, HS=190cm
Weak snow (2mm facets) was found BELOW the January crust in a couple of spots
and we had an ECTP13 SC in this layer. 3 more ECTs produced no remarkable
results. This was a “pockety” layer within the pit, much like what was observed
in Lynx creek on 2-20.

Surface Obs: Sun crust forming on S slopes >25 degrees.

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.