900 AM PST SUN DEC 28 2008 && ZONE AVALANCHE FORECASTS * EAST SLOPES WASHINGTON CASCADES Sunday: High avalanche danger above 5 to 6000 feet and considerable below. Sunday night: High danger above 5 to 6000 feet and considerable below but slightly decreasing. Monday and Monday night: Increasing high avalanche danger above 5000 feet and considerable below, slowly decreasing overnight. SNOWPACK ANALYSIS Additional heavy amounts of new snow have accumulated at warmer temperatures and strong winds. New snow amounts have ranged from 10-20 inches along the west slope areas of the Cascades, Olympics and Mt Hood area at higher elevations. Significantly warmer temperatures occurred Saturday with the heavy loading changing snow to rain in the central Cascades to near 4000 feet and above 5000 feet at Mt Hood. Above 4000 feet in Cascades and Olympics and 5000 ft in the Mt Hood area, this has created increasing amounts of dense snow deposited over a very weak underlying snowpack. These unusually unstable snow pack conditions have caused a generally high avalanche danger, especially above 4000 feet. Backcountry travel in avalanche terrain is not recommended until the snowpack has stabilized. Significant cooling is occurring early Sunday and has allowed previous wet snow to begin refreezing and forming a crust under the most recent snow at lower elevations, mainly below 4000 feet. At these lower elevations, this has caused a brief decrease in danger; however the continued moderate to heavy snowfall early Sunday should continue to stress the weak underlying layers. Strong winds and continued heavy amounts of recent snow over the past few days continue to stress and overburden a very weak underlying snowpack structure. The cold weather from mid December until recently has recrystalized and faceted much of the snowpack above the ground, especially in areas where strong winds in late December scoured much of the low density surface snow that was easily available for winds transport. There have been numerous avalanches reported over the past few days from natural, human or explosive triggers. Some natural slides have released down to the ground or near ground on the weak basal snow. DETAILED FORECASTS SUNDAY AND SUNDAY NIGHT Strong winds and moderate to heavy snow showers are expected Sunday at cooling temperatures. While cooling should allow for refreezing and strengthening of the snowpack below 4000 feet, a continued high danger is expected in avalanche terrain above 4000 feet Sunday. Decreasing winds and snow showers overnight Sunday should allow for a slow decrease in danger. Less recent snow and a shallower snowpack east of the Cascade crest is maintaining slightly lower danger along the east slopes. MONDAY AND MONDAY NIGHT Increasing winds and increasing moderate to heavy snow Monday morning should again cause an increasing danger. The significant amounts of dense new snow should continue to overload and burden weak underlying snow. This should cause a high danger in most areas and backcountry travel in avalanche terrain is not recommended Monday. Slightly decreasing snow showers and winds overnight should allow for a slight decrease in danger.