This is Matt Lutz of the Sawtooth National Forest Avalanche Center
 with your Backcountry Avalanche Advisory and Weather Forecast for
 Thursday, January 17, 2008 at 7:30 am.

 The Sun Valley Telemark Series & Smiley Creek Lodge & the Friends of
 the Sawtooth Avalanche Center bring you this advisory.

 Bottom Line:
 Today the avalanche danger is estimated to be MODERATE with
 pockets of CONSIDERABLE on steep recently wind loaded slopes.

 Faceted snow layers buried within our snowpack are widespread and
 remain a concern. Recent wind events have caused wind slabs to form on
 high elevation exposed slopes and ridgelines. Human triggered
 avalanches have the potential to be large and un-survivable.

 Primary Avalanche Concern:
 
 
 
 
 In the South and Central Valley faceted layers are widespread on all
 aspects and at all elevations. Basically one of 2 scenarios exists in
 the South and Central Valley. Either the entire snowpack is weak and
 faceted or there is a one to 2 foot deep slab sitting on top of weak
 large grained faceted/sugary snow. Areas of particular concern are
 slopes over 35 degrees, recently wind loaded slopes and areas that
 have a cohesive slab overlying the facets.

 In the North Valley, Smoky Mountains, and Sawtooth Mountains the snow
 pack is deeper and the distribution of faceted snow layers is more
 sporadic. Generally there are two faceted layers of concern in these
 areas. The first layer consists of large grained faceted/sugary snow
 near the ground. These layers are now between 4 to 5 feet deep. The
 second faceted layer of concern is buried between 2 to 3 feet deep.

 This layer is made up of near surface facets that are buried beneath
 the early January storm snow. This layer will reveal itself in
 stability tests as a clean thin shear sandwiched between relatively
 consolidated layers.

 Due to the spotty distribution of these faceted layers in our northern
 terrain, slope by slope evaluation, conservative decision making and
 use of lower angle terrain remains a prudent approach. No matter where
 you end up, when evaluating terrain the main red flag to look for
 within the snow pack is the presence of these faceted layers. This is
 true even if your stability tests are producing relatively strong test
 results and you are not seeing any other signs of instability. Due to
 the nature of our current snow pack, human trigger avalanches are
 possible and they have the potential to be large and destructive.

 Secondary Avalanche Concern:
 
 
 
 
 Tuesdays wind event moved a lot of snow around especially on higher
 elevation exposed slopes and ridgelines. Snow from this event was
 mainly deposited on southwest, south, southeast and east aspects. Most
 of this wind deposited snow followed higher elevation ridgelines but
 due to the strength of the recent winds, exposed slopes and spots like
 the Solider Mountain area also likely had wind slab formation mid
 slope along sub-ridges. Be on the lookout for wind pillows, hollow
 sounding supportable slabs, cracking, whumpfing and recent cornice
 failures as indications of areas with recently wind deposited snow.

 Additional Discussion With the recent cold and clear weather we have
 had, near surface faceting is occurring throughout our forecast area.

 Additionally we are likely to start to see the formation of surface
 hoar crystals. The forecast looks like we will be under high pressure
 for at least another week. If you observe surface hoar formation as
 you get out into the backcountry please let us know.

 Yesterday I posted some photos of slides I observed out Baker Creek.

 The photos were titled Thumper 1 and 2. Apparently these slides were
 the result of a remote skier trigger from the 14th of January and not
 from Tuesdays wind.

 Current Conditions:
 There are currently excellent soft snow riding conditions throughout
 our forecast area, especially in sheltered terrain. Wind pressed snow
 may be encountered on higher elevation exposed slopes and we have had
 reports of sun crusts starting to form on steep south aspects.

 This morning our forecast area is under clear skies with ridge top
 temperatures between 3 and 10 degrees. Valley temperatures are in the
 negative single digits. Ridge top winds are light with moderate gusts
 out or the northwest.

 Mountain Weather Forecast:
 Today will be mostly sunny with increasing clouds into the afternoon.

 Light snow showers will be possible over the Central Idaho Mountains
 this evening with precipitation amounts of an inch or less. Friday
 will be mostly sunny with slightly warmer temperatures. Winds will
 remain out of the northwest. I dont like to get into the habit of long
 range weather forecasting, but current models are indicating that we
 will be under the influence of fairly stable high pressure for the
 next week or two.