930 AM PST THU JAN 31 2008 && ZONE AVALANCHE FORECASTS * OLYMPICS-WASHINGTON CASCADES NEAR AND WEST OF THE CREST- MT HOOD AREA- ...AVALANCHE WARNING... HIGH avalanche danger below 7000 feet Thursday through early Friday. Slow decrease in avalanche danger Friday afternoon and night becoming HIGH above 5000 feet and CONSIDERABLE below. * WASHINGTON CASCADES EAST OF THE CREST- ...AVALANCHE WARNING... HIGH avalanche danger above 4000 feet and CONSIDERABLE below Thursday through early Friday. Gradually decreasing avalanche danger Friday afternoon and night becoming HIGH above 5 to 6000 feet and CONSIDERABLE below. SNOWPACK ANALYSIS Additional heavy snow of 12 to 20 inches has accumulated since early Wednesday with slightly less new snow along the east slopes but ranging up to 12 inches. The recent snow fell with briefly warming temperatures late Wednesday afternoon and again early Thursday morning with the frontal passage. These warming periods helped to cause widespread natural avalanches as weak lower density snow was loaded with denser wind and temperature affected denser snow. These conditions produced widespread natural avalanches that have occurred from late Wednesday through early Thursday morning. Many paths have released numerous times including controlled slopes have re-loaded and released. Smooth wind or sun crust layers were formed during fair weather a week ago. This is also when surface hoar formed as well as near surface faceting near these old crust layers or above older snow. This has created good sliding surfaces as well as supplying the weak layers. Subsequent low density snow that fell over the weekend is also contributing to weak layers. Some 4 to 6 feet of snow has accumulated over these weak layers over the past five days. This is maintaining the possibility of some large slides and potentially destructive slides. Continued heavy snow accumulations are expected through early Friday, especially along the west slope areas and volcanoes. This should maintain mostly unstable snow with additional natural avalanches likely and some large and potentially destructive slides possible. We do not recommend back country travel near avalanche terrain on Thursday. THURSDAY AND THURSDAY NIGHT In the wake of a strong cold front passage early Thursday, strong and moist westerly flow should maintain moderate to heavy snowfall at gradually cooling temperatures Thursday and Thursday night. The heaviest snowfall should be along the west slope areas and over the volcanic peaks. Dense wind affected new unstable snow layers should continue to load buried weak snow making natural or triggered slab avalanches likely. We do not recommend back country travel near avalanche terrain on Thursday. These conditions should continue Thursday night. FRIDAY AND FRIDAY NIGHT Continued moist westerly flow early Friday should maintain moderate snow along the west slopes, especially the central passes where an active convergence zone is expected to enhance snowfall. This should maintain mostly unstable snow and a generally high danger. Decreasing winds and gradual drying later Friday and Friday night should allow for a slow decrease in the danger as unstable layers begin to settle and stabilize. &&