Monday - December 31, 2007 - 7:08 am

AVALANCHE WARNING!!! >>>

Special Avalanche Advisory:

A Special Avalanche Advisory has been issued for the Uinta Mountains
where a HIGH avalanche danger exists.  High wind and heavy snow has
overloaded an especially weak, pre-existing snowpack.  Avalanches will
be large, deep and persistently unstable.  Backcountry travelers
should avoid all slopes especially ones that face the north and east
quadrants of the compass at elevations above about 9,500.

SUMMARY >>>

The danger is CONSIDERABLE on any slope approaching 35 degrees or
steeper, especially slopes with recent wind deposits.  This means that
human triggered avalanches are probable.   There is still a
possibility of lingering, deep-slab potential shady slopes facing
northwest, north and northeast, above about 9,500, where it is
possible to trigger a deep, dangerous slide releasing near the
ground.

Be advised, there is a HIGH avalanche danger in the Uinta Mountains
which has a much weaker pre-existing snowpack.
Forecaster: Bruce Tremper

CURRENT CONDITIONS >>>

Yesterday was a wild day in the mountains with very strong west to
northwest winds, heavy snow and widespread avalanche activity.  Very
difficult trail breaking in upside down snow and poor visibility
helped to limit backcountry avalanche incidents.  The winds blew as
hard as 55 mph, gusting to 80 on the most exposed peaks. 8-18 inches
of snow fell yesterday with storm totals of 2-3 feet over the
weekend.  The wind has decreased a little this morning, but its still
blowing hard from the northwest 20-40 mph with stronger gusts.  Ridge
top temperatures have plummeted to zero.  Its Frostbite City at 11,000
with winds blowing 40 mph, gusting to 70 and temperatures are -6. But
we expect winds to decrease today.  Trailbreaking will continue to be
hard in slabby, deep snow.  Bring equipment with a lot of surface
area.

RECENT AVALANCHES AND SNOWPACK INFO >>>

Ski area control work reported widespread, sensitive wind slabs at
almost all aspects and elevations and many natural avalanches occurred
in the backcountry yesterday within the new snow.  One experienced
backcountry skier backed off the steeper slopes in lower Butler Fork
in Big Cottonwood Canyon and on his way out, triggered an 8 inch deep,
100 wide, wind slab that buried the trail 4 deep .

AVALANCHE CONCERNS >>>

I expect that the snow has settled a bit overnight, especially with
the colder temperatures, which means that we may not see many natural
avalanches today, but theres still plenty of human-triggered potential
on any slope approaching 35 degrees or steeper, especially slopes with
recent wind deposits.  Since the wind affected nearly all terrain, you
will find these wind-deposited slopes from near the valley floor to
the tops of the mountains and on all aspects.  The slabs are stiff,
heavy and thick, so any avalanches you do trigger today could easily
be tree-snappers and hard to survive.

There is still a possibility of lingering, deep-slab potential shady
slopes facing northwest, north and northeast, above about 9,500, where
it is possible to trigger a deep, dangerous slide releasing near the
ground.

MOUNTAIN WEATHER >>>

Ridge top winds will diminish today but youll still need a down coat,
mittens and a face mask.  Winds should diminish from 30 mph from the
west to around 15 mph and ridge top temperatures should remain in the
single digits and near zero on the highest peaks. Theres still a few
lake-effect squalls lingering this morning but we should have partly
cloudy to clear skies for much of the day.

On New Years Day, the temperatures should warm dramatically to near
freezing and we will be in a strong high pressure ridge for most of
the week.  Then it looks like another strong storm for next weekend.