145 PM PST FRI JAN 18 2008 && ZONE AVALANCHE FORECASTS * OLYMPICS, WASHINGTON CASCADES NEAR AND WEST OF THE CREST- Friday: Moderate avalanche danger below 7000 feet. Saturday: Increasing considerable avalanche danger above 4-5000 feet and moderate below. * EAST SLOPES OF THE WASHINGTON CASCADES- Friday: Moderate avalanche danger below 7000 feet. Saturday: Increasing considerable avalanche danger above 5000 feet and moderate below. * MT HOOD AREA- Friday: Moderate avalanche danger below 7000 feet. Saturday: Increasing considerable avalanche danger above 5000 feet and moderate below. OUTLOOK TO SUNDAY Avalanche danger slightly decreasing Sunday. SNOWPACK ANALYSIS The most recent storm was Monday. This storm had strong west winds and began as rain or freezing rain in many areas followed by dramatic cooling and significant or heavy snow. Hurricane Ridge and sites near and west of the crest in the north Cascades received about 8-20 inches of snow. The most was seen at Stevens Pass in convergence. Sites near and west of the crest in the south Cascades and along the east slopes received about 5-9 inches of snow. In most areas this should have produced an upper snow pack structure on lee slopes of 1-3 feet or more of new snow on a rain crust. This also produced isolated wind slab layers on lee slopes near ridges. Natural and triggered surface wind slab avalanches were reported until midweek at Mt Baker, Washington Pass, Stevens Pass and Crystal Mountain. These avalanches on lee slopes were mostly releasing and sliding on the crust from Monday. We do not have any reports of avalanches from Thursday which should indicate partial stabilizing. Snowballing on slopes facing the sun was reported from Crystal Mountain on Thursday. This indicates that surface snow was close to becoming damp or wet and unstable. Stable powder snow of increasing density with depth has also been reported the past couple days on sheltered slopes. Significant surface hoar frost has also been noted the past couple days which may be a factor on Saturday. DETAILED FORECASTS FRIDAY AND FRIDAY NIGHT Mostly sunny weather should be seen at higher elevations on Friday. Some local warmer temperatures may also be seen at higher elevations with cooler temperatures at lower elevations. Isolated wind slab layers may linger on lee slopes. This should be mainly northeast to southeast slopes near ridges and summits. Also watch for potential wet unstable surface snow on steep slopes facing the sun Friday afternoon. Increasing west winds and increasing clouds should be seen Friday night with light snow showers possible in the Olympics and north Cascades. SATURDAY AND SATURDAY NIGHT Further increasing west winds and increasing light to moderate snow is expected Saturday. This is expected to build new local wind or soft surface slab layers on lee slopes. This should be mainly north to east slopes at higher elevations. Surface hoar frost that has developed late this week may act as a weak layer and help cause slab layers on somewhat lower angle slopes than the past couple days. Some natural or human triggered avalanches should be seen by Saturday afternoon. Use increasing caution near avalanche terrain on Saturday. Remember that an avalanche forecast is an estimate of conditions and to make your own stability assessments. West winds and light snow showers should decrease on Saturday night. But cool temperatures should help new wind or soft slab layers to linger on lee slopes. OUTLOOK TO SUNDAY Winds should decrease and light snow showers mainly near and west of the crest should end on Sunday with cold temperatures. Partial stabilizing should slightly decrease the avalanche danger. But new wind or soft slab layers should also persist on steeper lee slopes at higher elevations due to the cold temperatures. &&