0815 AM PST WED JAN 16 2008 && ZONE AVALANCHE FORECASTS * OLYMPICS, WASHINGTON CASCADES NEAR AND WEST OF THE CREST, MT HOOD AREA- Considerable avalanche danger above 5000 feet and moderate below slowly and slightly decreasing Wednesday and becoming moderate below 7000 feet Wednesday night, with greatest danger on lee slopes near higher ridges and slopes receiving sunshine Wednesday. Slightly increasing danger likely Thursday, mainly on sunny southeast through southwest facing terrain where locally considerable danger is expected. Slightly decreasing danger Thursday night. * EAST SLOPES WASHINGTON CASCADES- Considerable avalanche danger above 5 to 6000 feet and moderate below slowly and slightly decreasing Wednesday and becoming moderate below 7000 feet Wednesday night, with greatest danger on lee slopes near higher ridges and slopes receiving sunshine Wednesday. Slightly increasing danger likely Thursday, mainly on sunny southeast through southwest facing terrain where locally considerable danger is expected. Slightly decreasing danger Thursday night. SNOWPACK ANALYSIS Recent weather mid-late Monday through early Tuesday included strong winds, rapidly lowering freezing levels and increasing rain or local freezing rain changing to snow Monday afternoon with some moderate to heavy new snow amounts received overnight. This was followed by rapidly decreasing showers and winds early-mid Tuesday, and some partial clearing mid-late Tuesday along with further decreasing winds. Initially this weather allowed for formation of some near surface crusts that helped to reduce the danger from older buried weak layers of surface hoar and lower density lower wind deposited snow layers formed late last week and over the weekend, especially at lower and mid elevations and on wind exposed terrain. However, the new snow combined with strong winds helped produce new and in some cases hard wind slabs on southeast through northeast exposures, especially above about 4 to 5000 feet where a considerable avalanche danger developed. At lower elevations, shallow wind slabs were relatively well bonded to a moderate rain or freezing rain crust formed Monday afternoon; however some weak layers within the snow Monday night produced a moderate danger with mostly small human triggered slabs possible. While a similarly good bond developed between larger amounts of new snow and a weaker and very thin crust or refreezing wet heavy snow layer at higher elevations, more of the recent precipitation fell as snow mid-late Monday and stronger winds created some larger wind slabs over the weaker crust or denser snow layers. Although the high winds late Monday and early Tuesday should have scoured much of the new snow down to a fairly stable wind hardened or crusty surface on wind exposed terrain above about 5000 feet, the same winds produced a considerable danger and unstable wind slabs ranging up to 2 to 3 feet on wind loaded northeast through southeast exposures. Since this slab development, snowpack settlement of 3 to 7 inches Tuesday has helped to slowly reduce the danger with recent wind slabs beginning to settle. However, field reports from Tuesday indicated several easy to moderate shears within the most recently deposited new snow, along with some isolated natural slab releases and some easily ski triggered slabs up to about 1-2 feet on steeper wind loaded terrain, mainly southeast through northeast exposures. These slabs were reported releasing on a weakening bond to Mondays rain crust, which has experienced slow faceting since formation. DETAILED FORECASTS WEDNESDAY, WEDNESDAY NIGHT Considerable mid and high clouds are expected Wednesday through early Thursday, especially in the north along with a chance of a few flurries or light showers in the northern Washington Cascades and Olympics. However, considerable sunshine or filtered sunshine is likely in the south-central Washington Cascades and Mt Hood area along with slowly decreasing winds. Along with initially low temperatures this weather should allow for an overall slow decrease in the danger with little or no new snow accumulation expected and further slow snowpack settlement likely. However, a decreasing though still considerable danger should persist on wind loaded lee slopes above 5 to 6000 feet where the bond of recent slabs to the old crust should continue to weaken Also, a locally increased danger is likely on slopes receiving sunshine. Increasing surface hoar formation is also likely in areas experiencing clearing overnight. THURSDAY, THURSDAY NIGHT Clouds and light showers, mainly in the north, should decrease Thursday morning with relatively light winds, higher freezing levels and mostly sunny weather likely Thursday afternoon. The warming and sunshine should allow for a slight increase in the danger, especially on recently wind loaded northeast, east, and southeast through southwest slopes as well as on sun exposed terrain where natural loose or isolated slab releases are possible and human triggered slides probable. Mostly fair skies and relatively light winds Thursday night should allow for a slight decrease in the danger as wet snow refreezes and strengthens. However, it should also allow for more surface hoar formation over either the developing surface sun crust or older wind slabs. Both the surface hoar and any faceting that occurs near Mondays crust should be monitored as they may become important considerations when future snow loading occurs. &&