Introduction: Good
morning! This is Evan Stevens with the
USFS Manti-La Sal Avalanche Center with your avalanche and mountain weather
advisory. Today is Sunday, February 27th,
2005 at 7:30 am. This bulletin is
sponsored in part by Western Spirit,
offering cycling adventures in Moab and beyond, proud sponsors of the Friends
of the Manti-La Sal Avalanche Center.
This advisory will expire in 24 hours.
To see past advisories check out the ARCHIVE. To see current conditions go to our WEATHER PAGE. To see photos go to the AVIPHOTOS page.
General Conditions:
Well, if yesterday was a precursor, then today will provide snow
conditions that you dream about. With 6
inches new on Friday night and another 6” of snow during the day yesterday, we
are now skiing and riding about 1-1.5’ of fresh snow. If you get out early this morning, you should be able to catch
the southerly aspects with some decent snow, but the sun will hit them
hard. Northerly aspects at and below
treeline are providing amazing skiing and riding. The road to Geyser Pass is not plowed, but is not under too much
new snow, and 4WD is recommended. The
road to Dark Canyon is in pretty bad shape, unplowed, rutted out and
muddy-rough riding with high clearance and 4WD recommended.
Current Conditions: (click location for latest data)
Geyser
Pass Trailhead (9,600’): 55” at the
SNOTEL, it is 15 degrees at the TH at 6:00 am.
Pre-Laurel
Peak (11,700’): still trying to fix it!
Gold Basin and South Mountain:
90” to 105” of settled snow on the ground.
Mountain Weather: (At 10,500’)
The
low pressure system that was causing our afternoon snow showers is gone
now-partly cloudy to clear skies for a few days with temperatures warming
up. We might see a few gusts reach 15
mph during the day.
Today:
Partly cloudy, with
a high around 33. North northeast wind around 5 mph.
Tonight: Partly cloudy, with a low around 11. North northwest wind
around 5 mph.
Monday: Partly cloudy, with a high near 30. North northwest wind between
5 and 10 mph, with gusts as high as 20 mph.
Avalanche Conditions:
With
about 12” of new snow in the last 36 hours, and about 18” total since the
beginning of the week, not only are ski conditions perfect, but the ingredients
for avalanche activity are all there as well.
Our snowpack has an abundance of weak layers in it right now. About 18” down is a crust/facet interface-a
very weak combination-from the beginning of last weekend’s storm. We also have, in at least two different
depths in those upper 18” of snow, two buried surface hoar layers, which were
deposited in between our afternoon snow thunderstorms this week. Enough fancy talk, what does this all
mean? It is really simple, the
crust/facet interface 18” down is the perfect weak layer and bed surface
combination, with a sizeable slab on top of it. Yesterday’s snow did not bring us to the natural avalanche
breaking point but 2 slides were triggered intentionally that are indicative of
what our avalanche danger is. The most
significant slide was triggered on ‘Noriega’s Face’(photo1,
photo2,
photo3,
photo4,
photo5),
a 35 degree north aspect at about 10,500’.
The slide was triggered from 20 feet away on a low 20 degree slope on a
ridgeline. It averaged about 18” deep
and ran on the weak crust-facet interface.
The second slide triggered, was a small one in the Corkscrew Glades area
(photo1,
photo2),
on a 36 degree north facing slope at about 11,000’. It entrained the top 4-6” of new snow which fell on a surface
hoar layer formed the night before. What
is interesting about this last slide is that it also remotely triggered a small
pocket about 20 feet away-tell tale of how sensitive some of these weak layers
are. Although a slide like this might not bury you, it could still take you for
a nasty ride into the wrong spot. One
thing that has been on our side is the lack of winds-keep an eye to the sky for
increased winds, which should not happen today, but if they do will start some
avalanche activity.
So
the bottom line for today is an avalanche danger of CONSIDERABLE on open slopes steeper
than 30 to 35 degrees at all elevations especially on NE-N-NW aspects, but you
could see action on the open sunny slopes as well, harboring many weak
crust-facet interfaces. Remember that CONSIDERABLE means human triggered
avalanches are PROBABLE, as activity from yesterday tells us. Expect sluffing of the new snow on any steep
open and shady slope with our light and fluffy new snow. On slopes lower than 30 degrees the
avalanche danger is LOW to MODERATE.
Nordic and Skate Skiing:
New snow, so go out and break trail.