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Logan
A special avalanche
advisory has been issued for the mountains of northern Utah for the weekend. A weak snowpack and record breaking
temperatures have created a Considerable to High avalanche
danger,
with both human triggered and natural avalanches probable. These dangerous avalanches have the
potential to be very large and long running. Steep slopes and the areas below steep
slopes should be avoided. People
without excellent backcountry and route finding skills should stay out of the
backcountry this weekend.
Hello and happy Saint Patrick’s Day,
this is Toby Weed of the
Current Conditions:
Other than recommending a color
choice for your shorts, I’m afraid I’ll have to leave any mention of green out
of todays advisory. My calendar
tells me it’s still winter, but temperatures will be mid-summer-like in the
mountains today. In fact with the
solar-oven-effect in full play, it will actually be much hotter in some places
than it generally gets in July. Record-setting heat is wrecking havoc on
our sorry snowpack, and lower elevation roads and trails are completely melted
out. Across the region last night
overnight temperatures stayed well above freezing at all elevations. Any surface refreeze will by superficial
and supportable snow conditions won’t last long this morning. Under clear skies, temperatures on the
highest peaks will reach the mid-fifties by mid-afternoon, and you could
probably cook the corn-beef and cabbage in the intense reflected heat of a sunny
bowl.
Avalanche
Conditions:
Wet
loose and slab avalanches were quite common across the region earlier this
week. A couple nights with below
freezing temperatures settled down the natural activity in the last couple days,
but things will probably get moving again in today’s heat. Most steep sunny slopes in the region
show signs of recent wet avalanche activity, and some of this has been fairly
significant. As far as I can tell,
we’ve so far escaped the huge warmth related avalanche cycle which has been
producing very impressive natural and human triggered slides in the
With
continued exceptionally hot weather forecast through the weekend, wet avalanches
will be a serious problem in the backcountry. Today the superficially frozen
surface snow will get mushy and dangerous much earlier than yesterday, and
tomorrow it will “go off” even earlier. The warmth this weekend will continue to
deform cornices, and some are likely to fail, potentially triggering avalanches
on steep slushy slopes below. Once
the snow gets saturated by heat-induced melt, wet avalanches will become likely
on steep slopes at all elevations. Persistent slab avalanches are very
possible on steep upper elevation slopes, and the problem is most certainly
worsened by the continuing heat-wave.
Heat induced creep and glide could easily cause large natural slab
avalanches, like the recent huge natural avalanches in the Wasatch. Slab
softening (also due to the heat) will make previously thick hard slabs more
susceptible to human triggering.
Slopes that easily may have supported your weight yesterday may be
sensitive to the weight of a snowshoe hare today.
Bottom Line:
There’s a CONSIDERABLE danger today, and wet avalanches
are probable on steep slopes with saturated snow at all elevations in the
backcountry. The danger will rise
with heating during the day and may increase to HIGH in some areas. Some avalanches
might step down into buried weak layers and be large, destructive and deadly.
Some avalanches could be fairly long-running, and are likely to descend well
below the existing snow-line into dry lower elevation terrain. Avoid and stay
out from under obvious and historic avalanche paths and all saturated slopes
steeper than about 35 degrees.
Mountain Weather:
A strong high pressure system will
be over the region through the weekend, and unseasonably hot temperatures will
continue. An approaching Pacific
storm will bring increasing clouds and warm prefrontal wind to the region on
Monday. We could see a little
lightning and gusty conditions on Tuesday, and a bit of
Snowfall is likely Tuesday night into Wednesday.
General Information:
Check out photos of last week's
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 also recommend the recently-released Media Page, which
shows the forecast danger for our coverage areas across the state.
Please e-mail me at
[email protected] or leave me a message at 755-3638 if you see or trigger
avalanches in the backcountry. The information you provide may save
lives...
I will update this advisory again on
Sunday morning.
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.
