Hello, this
is Toby Weed of the
Current Conditions:
The freezing-rain or rime crust that formed
on the snow surface today at higher elevations reminded me of East Coast snow
conditions. Although it's always nice to get out, I thought the traveling
conditions in the backcountry were horrendous. First we got the truck
stuck in icy slush as we pulled into the trailhead parking. Then we got
soaked all day by East Coast-like drizzle as we slogged through shin-deep very
top-heavy snow. We needed windshield wipers on our goggles, and rain-gear
as opposed to the powder-shedding gear we wore. We found trail-breaking
both time-consuming and tedious. The loud turning conditions through the
forming crust were quite challenging...just like touring in
Avalanche Conditions:
Today we noticed a few recent localized natural slab avalanches above 8000', mostly on east facing slopes. As I took my turn breaking trail, I triggered a couple audible collapses or whoomfing noises, which are caused by a compressive failure of a weak layer overlain by a slab. Many of our test pits showed very weak snow right under the now sticky, mashed-potato-like snow that's fallen since Saturday morning. On lots of slopes in the region, a couple inches of light cold snow that fell near the end of last week nicely preserved a layer of frost crystals or surface hoar and small sugary grains called near-surface facets. The localized natural avalanches we saw today occurred on slopes steeper than about 35 degrees where this weekend's storm drifted heavy moist slabs onto this weak surface snow. If the rain-crust freezes up nicely tonight it could lock things up, but on some slopes the instability will probably linger for a few days.
Another problem is the warmth.
Tomorrow will be unseasonably warm, with high temperatures at 8500' forecast to
reach well into the forties. What a difference from last week's arctic
conditions. This afternoon we noticed a number of wet avalanches visible
from the road in
Bottom Line:
On Wednesday you'll find a CONSIDERABLE avalanche danger on slopes steeper than 35 degrees with significant deposits of previously wind-drifted snow. Slopes above 8000' facing north through east with weak sugary underlying snow are the most suspect. The danger is MODERATE and you might trigger avalanches on steep slopes even without obvious deposits of wind-drifted snow. There will also be a CONSIDERABLE danger of wet point-release avalanches on steep lower and mid-elevation slopes with shallow overall snow-cover.
Mountain Weather:
The moist Pacific flow will continue through the week. Tomorrow, we'll have the best chance for a break, with warm temperatures, mostly cloudy skies and a chance of snow or rain showers. Snow is in the forecast for Wednesday night and Thursday, with a stronger period of storminess predicted for Thursday night. At this point, Christmas weekend looks to be partly cloudy with a flake or two possible.
General Information:
For a list of our upcoming classes and awareness talks, go to our education page
Snow nerds, check out the new Snow Profiles page.
Please send backcountry observations to uaclogan@avalanche.org, especially if you see or trigger an avalanche in the backcountry.
This advisory will expire on Wednesday night. But, I will update it again on Thursday night.
The information in this advisory is from the U.S. Forest Service, which is solely responsible for its content. This advisory describes general avalanche conditions and local variations always occur.
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National Weather Service - Salt Lake City - Snow.
