Hello and good morning, this is Toby Weed of the
Current Conditions:
The mountians
around Logan picked up several feet of snow in the last week, and backcountry snow
conditions are looking good at all elevations. You’ll find good powder today on
most slopes, with some wind carnage in terrain exposed to west winds. The Tony
Grove Snotel reports 4/10s of an inch of water or around 6 inches of new snow
in the last 24 hrs, and there’s 74 inches of total snow on the ground. Water-wise the station has climbed to 83 % of
average water in the snow for the date.
Even with about 3’ of fresh light powder on the snow surface, trail
breaking and powder riding conditions have improved in the last couple days,
and I expect that a number of us will make it up into higher terrain this
weekend.
Avalanche
Conditions:
Numerous natural new snow
avalanches occurred across the region during or right after Wednesday’s storm,
and I greatly appreciate the helpful observations you’ve been sending my way. Of interest, is the number of low elevation
avalanches, like wind slab releases near the mouths of Logan and Green Canyons and
the lower roll of the Oscar Meyer slide path in Dry Canyon. Recent local activity has been confined to new
or freshly drifted snow, and I suspect that most of the culprit instabilities
have healed.
The additional weight from the
productive and snowy week might be just enough to put some slopes on the
edge. The good news is that the Deep
Slab instability caused by faceted or sugary snow near the ground is now so
deeply buried in many places that your weight alone probably won’t be enough to
activate it. The bad news is that you
might not get any tell-tail signs of danger until you actually trigger the slab
from a shallow or weak spot. Potential
hard slab avalanches could be several feet deep, very broad and deadly.
Possible trigger spots include rocky or generally shallow areas, like cliffy
lower elevation areas or upper elevation slopes scoured by previous winds. Overrunning wind slab avalanches or cornice
falls might trigger a deeper release, leading to a much larger avalanche.
Increasing west winds and
additional snowfall today will cause a rising danger in exposed terrain. Watch for freshly formed or building wind
slabs, and avoid them on steep slopes at all elevations. Be wary of the dangerous combination of
faceted snow near the ground and recent drifting on slopes with shallow overall
snowcover at mid and lower elevations.
Bottom Line:
There’s a MODERATE
danger and you could trigger wind slab avalanches at any elevation on steep
slopes exposed to drifting in the backcountry. Although less probable, deadly
triggered deep slab avalanches are still possible on slopes with existing weak
snow near the ground, mainly in exposed upper elevation terrain. Increasing west winds and snowfall today could
cause the danger in some areas to rise to CONSIDERABLE or become more
widespread. Use good snow assessment and
safe travel techniques to minimize your risks.
Mountain Weather:
The National Weather Service continued a Snow
and Blowing Snow Advisory for the mountains around Logan until 4:00 this
afternoon. Expect 4 to 8 additional inches of accumulation in the mountains and
west winds with ridgetop gusts in the 40 to 50 mph range. The snowfall and winds should taper off by
evening. An even weaker storm will move
over the region tomorrow afternoon and evening as a high pressure system builds
to our west. We’ll be in a mostly dry
and cold northerly flow for the early part of next week.
General Information:
Check out photos of avalanches in
the Logan Area on our images page.
Go to the Avalanche Encyclopedia if
you have any questions about terms I use in the advisory
I'm very interested to know what
you're seeing out there. Please e-mail observations to me at uaclogan@avalanche.org or leave me a message at 755-3638,
especially if you see or trigger an avalanche in the backcountry. We keep all
observations confidential.
This advisory will expire in 24
hours from the posting time.
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.